Development of Diagnostic Insecticide Concentrations and Assessment of Insecticide Susceptibility in German Cockroach (Dictyoptera: Blattellidae) Field Strains Collected From Public Housing

PubMed Central

Fardisi, Mahsa; Gondhalekar, Ameya D.

2017-01-01

Abstract Insecticide resistance in German cockroaches (Blattella germanica (L.)) has been a barrier to effective control since its first documentation in the 1950s. A necessary first step toward managing resistance is to understand insecticide susceptibility profiles in field-collected strains so that active ingredients (AIs) with lowest resistance levels can be identified. As a first step in this study, diagnostic concentrations (DCs) were determined for 14 insecticide AIs based on lethal concentrations that killed 99% or 90% of the individuals from a susceptible lab strain (JWax-S). Next, cockroaches were collected from two low-income multifamily housing complexes in Danville, IL, and Indianapolis, IN, and used to establish laboratory strains. These strains were screened against the 14 AI-DCs in vial bioassays, and susceptibility profiles were determined by comparing percent mortalities between the field strains relative to the JWax-S strain. Results revealed lowest resistance of field strains to boric acid, abamectin, dinotefuran, clothianidin, thiamethoxam, and chlorfenapyr. For the AIs hydramethylnon and imidacloprid, field strains did not display survivorship different than the lab strain, but >90% mortality was never achieved. Lastly, both field strains displayed resistance to indoxacarb, fipronil, acetamiprid, beta-cyfluthrin, bifenthrin, and lambda-cyhalothrin, but at varying levels. These results satisfy two objectives. First, baseline monitoring DCs were established for 14 insecticides presently registered for use against cockroaches, which represents a useful resource. Second, our findings reveal insecticide AIs with lowest resistance levels for use in forthcoming field studies that will investigate impacts of different insecticide deployment strategies on resistance management and evolution in cockroach field populations. PMID:28334270

Fipronil washoff to municipal wastewater from dogs treated with spot-on products.

PubMed

Teerlink, Jennifer; Hernandez, Jorge; Budd, Robert

2017-12-01

Fipronil and fipronil degradates have been reported in treated wastewater effluent at concentrations that exceed USEPA Aquatic Life Benchmarks, posing a potential risk to the surface waters to which they discharge. Fipronil is a common insecticide found in spot-on flea and tick treatment products that have the potential for down-the-drain transport and direct washoff into surface water. Volunteers currently treating their dogs with a fipronil-containing spot-on product were recruited. Dogs were washed either 2, 7, or 28days after product application, and rinsate from 34 discrete bathing events were analyzed by LC-MS/MS for fipronil and fipronil degradates (collectively known as fiproles). Total fipronil application dosage ranged from 67.1-410.0mg per dog following manufacturers' recommendation based on dog body weight. Total mass of fiproles measured in rinsate ranged from 3.6-230.6mg per dog (0.2 ̶ 86.0% of mass applied). Average percentage of fiproles detected in rinsate generally decreased with increasing time from initial application: 21±22, 16±13, and 4±5% respectively for 2, 7, and 28days post application. Fipronil was the dominant fiprole, >63% of total fiproles for all samples and >92% of total fiproles in 2 and 7day samples. Results confirm a direct pathway of pesticides to municipal wastewater through the use of spot-on products on dogs and subsequent bathing by either professional groomers or by pet owners in the home. Comparisons of mass loading calculated using California sales data and recent wastewater monitoring results suggest fipronil-containing spot-on products are a potentially important source of fipronil to wastewater treatment systems in California. This study highlights the potential for other active ingredients (i.e., bifenthrin, permethrin, etofenprox, imidacloprid) contained in spot-on and other pet products (i.e., shampoos, sprays) to enter wastewater catchments through bathing activities, posing a potential risk to the aquatic organisms downstream of wastewater discharge. Copyright © 2017 Elsevier B.V. All rights reserved.

Storm-event-transport of urban-use pesticides to streams likely impairs invertebrate assemblages.

PubMed

Carpenter, Kurt D; Kuivila, Kathryn M; Hladik, Michelle L; Haluska, Tana; Cole, Michael B

2016-06-01

Insecticide use in urban areas results in the detection of these compounds in streams following stormwater runoff at concentrations likely to cause toxicity for stream invertebrates. In this 2013 study, stormwater runoff and streambed sediments were analyzed for 91 pesticides dissolved in water and 118 pesticides on sediment. Detections included 33 pesticides, including insecticides, fungicides, herbicides, degradates, and a synergist. Patterns in pesticide occurrence reveal transport of dissolved and sediment-bound pesticides, including pyrethroids, from upland areas through stormwater outfalls to receiving streams. Nearly all streams contained at least one insecticide at levels exceeding an aquatic-life benchmark, most often for bifenthrin and (or) fipronil. Multiple U.S. EPA benchmark or criterion exceedances occurred in 40 % of urban streams sampled. Bed sediment concentrations of bifenthrin were highly correlated (p < 0.001) with benthic invertebrate assemblages. Non-insects and tolerant invertebrates such as amphipods, flatworms, nematodes, and oligochaetes dominated streams with relatively high concentrations of bifenthrin in bed sediments, whereas insects, sensitive invertebrates, and mayflies were much more abundant at sites with no or low bifenthrin concentrations. The abundance of sensitive invertebrates, % EPT, and select mayfly taxa were strongly negatively correlated with organic-carbon normalized bifenthrin concentrations in streambed sediments. Our findings from western Clackamas County, Oregon (USA), expand upon previous research demonstrating the transport of pesticides from urban landscapes and linking impaired benthic invertebrate assemblages in urban streams with exposure to pyrethroid insecticides.

Storm-event-transport of urban-use pesticides to streams likely impairs invertebrate assemblages

USGS Publications Warehouse

Carpenter, Kurt; Kuivila, Kathryn; Hladik, Michelle; Haluska, Tana L.; Michael B. Cole,

2016-01-01

Insecticide use in urban areas results in the detection of these compounds in streams following stormwater runoff at concentrations likely to cause toxicity for stream invertebrates. In this 2013 study, stormwater runoff and streambed sediments were analyzed for 91 pesticides dissolved in water and 118 pesticides on sediment. Detections included 33 pesticides, including insecticides, fungicides, herbicides, degradates, and a synergist. Patterns in pesticide occurrence reveal transport of dissolved and sediment-bound pesticides, including pyrethroids, from upland areas through stormwater outfalls to receiving streams. Nearly all streams contained at least one insecticide at levels exceeding an aquatic-life benchmark, most often for bifenthrin and (or) fipronil. Multiple U.S. EPA benchmark or criterion exceedances occurred in 40 % of urban streams sampled. Bed sediment concentrations of bifenthrin were highly correlated (p < 0.001) with benthic invertebrate assemblages. Non-insects and tolerant invertebrates such as amphipods, flatworms, nematodes, and oligochaetes dominated streams with relatively high concentrations of bifenthrin in bed sediments, whereas insects, sensitive invertebrates, and mayflies were much more abundant at sites with no or low bifenthrin concentrations. The abundance of sensitive invertebrates, % EPT, and select mayfly taxa were strongly negatively correlated with organic-carbon normalized bifenthrin concentrations in streambed sediments. Our findings from western Clackamas County, Oregon (USA), expand upon previous research demonstrating the transport of pesticides from urban landscapes and linking impaired benthic invertebrate assemblages in urban streams with exposure to pyrethroid insecticides.

Methoxyfenozide resistance of the housefly, Musca domestica L. (Diptera: Muscidae): cross-resistance patterns, stability and associated fitness costs.

PubMed

Shah, Rizwan Mustafa; Shad, Sarfraz Ali; Abbas, Naeem

2017-01-01

The housefly, Musca domestica L. (Diptera: Muscidae), is an insect pest of public health and veterinary importance with the ability to develop resistance to insecticides. Methoxyfenozide, an ecdysone agonist, is a biorational insecticide used for the management of various insect pests, including houseflies. To design an effective resistance management strategy, life history traits based on laboratory observations were established for methoxyfenozide-resistant (MXY-SEL), unselected counterpart (UNSEL) and reciprocal cross-strains of housefly. The MXY-SEL strain developed a resistance ratio of 160.99 after 30 generations of selection with methoxyfenozide by compared with the UNSEL strain. The MXY-SEL strain showed very low cross-resistance to cyromazine, fipronil and chlorpyrifos and no cross-resistance to spinosad and bifenthrin when compared with the Methoxy-Field population. Resistance to methoxyfenozide, cyromazine, fipronil, spinosad, chlorpyrifos and bifenthrin was unstable in the MXY-SEL strain. The MXY-SEL strain had a reduced relative fitness (0.31), with lower hatchability, a lower number of next-generation larvae, a lower intrinsic rate of natural increase and a lower biotic potential compared with the UNSEL strain. The disadvantageous life history traits of the MXY-SEL strain suggest that development of resistance to methoxyfenozide has considerable fitness costs for this strain. Moreover, the unstable resistance to the tested chemicals provides useful information for preserving the efficacy of these chemicals. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Treated wastewater effluent as a source of pyrethroids and fipronil at todos santos bay, Mexico: Its impact on sediments and organisms.

PubMed

Hernández-Guzmán, Félix Augusto; Macías-Zamora, José Vinicio; Ramírez-Álvarez, Nancy; Alvarez-Aguilar, Arturo; Quezada-Hernández, Cristina; Fonseca, Ana Paula

2017-11-01

Pyrethroids are insecticides widely used to control pests and disease vectors in residential areas and agricultural lands. Pyrethroids are emerging pollutants, and their use is a growing concern because of their toxicity potential to aquatic organisms. Todos Santos Bay and the Punta Banda estuary, 2 coastal bodies located to the south of the Southern California Bight, were studied to establish a baseline of the current conditions of pollution by pyrethroids and fipronil. Eight pyrethroids, along with fipronil and its 2 metabolites, were determined in effluents from wastewater-treatment plants (n = 3), surface sediments (n = 32), and 3 locations with mussels (Mytilus californianus, n = 9). Bifenthrin, permethrin, and cypermethrin were the most common pyrethroids found in the study areas and were widespread in sediments, mussels, and wastewater-treated effluents. Fipronil and its metabolites were detected in mussels and wastewater-treated effluents only. Total pyrethroid concentrations in sediments ranged from 0.04 to 1.95 ng/g dry weight in the Punta Banda estuary (n = 13) and from 0.07 to 6.62 ng/g dry weight in Todos Santos Bay (n = 19). Moreover, total pyrethroids in mussels ranged from 1.19 to 6.15 ng/g wet weight. Based on the toxic unit data calculated for pyrethroids and fipronil for Eohaustorius estuarius and Hyalella azteca, little to no impact is expected to the benthic population structure. Environ Toxicol Chem 2017;36:3057-3064. © 2017 SETAC. © 2017 SETAC.

Level 1 Water-Quality Inventory of Baseline Levels of Pesticides in Urban Creeks - Golden Gate National Recreation Area and the Presidio of San Francisco, California

USGS Publications Warehouse

Hladik, Michelle; Orlando, James L.

2008-01-01

To characterize baseline water-quality levels of pesticides in Golden Gate National Recreation Area and the Presidio of San Francisco, the U.S. Geological Survey collected and analyzed surface-water and bed-sediment samples at 10 creeks during February, April, and July 2006. Pesticide data were obtained using previously developed methods. Samples from sites in the Presidio were analyzed only for pyrethroid insecticides, whereas the remaining samples were analyzed for pyrethroids and additional current and historical-use pesticides. Pesticide concentrations were low in both the water (below 30 ng/L) and sediment (below 3 ng/g). The pyrethroid bifenthrin was detected in water samples from two sites at concentrations below 2 ng/L. Other compounds detected in water included the herbicides dacthal (DCPA) and prometryn, the insecticide fipronil, the insecticide degradates p,p'-DDE and fipronil sulfone, and the fungicides cyproconazole, myclobutanil and tetraconazole. The only pesticides detected in the sediment samples were p,p'-DDT and its degradates (p,p'-DDD and p,p'-DDE). Pesticide information from the samples collected can provide a reference point for future sampling and can help National Park Service managers assess the water quality of the urban creeks.

The impacts of modern-use pesticides on shrimp aquaculture: An assessment for north eastern Australia.

PubMed

Hook, Sharon E; Doan, Hai; Gonzago, Debra; Musson, Dean; Du, Jun; Kookana, Rai; Sellars, Melony J; Kumar, Anu

2018-02-01

The use of pyrethroid and neonicotinoid insecticides has increased in Australia over the last decade, and as a consequence, increased concentrations of the neonicotinoid insecticide imidacloprid have been measured in Australian rivers. Previous studies have shown that non-target crustaceans, including commercially important species, can be extremely sensitive to these pesticides. Most shrimp farms in Australia are predominantly located adjacent to estuaries so they can obtain their required saline water, which support multiple land uses upstream (e.g. sugar-cane farming, banana farming, beef cattle and urbanisation). Larval and post-larval shrimp may be most susceptible to the impacts of these pesticides because of their high surface area to volume ratio and rapid growth requirements. However, given the uncertainties in the levels of insecticides in farm intake water and regarding the impacts of insecticide exposure on shrimp larvae, the risks that the increased use of new classes of pesticide pose towards survival of post-larval phase shrimp cannot be adequately predicted. To assess the potential for risk, toxicity in 20day past hatch post-larval Black Tiger shrimp (Penaeus monodon) to modern use insecticides, imidacloprid, bifenthin, and fipronil was measured as decreased survival and feeding inhibition. Post-larval phase shrimp were sensitive to fipronil, bifenthrin, and imidacloprid, in that order, at concentrations that were comparable to those that cause mortality other crustaceans. Bifenthrin and imidacloprid exposure reduced the ability of post-larval shrimp to capture live prey at environmentally realistic concentrations. Concentrations of a broad suite of pesticides were also measured in shrimp farm intake waters. Some pesticides were detected in every sample. Most of the pesticides detected were measured below concentrations that are toxic to post-larval shrimp as used in this study, although pesticides exceed guideline values, suggesting the possibility of indirect or mixture-related impacts. However, at two study sites, the concentrations of insecticides were sufficient to cause toxicity in shrimp post larvae, based on the risk assessment undertaken in this study. Copyright © 2017 Elsevier Inc. All rights reserved.

Chlorfenapyr, a Potent Alternative Insecticide of Phoxim To Control Bradysia odoriphaga (Diptera: Sciaridae).

PubMed

Zhao, Yunhe; Wang, Qiuhong; Wang, Yao; Zhang, Zhengqun; Wei, Yan; Liu, Feng; Zhou, Chenggang; Mu, Wei

2017-07-26

Bradysia odoriphaga is the major pest affecting Chinese chive production, and in China, it has developed widespread resistance to organophosphorus insecticides. Chlorfenapyr is a promising pyrrole insecticide with a unique mechanism of action that does not confer cross-resistance to neurotoxic insecticides. However, the effect of chlorfenapyr on organophosphate-resistant B. odoriphaga is not well understood. The present study evaluated the potential of chlorfenapyr for the control of phoxim-resistant B. odoriphaga. The results showed that chlorfenapyr had significant insecticidal activity to B. odoriphaga in multiple developmental stages, and there were no significant differences in susceptibility between the field (phoxim-resistant) and laboratory (phoxim-susceptible) populations. The pot experiment and field trials confirmed the results of our laboratory bioassays. In the field trial, chlorfenapyr applied at 3.0, 6.0, or 12.0 kg of active ingredient (a.i.)/ha significantly decreased the number of B. odoriphaga and improved the yield compared to phoxim at 6.0 kg of a.i./ha and the control conditions. Moreover, the final residues of chlorfenapyr on plants were below the maximum residue limits (MRLs) as a result of its non-systemic activity. These results demonstrate that chlorfenapyr has potential as a potent alternative to phoxim for controlling B. odoriphaga.

Pheromone-assisted techniques to improve the efficacy of insecticide sprays against Linepithema humile (Hymenoptera: Formicidae).

PubMed

Choe, Dong-Hwan; Tsai, Kasumi; Lopez, Carlos M; Campbell, Kathleen

2014-02-01

Outdoor residual sprays are among the most common methods for targeting pestiferous ants in urban pest management programs. If impervious surfaces such as concrete are treated with these insecticides, the active ingredients can be washed from the surface by rain or irrigation. As a result, residual sprays with fipronil and pyrethroids are found in urban waterways and aquatic sediments. Given the amount of insecticides applied to urban settings for ant control and their possible impact on urban waterways, the development of alternative strategies is critical to decrease the overall amounts of insecticides applied, while still achieving effective control of target ant species. Herein we report a "pheromone-assisted technique" as an economically viable approach to maximize the efficacy of conventional sprays targeting the Argentine ant. By applying insecticide sprays supplemented with an attractive pheromone compound, (Z)-9-hexadecenal, Argentine ants were diverted from nearby trails and nest entrances and subsequently exposed to insecticide residues. Laboratory experiments with fipronil and bifenthrin sprays indicated that the overall kill of the insecticides on Argentine ant colonies was significantly improved (57-142% increase) by incorporating (Z)-9-hexadecenal in the insecticide sprays. This technique, once it is successfully implemented in practical pest management programs, has the potential of providing maximum control efficacy with reduced amount of insecticides applied in the environment.

Residual efficacy of chlorfenapyr for control of stored-product psocids (Psocoptera)

USDA-ARS?s Scientific Manuscript database

The residual effect of chlorfenapyr (Phantom®) was evaluated for residual control of three stored-product psocid species: Liposcelis bostrychophila Badonnel, Liposcelis entomophila (Enderlein), and Liposcelis paeta Pearman. Chlorfenapyr was applied to individual arenas with a concrete surface at rat...

Chlorfenapyr and mallard ducks: overview, study design, macroscopic effects, and analytical chemistry

USGS Publications Warehouse

Albers, P.H.; Klein, P.N.; Green, D.E.; Melancon, M.J.; Bradley, B.P.; Noguchi, G.

2006-01-01

The first commercial pesticide derived from a class of compounds known as halogenated pyrroles was registered for use in the United States in 2001. Chlorfenapyr degrades slowly in soil, sediment, and water and is highly toxic to birds. Information on biochemical or histological endpoints in birds is lacking; therefore, a two-year study was conducted to provide information needed to develop diagnostic criteria for chlorfenapyr toxicosis. In the first year, male mallard ducks were fed concentrations of 0, 2, 5, or 10 ppm technical chlorfenapyr or 5 ppm of a formulated product in their diet during a 10-week chronic exposure study. Survival, body weight, feed consumption (removal), behavior, and molt progression were monitored. Feed and liver were analyzed for chlorfenapyr and two metabolites. Five of 10 ducks in the 10-ppm group died, and neurotoxic effects were observed in the 5- and 10-ppm groups. Feed removal increased for ducks receiving chlorfenapyr and body weights of 5- and 10-ppm ducks were reduced. Loss of body fat, muscle atrophy, and bile retention were suggestive of metabolic disruption or a decreased ability to digest and absorb nutrients. Liver and kidney weights and liver and kidney weight/body weight ratios exhibited a positive response to concentrations of chlorfenapyr in the diet. Emaciation and elevated organ weight/body weight ratios are candidates for a suite of indicators of chronic chlorfenapyr exposure. Liver is the preferred tissue for chemical confirmation of exposure.

The activity of the pyrrole insecticide chlorfenapyr in mosquito bioassay: towards a more rational testing and screening of non-neurotoxic insecticides for malaria vector control.

PubMed

Oxborough, Richard M; N'Guessan, Raphael; Jones, Rebecca; Kitau, Jovin; Ngufor, Corine; Malone, David; Mosha, Franklin W; Rowland, Mark W

2015-03-24

The rapid selection of pyrethroid resistance throughout sub-Saharan Africa is a serious threat to malaria vector control. Chlorfenapyr is a pyrrole insecticide which shows no cross resistance to insecticide classes normally used for vector control and is effective on mosquito nets under experimental hut conditions. Unlike neurotoxic insecticides, chlorfenapyr owes its toxicity to disruption of metabolic pathways in mitochondria that enable cellular respiration. A series of experiments explored whether standard World Health Organization (WHO) guidelines for evaluation of long-lasting insecticidal nets, developed through testing of pyrethroid insecticides, are suitable for evaluation of non-neurotoxic insecticides. The efficacy of WHO recommended cone, cylinder and tunnel tests was compared for pyrethroids and chlorfenapyr. To establish bioassay exposure times predictive of insecticide-treated net (ITN) efficacy in experimental hut trials, standard three-minute bioassays of pyrethroid and chlorfenapyr ITNs were compared with longer exposures. Mosquito behaviour and response to chlorfenapyr ITN in bioassays conducted at night were compared to day and across a range of temperatures representative of highland and lowland transmission. Standard three-minute bioassay of chlorfenapyr produced extremely low levels of mortality compared to pyrethroids. Thirty-minute day-time bioassay produced mortality closer to hut efficacy of chlorfenapyr ITN but still fell short of the WHO threshold. Overnight tunnel test with chlorfenapyr produced 100% mortality and exceeded the WHO threshold of 80%. The endogenous circadian activity rhythm of anophelines results in inactivity by day and raised metabolism and flight activity by night. A model which explains improved toxicity of chlorfenapyr ITN when tested at night, and during the day at higher ambient temperature, is that activation of chlorfenapyr and disruption of respiratory pathways is enhanced when the insect is more metabolically and behaviourally active. Testing according to current WHO guidelines is not suitable for certain types of non-neurotoxic insecticide which, although highly effective in field trials, would be overlooked at the screening stage of evaluation through bioassay. Testing methods must be tailored to the characteristics and mode of action of each insecticide class. The WHO tunnel test on night-active anophelines is the most reliable bioassay for identifying the toxicity of novel insecticides.

Chlorfenapyr (A Pyrrole Insecticide) Applied Alone or as a Mixture with Alpha-Cypermethrin for Indoor Residual Spraying against Pyrethroid Resistant Anopheles gambiae sl: An Experimental Hut Study in Cove, Benin

PubMed Central

Ngufor, Corine; Critchley, Jessica; Fagbohoun, Josias; N’Guessan, Raphael; Todjinou, Damien; Rowland, Mark

2016-01-01

Background Indoor spraying of walls and ceilings with residual insecticide remains a primary method of malaria control. Insecticide resistance in malaria vectors is a growing problem. Novel insecticides for indoor residual spraying (IRS) which can improve the control of pyrethroid resistant malaria vectors are urgently needed. Insecticide mixtures have the potential to improve efficacy or even to manage resistance in some situations but this possibility remains underexplored experimentally. Chlorfenapyr is a novel pyrrole insecticide which has shown potential to improve the control of mosquitoes which are resistant to current WHO-approved insecticides. Method The efficacy of IRS with chlorfenapyr applied alone or as a mixture with alpha-cypermeththrin (a pyrethroid) was evaluated in experimental huts in Cove, Southern Benin against wild free flying pyrethroid resistant Anopheles gambiae sl. Comparison was made with IRS with alpha-cypermethrin alone. Fortnightly 30-minute in situ cone bioassays were performed to assess the residual efficacy of the insecticides on the treated hut walls. Results Survival rates of wild An gambiae from the Cove hut site in WHO resistance bioassays performed during the trial were >90% with permethrin and deltamethrin treated papers. Mortality of free-flying mosquitoes entering the experimental huts was 4% in the control hut. Mortality with alpha-cypermethrin IRS did not differ from the control (5%, P>0.656). The highest mortality was achieved with chlorfenapyr alone (63%). The alpha-cypermethrin + chlorfenapyr mixture killed fewer mosquitoes than chlorfenapyr alone (43% vs. 63%, P<0.001). While the cone bioassays showed a more rapid decline in residual mortality with chlorfenapyr IRS to <30% after only 2 weeks, fortnightly mortality rates of wild free-flying An gambiae entering the chlorfenapyr IRS huts were consistently high (50–70%) and prolonged, lasting over 4 months. Conclusion IRS with chlorfenapyr shows potential to significantly improve the control of malaria transmission in pyrethroid resistant areas compared to pyrethroid IRS or the mixture. Thirty minute in situ cone bioassays are not predictive of the performance of chlorfenapyr IRS under field conditions. PMID:27588945

Transfer of chlorfenapyr among workers of Reticulitermes flavipes (Isoptera: Rhinotermitidae) in the laboratory

Treesearch

Thomas G. Shelton; Joseph E. Mulroonery; Terence L. Wagner

2006-01-01

The potential for transfer of chlorfenapyr among subterranean termites was investigated using a donor-recipient (5:95 ratio) experiment. In one experiment, workers of Reticulitermes flavipeS(Kollar) (Isoptera: Rhinotermitidae) were exposed to treated sand at 0,50,100,250, and 500 ppm chlorfenapyr (wt [AI] /wt sand). Exposed workers were allowed to...

Using a Lethality Index to Assess Susceptibility of Tribolium confusum and Oryzaephilus surinamensis to Insecticides

PubMed Central

Vlontzos, George; Arthur, Frank H.

2015-01-01

We evaluated knockdown caused by four insecticides: alpha-cypermethrin, chlorfenapyr, pirimiphos-methyl and fipronil against adults of Tribolium confusum Jacquelin Duval, the confused flour beetle and Oryzaephilus surinamensis (L.), the sawtoothed grain beetle. Bioassays were conducted on concrete and metal surfaces. Adults of the tested species were exposed on both surfaces treated with the above insecticides at two doses (low and high). Knockdown assessment was done after 15, 30 and 60 min of adult exposure in the treated surfaces. Also, after 1, 3, 5, 7 and 14 d of exposure, a lethality index was calculated with an equation resulting to values from 0 to 100, where 100 indicated complete mortality and 0 complete survival. We also developed a lethality index by ranking each adult on each surface from 0 to 4, 0: adults moved normally, 1: adults were knocked down, but were able to walk for short intervals, 2: adults were knocked down and unable to walk, but with visible movement of antennae etc., 3: adults were knocked down, with very minimal movement of the tarsi and the antennae and 4: adults were dead (no movement). Knockdown of adults immediately after exposure (15–60 min) was higher for pirimiphos-methyl followed by alpha-cypermethrin, for both dose rates tested and species, but only on the metal surface. The lethality index was nearly 100 for all insecticides after 5d of exposure for O. surinamensis, while for T. confusum the adult lethality index was considerably lower for alpha-cypermethrin, suggesting that that recovery from knockdown occurred. Chlorfenapyr was the only insecticide that was more effective on concrete than on metal, while the reverse was noted for the other three insecticides. These results show that knockdown has different levels, which can be used as indicators of insect mortality or recovery. PMID:26560316

Residue behavior and risk assessment of mixed formulation of imidacloprid and chlorfenapyr in chieh-qua under field conditions.

PubMed

Huang, Jian Xiang; Liu, Cong Yun; Lu, Da Hai; Chen, Jia Jia; Deng, Yi Cai; Wang, Fu Hua

2015-10-01

A simple and rapid method based on high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was developed for the simultaneous determination of imidacloprid and chlorfenapyr residues in chieh-qua. Field trials were designed to investigate the dissipation and terminal residue behavior of the mixed formulation of imidacloprid and chlorfenapyr in chieh-qua in Guangzhou and Nanning areas. Risk assessment was performed by calculating the risk quotient (RQ) values. The developed analytical method exhibited recoveries of 89.9-110.3% with relative standard deviations (RSDs) of 2.8-12.5% at the spiked levels of 0.01, 0.10, and 1.00 mg/kg. The limit of detection (LOD) was 0.003 mg/kg, and the limit of quantification (LOQ) was 0.01 mg/kg for both imidacloprid and chlorfenapyr. It was found that the half-lives of imidacloprid in chieh-qua under field conditions were 3.3 and 3.5 days in Guangzhou and Nanning at a dose of 180 g ai/ha, while the half-lives of chlorfenapyr were 3.3 and 2.6 days, respectively. The terminal residues of imidacloprid and chlorfenapyr were from 0.01 to 0.21 mg/kg and from 0.01 to 0.46 mg/kg, respectively. Results of dietary exposure assessment showed that the RQ values were much lower than 1, indicating that the risk of imidacloprid and chlorfenapyr applied in chieh-qua was negligible to human health under recommended dosage and good agricultural practices. The proposed study would provide guidance for safe and reasonable use of imidacloprid and chlorfenapyr in chieh-qua cultivation in China.

Elevated expression of esterase and cytochrome P450 are related with lambda-cyhalothrin resistance and lead to cross resistance in Aphis glycines Matsumura.

PubMed

Xi, Jinghui; Pan, Yiou; Bi, Rui; Gao, Xiwu; Chen, Xuewei; Peng, Tianfei; Zhang, Min; Zhang, Hua; Hu, Xiaoyue; Shang, Qingli

2015-02-01

A resistant strain of the Aphis glycines Matsumura (CRR) has developed 76.67-fold resistance to lambda-cyhalothrin compared with the susceptible (CSS) strain. Synergists piperonyl butoxide (PBO), S,S,S-Tributyltrithiophosphate (DEF) and triphenyl phosphate (TPP) dramatically increased the toxicity of lambda-cyhalothrin to the resistant strain. Bioassay results indicated that the CRR strain had developed high levels of cross-resistance to chlorpyrifos (11.66-fold), acephate (8.20-fold), cypermethrin (53.24-fold), esfenvalerate (13.83-fold), cyfluthrin (9.64-fold), carbofuran (14.60-fold), methomyl (9.32-fold) and bifenthrin (4.81-fold), but did not have cross-resistance to chlorfenapyr, imidacloprid, diafenthiuron, abamectin. The transcriptional levels of CYP6A2-like, CYP6A14-like and cytochrome b-c1 complex subunit 9-like increased significantly in the resistant strain than that in the susceptible. Similar trend were observed in the transcripts and DNA copy number of CarE and E4 esterase. Overall, these results demonstrate that increased esterase hydrolysis activity, combined with elevated cytochrome P450 monooxygenase detoxicatication, plays an important role in the high levels of lambda-cyhalothrin resistance and can cause cross-resistance to other insecticides in the CRR strain. Copyright © 2014 Elsevier Inc. All rights reserved.

77 FR 40039 - Notice of Receipt of Requests To Voluntarily Cancel Certain Pesticide Registrations

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-06

...% Bifenthrin. Plus Fertilizer. 000228-00438 Bifenthrin 7.9% FL Bifenthrin. Nursery. 000228-00439 Bifenthrin Pl... Herbicide. Triclopyr, triethylamine salt. 000228-00519 Menace GC 0.058% Bifenthrin. Plus Fertilizer. 000228...-00578 Atera 0.3 GC Bifenthrin, Fertilizer Imidacloprid. Insecticide. 000228-00579 Atera 0.3 LC...

Fipronil and its degradates in indoor and outdoor dust

USGS Publications Warehouse

Mahler, B.J.; Van Metre, P.C.; Wilson, J.T.; Musgrove, M.; Zaugg, S.D.; Burkhardt, M.R.

2009-01-01

Fipronil is a potent insecticide used for control of termites, fleas, roaches, ants, and other pests. We measured fipronil, fipronil sulfide, and desulfinyl fipronil concentrations in indoor and outdoor dust from 24 residences in Austin, Texas. At least one of these three fipronil compounds was detected in every sample. Fipronil accounted for most of the total fipronil (T-fipronil; fipronil+desulfinyl fipronil+fipronil sulfide), followed by desulfinyl fipronil and fipronil sulfide. Nineteen of 24 samples of indoor dust had T-fipronil concentrations less than 270 ??g/kg; the remaining five had concentrations from 1320 to 14,200 ??g/kg. All three of the residences with a dog on which a flea-control product containing fipronil was used were among the five residences with elevated fipronil concentrations. In outdoor dust, all concentrations of T-fipronil were less than 70??g/kg with one exception (430??g/kg). For every residence, the concentration of T-fipronil in indoor dust exceeded that in outdoor dust, and the median concentration of T-fipronil was 15 times higher indoors than outdoors.

40 CFR 180.513 - Chlorfenapyr; tolerances for residues.

Code of Federal Regulations, 2010 CFR

2010-07-01

... after each use of the product. (iv) Contamination of food or food contact surfaces shall be avoided...) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Specific Tolerances... residues of chlorfenapyr in or on all food commodities (other than those covered by a higher tolerance as a...

40 CFR 180.513 - Chlorfenapyr; tolerances for residues.

Code of Federal Regulations, 2013 CFR

2013-07-01

.... Application excludes any direct application to any food, food packaging, or any food contact surfaces. (v) To...) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Specific Tolerances... residues of chlorfenapyr in or on all food commodities (other than those covered by a higher tolerance as a...

40 CFR 180.513 - Chlorfenapyr; tolerances for residues.

Code of Federal Regulations, 2014 CFR

2014-07-01

.... Application excludes any direct application to any food, food packaging, or any food contact surfaces. (v) To...) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Specific Tolerances... residues of chlorfenapyr in or on all food commodities (other than those covered by a higher tolerance as a...

40 CFR 180.513 - Chlorfenapyr; tolerances for residues.

Code of Federal Regulations, 2012 CFR

2012-07-01

.... Application excludes any direct application to any food, food packaging, or any food contact surfaces. (v) To...) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Specific Tolerances... residues of chlorfenapyr in or on all food commodities (other than those covered by a higher tolerance as a...

Degradation of fipronil in anaerobic sediments and the effect on porewater concentrations.

PubMed

Brennan, Amanda A; Harwood, Amanda D; You, Jing; Landrum, Peter F; Lydy, Michael J

2009-09-01

The current study measured the degradation of fipronil in laboratory-spiked silt loam sediment under anaerobic conditions at different aging times. The half-life of fipronil in anaerobic sediments spiked at 5.8+/-0.049 and 21+/-1.4microg/kg dry weight (dw) was 21+/-0.22 and 15+/-0.11d, respectively. Fipronil-sulfide was the primary degradation product with fipronil-sulfone detected at lower concentrations. No degradation occurred to fipronil-sulfide and fipronil-sulfone over 200d in separate systems. A concurrent decline in sediment concentrations resulted in a decline of fipronil in sediment porewater with an increase in fipronil-sulfide and fipronil-sulfone measured by matrix-solid phase microextraction (matrix-SPME). Equilibrium among sediment, porewater, and matrix-SPME fiber occurred within 138d for fipronil and fipronil-sulfone; however, fipronil-sulfide did not reach equilibrium during the test, and modeling predicted upwards of 1083d to reach equilibrium. Regardless of the time to reach equilibrium, the rapid degradation of fipronil has little ecological significance given that fipronil-sulfide and fipronil-sulfone have equal or greater toxicity, and exhibit greater environmental stability in both the sediment and porewater, thereby becoming bioavailable.

Hydroxy-fipronil is a new urinary biomarker of exposure to fipronil

PubMed Central

Vasylieva, Natalia; Barnych, Bogdan; Wan, Debin; El-Sheikh, El-Sayed A.; Nguyen, Hai M.; Wulff, Heike; McMahen, Rebecca; Strynar, Mark; Gee, Shirley J.; Hammock, Bruce D.

2017-01-01

Occupational medical surveillance is highly desirable in manufacturing facilities where exposure to chemicals is significant. The insecticide fipronil is generally considered safe for humans but with increasing use, exposure to fipronil is of concern. Identification of urinary metabolites of fipronil may allow development of affordable, cheap and rapid procedures for human exposure evaluation. In this study we developed a fast and easy approach for synthesis of hydroxy-fipronil, a potential urinary metabolite of fipronil. This standard was used to develop a sensitive analytical LC-MS/MS method with a limit of quantification (LOQ) of 0.4 ng/mL. Fipronil sulfone, a known metabolite, and hydroxy-fipronil were quantified in urine samples from rats treated with a fipronil containing diet. Fipronil sulfone concentration centered around 20 ng/mL, while the concentration of hydroxy-fipronil was dose-dependent ranging in 10–10 000 ng/mL and thus being a more sensitive marker of fipronil exposure. A fipronil immunoassay with cross-reactivity to hydroxy-fipronil showed a good correlation in signal intensity with LC-MS data. It was also used to demonstrate the applicability of the method for sample screening in the evaluation of exposure levels. PMID:28343720

Food source and residual efficacy of chlorfenapyr on sealed and unsealed concrete

USDA-ARS?s Scientific Manuscript database

Adult Tribolium castaneum (Herbst), the red flour beetle, were exposed at 1 day, and 2, 4, and 6 weeks post-treatment on sealed and unsealed concrete arenas treated with chlorfenapyr at rates of 2.8, 6.9, 13.5, 20.6, 27.5 mg active ingredient/m2. Beetles were held either with or without flour, and a...

Food source provisioning and susceptibility of immature and adult Tribolium castaneum on concrete partially treated with chlorfenapyr (Phantom®)

USDA-ARS?s Scientific Manuscript database

A series of experiments were conducted in which adults, pupae, and 4-week-old larvae of Tribolium castaneum (Herbst), the red flour beetle, were exposed separately on concrete arenas partially treated (14.4 % of the total area) with the insecticide chlorfenapyr (Phantom®) at 1.1 g active ingredient/...

Hydroxy-fipronil is a new urinary biomarker of exposure to ...

EPA Pesticide Factsheets

Occupational medical surveillance is highly desirable in manufacturing facilities where exposure to chemicals is significant. The insecticide fipronil is generally considered safe for humans but with increasing use, exposure to fipronil is of concern. Identification of urinary metabolites of fipronil may allow development of affordable, cheap and rapid procedures for human exposure evaluation. In this study we developed a fast and easy approach for synthesis of hydroxy-fipronil, a potential urinary metabolite of fipronil. This standard was used to develop a sensitive analytical LC-MS/MS method with a limit of quantification (LOQ) of 0.4 ng/mL. Fipronil sulfone, a known metabolite, and hydroxy-fipronil were quantified in urine samples from rats treated with a fipronil containing diet. Fipronil sulfone concentration centered around 20 ng/mL, while the concentration of hydroxy-fipronil was dose-dependent ranging in 10–10,000 ng/mL and thus being a more sensitive marker of fipronil exposure. A fipronil immunoassay with cross-reactivity to hydroxy-fipronil showed a good correlation in signal intensity with LC-MS data. It was also used to demonstrate the applicability of the method for sample screening in the evaluation of exposure levels. Fipronil is a broad spectrum insecticide from the phenylpyrazole family. It is often used in four major domains: pest control in a wide variety of field crops, urban pest management, veterinary applications (especially in topical

Survival, growth, and body residues of hyalella azteca (Saussure) exposed to fipronil contaminated sediments from non-vegetated and vegetated microcosms.

PubMed

Kröger, Robert; Lizotte, Richard E; Moore, Matthew T

2009-09-01

We assessed chronic effects of fipronil and metabolite contaminated sediments from non-vegetated and Thallia dealbata vegetated wetland microcosms on Hyalella azteca during wet and dry exposures. Mean sediment concentrations (ng g(-1)) ranged from 0.72-1.26, 0.01-0.69, 0.07-0.23, and 0.49-7.87 for fipronil, fipronil-sulfide, fipronil-sulfone, and fipronil-desulfinyl, respectively. No significant differences in animal survival or growth were observed between non-vegetated and vegetated microcosms during wet or dry exposures. Mean animal body residue concentrations (ng g(-1)) ranged from 28.4-77.6, 0-30.7, and 8.3-43.8 for fipronil, fipronil-sulfide, and fipronil-sulfone. Fipronil-desulfinyl was not detected in any animal samples.

Metabolization and degradation kinetics of the urban-use pesticide fipronil by white rot fungus Trametes versicolor.

PubMed

Wolfand, Jordyn M; LeFevre, Gregory H; Luthy, Richard G

2016-10-12

Fipronil is a recalcitrant phenylpyrazole-based pesticide used for flea/tick treatment and termite control that is distributed in urban aquatic environments via stormwater and contributes to stream toxicity. We discovered that fipronil is rapidly metabolized (t 1/2 = 4.2 d) by the white rot fungus Trametes versicolor to fipronil sulfone and multiple previously unknown fipronil transformation products, lowering fipronil concentration by 96.5%. Using an LC-QTOF-MS untargeted metabolomics approach, we identified four novel fipronil fungal transformation products: hydroxylated fipronil sulfone, glycosylated fipronil sulfone, and two compounds with unresolved structures. These results are consistent with identified enzymatic detoxification pathways wherein conjugation with sugar moieties follows initial ring functionalization (hydroxylation). The proposed pathway is supported by kinetic evidence of transformation product formation. Fipronil loss by sorption, hydrolysis, and photolysis was negligible. When T. versicolor was exposed to the cytochrome P450 enzyme inhibitor 1-aminobenzotriazole, oxidation of fipronil and production of hydroxylated and glycosylated transformation products significantly decreased (p = 0.038, 0.0037, 0.0023, respectively), indicating that fipronil is metabolized intracellularly by cytochrome P450 enzymes. Elucidating fipronil transformation products is critical because pesticide target specificity can be lost via structural alteration, broadening classes of impacted organisms. Integration of fungi in engineered natural treatment systems could be a viable strategy for pesticide removal from stormwater runoff.

Comparison of fipronil sources in North Carolina surface water ...

EPA Pesticide Factsheets

Fipronil is a phenylpyrazole insecticide that is widely used in residential and agricultural settings to control ants, roaches, termites, and other pests. Fipronil and its transformation products have been found in a variety of environmental matrices, but the source[s] which makes the greatest contribution to fipronil in surface water has yet to be determined. A sampling effort designed to prioritize known fipronil inputs (golf courses, residential areas, biosolids application sites and wastewater facilities) was conducted in North Carolina to learn more about the origins of fipronil in surface water. High resolution mass spectrometry (HRMS) analysis indicated that fipronil and its known derivatives were routinely present in all samples, but concentrations were substantially elevated near wastewater treatment plant outfalls (range 10–500 ng/L combined), suggesting that they predominate as environmental sources. Corresponding recycled wastewater samples, which were treated with NaOCl for disinfection, showed disappearance of fipronil and all known degradates. HRMS and nuclear magnetic resonance (NMR) analysis techniques were used to determine that all fipronil-related compounds are oxidized to a previously unidentified fipronil sulfone chloramine species in recycled wastewater. The implications of the presence of a new fipronil-related compound in recycled wastewater need to be considered. Journal Article Highlights • The most important sources of fipronil in

Mass Balance of Fipronil and Total Toxicity of Fipronil-Related Compounds in Process Streams during Conventional Wastewater and Wetland Treatment

PubMed Central

2015-01-01

Attenuation of the pesticide fipronil and its major degradates was determined during conventional wastewater treatment and wetland treatment. Analysis of flow-weighted composite samples by liquid and gas chromatography–tandem mass spectrometry showed fipronil occurrence at 12–31 ng/L in raw sewage, primary effluent, secondary effluent, chlorinated effluent, and wetland effluent. Mean daily loads of total fipronil related compounds in raw sewage and in plant effluent after chlorination were statistically indistinguishable (p = 0.29; n = 10), whereas fipronil itself was partially removed (25 ± 3%; p = 0.00025; n = 10); the associated loss in toxicity was balanced by the formation of toxic fipronil degradates, showing conventional treatment to be unfit for reducing overall toxicity. In contrast to these findings at the municipal wastewater treatment, both parental fipronil and the sum of fipronil-related compounds were removed in the wetland with efficiencies of 44 ± 4% and 47 ± 13%, respectively. Total fipronil concentrations in plant effluent (28 ± 6 ng/L as fipronil) were within an order of magnitude of half-maximal effective concentrations (EC50) of nontarget invertebrates. This is the first systematic assessment of the fate of fipronil and its major degradates during full-scale conventional wastewater and constructed wetland treatment. PMID:26710933

Comparison of fipronil sources in North Carolina surface water and identification of a novel fipronil transformation product in recycled wastewater.

PubMed

McMahen, Rebecca L; Strynar, Mark J; McMillan, Larry; DeRose, Eugene; Lindstrom, Andrew B

2016-11-01

Fipronil is a phenylpyrazole insecticide that is widely used in residential and agricultural settings to control ants, roaches, termites, and other pests. Fipronil and its transformation products have been found in a variety of environmental matrices, but the source[s] which makes the greatest contribution to fipronil in surface water has yet to be determined. A sampling effort designed to prioritize known fipronil inputs (golf courses, residential areas, biosolids application sites and wastewater facilities) was conducted in North Carolina to learn more about the origins of fipronil in surface water. High resolution mass spectrometry (HRMS) analysis indicated that fipronil and its known derivatives were routinely present in all samples, but concentrations were substantially elevated near wastewater treatment plant outfalls (range 10-500ng/L combined), suggesting that they predominate as environmental sources. Corresponding recycled wastewater samples, which were treated with NaOCl for disinfection, showed disappearance of fipronil and all known degradates. HRMS and nuclear magnetic resonance (NMR) analysis techniques were used to determine that all fipronil-related compounds are oxidized to a previously unidentified fipronil sulfone chloramine species in recycled wastewater. The implications of the presence of a new fipronil-related compound in recycled wastewater need to be considered. Published by Elsevier B.V.

Sorption-desorption of fipronil in some soils, as influenced by ionic strength, pH and temperature.

PubMed

Singh, Anand; Srivastava, Anjana; Srivastava, Prakash C

2016-08-01

The sorption-desorpion of fipronil insecticide is influenced by soil properties and variables such as pH, ionic strength, temperature, etc. A better understanding of soil properties and these variables in sorption-desorption processes by quantification of fipronil using liquid chromatography may help to optimise suitable soil management to reduce contamination of surface and groundwaters. In the present investigation, the sorption-desorption of fipronil was studied in some soils at varying concentrations, ionic strengths, temperatures and pH values, and IR specta of fipronil sorbed onto soils were studied. The sorption of fipronil onto soils conformed to the Freundlich isotherm model. The sorption-desorption of fipronil varied with ionic strength in each of the soils. Sorption decreased but desorption increased with temperature. Sorption did not change with increasing pH, but for desorption there was no correlation. The cumulative desorption of fipronil from soil was significantly and inversely related to soil organic carbon content. IR spectra of sorbed fipronil showed the involvement of amino, nitrile, sulfone, chloro and fluoro groups and the pyrazole nucleus of the fipronil molecule. The sorption of fipronil onto soils appeared to be a physical process with the involvement of hydrogen bonding. An increase in soil organic carbon may help to reduce desorption of fipronil. High-temperature regimes are more conducive to the desorption. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

Correlation of tissue concentrations of the pyrethroid bifenthrin with neurotoxicity in the rat.

PubMed

Scollon, Edward J; Starr, James M; Crofton, Kevin M; Wolansky, Marcelo J; DeVito, Michael J; Hughes, Michael F

2011-11-28

The potential for human exposure to pyrethroid pesticides has prompted pharmacodynamic and pharmacokinetic research to better characterize risk. This work tested the hypothesis that blood and brain concentrations of the pyrethroid bifenthrin are predictive of neurotoxic effects. Adult male Long Evans rats received a single oral dose of bifenthrin dissolved in corn oil. Using figure-eight mazes, motor activity was measured for 1h at 4- and 7-h following exposure to bifenthrin (0-16mg/kg or 0-9mg/kg, respectively; n=4-8/group). Whole blood and brains were collected immediately following motor activity assays. Bifenthrin concentrations in blood and brain were quantified using HPLC/MS/MS. Bifenthrin exposure decreased motor activity from 20% to 70% in a dose-dependent manner at both time points. The relationship between motor activity data and administered dose, and blood and brain bifenthrin concentrations were described using a sigmoidal E(max) model. The relationships between motor activity and administered dose or blood concentrations were different between the 4- and 7-h time points. The relationship between motor activity and brain concentration was not significantly different between the two time points. These data suggest that momentary brain concentration of bifenthrin may be a more precise dose metric for predicting behavioral effects because the relationship between brain concentration and locomotor activity is independent of the time of exposure. Published by Elsevier Ireland Ltd.

Determination of residues of fipronil and its metabolites in cauliflower by using gas chromatography-tandem mass spectrometry.

PubMed

Duhan, Anil; Kumari, Beena; Duhan, Saroj

2015-02-01

Fipronil is a widely used insecticide with a well-described toxicological pathway. Recently it has been widely used in India to control vegetable pests. The present study has been carried out to observe the persistence pattern of fipronil and its metabolites-fipronil sulfone, fipronil sulfide, fipronil desulfinyl in cauliflower and soil so as to know the potential risk if any to consumers and environment. Fipronil was applied @ 56 g a.i. ha(-1). Samples of cauliflower and soil were collected periodically; processed using QuEChERS method and analyzed by GCMS/MS. In cauliflower, residues of fipronil and its metabolites reached below detectable level before 30 days of application whereas in soil about 95% of total fipronil residues got degraded within same time period. Washing and washing followed by cooking or boiling was found effective in reducing residues. A safe waiting period of 15 days is therefore suggested before consuming cauliflower.

The insecticide fipronil and its metabolite fipronil sulphone inhibit the rat α1β2γ2L GABAA receptor

PubMed Central

Li, P; Akk, G

2008-01-01

Background and purpose: Fipronil is the active ingredient in a number of widely used insecticides. Human exposure to fipronil leads to symptoms (headache, nausea and seizures) typically associated with the antagonism of GABAA receptors in the brain. In this study, we have examined the modulation of the common brain GABAA receptor subtype by fipronil and its major metabolite, fipronil sulphone. Experimental approach: Whole-cell and single-channel recordings were made from HEK 293 cells transiently expressing rat α1β2γ2L GABAA receptors. Key results: The major effect of fipronil was to increase the rate of current decay in macroscopic recordings. In single-channel recordings, the presence of fipronil resulted in shorter cluster durations without affecting the intracluster open and closed time distributions or the single-channel conductance. The α1V256S mutation, previously shown alleviate channel inhibition by inhibitory steroids and several insecticides, had a relatively small effect on channel block by fipronil. The mode of action of fipronil sulphone was similar to that of its parent compound but the metabolite was less potent at inhibiting the α1β2γ2L receptor. Conclusions and implications: We conclude that exposure to fipronil induces accumulation of receptors in a novel, long-lived blocked state. This process proceeds in parallel with and independently of, channel desensitization. The lower potency of fipronil sulphone indicates that the conversion serves as a detoxifying process in mammalian brain. PMID:18660823

The insecticide fipronil and its metabolite fipronil sulphone inhibit the rat alpha1beta2gamma2L GABA(A) receptor.

PubMed

Li, P; Akk, G

2008-11-01

Fipronil is the active ingredient in a number of widely used insecticides. Human exposure to fipronil leads to symptoms (headache, nausea and seizures) typically associated with the antagonism of GABA(A) receptors in the brain. In this study, we have examined the modulation of the common brain GABA(A) receptor subtype by fipronil and its major metabolite, fipronil sulphone. Whole-cell and single-channel recordings were made from HEK 293 cells transiently expressing rat alpha1beta2gamma2L GABA(A) receptors. The major effect of fipronil was to increase the rate of current decay in macroscopic recordings. In single-channel recordings, the presence of fipronil resulted in shorter cluster durations without affecting the intracluster open and closed time distributions or the single-channel conductance. The alpha1V256S mutation, previously shown alleviate channel inhibition by inhibitory steroids and several insecticides, had a relatively small effect on channel block by fipronil. The mode of action of fipronil sulphone was similar to that of its parent compound but the metabolite was less potent at inhibiting the alpha1beta2gamma2L receptor. We conclude that exposure to fipronil induces accumulation of receptors in a novel, long-lived blocked state. This process proceeds in parallel with and independently of, channel desensitization. The lower potency of fipronil sulphone indicates that the conversion serves as a detoxifying process in mammalian brain.

Degradation of fipronil by Stenotrophomonas acidaminiphila isolated from rhizospheric soil of Zea mays.

PubMed

Uniyal, Shivani; Paliwal, Rashmi; Sharma, R K; Rai, J P N

2016-06-01

Fipronil is a widely used insecticide in agriculture and can cause potential health hazards to non-target soil invertebrates and nearby aquatic systems. In the present study, a fipronil degrading bacterium was isolated from fipronil contaminated soil, i.e. rhizospheric zone of Zea mays. Morphological, biochemical and molecular characterization of strain indicated that it clearly belongs to Stenotrophomonas acidaminiphila (accession no. KJ396942). A three-factor Box-Behnken experimental design combined with response surface modeling was employed to predict the optimum conditions for fipronil degradation. The optimum pH, temperature and total inocula biomass for the degradation of fipronil were 7.5, 35 °C and 0.175 g L -1 , respectively. The bacterial strain was able to metabolize 25 mg L -1 fipronil with 86.14 % degradation in Dorn's broth medium under optimum conditions. Metabolites formed as a result of fipronil degradation were characterized with gas liquid chromatograph. A novel fipronil degradation pathway was proposed for S. acidaminiphila on the basis of metabolites formed. Non-sterilized soil inoculated with S. acidaminiphila was found to follow first order kinetics with a rate constant of 0.046 d -1 . Fipronil sulfone, sulfide and amide were formed as the metabolites and were degraded below the quantifiable limit after 90 days of time period. Given the high fipronil degradation observed in the present study, S. acidaminiphila may have potential for use in bioremediation of fipronil contaminated soils.

Origin and extent of resistance to fipronil in the German cockroach, Blattella germanica (L.) (Dictyoptera: Blattellidae).

PubMed

Holbrook, Glenn L; Roebuck, Jamie; Moore, Clyde B; Waldvogel, Michael G; Schal, Coby

2003-10-01

Fipronil, a phenylpyrazole insecticide, was made available in 1999 in bait formulations for use against the German cockroach, Blattella germanica (L.). We have investigated resistance to fipronil in the descendants of cockroaches collected just before, or contemporaneously with, the introduction of fipronil baits. Cockroaches were obtained in two types of settings: homes that either had or had not been serviced by a pest management professional while occupied by their current residents. Thorough inspections by us turned up no evidence that fipronil had been used in any of the homes, and in addition, no residents claimed to have used baits containing fipronil. Resistance to fipronil was detected by topically dosing adult males with the LC99 of fipronil, the value of which was determined in a dose-response assay with males of an insecticide-susceptible strain. Fewer than 99 of 100 males of all field-collected strains died within 72 h of being treated. Moreover, substantial numbers of males survived doses three and 10-fold greater than the LC99. Regression analysis showed that 67% of the variation in the percentage of males that died after being treated with fipronil was explained by a linear relationship with the percentage that died after being treated with dieldrin. Therefore, it appears that resistance to fipronil in German cockroaches--whose ancestors had never been exposed to it--is attributable to enduring resistance to the cyclodienes, which were formerly used for cockroach control and have a similar mode of action as fipronil. Lastly, we found that insects resistant to topically administered fipronil were likewise resistant, and to a similar degree, to ingested fipronil.

The effects of fipronil and the photodegradation product fipronil desulfinyl on growth and gene expression in juvenile blue crabs, Callinectes sapidus, at different salinities

USGS Publications Warehouse

Goff, Andrew D.; Saranjampour, Parichehr; Ryan, Lauren M.; Hladik, Michelle; Covi, Joseph A.; Armbrust, Kevin L.; Brander, Susanne M.

2017-01-01

Endocrine disrupting compounds (EDCs) are now widely established to be present in the environment at concentrations capable of affecting wild organisms. Although many studies have been conducted in fish, less is known about effects in invertebrates such as decapod crustaceans. Decapods are exposed to low concentrations of EDCs that may cause infertility, decreased growth, and developmental abnormalities. The objective herein was to evaluate effects of fipronil and its photodegradation product fipronil desulfinyl. Fipronil desulfinyl was detected in the eggs of the decapod Callinectes sapidus sampled off the coast of South Carolina. As such, to examine specific effects on C. sapidus exposed in early life, we exposed laboratory-reared juveniles to fipronil and fipronil desulfinyl for 96 hours at three nominal concentrations (0.01, 0.1, 0.5 μg/L) and two different salinities (10, 30 ppt). The size of individual crabs (weight, carapace width) and the expression of several genes critical to growth and reproduction were evaluated. Exposure to fipronil and fipronil desulfinyl resulted in significant size increases in all treatments compared to controls. Levels of expression for vitellogenin (Vtg), an egg yolk precursor, and the ecdysone receptor (EcR), which binds to ecdysteroids that control molting, were inversely correlated with increasing fipronil and fipronil desulfinyl concentrations. Effects on overall growth and on the expression of EcR and Vtg differ depending on the exposure salinity. The solubility of fipronil is demonstrated to decrease considerably at higher salinities. This suggests that fipronil and its photodegradation products may be more bioavailable to benthic organisms as salinity increases, as more chemical would partition to tissues. Our findings suggest that endocrine disruption is occurring through alterations to gene expression in C. sapidus populations exposed to environmental levels of fipronil, and that effects may be dependent upon the salinity at which exposure occurs.

The combined mode of action of fipronil and amitraz on the motility of Rhipicephalus sanguineus.

PubMed

Prullage, Joseph B; Tran, Hai V; Timmons, Phil; Harriman, Jay; Chester, S Theodore; Powell, Kerrie

2011-07-15

The motility of adult Rhipicephalus sanguineus was evaluated subsequent to treatments of amitraz, fipronil and the combination of fipronil plus amitraz against a vehicle control in a Petri dish assay using the LemnaTec Scanalyzer Imaging System. The assay was run using a fixed dilution of amitraz (0.32μg/cm(2)); serial dilutions of fipronil (1.3, 0.33, 0.08, 0.02, or 0.005μg/cm(2)); and the same serial dilutions of fipronil in combination with the fixed dilution of amitraz. Measurement of motility was made of unstimulated ticks and then after stimulation at 1, 4, 18-22, and 24h post exposure (hpe) of the Petri dishes. For the unstimulated ticks, there was no difference in motility between the amitraz treatment group and the fipronil plus amitraz treatment group at the early time points. However, these two treatment groups had significantly higher motility than the solvent control and fipronil treatment groups. The unstimulated ticks in the amitraz treatment group had significantly higher motility than the fipronil plus amitraz treatment group at the later time points. Measurements after stimulation demonstrated there was no difference in motility between the amitraz treatment group and the fipronil plus amitraz treatment group at the early time points. By 18 hpe, the fipronil plus amitraz treatment group had significantly lower motility than all other treatment groups and at 21-22 and 24 hpe the other treatment groups did not differ from the control group. The action could be divided in two phases in the combination experiment: phase 1: an early increase in motility due to amitraz is identified in both amitraz alone or fipronil plus amitraz groups; phase 2: the combination of fipronil plus amitraz caused a significantly greater reduction in motility, suggesting mortality of the ticks, compared to fipronil or amitraz alone. These results demonstrate a synergism resulting from the combination of fipronil plus amitraz. Copyright © 2011 Elsevier B.V. All rights reserved.

Perturbation of metabonome of embryo/larvae zebrafish after exposure to fipronil.

PubMed

Yan, Lu; Gong, Chenxue; Zhang, Xiaofeng; Zhang, Quan; Zhao, Meirong; Wang, Cui

2016-12-01

The escalating demand for fipronil by the increasing insects' resistance to synthetic pyrethroids placed a burden on aquatic vertebrates. Although awareness regarding the toxicity of fipronil to fish is arising, the integral alteration caused by fipronil remains unexplored. Here, we investigated on the development toxicity of fipronil and the metabolic physiology perturbation at 120h post fertilization through GC-MS metabolomics on zebrafish embryo. We observed that fipronil dose-dependently induced malformations including uninflated swim bladder and bent spine. Further, the "omic" technique hit 26 differential metabolites after exposure to fipronil and five significant signaling pathways. We speculated that changes in primary bile acid synthesis pathway and the content of saturated fatty acid in the chemical-related group indicated the liver toxicity. Pathway of Aminoacyl-tRNA biosynthesis changed by fipronil may relate to the macromolecular synthesis. Concurrently, methane metabolism pathway was also identified while the role in zebrafish needs further determination. Overall, this study revealed several new signaling pathways in fipronil-treated zebrafish embryo/larval. Copyright © 2016 Elsevier B.V. All rights reserved.

Isolation and Characterization of Fipronil Degrading Acinetobacter calcoaceticus and Acinetobacter oleivorans from Rhizospheric Zone of Zea mays.

PubMed

Uniyal, Shivani; Paliwal, Rashmi; Verma, Megha; Sharma, R K; Rai, J P N

2016-06-01

An enrichment culture technique was used for the isolation of bacteria capable of utilizing fipronil as a sole source of carbon and energy. Based on morphological, biochemical characteristics and phylogenetic analysis of 16S rRNA sequence, the bacterial strains were identified as Acinetobacter calcoaceticus and Acinetobacter oleivorans. Biodegradation experiments were conducted in loamy sand soil samples fortified with fipronil (50 µg kg(-1)) and inoculated with Acinetobacter sp. cells (45 × 10(7) CFU mL(-1)) for 90 days. Soil samples were periodically analyzed by gas liquid chromatography equipped with electron capture detector. Biodegradation of fipronil fitted well with the pseudo first-order kinetics, with rate constant value between 0.041 and 0.051 days(-1). In pot experiments, fipronil and its metabolites fipronil sulfide, fipronil sulfone and fipronil amide were found below quantifiable limit in soil and root, shoot and leaves of Zea mays. These results demonstrated that A. calcoaceticus and A. oleivorans may serve as promising strains in the bioremediation of fipronil-contaminated soils.

Hydroxy-fipronil is a new urinary biomarker of exposure to fipronil

EPA Science Inventory

Occupational medical surveillance is highly desirable in manufacturing facilities where exposure to chemicals is significant. The insecticide fipronil is generally considered safe for humans but with increasing use, exposure to fipronil is of concern. Identification of urinary me...

ENANTIOSELECTIVE MICROBIAL TRANSFORMATION OF THE PHENYLPYRAZOLE INSECTICIDE FIPRONIL IN ANOXIC SEDIMENTS

EPA Science Inventory

Fipronil, a chiral insecticide, was biotransformed initially to fipronil sulfide in anoxic sediment slurries following a short lag period. Sediment slurries characterized as either sulfidogenic or methanogenic transformed fipronil with half-lives of approximately 35 and 40 days, ...

Utilization of common ditch vegetation in the reduction of fipronil and its sulfone metabolite.

PubMed

Kröger, Robert; Moore, Matt T

2008-12-01

Fipronil, a phenylpyrazole insecticide, and its oxidative sulfone metabolite are two potential pollutants from treated rice and cotton production. A consequence of these pollutants occurring in surface runoff is degradation of downstream aquatic ecosystems. Utilization of primary intercept drainage ditches as management practices to reduce fipronil concentrations and loads has not been examined. This study used ditch mesocosms planted with monospecific stands of common emergent wetland vegetation to determine if certain plant species were more proficient in fipronil mitigation. Three replicates of four plant species were compared against a non-vegetated control to determine differences in water column outflow concentrations (microg L(-1)) and loads (microg). There were no significant differences between vegetated and control treatments in outflow concentrations (F = 0.35, P = 0.836) and loads (F = 0.35, P = 0.836). The range of fipronil reduction was 28-45% for both concentration and load. Unlike fipronil, fipronil sulfone concentrations and load increased by 96-328%. The increase in fipronil sulfone was hypothesized as a direct consequence of oxidation of fipronil within each mesocosm. The type of ditch vegetation had no effect on fipronil reduction. Future research needs to examine initial concentrations and hydraulic retention times to examine potential changes in reduction capacities.

Identification of fipronil metabolites by time-of-flight mass spectrometry for application in a human exposure study

PubMed Central

McMahen, Rebecca L.; Strynar, Mark J.; Dagnino, Sonia; Herr, David W.; Moser, Virginia C.; Garantziotis, Stavros; Andersen, Erik M.; Freeborn, Danielle L.; McMillan, Larry; Lindstrom, Andrew B.

2016-01-01

Fipronil is a phenylpyrazole insecticide commonly used in residential and agricultural applications. To understand more about the potential risks for human exposure associated with fipronil, urine and serum from dosed Long Evans adult rats (5 and 10 mg/kg bw) were analyzed to identify metabolites as potential biomarkers for use in human biomonitoring studies. Urine from treated rats was found to contain seven unique metabolites, two of which had not been previously reported—M4 and M7 which were putatively identified as a nitroso compound and an imine, respectively. Fipronil sulfone was confirmed to be the primary metabolite in rat serum. The fipronil metabolites identified in the respective matrices were then evaluated in matched human urine (n = 84) and serum (n = 96) samples from volunteers with no known pesticide exposures. Although no fipronil or metabolites were detected in human urine, fipronil sulfone was present in the serum of approximately 25% of the individuals at concentrations ranging from 0.1 to 4 ng/mL. These results indicate that many fipronil metabolites are produced following exposures in rats and that fipronil sulfone is a useful biomarker in human serum. Furthermore, human exposure to fipronil may occur regularly and require more extensive characterization. PMID:25687022

Identification of fipronil metabolites by time-of-flight mass spectrometry for application in a human exposure study.

PubMed

McMahen, Rebecca L; Strynar, Mark J; Dagnino, Sonia; Herr, David W; Moser, Virginia C; Garantziotis, Stavros; Andersen, Erik M; Freeborn, Danielle L; McMillan, Larry; Lindstrom, Andrew B

2015-05-01

Fipronil is a phenylpyrazole insecticide commonly used in residential and agricultural applications. To understand more about the potential risks for human exposure associated with fipronil, urine and serum from dosed Long Evans adult rats (5 and 10mg/kg bw) were analyzed to identify metabolites as potential biomarkers for use in human biomonitoring studies. Urine from treated rats was found to contain seven unique metabolites, two of which had not been previously reported-M4 and M7 which were putatively identified as a nitroso compound and an imine, respectively. Fipronil sulfone was confirmed to be the primary metabolite in rat serum. The fipronil metabolites identified in the respective matrices were then evaluated in matched human urine (n=84) and serum (n=96) samples from volunteers with no known pesticide exposures. Although no fipronil or metabolites were detected in human urine, fipronil sulfone was present in the serum of approximately 25% of the individuals at concentrations ranging from 0.1 to 4ng/mL. These results indicate that many fipronil metabolites are produced following exposures in rats and that fipronil sulfone is a useful biomarker in human serum. Furthermore, human exposure to fipronil may occur regularly and require more extensive characterization. Published by Elsevier Ltd.

Differential fipronil susceptibility and metabolism in two rice stem borers from China.

PubMed

Fang, Qi; Huang, Cheng-Hua; Ye, Gong-Yin; Yao, Hong-Wei; Cheng, Jia-An; Akhtar, Zunnu-Raen

2008-08-01

The susceptibilities of larvae of two rice stem borers, namely, Chilo suppressalis (Walker) (Lepidoptera: Crambidae) and Sesamia inferens (Walker) (Lepidoptera: Nocutidae) to fipronil and its metabolites were investigated, and then the activities of microsomal O-demethylase, and glutathione transferase (GST) in two species were measured. The metabolism of fipronil in both stem borers was determined in vivo and in vitro. The LD50 value of fipronil to S. inferens was 118.5-fold higher than that of C. suppressalis. The bioassay results offipronil metabolites showed that the toxicities of sulfone and sulfide were higher than fipronil for both species, and the differential toxicity between sulfone and fipronil was remarkable. Alternatively, the activities of microsomal O-demethylase and GST of C. suppressalis were 1.35- and 2.06-fold higher than S. inferens, respectively. The in vivo and in vitro studies on metabolism of fipronil showed that all of fipronil, sulfone, and sulfide were detected and the content of sulfone was higher than sulfide in both stem borers. The residue of sulfone in C. suppressalis was significantly higher than that in S. inferens. These results suggest that the higher activity of mixed function oxidases may cause the higher capacity of C. suppressalis to produce fipronil-sulfone, which is more toxic than fipronil leading to the higher susceptibility of this species.

Synthesis of AzPhchitosan-bifenthrin-PVC to protect cables against termites.

PubMed

Zhang, Lingkun; Cai, Weiwei; Chen, Wu-Ya; Zhang, Li; Hu, Kaikai; Guan, Yan-Qing

2016-03-30

The destruction of PVC cables by termites is a continuing and long-standing problem, which can lead to power leakage and power cut. Given the environmental demerits of insecticide overuse, alternative methods of addressing this problem are a highly desirable goal. In this study, we used photo-immobilization to develop a chitosan carrier system to help bifenthrin immobilize on the surface of the PVC substrate. The immobilization was analyzed using nuclear magnetic resonance (NMR), UV absorption, reverse-phase high-performance liquid chromatography (RP-HPLC), Raman absorption spectroscopy, and thermal gravimetric analysis (TGA). The surface structure and biological activity of the embedded and immobilized bifenthrin were examined using scanning electron microscopy (SEM), atomic force microscopy (AFM), and X-ray photon-electron spectroscopy (XPS). Its efficacy was assessed in pest experiments. The results indicate a successful embedding and immobilization of bifenthrin. Furthermore, the chemical bonding network between AzPhchitosan, bifenthrin, and PVC is stable, guaranteeing no environmental release of bifenthrin, and also providing more efficacious protection against termites. The evidence suggests that this photo-immobilization of bifenthrin-embedded chitosan on the surface of PVC substrates is a novel and environmentally friendly technique for termite control. This paper also reports a modification of chitosan with respect to its novel application in environmental protection. Copyright © 2015 Elsevier Ltd. All rights reserved.

Bioaccessibility of Fipronil Sorbed to Soil and House Dust

EPA Science Inventory

Fipronil is a phenylpyrazole insecticide with uses ranging from soil treatment, to the control of household pests and ectoparasites on pets. Soils and house dusts readily sorb fipronil and when these soils and dusts are ingested, the fipronil may become bioaccessible for uptake ...

Fipronil is a powerful uncoupler of oxidative phosphorylation that triggers apoptosis in human neuronal cell line SHSY5Y.

PubMed

Vidau, Cyril; González-Polo, Rosa A; Niso-Santano, Mireia; Gómez-Sánchez, Rubén; Bravo-San Pedro, José M; Pizarro-Estrella, Elisa; Blasco, Rafael; Brunet, Jean-Luc; Belzunces, Luc P; Fuentes, José M

2011-12-01

Fipronil is a phenylpyrazole insecticide known to elicit neurotoxicity via an interaction with ionotropic receptors, namely GABA and glutamate receptors. Recently, we showed that fipronil and other phenylpyrazole compounds trigger cell death in Caco-2 cells. In this study, we investigated the mode of action and the type of cell death induced by fipronil in SH-SY5Y human neuroblastoma cells. Flow cytometric and western blot analyses demonstrated that fipronil induces cellular events belonging to the apoptosis process, such as mitochondrial potential collapse, cytochrome c release, caspase-3 activation, nuclear condensation and phosphatidylserine externalization. In addition, fipronil induces a rapid ATP depletion with concomitant activation of anaerobic glycolysis. This cellular response is characteristic of mitochondrial injury associated with a defect of the respiration process. Therefore, we also investigated the effect of fipronil on the oxygen consumption in isolated mitochondria. Interestingly, we show for the first time that fipronil is a strong uncoupler of oxidative phosphorylation at relative low concentrations. Thus in this study, we report a new mode of action by which the insecticide fipronil could triggers apoptosis. Copyright © 2011 Elsevier Inc. All rights reserved.

Bifenthrin causes trophic cascades and alters insect emergence in mesocosms: implication for small streams

USGS Publications Warehouse

Rogers, Holly; Schmidt, Travis S.; Dabney, Brittanie L.; Hladik, Michelle; Mahler, Barbara J.; Van Metre, Peter C.

2016-01-01

Direct and indirect ecological effects of the widely used insecticide bifenthrin on stream ecosystems are largely unknown. To investigate such effects, a manipulative experiment was conducted in stream mesocosms that were colonized by aquatic insect communities and exposed to bifenthrin-contaminated sediment; implications for natural streams were interpreted through comparison of mesocosm results to a survey of 100 Midwestern streams, USA. In the mesocosm experiment, direct effects of bifenthrin exposure included reduced larval macroinvertebrate abundance, richness, and biomass at concentrations (EC50s ranged 197.6 – 233.5 ng bifenthrin/ g organic carbon) previously thought safe for aquatic life. Indirect effects included a trophic cascade in which periphyton abundance increased after macroinvertebrate scrapers decreased. Adult emergence dynamics and corresponding terrestrial subsidies were altered at all bifenthrin concentrations tested. Extrapolating these results to the Midwestern stream assessment suggests pervasive ecological effects, with altered emergence dynamics likely in 40% of streams and a trophic cascade in 7% of streams. This study provides new evidence that a common pyrethroid might alter aquatic and terrestrial ecosystem function at the regional scale.

Bifenthrin Causes Trophic Cascade and Altered Insect Emergence in Mesocosms: Implications for Small Streams.

PubMed

Rogers, Holly A; Schmidt, Travis S; Dabney, Brittanie L; Hladik, Michelle L; Mahler, Barbara J; Van Metre, Peter C

2016-11-01

Direct and indirect ecological effects of the widely used insecticide bifenthrin on stream ecosystems are largely unknown. To investigate such effects, a manipulative experiment was conducted in stream mesocosms that were colonized by aquatic insect communities and exposed to bifenthrin-contaminated sediment; implications for natural streams were interpreted through comparison of mesocosm results to a survey of 100 Midwestern streams, USA. In the mesocosm experiment, direct effects of bifenthrin exposure included reduced larval macroinvertebrate abundance, richness, and biomass at concentrations (EC 50 's ranged from 197.6 to 233.5 ng bifenthrin/g organic carbon) previously thought safe for aquatic life. Indirect effects included a trophic cascade in which periphyton abundance increased after macroinvertebrate scrapers decreased. Adult emergence dynamics and corresponding terrestrial subsidies were altered at all bifenthrin concentrations tested. Extrapolating these results to the Midwestern stream assessment suggests pervasive ecological effects, with altered emergence dynamics likely in 40% of streams and a trophic cascade in 7% of streams. This study provides new evidence that a common pyrethroid might alter aquatic and terrestrial ecosystem function at the regional scale.

Oral toxicity of abamectin, boric acid, fipronil, and hydramethylnon to laboratory colonies of Argentine ants (Hymenoptera: Formicidae).

PubMed

Hooper-Bui, L M; Rust, M K

2000-06-01

Comprehensive laboratory baiting studies with the 4 insecticides abamectin, boric acid, fipronil, and hydramethylnon were conducted against Argentine ant, Linepithema humile (Mayr). Serial dilutions of each insecticide prepared in a 25% sucrose solution were provided for 24 h or 14 d to groups of workers and queens. Sucrose-water baits containing 1 x 10(-5)% fipronil and 0.1% hydramethylnon provided complete mortality of L. humile workers baited for 24 h. Baits containing 1 x 10(-4) and 1 x 10(-5)% fipronil provided 100% kill of queens. In the continuous baiting, 0.5% boric acid, 1 x 10(-6)% fipronil, and 0.025% hydramethylnon provided 100% mortality of workers. The queens and workers provided baits containing 1 x 10(-5)% fipronil and 0.5% boric acid all died within 14 d. Low concentrations of fipronil and boric acid in sucrose may be promising candidates for Argentine ant control.

Comparison of fipronil sources in North Carolina surface water and identification of a novel fipronil transformation product in recycled wastewater

EPA Science Inventory

Fipronil is a phenylpyrazole insecticide that is widely used in residential and agricultural settings to control ants, roaches, termites, and other pests. Fipronil and its transformation products have been found in a variety of environmental matrices, but the source[s] which make...

Investigation into Sources of Fipronil in Surface Water and Identification of a Novel Fipronil Metabolite in Reclaimed Wastewater

EPA Science Inventory

Fipronil is a phenyl pyrazole insecticide used to control termites, fleas, roaches, ants, and other pests in residential and agricultural settings. Fipronil has been found in various environmental media (surface water, wastewater, indoor and outdoor dust, etc) and is known to un...

Investigation into sources of fipronil in surface water and identification of a novel fipronil metabolite in reclaimed wastewater (Carolinas SETAC 2015 presentation)

EPA Science Inventory

Fipronil is a phenyl pyrazole insecticide used to control termites, fleas, roaches, ants, and otherpests in residential and agricultural settings. Fipronil has been found in various environmentalmedia (surface water, wastewater, indoor and outdoor dust, etc) and is known to under...

Synergistic and Antagonistic Effects of Piperonyl Butoxide in Fipronil-Susceptible and Resistant Rice Stem Borrers, Chilo suppressalis

PubMed Central

Huang, Qingchun; Deng, Yunfei; Zhan, Taisong; He, Yuan

2010-01-01

Using the phenylpyrazole insecticide, fipronil for selection in the laboratory, a resistant Wenzhou strain of the rice stem borer, Chilo suppressalis (Walker) (Lepidoptera: Crambidae) had an LD50 at least 45.3 times greater than the susceptible Anhui strain. The realized resistant heritability (h2) of 0.213 showed that the tolerant phenotype was moderately heritable and had potential to develop higher tolerance to fipronil. Piperonyl butoxide decreased the effects of fipronil on the mortality of the susceptible larvae with 0.27–0.44 times synergistic rates, but increased the toxicity of fipronil on the resistant larvae with 1.85–2.53 times synergistic rates as compared to that of fipronil alone. The inhibitory effect of piperonyl butoxide on the activity of microsomal O-demethylase was greater in susceptible larvae than in the resistant larvae. The differential synergism of fipronil by piperonyl butoxide in the susceptible and resistant C. suppressalis may be caused by the reduced penetration of fipronil in the lab-selected Wenzhou strain. PMID:21062143

Characteristics of suspended solids affect bifenthrin toxicity to the calanoid copepods Eurytemora affinis and Pseudodiaptomus forbesi.

PubMed

Parry, Emily; Lesmeister, Sarah; Teh, Swee; Young, Thomas M

2015-10-01

Bifenthrin is a pyrethroid pesticide that is highly toxic to aquatic invertebrates. The dissolved concentration is generally thought to be the best predictor of acute toxicity. However, for the filter-feeding calanoid copepods Eurytemora affinis and Pseudodiaptomus forbesi, ingestion of pesticide-bound particles could prove to be another route of exposure. The present study investigated bifenthrin toxicity to E. affinis and P. forbesi in the presence of suspended solids from municipal wastewater effluent and surface water of the San Francisco (CA, USA) Estuary. Suspended solids mitigated the toxicity of total bifenthrin to E. affinis and P. forbesi, but mortality was higher than what would be predicted from dissolved concentrations alone. The results indicate that the toxicity and bioavailability of particle-associated bifenthrin was significantly correlated with counts of 0.5-µm to 2-µm particle sizes. Potential explanations could include direct ingestion of bifenthrin-bound particles, changes in food consumption and feeding behavior, and physical contact with small particles. The complex interactions between pesticides and particles of different types and sizes demonstrate a need for future ecotoxicological studies to investigate the role of particle sizes on aquatic organisms. © 2015 SETAC.

Interaction between Short-Term Heat Pretreatment and Fipronil on 2nd Instar Larvae of Diamondback Moth, Plutella Xylostella (Linn)

PubMed Central

Gu, Xiaojun; Tian, Sufen; Wang, Dehui; Gao, Fei; Wei, Hui

2010-01-01

Based on the cooperative virulence index (c.f.) and LC50 of fipronil, the interaction effect between short-term heat pretreatment and fipronil on 2nd instar larvae of diamondback moth (DBM), Plutella xylostella (Linnaeus), was assessed. The results suggested that pretreatment of the tested insects at 30 °C for 2, 4 and 8h could somewhat decrease the toxicity of fipronil at all set concentrations. The LC50 values of fipronil increased after heat pretreatment and c.f. values in all these treatments were below zero. These results indicated that real mortalities were less than theoretical ones and antagonism was found in the treatments of fipronil at 0.39 and 0.78 mg/L after heat pretreatment at 30 °C at 2, 4 and 8 h. However, pretreatment at 30 °C for 12h could increase the toxicity of fipronil at all set concentrations, the LC50 of fipronil decreased after heat pretreatment and c.f. values in all these treatments were above zero, which indicated real mortalities were higher than theoretical ones. Pretreatment of the tested insects at 35 °C for 2, 4, 8 and 12h was found to increase the toxicity of fipronil at all set concentrations which resulted in the decrease of LC50 values of fipronil and c.f. above zero in all treatments with only one exception. Most interactions were assessed as synergism. The results indicated that cooperative virulence index (c.f.) may be adopted in hormetic effect assessment. PMID:20877489

Contact versus feeding intoxication by fipronil in Reticulitermes termites (Isoptera: Rhinotermitidae): laboratory evaluation of toxicity, uptake, clearance, and transfer among individuals.

PubMed

Bagnères, A G; Pichon, A; Hope, J; Davis, R W; Clément, J L

2009-02-01

The susceptibility to fipronil of U.S. and French populations of Reticulitermes flavipes (Kollar) (Isoptera: Rhinotermitidae) was evaluated in two types of laboratory bioassays: contact intoxication with 0.01-1 ppm treated sand and feeding intoxication with 0.1-10 ppm treated filter paper. Contact intoxication with 0.01 ppm fipronil caused 60% mortality after 55 and 64 h in the French and U.S. populations, respectively, whereas in the 5 ppm feeding assay 70 and 60% mortality was observed after 7 d in the French and U.S. populations, respectively. We evaluated the uptake, clearance, and transfer of fipronil among workers of French R. flavipes using [14C] fipronil in contact (0.01 ppm) and feeding (3 ppm) bioassays. Fipronil amounts were measured on their cuticle and in their bodies. Maximal uptake was observed in the contact assay. A significant uptake of fipronil occurred in the feeding assay. Transfer from exposed donors to unexposed recipients occurred within 24 h. Frequent horizontal transfer resulted in a significant uptake in recipients, particularly when donor fipronil acquisition was by feeding. Donors transferred approximately 46% of the toxicant to recipients. Social behaviors such as contact and grooming, together with internalization of the biocide, may be components of the horizontal transfer process and contribute to the efficacy of fipronil in the field.

Photodegradation of bifenthrin and deltamethrin-effect of copper amendment and solvent system.

PubMed

Tariq, Saadia Rashid; Ahmed, Dildar; Farooq, Amna; Rasheed, Sonia; Mansoor, Mubarkah

2017-02-01

The photodegradation of bifenthrin and deltamethrin was studied in the presence of Cu salts and two different solvents, methanol and acetonitrile. Results of the study showed that in the absence of any metal salt, the two pesticides degraded more rapidly in acetonitrile than in methanol. After 24 h of UV irradiation, 70% of deltamethrin had degraded in acetonitrile, while only 41% bifenthrin degraded in this solvent. In methanol, bifenthrin degraded at a much enhanced rate than in acetonitrile while the rate of degradation of deltamethrin was comparable to that in acetonitrile. The photodegradation was further enhanced by the addition of copper to the solution of bifenthrin and deltamethrin in acetonitrile. The rate of photodegradation of deltamethrin increased from 2.4 × 10 -2 to 3.5 × 10 -2  h -1 in acetonitrile and 2.5 × 10 -2 to 3.4 × 10 -2  h -1 in methanol after the addition of copper. Similarly, the rate of photodegradation of bifenthrin was increased from 5.0 × 10 -3 to 9.0 × 10 -3  h -1 in acetonitrile and 7.0 × 10 -3 to 9.05 × 10 -3  h -1 in methanol with the addition of copper. Thus, copper has the potential to enhance the photodegradation of bifenthrin and deltamethrin in both the solvents.

Fipronil-induced genotoxicity and DNA damage in vivo: Protective effect of vitamin E.

PubMed

Badgujar, P C; Selkar, N A; Chandratre, G A; Pawar, N N; Dighe, V D; Bhagat, S T; Telang, A G; Vanage, G R

2017-05-01

Fipronil, an insecticide of the phenylpyrazole class has been classified as a carcinogen by United States Environmental Protection Agency, yet very limited information is available about its genotoxic effects. Adult male and female animals were gavaged with various doses of fipronil (2.5, 12.5, and 25 mg/kg body weight (bw)) to evaluate micronucleus test (mice), chromosome aberration (CA), and comet assay (rats), respectively. Cyclophosphamide (40 mg/kg bw; intraperitoneal) was used as positive control. Another group of animals were pretreated with vitamin E orally (400 mg/kg bw) for 5 days prior to administration of fipronil (12.5 mg/kg). Fipronil exposure in both male and female mice caused significant increase in the frequency of micronuclei (MN) in polychromatic erythrocytes. Similarly, structural CAs in bone marrow cells and DNA damage in the lymphocytes was found to be significantly higher in the male and female rats exposed to fipronil as compared to their respective controls. The average degree of protection (male and female animals combined together) shown by pretreatment of vitamin E against fipronil-induced genotoxicity was 63.28%: CAs; 47.91%: MN formation; and 74.70%: DNA damage. Findings of this study demonstrate genotoxic nature of fipronil regardless of gender effect and documents protective role of vitamin E.

Fipronil induces apoptosis through caspase-dependent mitochondrial pathways in Drosophila S2 cells.

PubMed

Zhang, Baoyan; Xu, Zhiping; Zhang, Yixi; Shao, Xusheng; Xu, Xiaoyong; Cheng, Jiaogao; Li, Zhong

2015-03-01

Fipronil is the first phenylpyrazole insecticide widely used in controlling pests, including pyrethroid, organophosphate and carbamate insecticides. It is generally accepted that fipronil elicits neurotoxicity via interactions with GABA and glutamate receptors, although alternative mechanisms have recently been proposed. This study evaluates the genotoxicity of fipronil and its likely mode of action in Drosophila S2 cells, as an in vitro model. Fipronil administrated the concentration- and time-dependent S2 cell proliferation. Intracellular biochemical assays showed that fipronil-induced S2 cell apoptosis coincided with a decrease in the mitochondrial membrane potential and an increase reactive oxygen species generation, a significant decrease of Bcl-2 and DIAP1, and a marked augmentation of Cyt c and caspase-3. Because caspase-3 is the major executioner caspase downstream of caspase-9 in Drosophila, enzyme activity assays were used to determine the activities of caspase-3 and caspase-9. Our results indicated that fipronil effectively induced apoptosis in Drosophila S2 cells through caspase-dependent mitochondrial pathways. Copyright © 2015 Elsevier Inc. All rights reserved.

Age dependent in vitro metabolism of bifenthrin in rat and human hepatic microsomes.

PubMed

Nallani, Gopinath C; Chandrasekaran, Appavu; Kassahun, Kelem; Shen, Li; ElNaggar, Shaaban F; Liu, Zhiwei

2018-01-01

Bifenthrin, a pyrethroid insecticide, undergoes oxidative metabolism leading to the formation of 4'-hydroxy-bifenthrin (4'-OH-BIF) and hydrolysis leading to the formation of TFP acid in rat and human hepatic microsomes. In this study, age-dependent metabolism of bifenthrin in rats and humans were determined via the rates of formation of 4'-OH-BIF and TFP acid following incubation of bifenthrin in juvenile and adult rat (PND 15 and PND 90) and human (<5years and >18years) liver microsomes. Furthermore, in vitro hepatic intrinsic clearance (CL int ) of bifenthrin was determined by substrate consumption method in a separate experiment. The mean V max (±SD) for the formation of 4'-OH-BIF in juvenile rat hepatic microsomes was 25.0±1.5pmol/min/mg which was significantly lower (p<0.01) compared to that of adult rats (86.0±17.7pmol/min/mg). However, the mean K m values for juvenile (19.9±6.6μM) and adult (23.9±0.4μM) rat liver microsomes were similar. On the other hand, in juvenile human hepatic microsomes, V max for the formation of 4'-OH-BIF (73.9±7.5pmol/min/mg) was significantly higher (p<0.05) than that of adults (21.6±0.6pmol/min/mg) albeit similar K m values (10.5±2.8μM and 8.9±0.6μM) between the two age groups. The trends in the formation kinetics of TFP acid were similar to those of 4'-OH-BIF between the species and age groups, although the differences between juveniles and adults were less pronounced. The data also show that metabolism of bifenthrin occurs primarily via oxidative pathway with relatively lesser contribution (~30%) from hydrolytic pathway in both rat and human liver microsomes. The CL int values for bifenthrin, determined by monitoring the consumption of substrate, in juvenile and adult rat liver microsomes fortified with NADPH were 42.0±7.2 and 166.7±20.5μl/min/mg, respectively, and the corresponding values for human liver microsomes were 76.0±4.0 and 21.3±1.2μl/min/mg, respectively. The data suggest a major species difference in the age dependent metabolism of bifenthrin. In human liver microsomes, bifenthrin is metabolized at a much higher rate in juveniles than in adults, while the opposite appears to be true in rat liver microsomes. Copyright © 2017 Elsevier Inc. All rights reserved.

Salinity impacts on water solubility and n-octanol/water partition coefficients of selected pesticides and oil constituents.

PubMed

Saranjampour, Parichehr; Vebrosky, Emily N; Armbrust, Kevin L

2017-09-01

Salinity has been reported to influence the water solubility of organic chemicals entering marine ecosystems. However, limited data are available on salinity impacts for chemicals potentially entering seawater. Impacts on water solubility would correspondingly impact chemical sorption as well as overall bioavailability and exposure estimates used in the regulatory assessment. The pesticides atrazine, fipronil, bifenthrin, and cypermethrin, as well as the crude oil constituent dibenzothiophene together with 3 of its alkyl derivatives, all have different polarities and were selected as model compounds to demonstrate the impact of salinity on their solubility and partitioning behavior. The n-octanol/water partition coefficient (K OW ) was measured in both distilled-deionized water and artificial seawater (3.2%). All compounds had diminished solubility and increased K OW values in artificial seawater compared with distilled-deionized water. A linear correlation curve estimated salinity may increase the log K OW value by 2.6%/1 log unit increase in distilled water (R 2  = 0.97). Salinity appears to generally decrease the water solubility and increase the partitioning potential. Environmental fate estimates based on these parameters indicate elevated chemical sorption to sediment, overall bioavailability, and toxicity in artificial seawater. These dramatic differences suggest that salinity should be taken into account when exposure estimates are made for marine organisms. Environ Toxicol Chem 2017;36:2274-2280. © 2017 SETAC. © 2017 SETAC.

Inhibition of fipronil and nonane metabolism in human liver microsomes and human cytochrome P450 isoforms by chlorpyrifos.

PubMed

Joo, Hyun; Choi, Kyoungju; Rose, Randy L; Hodgson, Ernest

2007-01-01

Previous studies have established that chlorpyrifos (CPS), fipronil, and nonane can all be metabolized by human liver microsomes (HLM) and a number of cytochrome P450 (CYP) isoforms. However, metabolic interactions between these three substrates have not been described. In this study the effect of either coincubation or preincubation of CPS with HLM or CYP isoforms with either fipronil or nonane as substrate was investigated. In both co- and preincubation experiments, CPS significantly inhibited the metabolism of fipronil or nonane by HLM although CPS inhibited the metabolism of fipronil more effectively than that of nonane. CPS significantly inhibited the metabolism of fipronil by CYP3A4 as well as the metabolism of nonane by CYP2B6. In both cases, preincubation with CPS caused greater inhibition than coincubation, suggesting that the inhibition is mechanism based.

Fipronil promotes motor and behavioral changes in honey bees (Apis mellifera) and affects the development of colonies exposed to sublethal doses.

PubMed

Zaluski, Rodrigo; Kadri, Samir Moura; Alonso, Diego Peres; Martins Ribolla, Paulo Eduardo; de Oliveira Orsi, Ricardo

2015-05-01

Bees play a crucial role in pollination and generate honey and other hive products; therefore, their worldwide decline is cause for concern. New broad-spectrum systemic insecticides such as fipronil can harm bees and their use has been discussed as a potential threat to bees' survival. In the present study, the authors evaluate the in vitro toxicity of fipronil and note behavioral and motor activity changes in Africanized adult Apis mellifera that ingest or come into contact with lethal or sublethal doses of fipronil. The effects of sublethal doses on brood viability, population growth, behavior, and the expression of the defensin 1 gene in adult bees were studied in colonies fed with contaminated sugar syrup (8 µg fipronil L(-1) ). Fipronil is highly toxic to bees triggering agitation, seizures, tremors, and paralysis. Bees that are exposed to a lethal or sublethal doses showed reduced motor activity. The number of eggs that hatched, the area occupied by worker eggs, and the number of larvae and pupae that developed were reduced, adult bees showed lethargy, and colonies were abandoned when they were exposed to sublethal doses of fipronil. No change was seen in the bees' expression of defensin 1. The authors conclude that fipronil is highly toxic to honey bees and even sublethal doses may negatively affect the development and maintenance of colonies. © 2015 SETAC.

Enantioselective Toxicity and Biotransformation of Fipronil in the Fathead Minnow (Pimephales promelas)

EPA Science Inventory

Fipronil is a relatively new chiral phenylpyrazole insecticide used to control both agricultural and household invertebrate pests. Fipronil is applied as a racemate, or equal mixture, of its two enantiomers. As regulations on older pesticides increase, production and applicatio...

Influence of temperature on rate of uptake and subsequent horizontal transfer of [14C]fipronil by eastern subterranean termites (Isoptera: Rhinotermitidae).

PubMed

Spomer, Neil A; Kamble, Shripat T; Warriner, Richard A; Davis, Robert W

2008-06-01

The effect of temperature on [14C]fipronil uptake and transfer from donor (D) to recipient (R) Reticulitermes flavipes (Kollar) (Isoptera: Rhinotermitidae) workers was evaluated. Test chambers used in the fipronil uptake study were constructed from petri dishes containing autoclaved soil treated with 1 ppm [14C]fipronil (1.14 microCi of total radioactivity per petri dish), distilled water, and R. flavipes workers. Test chambers were held in environmental growth chambers preset at 12, 17, 22, 27, and 32 degrees C. For the fipronil transfer study, donor termites stained with Nile blue-A were exposed to soil treated with 1 ppm [14C]fipronil for 2 h. Donors were then combined with unexposed recipient termite workers at either 1D:5R, 1D:10R, or 1D:20R ratios. Test chambers consisted of a nest and feeding chamber connected by a piece of polyethylene tube and held in growth chambers at 12, 17, 22, 27, and 32 degrees C. Worker termites were sampled over time and the amount of [14C]fipronil present was measured by scintillation counting. Some degree of uptake and transfer occurred at all temperatures and ratios in this study. The highest level of uptake occurred by termites held at 22-32 degrees C, followed decreasingly by 17 and 12 degrees C. Maximum transfer of [14C]fipronil occurred at the higher ratios (1:5 > 1:10 > 1:20) of donors to recipients. Data presented in this study suggest that temperature is one of the key factors affecting the rate of uptake and subsequent horizontal transfer of [14C]fipronil in subterranean termites.

40 CFR 180.517 - Fipronil; tolerances for residues.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 24 2011-07-01 2011-07-01 false Fipronil; tolerances for residues. 180... PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Specific Tolerances § 180.517 Fipronil; tolerances for residues. (a) General. Therefore, tolerances are established for combined residues...

ENANTIOSELECTIVE ELIMINATION OF FIPRONIL AND SELECTED ORGANOCHLORINES BY RAINBOW TROUT (ONCORHYNCHUS MYKISS)

EPA Science Inventory

Fipronil is a phenylpyrazole pesticide widely used in applications such as rice culture, turf grass management, and residential pest control with a high probability to contaminate aquatic environments. Fipronil has moderate partitioning (log Kow = 4.01) for accumulation in biota...

TOXICITY OF FIPRONIL AND ITS ENANTIOMERS TO MARINE AND FRESHWATER NON-TARGETS

EPA Science Inventory

Fipronil is a phenylpyrazole insecticide used in agricultural and domestic settings for controlling various insect pests in crops, lawns, and residential structures. Fipronil is chiral; however, it is released into the environment as a racemic mixture of two enantiomers. In this ...

ENANTIOSELECTIVE CHRONIC TOXICITY OF FIPRONIL TO CERIODAPHNIA DUBIA

EPA Science Inventory

Fipronil is a phenylpyrazole pesticide that has greatly increased in popularity in recent years. As a chiral molecule, fipronil is released into the environment as a 1:1 mixture (called a racemate) of its two enantiomers. Previous toxicity work has indicated that the enantiomer...

Chemical residence time and hydrological conditions influence fipronil reduction in vegetated aquatic mesocosms

USDA-ARS?s Scientific Manuscript database

Fipronil, a phenyl-pyrazole insecticide and its metabolites (Fipronil sulfone, sulfide and desulfinyl) is often used in rice production agriculture with elevated runoff concentrations and loads having potential toxicological effects on downstream aquatic environments. This study evaluated two specie...

Toxicity of three pesticides individually and in mixture to larval grass shrimp (Palaemonetes pugio).

PubMed

Key, Peter; Chung, Katy; Siewicki, Tom; Fulton, Mike

2007-10-01

This study examined the toxicity of three pesticides, singly and in mixture, to grass shrimp (Palaemonetes pugio) larvae. The pesticides included atrazine, an herbicide used on turf grass and field crops; fipronil, a persistent insecticide used against termites and fire ants; and imidacloprid, a systemic insecticide used in agricultural and home products. Fipronil was the most toxic to shrimp larvae with a 96-h LC50 of 0.68microg/L (95% CI 0.57-0.79microg/L). Shrimp larvae were less sensitive to imidacloprid with a 96-h LC50 of 308.8microg/L (95% CI 273.6-348.6microg/L). Atrazine was non-toxic to shrimp larvae at concentrations up to 10,000microg/L. In mixtures, fipronil plus atrazine and imidacloprid plus atrazine had no change in toxicity compared to fipronil and imidacloprid tested singly. Similarly, a fipronil/imidacloprid mixture did not show greater than additive toxicity. However, when atrazine was added to the fipronil/imidacloprid mix, greater than additive toxicity occurred.

Influence of fipronil compounds and rice-cultivation land-use intensity on macroinvertebrate communities in streams of southwestern Louisiana, USA

USGS Publications Warehouse

Mize, S.V.; Porter, S.D.; Demcheck, D.K.

2008-01-01

Laboratory tests of fipronil and its degradation products have revealed acute lethal toxicity at very low concentrations (LC50) of <0.5 ??g/L to selected aquatic macroinvertebrates. In streams draining basins with intensive rice cultivation in southwestern Louisiana, USA, concentrations of fipronil compounds were an order of magnitude larger than the LC50. The abundance (?? = -0.64; p = 0.015) and taxa richness (r2 = 0.515, p < 0.005) of macroinvertebrate communities declined significantly with increases in concentrations of fipronil compounds and rice-cultivation land-use intensity. Macroinvertebrate community tolerance scores increased linearly (r2 = 0.442, p < 0.005) with increases in the percentage of rice cultivation in the basins, indicating increasingly degraded stream conditions. Similarly, macroinvertebrate community-tolerance scores increased rapidly as fipronil concentrations approached about 1 ??g/L. Pesticide toxicity index determinations indicated that aquatic macroinvertebrates respond to a gradient of fipronil compounds in water although stream size and habitat cannot be ruled out as contributing influences.

Fipronil mobility and transformation in undisturbed soil columns.

PubMed

Chatterjee, Niladri Sekhar; Gupta, Suman

2010-08-01

The downward movement of fipronil and its two toxic metabolites i.e. sulfone and desulfinyl were studied in undisturbed soil columns. Mobility behavior of two different formulations of fipronil viz granular and suspension concentrate were also studied. The undisturbed columns containing sandy loam soil were leached with water equivalent to 400 mm rainfall. Results revealed that although majority of the fipronil (approximately 80%) remained in top 0-5 cm layer, substantial amount (approximately 15%) moved to 5-10 cm depth. In case of metabolites sulfone and desulfinyl >90% of the residues remained in 0-5 cm core indicating low mobility of these metabolites in comparison to fipronil. Results of mobility behavior of fipronil in granular and SC formulations revealed low mobility in granular formulation. Sulfide was detected as the major degradation product in both the formulations and was found to be distributed throughout the column. A little amount of sulfone (0.1% of the total recovered) was also detected upto 10 cm depth.

Acute Human Self-Poisoning with the N-Phenylpyrazole Insecticide Fipronil –A GABAA-Gated Chloride Channel Blocker

PubMed Central

Mohamed, Fahim; Senarathna, Lalith; Percy, Adrian; Abeyewardene, Manel; Eaglesham, Geoffrey; Cheng, Ron; Azher, Shifa; Hittarage, Ariyasena; Dissanayake, Wasantha; Sheriff, MH Rezvi; Davies, Willie; Buckley, Nick; Eddleston, Michael

2005-01-01

Objective Fipronil, a broad spectrum N-phenylpyrazole insecticide that inhibits GABAA-gated chloride channels, has been in use since the mid-1990s. A high affinity for insect compared to mammalian GABA receptors results in lower animal toxicity than other insecticides blocking this channel. To date, only two accidental cases of fipronil poisoning in humans have been published. Case series We report seven patients with fipronil self-poisoning seen prospectively in Sri Lanka together with pharmacokinetics for four patients. Non-sustained generalized tonic-clonic seizures were seen in two patients (peak measured plasma fipronil concentrations 1600 and 3744 μg/L); both were managed with diazepam without complications. A patient with a peak measured plasma concentration of 1040 μg/L was asymptomatic throughout his stay. Plasma concentration was still high at discharge 3–4 days post-ingestion when the patients were well. Retrospective review of >1000 pesticide poisoning deaths since 1995 found only one death from fipronil-based products. In contrast to the good outcome of the above cases, this patient required intubation and ventilation and had continuous fits despite therapy with barbiturates and benzodiazepines. Conclusions Our experience with prospectively observed patients suggests that fipronil poisoning is characterized by vomiting, agitation, and seizures, and normally has a favorable outcome. Management should concentrate on supportive care and early treatment of seizures. However, further experience is needed to determine whether increased susceptibility to fipronil or larger doses can produce status epilepticus. PMID:15641641

ACUTE AND CHRONIC EFFECTS OF FIPRONIL AND ITS ENANTIOMERS TO AQUATIC ORGANISMS

EPA Science Inventory

Fipronil is a phenylpyrazole insecticide used in agriculture and domestic settings for controlling various insect pests in crops, lawns and residential structures. Fipronil is chiral; however, it is released into the environment as a racemic mixture of two enantiomers. In this st...

Meeting in China: Differential Toxicity and Accumulation of Fipronil Enantiomers in the Fathead Minnow (Pimephales promelas)

EPA Science Inventory

Fipronil is a chiral insecticide applied as a racemate with two enantiomers. Because of its high log KOC, fipronil will be found primarily in sediments of aquatic environments. Although a number of studies have examined toxicity in aquatic invertebrates, data on enantioselective...

Differential Toxicity and Accumulation of Fipronil Enantiomers in the Fathead Minnow (Pimephales promelas)

EPA Science Inventory

Fipronil is a chiral insecticide applied as a racemate of two enantiomers. Because of its high log Koc, fipronil will be found primarily in sediments of aquatic environments. Although a number of studies have examined toxicity in aquatic invertebrates, data on enantioselective t...

Detection of permethrin resistance and fipronil tolerance in Rhipicephalus sanguineus (Acari: Ixodidae) in the United States

USDA-ARS?s Scientific Manuscript database

Permethrin is a commonly used acaricide for tick control on domestic animals and in residential environments, while fipronil use is restricted to on-animal treatment. Following widespread reports of permethrin and fipronil application failures to control indoor infestations of Rhipicephalus sanguin...

Enantioselective toxicity and bioaccumulation of fipronil in fathead minnows (Pimephales promelas) following water and sediment exposures

EPA Science Inventory

Fipronil is a widely used, broad-spectrum pesticide that is applied as an equal mixture of two enantiomers. As regulations on older pesticides become more stringent, production and application of fipronil is expected to grow, leading to increased inputs into aquatic environments ...

Cross-resistance, genetics, and realized heritability of resistance to fipronil in the house fly, Musca domestica (Diptera: Muscidae): a potential vector for disease transmission.

PubMed

Abbas, Naeem; Khan, Hafiz Azhar Ali; Shad, Sarfraz Ali

2014-04-01

Houseflies, Musca domestica (L.), are ubiquitous pests that have the potential to spread a variety of pathogens to humans, poultries, and dairies. Pesticides are commonly used for the management of this pest. Fipronil is a GABA-gated chloride channel-inhibiting insecticide that has been commonly used for the management of different pests including M. domestica throughout the world. Many pests have developed resistance to this insecticide. A field-collected strain of M. domestica was selected with fipronil for continuous 11 generations to assess the cross-resistance, genetics, and realized heritability for designing a resistance management strategy. Laboratory bioassays were performed using the feeding method of mixing insecticide concentrations with 20% sugar solutions and cotton soaks dipped in insecticide solutions were provided to tested adult flies. Bioassay results at G12 showed that the fipronil-selected strain developed a resistance ratio of 140-fold compared to the susceptible strain. Synergism bioassay with piperonyl butoxide (PBO) and S,S,S,-tributyl phosphorotrithioate (DEF) indicated that fipronil resistance was associated with microsomal oxidase and also esterase. Reciprocal crosses between resistant and susceptible strains showed an autosomal and incompletely dominant resistance to fipronil. The LC50 values of F1 and F'1 strains were not significantly different and dominance values were 0.74 and 0.64, respectively. The resistance to fipronil was completely recessive (D(ML) = 0.00) at the highest dose and incompletely dominant at the lowest dose (D(ML) = 0.87). The monogenic resistance based on chi-square goodness of fit test and calculation of the minimum number of segregating genes showed that resistance to fipronil is controlled by multiple genes. The fipronil resistance strain confirmed very low cross-resistance to emamectin benzoate and spinosad while no cross-resistance to chlorpyrifos and acetamiprid when compared to that of the field population. The heritability values were 0.112, 0.075, 0.084, 0.008, and 0.052 for fipronil, emamectin benzoate, spinosad, acetamiprid, and chlorpyrifos, respectively. It was concluded that fipronil resistance in M. domestica was autosomally inherited, incompletely dominant, and polygenic. These findings would be helpful for the better and successful management of M. domestica.

Resistance Status and Resistance Mechanisms in a Strain of Aedes aegypti (Diptera: Culicidae) From Puerto Rico.

PubMed

Estep, Alden S; Sanscrainte, Neil D; Waits, Christy M; Louton, Jessica E; Becnel, James J

2017-11-07

Puerto Rico (PR) has a long history of vector-borne disease and insecticide-resistant Aedes aegypti (L.). Defining contributing mechanisms behind phenotypic resistance is critical for effective vector control intervention. However, previous studies from PR have each focused on only one mechanism of pyrethroid resistance. This study examines the contribution of P450-mediated enzymatic detoxification and sodium channel target site changes to the overall resistance phenotype of Ae. aegypti collected from San Juan, PR, in 2012. Screening of a panel of toxicants found broad resistance relative to the lab susceptible Orlando (ORL1952) strain. We identified significant resistance to representative Type I, Type II, and nonester pyrethroids, a sodium channel blocker, and a sodium channel blocking inhibitor, all of which interact with the sodium channel. Testing of fipronil, a chloride channel agonist, also showed low but significant levels of resistance. In contrast, the PR and ORL1952 strains were equally susceptible to chlorfenapyr, which has been suggested as an alternative public health insecticide. Molecular characterization of the strain indicated that two common sodium channel mutations were fixed in the population. Topical bioassay with piperonyl butoxide (PBO) indicated cytochrome P450-mediated detoxification accounts for approximately half of the resistance profile. Transcript expression screening of cytochrome P450s and glutathione-S-transferases identified the presence of overexpressed transcripts. This study of Puerto Rican Ae. aegypti with significant contributions from both genetic changes and enzymatic detoxification highlights the necessity of monitoring for resistance but also defining the multiple resistance mechanisms to inform effective mosquito control. Published by Oxford University Press on behalf of Entomological Society of America 2017. This work is written by US Government employees and is in the public domain in the US.

Evaluation of Commercial Agrochemicals as New Tools for Malaria Vector Control.

PubMed

Hoppé, Mark; Hueter, Ottmar F; Bywater, Andy; Wege, Philip; Maienfisch, Peter

2016-10-01

Malaria is a vector-borne and life-threatening disease caused by parasites that are transmitted to people through the bites of infected female Anopheles mosquitoes. The vector control insecticide market represents a small fraction of the crop protection market and is estimated to be valued at up to $500 million at the active ingredient level. Insecticide resistance towards the current WHOPES-approved products urgently requires the development of new tools to protect communities against the transmission of malaria. The evaluation of commercial products for malaria vector control is a viable and cost effective strategy to identify new malaria vector control products. Several examples of such spin-offs from crop protection insecticides are already evidencing the success of this strategy, namely pirimiphos-methyl for indoor residual sprays and spinosad, diflubenzuron, novaluron, and pyriproxifen for mosquito larvae control, a supplementary technology for control of malaria vectors. In our study the adulticidal activities of 81 insecticides representing 23 insecticidal modes of action classes, 34 fungicides from 6 fungicidal mode of action classes and 15 herbicides from 2 herbicidal modes of action classes were tested in a newly developed screening system. WHOPES approved insecticides for malaria vector control consistently caused 80-100% mortality of adult Anopheles stephensi at application rates between 0.2 and 20 mg active ingradient (AI) litre -1 . Chlorfenapyr, fipronil, carbosulfan and endosulfan showed the expected good activity. Four new insecticides and three fungicides with promising activity against adult mosquitoes were identified, namely the insecticides acetamiprid, thiamethoxam, thiocyclam and metaflumizone and the fungicides diflumetorin, picoxystrobin, and fluazinam. Some of these compounds certainly deserve to be further evaluated for malaria vector control. This is the first report describing good activity of commercial fungicides against malaria vectors.

Phototransformation of the insecticide fipronil: identification of novel photoproducts and evidence for an alternative pathway of photodegradation.

PubMed

Raveton, Muriel; Aajoud, Asmae; Willison, John C; Aouadi, Heddia; Tissut, Michel; Ravanel, Patrick

2006-07-01

Fipronil is a recently discovered insecticide of the phenylpyrazole series. It has a highly selective biochemical mode of action, which has led to its use in a large number of important agronomical, household, and veterinary applications. Previous studies have shown that, during exposure to light, fipronil is converted into a desulfurated derivative (desulfinyl-fipronil), which has slightly reduced insecticidal activity. In this study, the photodegradation of fipronil was studied in solution at low light intensities (sunlight or UV lamp). In addition to desulfinyl-fipronil, a large number of minor photoproducts were observed, including diversely substituted phenylpyrazole derivatives and aniline derivatives that had lost the pyrazole ring. Desulfinylfipronil itself was shown to be relatively stable under both UV light and sunlight, with only limited changes occurring in the substitution of the aromatic ring. Since this compound accumulated to levels corresponding to only 30-55% of the amount of fipronil degraded, it was concluded that one or more alternative pathways of photodegradation must be operating. On the basis of the structurally identified photoproducts, it is proposed that fipronil photodegradation occurs via at least two distinct pathways, one of which involves desulfuration at the 4-position of the pyrazole ring giving the desulfinyl derivative and the other of which involves a different modification of the 4-substituent, leading to cleavage of the pyrazole ring and the formation of aniline derivatives. The latter compounds do not accumulate to high levels and may, therefore, be degraded further. The ecological significance of these results is discussed, particularly with regard to the insecticidal activity of the photoproducts.

Identification of fipronil metabolites in rodents by time-of-flight mass spectrometry for application in a human exposure study

EPA Science Inventory

Fipronil is a phenylpyrazole insecticide commonly used in residential and agricultural applications. To understand more about the potential risks associated with fipronil, dosed Long Evans rats were evaluated for metabolites to develop a set of biomarkers for use in human exposur...

75 FR 5584 - Fipronil; Product Cancellation Order and Amendment to Terminate Uses

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-03

... sequence by registration number in Tables 1 and 2 of this unit. Table 1.--Fipronil Product Cancellations... / ``Over n Out''432-1451 BES 1000 Insecticide Table 2.--Fipronil Product Registration Amendment to Terminate Uses EPA Registration Number Product Name 7969-207 Regent 4SC Table 3 of this unit includes the...

Oral toxicity of fipronil insecticide against the stingless bee Melipona scutellaris (Latreille, 1811).

PubMed

Lourenço, Clara Tavares; Carvalho, Stephan Malfitano; Malaspina, Osmar; Nocelli, Roberta Cornélio Ferreira

2012-10-01

For a better evaluation of the model using Apis mellifera in toxicology studies with insecticides, the oral acute toxicity of the insecticide fipronil against the stingless bee Melipona scutellaris was determined. The results showed that fipronil was highly toxic to M. scutellaris, with a calculated LC(50) (48 h) value of 0.011 ng a.i./μL of sucrose solution and an estimated oral LD(50) (48 h) of 0.6 ng a.i./bee. Our results showed that M. scutellaris bee is more sensitive to fipronil than the model specie A. mellifera.

Fipronil: environmental fate, ecotoxicology, and human health concerns.

PubMed

Tingle, Colin C D; Rother, Joachim A; Dewhurst, Charles F; Lauer, Sasha; King, William J

2003-01-01

Fipronil is a highly effective, broad-spectrum insecticide with potential value for the control of a wide range of crop, public hygiene, amenity, and veterinary pests. It can generally be applied at low to very low dose rates to achieve effective pest control. Application rates vary between 0.6 and 200 g a.i./ha, depending on the target pest and formulation. It belongs to the phenyl pyrazole or fiprole group of chemicals and is a potent disrupter of the insect central nervous system via interference with the gamma-aminobutyric acid (GABA-) regulated chloride channel. Fipronil degrades slowly on vegetation and relatively slowly in soil and in water, with a half-life ranging between 36 hr and 7.3 mon depending on substrate and conditions. It is relatively immobile in soil and has low potential to leach into groundwater. One of its main degradation products, fipronil desulfinyl, is generally more toxic than the parent compound and is very persistent. There is evidence that fipronil and some of its degradates may bioaccumulate, particularly in fish. Further investigation on bioaccumulation is warranted, especially for the desulfinyl degradate. The suitability of fipronil for use in IPM must be evaluated on a case-by-case basis. In certain situations, fipronil may disrupt natural enemy populations, depending on the groups and species involved and the timing of application. The indications are that fipronil may be incompatible with locust IPM; hence, this possibility requires further urgent investigation. It is very highly toxic to termites and has severe and long-lasting negative impacts on termite populations. It thus presents a long-term risk to nutrient cycling and soil fertility where termites are "beneficial" key species in these ecological processes. Its toxicity to termites also increases the risk to the ecology of habitats in which termites are a dominant group, due to their importance as a food source to many higher animals. This risk has been demonstrated in Madagascar, where two endemic species of lizard and an endemic mammal decline in abundance because of their food chain link to termites. Fipronil is highly toxic to bees (LD50 = 0.004 microgram/bee), lizards [LD50 for Acanthodactylus dumerili (Lacertidae) is 30 micrograms a.i./g bw], and gallinaceous birds (LD50 = 11.3 mg/kg for Northern bobwhite quail), but shows low toxicity to waterfowl (LD50 > 2150 mg/kg for mallard duck). It is moderately toxic to laboratory mammals by oral exposure (LD50 = 97 mg/kg for rats; LD50 = 91 mg/kg for mice). Technical fipronil is in toxicity categories II and III, depending on route of administration, and is classed as a nonsensitizer. There are indications of carcinogenic action in rats at 300 ppm, but it is not carcinogenic to female mice at doses of 30 ppm. The acute toxicity of fipronil varies widely even in animals within the same taxonomic groups. Thus, toxicological findings from results on standard test animals are not necessarily applicable to animals in the wild. Testing on local species seems particularly important in determining the suitability of fipronil-based products for registration in different countries or habitats and the potential associated risk to nontarget wildlife. Risk assessment predictions have shown that some fipronil formulations present a risk to endangered bird, fish, and aquatic and marine invertebrates. Great care should thus be taken in using these formulations where they may impact any of these endangered wildlife groups. Work in Madagascar has highlighted field evidence of this risk. The dose levels at which fipronil produces thyroid cancer in rats are very high and are unlikely to occur under normal conditions of use. There is also dispute as to whether this is relevant to human health risk. However, as fipronil is a relatively new insecticide that has not been in use for long enough to evaluate the risk it may pose to human health, from data on human exposure to the product, a precautionary approach may be warranted. The use of some fipronil-based products on domestic animals is not recommended where handlers spend significant amounts of time grooming or handling treated animals. In general, it would appear unwise to use fipronil-based insecticides without accompanying environmental and human health monitoring, in situations, regions, or countries where it has not been used before, and where its use may lead to its introduction into the wider environment or bring it into contact with people. Further work is needed on the impacts of fipronil on nontarget vertebrate fauna (amphibians, reptiles, birds, and mammals) in the field before the risk to wildlife from this insecticide can be adequately validated. Further field study of the effects of fipronil on the nutrient cycling and soil water-infiltration activities of beneficial termites is required to assess the ecological impacts of the known toxicity of fipronil to these insects.

Differences in fate, behavior and uptake of conventional- and nano-pesticides

NASA Astrophysics Data System (ADS)

Anuar, M. Firdaus Mohd; E Hodson, Mark; Boxall, Alistair BA

2017-04-01

Nanopesticides, in which conventional pesticides are designed into nanoparticles, are now available and are marketed as having improved longevity and efficacy in the environment. Nanoparticles are known to have different properties to dissolved chemicals and as such it is possible that the fate and behaviour of nanopesticides differs from conventional pesticides. We present work on the synthetic pyrethroid bifenthrin to explore the implications of nanoencapsulation for the sorption, persistence and uptake of the active ingredient in soil-earthworm systems. Studies were done using the active ingredient, a traditional formulation and two nanoformulations. In adsorption experiments conducted using five soils with a range of properties (pH 4.7 - 7.7; % organic carbon 1.2 - 5.2; texture silt loam to loamy sand), adsorption was well described by linear isotherms. Adsorption of analytical grade bifenthrin (Kd = 1800 - 7200 mL / g) was greater than that of a commercial formulation (Kd = 190 - 470 mL / g) which in turn was greater than that of nanoformulations (Kd = 52 - 150 mL / g). For all bifenthrin types adsorption increased with increasing soil organic matter content. Degradation rates of the analytical grade bifenthrin and commercial formulation were similar and faster than those of nanoformulations. Degradation rates were faster in non-sterile compared to sterile conditions. These results suggest that nano-encapsulation could lead to increased mobility and persistence of bifenthrin in the environment and therefore potentially increased exposure and bioavailability. To investigate the effects of nanoencapsulation on uptake we carried out a series of uptake and excretion experiments using the earthworms Eisenia fetida and Lumbricus terrestris. Over the exposure period the concentration of bifenthrin in the soil decreased and increased in the earthworms. Rates of accumulation and excretion were greater for the nanobifenthrin than the non-nanoformulation and active ingredient. Dissection and analysis of earthworm tissues indicated that the accumulated bifenthrin from the nano exposure was concentrated in the earthworm gut whereas the accumulated bifenthrin in the conventional exposure was concentrated in the earthworm tissues. We used kinetic modelling to determine bioconcentration factors. The higher accumulation and excretion rates result in predicted lower bioconcentration factors for the nanobofenthrin compared to the conventional and analytical grade forms. Our experiments demonstrate the differing behaviours of a conventional and nano-formluated pesticide therefore suggesting that current environmental risk assessment methodologies for conventional pesticides may not be appropriate for nanoformulations.

Mechanism of action of the insecticides, lindane and fipronil, on glycine receptor chloride channels

PubMed Central

Islam, Robiul; Lynch, Joseph W

2012-01-01

BACKGROUND AND PURPOSE Docking studies predict that the insecticides, lindane and fipronil, block GABAA receptors by binding to 6′ pore-lining residues. However, this has never been tested at any Cys-loop receptor. The neurotoxic effects of these insecticides are also thought to be mediated by GABAA receptors, although a recent morphological study suggested glycine receptors mediated fipronil toxicity in zebrafish. Here we investigated whether human α1, α1β, α2 and α3 glycine receptors were sufficiently sensitive to block by either compound as to represent possible neurotoxicity targets. We also investigated the mechanisms by which lindane and fipronil inhibit α1 glycine receptors. EXPERIMENTAL APPROACH Glycine receptors were recombinantly expressed in HEK293 cells and insecticide effects were studied using patch-clamp electrophysiology. KEY RESULTS Both compounds completely inhibited all tested glycine receptor subtypes with IC50 values ranging from 0.2–2 µM, similar to their potencies at vertebrate GABAA receptors. Consistent with molecular docking predictions, both lindane and fipronil interacted with 6′ threonine residues via hydrophobic interactions and hydrogen bonds. In contrast with predictions, we found no evidence for lindane interacting at the 2′ level. We present evidence for fipronil binding in a non-blocking mode in the anaesthetic binding pocket, and for lindane as an excellent pharmacological tool for identifying the presence of β subunits in αβ heteromeric glycine receptors. CONCLUSIONS AND IMPLICATIONS This study implicates glycine receptors as novel vertebrate toxicity targets for fipronil and lindane. Furthermore, lindane interacted with pore-lining 6′ threonine residues, whereas fipronil may have both pore and non-pore binding sites. PMID:22035056

Mechanism of action of the insecticides, lindane and fipronil, on glycine receptor chloride channels.

PubMed

Islam, Robiul; Lynch, Joseph W

2012-04-01

Docking studies predict that the insecticides, lindane and fipronil, block GABA(A) receptors by binding to 6' pore-lining residues. However, this has never been tested at any Cys-loop receptor. The neurotoxic effects of these insecticides are also thought to be mediated by GABA(A) receptors, although a recent morphological study suggested glycine receptors mediated fipronil toxicity in zebrafish. Here we investigated whether human α1, α1β, α2 and α3 glycine receptors were sufficiently sensitive to block by either compound as to represent possible neurotoxicity targets. We also investigated the mechanisms by which lindane and fipronil inhibit α1 glycine receptors. Glycine receptors were recombinantly expressed in HEK293 cells and insecticide effects were studied using patch-clamp electrophysiology. Both compounds completely inhibited all tested glycine receptor subtypes with IC(50) values ranging from 0.2-2 µM, similar to their potencies at vertebrate GABA(A) receptors. Consistent with molecular docking predictions, both lindane and fipronil interacted with 6' threonine residues via hydrophobic interactions and hydrogen bonds. In contrast with predictions, we found no evidence for lindane interacting at the 2' level. We present evidence for fipronil binding in a non-blocking mode in the anaesthetic binding pocket, and for lindane as an excellent pharmacological tool for identifying the presence of β subunits in αβ heteromeric glycine receptors. This study implicates glycine receptors as novel vertebrate toxicity targets for fipronil and lindane. Furthermore, lindane interacted with pore-lining 6' threonine residues, whereas fipronil may have both pore and non-pore binding sites. © 2011 The Authors. British Journal of Pharmacology © 2011 The British Pharmacological Society.

Weathering trials of Amulet cue-lure and Amulet methyl eugenol "attract-and-kill" stations with male melon flies and oriental fruit flies (Diptera: Tephritidae) in Hawaii.

PubMed

Vargas, Roger I; Stark, John D; Mackey, Bruce; Bull, Richard

2005-10-01

Amulet C-L (cue-lure) and Amulet ME (methyl eugenol) molded paper fiber "attract-and-kill" dispensers containing fipronil were tested under Hawaiian weather conditions against Bactrocera cucurbitae (Coquillett) (melon fly) and Bactrocera dorsalis (Hendel) (oriental fruit fly), respectively. In paired tests (fresh versus weathered), C-L dispensers were effective for at least 77 d, whereas ME dispensers were effective for at least 21 d. Thus, C-L dispensers exceeded, whereas ME dispensers did not meet the label interval replacement recommendation of 60 d. Addition of 4 ml of ME to 56-d-old ME dispensers restored attraction and kill for an additional 21 d. This result suggested the fipronil added at manufacture was still effective. By enclosing and weathering ME dispensers inside small plastic bucket traps, longevity of ME dispensers was extended up to 56 d. Fipronil ME and C-L dispensers also were compared, inside bucket traps, to other toxicants: spinosad, naled, DDVP, malathion, and permethrin. Against B. dorsalis, fipronil ME dispensers compared favorably only up to 3 wk. Against B. cucurbitae, fipronil C-L dispensers compared favorably for at least 15 wk. Our results suggest that fipronil C-L dispensers can potentially be used in Hawaii; however, fipronil ME dispensers need to be modified or protected from the effects of weathering to extend longevity and meet label specifications. Nonetheless, Amulet C-L and ME dispensers are novel prepackaged formulations containing C-L or ME and fipronil that are more convenient and safer to handle than current liquid insecticide formulations used for areawide suppression of B. dorsalis and B. cucurbitae in Hawaii.

[The systemic effects of imidacloprid and fipronil on Xenopsylla cheopis fleas (Siphonaptera) and blood-sucking Ornithonyssus bacoti gamasid mites (Gamasina: Macronyssidae)].

PubMed

Lopatina, Iu V; Eremina, O Iu

2013-01-01

The systemic effects of imidacloprid and fipronil on Xenopsylla cheopis fleas and blood-sucking Ornithonyssus bacoti gamasid mites were studied under laboratory conditions. Albino rats were forcibly administered insectoacaricides per os in doses of 1, 10, 30 mg/kg or fed with dietary bait (the doses of fipronil and imidacloprid were 10-33 and 18-70 mg/kg/day, respectively) for 3 or more days. Fipronil had a pronounced systemic effect on both X. cheopis and O. baconi. Imidacloprid was markedly active against the fleas and, on the contrary, inactive against the mites.

Antioxidant status in oral subchronic toxicity of fipronil and fluoride co-exposure in buffalo calves.

PubMed

Gill, Kamalpreet Kaur; Dumka, Vinod Kumar

2016-02-01

The effects of fipronil and fluoride co-exposure were investigated on antioxidant status of buffalo calves. A total of 24 healthy male buffalo calves divided into 4 groups were treated for 98 consecutive days. Group I, receiving no treatment, served as the control. Animals of groups II and III were orally administered with fipronil at the dosage of 0.5 mg/kg/day and sodium fluoride (NaF) at the dosage of 6.67 mg/kg/day, respectively, for 98 days. Group IV was coadministered with fipronil and NaF at the same dosages as groups II and III. Administration of fipronil alone produced significant elevation in lipid peroxidation (LPO) and decrease in the levels of nonenzymatic antioxidant glutathione (GSH). However, it did not produce any significant effect on the activities of enzymatic antioxidants including glutathione peroxidase (GPx), catalase (CAT), and superoxide dismutase (SOD). NaF exposure led to enhanced oxidative stress as shown by significant increase in the LPO and SOD activities while GPx and CAT activities and GSH levels were significantly decreased. Co-exposure to fipronil and NaF showed additive effects on LPO, GPx activity, and GSH levels. © The Author(s) 2013.

Effects of the commercial formulation containing fipronil on the non-target organism Cyprinus carpio: implications for rice-fish cultivation.

PubMed

Clasen, Bárbara; Loro, Vania Lucia; Cattaneo, Roberta; Moraes, Bibiana; Lópes, Thais; de Avila, Luis Antonio; Zanella, Renato; Reimche, Geovane Boschmann; Baldisserotto, Bernardo

2012-03-01

The aim of this research was to evaluate possible toxic effects of commercial formulation containing fipronil on Cyprinus carpio tissues under rice field conditions. Antioxidant profile (SOD, catalase, glutathione S-transferase), oxidative stress parameters (thiobarbituric acid-reactive substances, protein carbonyl), and growth were investigated in carp exposed to fipronil under rice field conditions for 7, 30, and 90 days. Waterborne insecticide concentrations were measured and the detectable concentration of fipronil was observed up to 45 day after application. Common carp survival and growth was not affected by fipronil. Liver superoxide dismutase activity was enhanced while liver catalase activity was inhibited at 7, 30, and 90 days. Alterations were not observed in the glutathione S-transferase activity in any experimental periods. Protein carbonyl increased only after 30 and 90 days of exposure. The thiobarbituric acid-reactive substances levels were enhanced in all analyzed tissues (liver, muscle, and brain) and periods of exposure. This study demonstrates that fipronil insecticides cause alterations in the biochemical parameters in different tissues of carp without affecting the growth or the survival of the fish. Copyright © 2011 Elsevier Inc. All rights reserved.

Evaluation of fipronil and imidacloprid as bait active ingredients against fungus-growing termites (Blattodea: Termitidae: Macrotermitinae).

PubMed

Iqbal, N; Evans, T A

2018-02-01

Fungus-growing termites (Macrotermitinae) are important pests in tropical countries. They are difficult to control with existing baiting methods, as chitin synthesis inhibitors are not effectual as active ingredients. We tested two neurotoxins, fipronil and imidacloprid, as potential bait active ingredients against Macrotermes gilvus (Hagen) in Singapore. In laboratory bioassays, M. gilvus showed no preference for doses of 0-64 ppm fipronil, or for doses of 0-250 ppm imidacloprid, indicating no repellence. We tested each insecticide in toilet paper as a bait matrix in a field experiment. After 28 days, termites had eaten 5-13% of the fipronil treated toilet paper, abandoned bait and monitoring stations, contacted no new stations, and repaired poorly their experimentally damaged mounds. Termites ate no imidacloprid treated toilet paper, abandoned bait stations although contacted new stations, and repaired fully their damaged mounds. Termites ate 60-70% of the control toilet paper, remained in bait stations, and fully repaired damaged mounds. After 56 days, all five fipronil colonies were eliminated, whereas all of the imidacloprid and control colonies were healthy. The results suggest that fipronil could be an effective active ingredient in bait systems for fungus-growing termites in tropical countries.

Acute illnesses associated with exposure to fipronil--surveillance data from 11 states in the United States, 2001-2007.

PubMed

Lee, Soo-Jeong; Mulay, Prakash; Diebolt-Brown, Brienne; Lackovic, Michelle J; Mehler, Louise N; Beckman, John; Waltz, Justin; Prado, Joanne B; Mitchell, Yvette A; Higgins, Sheila A; Schwartz, Abby; Calvert, Geoffrey M

2010-08-01

Fipronil is a broad-spectrum phenylpyrazole insecticide widely used to control residential pests and is also commonly used for flea and tick treatment on pets. It is a relatively new insecticide and few human toxicity data exist on fipronil. This paper describes the magnitude and characteristics of acute illnesses associated with fipronil exposure. Illness cases associated with exposure to fipronil-containing products from 2001 to 2007 were identified from the Sentinel Event Notification System for Occupational Risks (SENSOR)-Pesticides Program and the California Department of Pesticide Regulation. A total of 103 cases were identified in 11 states. Annual case counts increased from 5 in 2001 to 30 in 2007. Of the cases, 55% were female, the median age was 37 years, and 11% were <15 years old. The majority (76%) had exposure in a private residence, 37% involved the use of pet-care products, and 26% had work-related exposures. Most cases (89%) had mild, temporary health effects. Neurological symptoms (50%) such as headache, dizziness, and paresthesia were the most common, followed by ocular (44%), gastrointestinal (28%), respiratory (27%), and dermal (21%) symptoms/signs. Exposures usually occurred from inadvertent spray/splash/spill of products or inadequate ventilation of the treated area before re-entry. Our findings indicate that exposure to fipronil can pose a risk for mild, temporary health effects in various body systems. Precautionary actions should be reinforced to prevent fipronil exposure to product users.

40 CFR 180.442 - Bifenthrin; tolerances for residues.

Code of Federal Regulations, 2010 CFR

2010-07-01

... application of bifenthrin in food handling establishments, including food service, manufacturing and... ingredient. Contamination of food/feed or food/feed contact surfaces shall be avoided. (B) To assure safe use...) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Specific Tolerances...

Estimating occupational exposure to the pyrethroid termiticide bifenthrin by measuring metabolites in urine.

PubMed

Smith, P A; Thompson, M J; Edwards, J W

2002-10-05

The control of subterranean termites in Australia is predominantly through the application of chemical barriers in the soil beneath and surrounding buildings. The chemicals used to repel or kill termites are the organophosphorus insecticide, chlorpyrifos, and the synthetic pyrethroid, bifenthrin. These are applied through surface sprays and subfloor injection by licensed pest control operators. To determine the exposure of these personnel to these pesticides it is most usual to measure airborne concentrations or dermal deposition rates. However, to support information obtained from these methods it is often appropriate to determine the amount of the chemicals absorbed, using biological monitoring techniques including measurement of the chemicals or their metabolites in urine. While there are effective techniques for the monitoring of chlorpyrifos exposure by measuring either the alkyl phosphate or trichloropyridinol metabolites, there have been no published reports of suitable methods to measure bifenthrin metabolites in urine. This paper describes an extraction and HPLC-UV method used to simultaneously measure the urinary excretion of 2-methyl-3-phenylbenzoic acid (MPA), a metabolite of bifenthrin, and 3-phenoxybenzoic acid (PBA), a metabolite of several other common pyrethroid insecticides, with a detection limit for each of 2.5 ng/ml. The paper also describes the pilot application of this method to a study of South Australian pest control operators handling bifenthrin. MPA ranged from 1.8 to 31.9 microg/g creatinine and PBA from 1.3 to 30.0 microg/g in the urine of pest control workers. MPA was detected in urine of control workers without bifenthrin exposure only at low levels (1.0-1.4 microg/g creatinine), but PBA was found in both at higher levels (1.2-61.1 microg/g creatinine). Copyright 2002 Elsevier Science B.V.

The influence of fipronil on Reticulitermes flavipes (Isoptera: Rhinotermitidae) feeding beyond treated plots

Treesearch

Thomas Shelton

2013-01-01

A small-plot field trial was conducted to examine the area of influence of fipronil at incremental distances away from treated plots on the Harrison Experimental Forest near Saucier, MS. Small treated (water and fipronil) plots were surrounded by untreated wooden boards in an eight-point radial pattern, and examined for evidence of termite feeding every 60 d for 1 yr...

Efficacy of fipronil aerially applied in oil adjuvants and drift retardants against boll weevils, Anthonomus Grandis Boheman (Coleoptera:Curculionidae)

Treesearch

Joseph E. Mulrooney

2002-01-01

Results of aerial application tests in the field and insecticide transfer tests in the laboratory showed that cottonseed oil was the most effective oil adjuvant to use with fipronil for controlling boll weevils under field conditions and for transferring fipronil from cotton leaf surfaces to boll weevils. The mineral oil and mineral oil + drift retardant more...

Toxicity of Fipronil in Mississippi Soil Types Against Reticulitermes flavipes (Isoptera: Rhinotermitidae)

Treesearch

J. E. Mulrooney; P. D. Gerard

2007-01-01

Three soils (a silt loam, loamy sand, sandy loam) found in Mississippi and pure silica sand were treated with fipronil and bioassayed using eastern subterranean termites, Reticulitermes flavipes. Soils were treated with aqueous solutions of Termidor (fipronil) at concentrations of 0, 0.12, 0.25,2.5, 5.0 and 20.0 ppm (wt AI: wt soil) that brought the soils to 15%...

Comparative metabolism of the pyrethroids bifenthrin and deltamethrin in the bulb mite Rhizoglyphus robini

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ruzo, L.O.; Cohen, E.; Capua, S.

The fate of {sup 14}C-radiolabeled bifenthrin and deltamethrin was studied in the mite, Rhizoglyphus robini. Administered either by ingestion or by contact, both pyrethroids were efficiently metabolized, but deltamethrin was degraded to a much greater extent. The identified metabolites arise from a combination of ester cleavage, oxidation, and conjugation reactions. With {sup 14}C-acid- and {sup 14}C-alcohol-labeled bifenthrin, the free metabolites detected were the 4{prime}-hydroxy derivative of the ester, the primary ester cleavage products, the acid, and its 4{prime}-hydroxy derivative from the alcohol moiety, as well as several unidentified metabolites. Using {sup 14}C-alcohol-labeled deltamethrin, 3-phenoxybenzoic acid and its 4{prime}-hydroxylated product andmore » several unknown metabolites were detected. Conjugates comprised the bulk of total pyrethroid metabolites. In addition to ester cleavage products, the 4{prime}-hydroxylated bifenthrin was also identified. For the first time in invertebrates, a conjugated pyrethroid ester was observed.« less

In Vitro Selection of a Single-Stranded DNA Molecular Recognition Element against the Pesticide Fipronil and Sensitive Detection in River Water

PubMed Central

Sooter, Letha J.

2017-01-01

Fipronil is a commonly used insecticide that has been shown to have environmental and human health risks. The current standard methods of detection for fipronil and its metabolites, such as GC-MS, are time consuming and labor intensive. In this study, a variant of systematic evolution of ligands by exponential enrichment (SELEX), was utilized to identify the first single-stranded DNA (ssDNA) molecular recognition element (MRE) that binds to fipronil with high affinity (Kd = 48 ± 8 nM). The selected MRE displayed low cross binding activity on various environmentally relevant, structurally unrelated herbicides and pesticides, in addition to broad-spectrum binding activity on major metabolites of fipronil and a structurally similar pesticide in prepared river samples. Additionally, a proof-of-principle fluorescent detection assay was developed by using the selected ssDNA MRE as a signal-reporting element, with a limit of detection of 105 nM in a prepared river water sample. PMID:29283416

Physiological selectivity and activity reduction of insecticides by rainfall to predatory wasps of Tuta absoluta.

PubMed

Barros, Emerson C; Bacci, Leandro; Picanco, Marcelo C; Martins, Júlio C; Rosado, Jander F; Silva, Gerson A

2015-01-01

In this study, we carried out three bioassays with nine used insecticides in tomato crops to identify their efficiency against tomato leaf miner Tuta absoluta, the physiological selectivity and the activity reduction of insecticides by three rain regimes to predatory wasps Protonectarina sylveirae and Polybia scutellaris. We assessed the mortality caused by the recommended doses of abamectin, beta-cyfluthrin, cartap, chlorfenapyr, etofenprox, methamidophos, permethrin, phenthoate and spinosad to T. absoluta and wasps at the moment of application. In addition, we evaluated the wasp mortality due to the insecticides for 30 days on plants that did not receive rain and on plants that received 4 or 125 mm of rain. Spinosad, cartap, chlorfenapyr, phenthoate, abamectin and methamidophos caused mortality higher than 90% to T. absoluta, whereas the pyrethroids beta-cyfluthrin, etofenprox and permethrin caused mortality between 8.5% and 46.25%. At the moment of application, all the insecticides were highly toxic to the wasps, causing mortality higher than 80%. In the absence of rain, all the insecticides continued to cause high mortality to the wasps for 30 days after the application. The toxicity of spinosad and methamidophos on both wasp species; beta-cyfluthrin on P. sylveirae and chlorfenapyr and abamectin on P. scutellaris, decreased when the plants received 4 mm of rain. In contrast, the other insecticides only showed reduced toxicity on the wasps when the plants received 125 mm of rain.

Longevity of ultra-low-volume sprays of fipronil and malathion on cotton in Mexico

Treesearch

Joseph E. Mulrooney; K.A. Holmes; R.A. Shaw; D. Goli

2003-01-01

In 1996, fipronil and malathion residues were evaluated after four ultra-low-volume (ULV) spray applications in northeastern Tarnaulipas, Mexico. Sprays were applied at 0.88 L/ha. Fipronil was applied at 28 and 56 g A.I./ha and malathion at 840 g A.I./ha. Four applications were made beginning 23 May at four, five and six day intervals. Leaf surface residues of...

Dominant fitness costs of resistance to fipronil in Musca domestica Linnaeus (Diptera: Muscidae).

PubMed

Abbas, Naeem; Shah, Rizwan Mustafa; Shad, Sarfraz Ali; Azher, Faheem

2016-08-15

House fly, Musca domestica L., (Diptera: Muscidae) a common pest of poultry, has developed resistance to the commonly used insecticide fipronil. The life history traits were examined in the fipronil-selected (Fipro-SEL), susceptible counterpart (UNSEL), and their hybrid progeny strains in order to design an effective resistant management strategy. Compared to the UNSEL strain, the Fipro-SEL was 181.94-fold resistant to fipronil. This resistance was unstable after five generations without selection. The Fipro-SEL had a significantly longer larval duration, lower pupal weight, lower fecundity, lower hatchability, lower number of next generation larvae, lower intrinsic rate of population increase and lower biotic potential than the UNSEL strain. Most fitness parameters of the hybrid progeny were similar and significantly lower than that in the UNSEL strain, suggesting autosomal and dominant fitness costs. Compared to the UNSEL strain, relative the fitness of the Fipro-SEL, Hybrid1 and Hybrid2 was 0.13, 0.33 and 0.30, respectively. Fipronil resistance resulted in high fitness costs and these fitness costs were dominant and autosomal in the Fipro-SEL strain of M. domestica. Rotation of fipronil with other insecticides having no cross resistance should be useful for delaying the development of resistance in M. domestica. Copyright © 2016 Elsevier B.V. All rights reserved.

Short- and long-term control of Vespula pensylvanica in Hawaii by fipronil baiting

USGS Publications Warehouse

Hanna, Cause; Foote, David; Kremen, Claire

2012-01-01

BACKGROUND: The invasive western yellowjacket wasp, Vespula pensylvanica (Saussure), has significantly impacted the ecological integrity and human welfare of Hawaii. The goals of the present study were (1) to evaluate the immediate and long-term efficacy of a 0.1% fipronil chicken bait on V. pensylvanica populations in Hawaii Volcanoes National Park, (2) to quantify gains in efficacy using the attractant heptyl butyrate in the bait stations and (3) to measure the benefits of this approach for minimizing non-target impacts to other arthropods. RESULTS: The 0.1% fipronil chicken bait reduced the abundance of V. pensylvanica by 95 ± 1.2% during the 3 months following treatment and maintained a population reduction of 60.9 ± 3.1% a year after treatment in the fipronil-treated sites when compared with chicken-only sites. The addition of heptyl butyrate to the bait stations significantly increased V. pensylvanica forager visitation and bait take and significantly reduced the non-target impacts of fipronil baiting. CONCLUSION: In this study, 0.1% fipronil chicken bait with the addition of heptyl butyrate was found to be an extremely effective large-scale management strategy and provided the first evidence of a wasp suppression program impacting Vepsula populations a year after treatment. Copyright © 2011 Society of Chemical Industry

An exposure study to assess the potential impact of fipronil in treated sunflower seeds on honey bee colony losses in Spain.

PubMed

Bernal, José; Martin-Hernandez, Raquel; Diego, Juan C; Nozal, María J; Gozalez-Porto, Amelia V; Bernal, José L; Higes, Mariano

2011-10-01

There is great concern about the high losses and strong depopulation of honey bee colonies in some areas of Spain. Some beekeepers have suggested that sunflower seeds treated with the insecticide fipronil could be an important factor in causing those losses. Therefore, an in-depth field study has been carried out in two regions of Spain where sunflower production is intense (Cuenca and Andalucía) and where, for some crops and varieties, fipronil has been used as seed insecticide. Samples of adult bees and pollen were analysed for bee pathogens and pesticide residues respectively. Neither fipronil residues nor its metabolites were detected in any of the samples analysed, indicating that short-term or chronic exposure of bees to fipronil and/or its metabolites can be ruled out in the apiaries surveyed. Varroa destructor and Nosema ceranae were found to be very prevalent. The combination of the two pathogens could augment the risk of colony death in infected colonies, without fipronil residues exerting a significant effect in the given field conditions. Indeed, in this study the losses observed in apiaries located close to sunflower crops were similar to those in apiaries situated in forested areas with wild vegetation. Copyright © 2011 Society of Chemical Industry.

Passage of fiproles and imidacloprid from urban pest control uses through wastewater treatment plants in northern California, USA.

PubMed

Sadaria, Akash M; Sutton, Rebecca; Moran, Kelly D; Teerlink, Jennifer; Brown, Jackson Vanfleet; Halden, Rolf U

2017-06-01

Urban pest control insecticides-specifically fipronil and its 4 major degradates (fipronil sulfone, sulfide, desulfinyl, and amide), as well as imidacloprid-were monitored during drought conditions in 8 San Francisco Bay (San Francisco, CA, USA) wastewater treatment plants (WWTPs). In influent and effluent, ubiquitous detections were obtained in units of ng/L for fipronil (13-88 ng/L), fipronil sulfone (1-28 ng/L), fipronil sulfide (1-5 ng/L), and imidacloprid (58-306 ng/L). Partitioning was also investigated; in influent, 100% of imidacloprid and 62 ± 9% of total fiproles (fipronil and degradates) were present in the dissolved state, with the balance being bound to filter-removable particulates. Targeted insecticides persisted during wastewater treatment, regardless of treatment technology utilized (imidacloprid: 93 ± 17%; total fiproles: 65 ± 11% remaining), with partitioning into sludge (3.7-151.1 μg/kg dry wt as fipronil) accounting for minor losses of total fiproles entering WWTPs. The load of total fiproles was fairly consistent across the facilities but fiprole speciation varied. This first regional study on fiprole and imidacloprid occurrences in raw and treated California sewage revealed ubiquity and marked persistence to conventional treatment of both phenylpyrazole and neonicotinoid compounds. Flea and tick control agents for pets are identified as potential sources of pesticides in sewage meriting further investigation and inclusion in chemical-specific risk assessments. Environ Toxicol Chem 2017;36:1473-1482. © 2016 SETAC. © 2016 SETAC.

Synergistic Combinations of a Pyrethroid Insecticide and an Emulsifiable Oil Formulation of Beauveria bassiana to Overcome Insecticide Resistance in Listronotus maculicollis (Coleoptera: Curculionidae).

PubMed

Wu, Shaohui; Kostromytska, Olga S; Koppenhöfer, Albrecht M

2017-08-01

The annual bluegrass weevil, Listronotus maculicollis (Kirby), is a major pest of golf course turf in eastern North America and has become particularly problematic owing to widespread development of insecticide resistance. As an alternative option to manage resistant adult L. maculicollis, we explored combinations of the pyrethroid insecticide bifenthrin with an emulsifiable oil formulation of the entomopathogenic fungus Beauveria bassiana strain GHA (Bb ES). Combinations synergistically enhanced mortality in both insecticide-susceptible and insecticide-resistant L. maculicollis adults in the laboratory when bifenthrin was used at LC50s for each population. To determine the component behind the synergism, technical spores of B. bassiana GHA and the emulsifiable oil carrier in the fungal formulation were tested separately or in combination with bifenthrin. In both separate and combined applications, the emulsifiable oil carrier was responsible for high mortality within 3 d after treatment and interacted synergistically with bifenthrin, whereas fungus-induced mortality started later. Strong synergism was also observed in three field experiments with a relatively resistant L. maculicollis population. Combinations of Bb ES and bifenthrin hold promise as an effective L. maculicollis management tool, particularly of pyrethroid-resistant populations. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Validation, residue analysis, and risk assessment of fipronil and flonicamid in cotton (Gossypium sp.) samples and soil.

PubMed

Chawla, Suchi; Gor, Hetal N; Patel, Hemlatta K; Parmar, Kaushik D; Patel, Anil R; Shukla, Varsha; Ilyas, Mohammad; Parsai, Satish K; Somashekar; Meena, Roop Singh; Shah, Paresh G

2018-05-04

Cotton crop is highly susceptible to attack by sucking pests. Being an important oilseed and feed crop, it is essential to monitor the pesticides and ensure health protection at consumer level. Therefore, a method was validated to estimate fipronil and flonicamid in various cotton samples and risk assessment was performed. Contamination of oil in the extracts from the various oil seeds and cake samples is a major problem as this oil contaminates the column and interferes with the detection of pesticides. The present manuscript for the first time describes successful analysis of the pesticides from various cotton samples including cotton oil, seed, and cake. Quick, easy, cheap, effective, rugged, and safe (QuEChERS)-based methods were validated for estimation of fipronil and flonicamid in cotton samples and in soil by LC-MS/MS. Recoveries were within the acceptable range of 70-120% with relative standard deviation ≤ 20% and HorRat values < 0.3-1.3. R 2 was > 0.99. Matrix effects of 150 and 13.5% were observed for fipronil and flonicamid, respectively, in cotton leaves. Limits of quantitation (LOQs) were in the range of 0.0004 to 0.004 mg kg -1 for fipronil and flonicamid. Cotton samples collected from a field study at different locations were analyzed. Half-life ranged from 2.2 to 5.8 for fipronil and 4.6 to 7.0 days for flonicamid. A pre-harvest interval of 33 days is suggested. The risk assessment studies at maximum residue level values showed HQ < 1 at pre-harvest interval (PHI). The methods being short and easy can be extended to estimate more types of pesticides in different oilseeds. Following a PHI of 33 days, fipronil and flonicamid can be used on cotton at standard dose. As the levels of fipronil and flonicamid were below determination limit in all the soils, the environmental risk is negligible.

Toxicokinetics of the pyrethroid insecticide bifenthrin in blood and brain of the rat

EPA Science Inventory

Bifenthrin is a pyrethroid insecticide and human exposure to it can occur by oral, pulmonary and dermal routes. Pyrethroids are neurotoxic agents and it is generally believed that the parent pyrethroid is the toxic entity. The objective of this study was to assess the toxicokinet...

Tissue time course and bioavailability of the pyrethroid insecticide bifenthrin in the Long-Evans rat

EPA Science Inventory

Bifenthrin is a pyrethroid insecticide and human exposure to it can occur by oral, pulmonary and dermal routes. Pyrethroids are neurotoxic agents and it is generally believed that the parent pyrethroid is the toxic entity. This study evaluated the oral disposition and bioavaila...

Effects of an atrazine, metolachlor and fipronil mixture on Hyalella azteca (Saussure) in a modified backwater wetland.

PubMed

Lizotte, Richard E; Knight, Scott S; Shields, F Douglas; Bryant, Charles T

2009-12-01

We examined the toxicity mitigation efficiency of a hydrologically modified backwater wetland amended with a pesticide mixture of atrazine, metolachlor, and fipronil, using 96 h survival bioassays with Hyalella azteca. Significant H. azteca 96 h mortality occurred within the first 2 h of amendment at the upstream amendment site but not at any time at the downstream site. H. azteca survival varied spatially and temporally in conjunction with measured pesticide mixture concentrations. Hyalella azteca 96 h survival pesticide mixture effects concentrations ranges were 10.214–11.997, 5.822–6.658, 0.650–0.817, and 0.030–0.048 μg L−1 for atrazine, metolachlor, fipronil, and fipronil-sulfone, respectively.

Dominant Inheritance of Field-Evolved Resistance to Fipronil in Plutella xylostella (Lepidoptera: Plutellidae).

PubMed

Wang, Xingliang; Wu, Shuwen; Gao, Weiyue; Wu, Yidong

2016-02-01

A field-collected strain (HF) of Plutella xylostella (L.) showed 420-fold resistance to fipronil compared with a susceptible laboratory strain (Roth). The HF-R strain, derived from the HF strain by 25 generations of successive selection with fipronil in the laboratory, developed 2,200-fold resistance to fipronil relative to the Roth strain. The F(1) progeny of the reciprocal crosses between HF-R and Roth showed 640-fold (R♀ × S♂) and 1,380-fold (R♂ × S♀) resistance to fipronil, indicating resistance is inherited as an incompletely dominant trait. Analysis of progeny from a backcross (F1♂ × S♀) suggests that resistance is controlled by one major locus. The LC(50) of the R♂ × S♀ cross F(1) progeny is slightly but significantly higher than that of the R♀ × S♂ cross F(1) progeny, suggesting a minor resistance gene on the Z chromosome. Sequence analysis of PxGABARα1 (an Rdl-homologous GABA receptor gene of P. xylostella) from the HF-R strain identified two mutations A282S and A282G (corresponding to the A302S mutation of the Drosophila melanogaster Rdl gene), which have been previously implicated in fipronil resistance in several insect species including P. xylostella. PxGABARα1 was previously mapped to the Z chromosome of P. xylostella. In conclusion, fipronil resistance in the HF-R strain of P. xylostella was incompletely dominant, and controlled by a major autosomal locus and a sex-linked minor gene (PxGABARα1) on the Z chromosome. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Horizontal and trophic transfer of diflubenzuron and fipronil among grasshoppers (Melanoplus sanguinipes) and between grasshoppers and darkling beetles (Tenebrionidae).

PubMed

Smith, D I; Lockwood, J A

2003-04-01

The possibility of horizontal transmission of diflubenzuron and fipronil was assessed in rangeland grasshoppers. Laboratory studies of Melanoplus sanguinipes demonstrated that fipronil was horizontally transferred at lethal levels (p < 0.05) via cannibalism through four passages when the initial dose applied to a food source was 250 times the label rate for rangeland grasshopper and locust control (label rate is 4 g AI/ha). Mortality was 100% on the first three passages through cannibalism. At 25 and 1 times the label rate, fipronil was lethal (p < 0.05) only on the first cannibalistic passage. Diflubenzuron generated significant (p < 0.05) mortality via horizontal transmission through two passages when the initial dose applied to a food source was 2,000 times the label rate for rangeland grasshopper control (label rate is 8.71 g AI/ha). There was 100% mortality in the first passage via cannibalism. At 250 and 25 times the label rate, diflubenzuron was lethal only on the first cannibalistic passage. Field applications of these two acridicides followed by collection of cadavers (Amphitornus coloradus and Ageneotettix deorum) that were fed to M. sanguinipes in the laboratory revealed that fipronil (25 times the label rate) generated significant (p < 0.05) mortality through two passages and diflubenzuron (label rate) caused no mortality via necrophagy. Tenebrionid beetles fed grasshopper cadavers collected from the field application of fipronil yielded 45% mortality, compared with 25% mortality in the controls. These findings suggest that horizontal and trophic transfer probably play a nominal ecotoxicological role in rangeland grasshopper control programs with diflubenzuron, but the transfer of fipronil to grasshoppers, scavengers, and natural enemies via necrophagy may increase both the efficacy of control programs and their environmental affects.

Insecticide Transfer Efficiency and Lethal Load in Argentine Ants

DOE PAGES

Hooper-Bui, L. M.; Kwok, E S.C.; Buchholz, B. A.; ...

2015-07-03

Trophallaxis between individual worker ants and the toxicant load in dead and live Argentine ants (Linepithema humile) in colonies exposed to fipronil and hydramethylnon experimental baits were examined using accelerator mass spectrometry (AMS). About 50% of the content of the crop containing trace levels of 14C-sucrose, 14C-hydramethylnon, and 14C-fipronil was shared between single donor and recipient ants. Dead workers and queens contained significantly more hydramethylnon (122.7 and 22.4 amol/μg ant, respectively) than did live workers and queens (96.3 and 10.4 amol/μg ant, respectively). Dead workers had significantly more fipronil (420.3 amol/μg ant) than did live workers (208.5 amol/μg ant), butmore » dead and live queens had equal fipronil levels (59.5 and 54.3 amol/μg ant, respectively). Moreover, the distribution of fipronil differed within the bodies of dead and live queens; the highest amounts of fipronil were recovered in the thorax of dead queens whereas live queens had the highest levels in the head. Resurgence of polygynous ant colonies treated with hydramethylnon baits may be explained by queen survival resulting from sublethal doses due to a slowing of trophallaxis throughout the colony. The bait strategies and dose levels for controlling insect pests need to be based on the specific toxicant properties and trophic strategies for targeting the entire colony.« less

Insecticide Transfer Efficiency and Lethal Load in Argentine Ants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hooper-Bui, L. M.; Kwok, E S.C.; Buchholz, B. A.

Trophallaxis between individual worker ants and the toxicant load in dead and live Argentine ants (Linepithema humile) in colonies exposed to fipronil and hydramethylnon experimental baits were examined using accelerator mass spectrometry (AMS). About 50% of the content of the crop containing trace levels of 14C-sucrose, 14C-hydramethylnon, and 14C-fipronil was shared between single donor and recipient ants. Dead workers and queens contained significantly more hydramethylnon (122.7 and 22.4 amol/μg ant, respectively) than did live workers and queens (96.3 and 10.4 amol/μg ant, respectively). Dead workers had significantly more fipronil (420.3 amol/μg ant) than did live workers (208.5 amol/μg ant), butmore » dead and live queens had equal fipronil levels (59.5 and 54.3 amol/μg ant, respectively). Moreover, the distribution of fipronil differed within the bodies of dead and live queens; the highest amounts of fipronil were recovered in the thorax of dead queens whereas live queens had the highest levels in the head. Resurgence of polygynous ant colonies treated with hydramethylnon baits may be explained by queen survival resulting from sublethal doses due to a slowing of trophallaxis throughout the colony. The bait strategies and dose levels for controlling insect pests need to be based on the specific toxicant properties and trophic strategies for targeting the entire colony.« less

Toxicity and motor changes in Africanized honey bees (Apis mellifera L.) exposed to fipronil and imidacloprid.

PubMed

Bovi, Thaís S; Zaluski, Rodrigo; Orsi, Ricardo O

2018-01-01

This study evaluated the in vitro toxicity and motor activity changes in African-derived adult honey bees (Apis mellifera L.) exposed to lethal or sublethal doses of the insecticides fipronil and imidacloprid. Mortality of bees was assessed to determine the ingestion and contact lethal dose for 24 h using probit analysis. Motor activities in bees exposed to lethal (LD50) and sublethal doses (1/500th of the lethal dose) of both insecticides were evaluated in a behavioral observation box at 1 and 4 h. Ingestion and contact lethal doses of fipronil were 0.2316 ? 0.0626 and 0.0080 ? 0.0021 μg/bee, respectively. Ingestion and contact lethal doses of imidacloprid were 0.1079 ? 0.0375 and 0.0308 ? 0.0218 μg/bee, respectively. Motor function of bees exposed to lethal doses of fipronil and imidacloprid was impaired; exposure to sublethal doses of fipronil but not imidacloprid impaired motor function. The insecticides evaluated in this study were highly toxic to African-derived A. mellifera and caused impaired motor function in these pollinators.

Fipronil application on rice paddy fields reduces densities of common skimmer and scarlet skimmer

PubMed Central

Kasai, Atsushi; Hayashi, Takehiko I.; Ohnishi, Hitoshi; Suzuki, Kazutaka; Hayasaka, Daisuke; Goka, Koichi

2016-01-01

Several reports suggested that rice seedling nursery-box application of some systemic insecticides (neonicotinoids and fipronil) is the cause of the decline in dragonfly species noted since the 1990s in Japan. We conducted paddy mesocosm experiments to investigate the effect of the systemic insecticides clothianidin, fipronil and chlorantraniliprole on rice paddy field biological communities. Concentrations of all insecticides in the paddy water were reduced to the limit of detection within 3 months after application. However, residuals of these insecticides in the paddy soil were detected throughout the experimental period. Plankton species were affected by clothianidin and chlorantraniliprole right after the applications, but they recovered after the concentrations decreased. On the other hand, the effects of fipronil treatment, especially on Odonata, were larger than those of any other treatment. The number of adult dragonflies completing eclosion was severely decreased in the fipronil treatment. These results suggest that the accumulation of these insecticides in paddy soil reduces biodiversity by eliminating dragonfly nymphs, which occupy a high trophic level in paddy fields. PMID:26979488

Horizontal transfer of fipronil is enhanced with increased group size in Coptotermes formosanus (Isoptera: Rhinotermitidae).

PubMed

Wang, Cai; Henderson, Gregg; Chen, Xuan; Gautam, Bal K

2013-12-01

Fipronil is a widely used insecticide for termite control. Although transfer of fipronil among termite cohorts has been investigated in previous studies, no study has yet focused on the influence of termite group size (density) on horizontal transfer. In this study, the mortality of donor and recipient Coptotermes formosanus Shiraki (Isoptera: Rhinotermitidae) was compared among groups of 10, 25, and 50 workers. Most donor termites were dead within 20 h. There was a significantly higher mortality of recipient termites starting at 44 h when in bigger groups. LT50 and LT90 of recipient termites decreased with increase in group size, being significantly shorter in groups of 50 termites compared with groups of 10 termites. Moreover, the variance (within-group difference) of recipient mortality and lethal time estimations was lowest in the groups of 50 termites, indicating a more uniform horizontal transfer of fipronil by termites in bigger groups. Our findings suggest that group size has an influence on fipronil transfer among C. formosanus workers and should be considered as a variable of importance.

Safety Evaluation of Parastar® Plus in Dogs and Assessment of Transferable Residue of Fipronil and Cyphenothrin from Dogs to Humans

PubMed Central

Case, Katharine M.; Vega, Natalia M.; Gupta, Ramesh C.; Lasher, Michelle A.; Canerdy, Terry D.

2016-01-01

Dogs are easily infested with fleas, ticks, and other ectoparasites serving as vectors for transmitting bacterial, viral, and parasitic diseases. Therefore, the use of ectoparasiticides is inevitable and important. The present investigation was undertaken with two specific objectives: one, to evaluate the safety of fipronil and cyphenothrin in dogs after topical application of Parastar® Plus, and two, to determine the transferable residue of these insecticides from dogs to humans. Six healthy, adult dogs (medium length hair, weighing between 20.5 and 27.3 kg) received topical application of Parastar® Plus (2.68 mL; fipronil, 9.8%, and cyphenothrin, 5.2%) on the back between the shoulder blades. At predetermined intervals, dogs were given a full physical exam, and residues of fipronil and cyphenothrin were determined in dog blood and cotton glove extracts using GC/MS. Fipronil and cyphenothrin peaks eluted at 7.453 and 9.913 min, correspondingly, and the compounds were confirmed based on characteristic ions. At no time was fipronil or cyphenothrin residue detected in blood samples. In glove extracts, residues of fipronil and cyphenothrin were maximally present at 24-h posttreatment (43.84 ± 5.69 and 59.26 ± 8.97 ppm, respectively). By 48 h, the residue levels sharply declined (16.89 ± 2.82 and 17.98 ± 2.07 ppm, respectively). The insecticides’ residues were detected in insignificant amounts after 1 week (5.69 ± 2.16 and 10.00 ± 1.51 ppm, respectively), and only in trace amounts after 2 weeks. At no time did any dog show side effects, except itching at the site of Parastar® Plus application. The findings suggest that Parastar® Plus was safe for dogs, and transferable residues of fipronil and cyphenothrin were minimal, posing very little or no health concern to pet owners or veterinary personnel. Of course, veterinary personnel, who handle many dogs daily, may require proper protection to avoid cumulative exposure. PMID:27747219

Assessing mechanisms of toxicant response in the amphipod Melita plumulosa through transcriptomic profiling.

PubMed

Hook, Sharon E; Osborn, Hannah L; Spadaro, David A; Simpson, Stuart L

2014-01-01

This study describes the function of transcripts with altered abundance in the epibenthic amphipod, Melita plumulosa, following whole-sediment exposure to a series of common environmental contaminants. M. plumulosa were exposed for 48 h to sediments spiked and equilibrated with the following contaminants at concentrations predicted to cause sublethal effects to reproduction: porewater ammonia 30 mg L(-1); bifenthrin at 100 μg kg(-1); fipronil at 50 μg kg(-1); 0.6% diesel; 0.3% crude oil; 250 mg Cu kg(-1); 400 mg Ni kg(-1); and 400 mg Zn kg(-1). RNA was extracted and hybridized against a custom Agilent microarray developed for this species. Although the microarray represented a partial transcriptome and not all features on the array could be annotated, unique transcriptomic profiles were generated for each of the contaminant exposures. Hierarchical clustering grouped the expression profiles together by contaminant class, with copper and zinc, the petroleum products and nickel, and the pesticides each forming a distinct cluster. Many of the transcriptional changes observed were consistent with patterns previously described in other crustaceans. The changes in the transcriptome demonstrated that contaminant exposure caused changes in digestive function, growth and moulting, and the cytoskeleton following metal exposure, whereas exposure to petroleum products caused changes in carbohydrate metabolism, xenobiotic metabolism and hormone cycling. Functional analysis of these gene expression profiles can provide a better understanding of modes of toxic action and permits the prediction of mixture effects within contaminated ecosystems. Crown Copyright © 2013. Published by Elsevier B.V. All rights reserved.

Fipronil and two of its transformation products in water and European eel from the river Elbe.

PubMed

Michel, N; Freese, M; Brinkmann, M; Pohlmann, J-D; Hollert, H; Kammann, U; Haarich, M; Theobald, N; Gerwinski, W; Rotard, W; Hanel, R

2016-10-15

Fipronil is an insecticide which, based on its mode of action, is intended to be predominantly toxic towards insects. Fipronil bioaccumulates and some of its transformation products were reported to be similar or even more stable in the environment and to show an enhanced toxicity against non-target organisms compared to the parent compound. The current study investigated the occurrence of Fipronil and two of its transformation products, Fipronil-desulfinyl and Fipronil-sulfone, in water as well as muscle and liver samples of eels from the river Elbe (Germany). In water samples total concentrations of FIP, FIP-d and FIP-s ranged between 0.5-1.6ngL(-1) with FIP being the main component in all water samples followed by FIP-s and FIP-d. In contrast, FIP-s was the main component in muscle and liver tissues of eels with concentrations of 4.05±3.73ngg(-1) ww and 19.91±9.96ngg(-1) ww, respectively. Using a physiologically based toxicokinetic (PBTK) model for moderately hydrophobic organic chemicals, the different distributions of FIP, FIP-d and FIP-s in water and related tissue samples could be attributed to metabolic processes of eels. The measured concentrations in water of all analytes and their fractional distribution did not reflect the assumed seasonal application of FIP and it seems that the water was constantly contaminated with FIP, FIP-d and FIP-s. Copyright © 2016 Elsevier B.V. All rights reserved.

Biochemical alterations induced by oral subchronic exposure to fipronil, fluoride and their combination in buffalo calves.

PubMed

Gill, Kamalpreet Kaur; Dumka, Vinod Kumar

2013-11-01

The effects of various pesticides and minerals on biochemical parameters have been explored in different species, but hardly any data exist regarding the combined toxicological effect of pesticides and minerals on these parameters in animals. The present study investigated the effects of fipronil and fluoride co-exposure on biochemical parameters in buffalo calves. Twenty-four healthy male buffalo calves divided into four groups were treated for 98 consecutive days. Group I, receiving no treatment served as the control. Animals of groups II and III were orally administered with fipronil @ 0.5mg/kg/day and sodium fluoride (NaF) @ 6.67 mg/kg/day, respectively, for 98 days. An additional group IV was co-administered fipronil and NaF at the same dosages as groups II and III. Administration of fipronil alone produced mild toxic signs, significant elevation in plasma proteins, blood glucose, blood urea nitrogen (BUN) and significant decline in the plasma cholesterol levels. NaF exposure produced toxic signs specifically of muscle weakness and brown and black discoloration of teeth. Significant elevation was seen in whole blood cholinesterase, BUN and creatinine levels. However, it produced significant decline in blood glucose, cholesterol and plasma protein levels. Combined exposure to fipronil and sodium fluoride produced toxic signs with greater intensity while biochemical alterations produced were similar to those that were produced by their individual exposures. Copyright © 2013 Elsevier B.V. All rights reserved.

Evaluation of indoxacarb and fipronil (s)-methoprene topical spot-on formulations to control flea populations in naturally infested dogs and cats in private residences in Tampa FL. USA

PubMed Central

2013-01-01

Background A study was conducted to evaluate and compare the effectiveness of two different spot-on topical flea products to control flea infestations on naturally infested dogs and cats in Tampa, FL USA. Methods Thirty-two dogs and 3 cats with natural flea infestations living in 18 homes were treated topically with a 19.53% w/w spot-on formulation of indoxacarb. Another thirty dogs and 2 cats living in 19 different homes were treated topically with either fipronil (9.8% w/w)/(s)-methoprene (8.89% w/w) or fipronil (9.8% w/w)/(s)-methoprene (11.8% w/w), respectively. All products were applied according to label directions by study investigators on day 0 and again between days 28 and 30. Flea populations on pets were assessed using visual area counts and premise flea infestations were assessed using intermittent-light flea traps on days 0, 7, 14, 21, 28–30, 40–45, and 54–60. Results A single application of the indoxacarb or fipronil (s)-methoprene formulations reduced flea populations on pets by 97.8% and 85.5%, respectively within 7 days. One month (28–30 days) after treatment the indoxacarb and fipronil (s)-methoprene formulations reduced on-animal flea burdens by 95.0% and 49.5%, respectively. Following two monthly applications of either the indoxacarb or fipronil (s)-methoprene formulations, pet flea burdens were reduced by 99.1% and 54.8%, respectively, by days 54 – 60. At the end of the two month study, 77.1% and 15.6% of the dogs and cats in the indoxacarb and fipronil (s)-methoprene treatment groups, respectively were flea free. Flea numbers in the indoor-premises were markedly reduced in both treatment groups by days 54–60, with 97.7% and 84.6% reductions in intermittent-light flea trap counts in the indoxacarb and fipronil (s)-methoprene treatment groups, respectively. Conclusions This in-home investigation conducted during the summer of 2013 in subtropical Tampa, FL, is the first published U.S field investigation of the indoxacarb topical formulation. The indoxacarb formulation was able to effectively control flea populations in heavily flea infested pets and homes. The efficacy achieved by the fipronil (s)-methoprene formulation against flea infestations on these pets was lower than in previous investigations using the same study design. PMID:24373508

40 CFR 180.513 - Chlorfenapyr; tolerances for residues.

Code of Federal Regulations, 2011 CFR

2011-07-01

... greater than a 0.5% active ingredient solution for spot crack and crevice use in food/feed handling.... Application excludes any direct application to any food, food packaging, or any food contact surfaces. (v) To...

The mobility of thiobencarb and fipronil in two flooded rice-growing soils.

PubMed

Doran, Gregory; Eberbach, Philip; Helliwell, Stuart

2008-08-01

The mobility of the rice pesticides thiobencarb (S-[(4-chlorophenyl) methyl] diethylcarbamothioate) and fipronil ([5-amino-3-cyano-1-[2,6-dichloro-4-(trifluoromethyl)phenyl]-4-[(trifluoromethyl)sulfinyl]pyrazole) were investigated in the glasshouse under flooded conditions using two Australian rice-growing soils. When using leakage rates of 10 mm day(-1), less than 20% of applied thiobencarb and fipronil remained in the water column after 10 days due to rapid transfer to the soil phase. Up to 70% and 65% of the applied thiobencarb and fipronil, respectively, were recovered from the 0-1 cm layer of soils. Only 5-7% of each pesticide was recovered from the 1-2 cm layer, and less than 2% was recovered from each 1 cm layer in the 2-10 cm region of the soils. Analysis of the water leaking from the base of the soil cores showed between 5-10% of the applied thiobencarb and between 10-20% of the applied fipronil leaching from the soil cores. The high levels of pesticide in the effluent was attributed to preferential flow of pesticide-laden water via soil macropores resulting from the wetting and drying process, worm holes and root channels.

Use of a 0.25 per cent fipronil pump spray formulation to treat canine cheyletiellosis.

PubMed

Chadwick, A J

1997-06-01

Two outbreaks of cheyletiellosis are described. In one of the outbreaks, a human member of the household was also affected. A 0.25 per cent fipronil pump spray formulation was applied to the affected and in-contact animals. A permethrin spray was used in an attempt to eliminate environmental contamination. One month later, the affected animals were re-examined. No evidence of Cheyletiella mites could be found. A second application of fipronil was undertaken. No further outbreaks were reported during an eight month follow-up.

IN VITRO ESTIMATES OF METABOLIC PARAMETERS AND THEIR USE IN PREDICTIVE PHYSIOLOGICALLY BASED PHARMACOKINETIC MODELING (PBPK) OF THE TYPE I PYRETHROIDS PERMETHRIN AND BIFENTHRIN

EPA Science Inventory

Pyrethroids are a class of neurotoxic insecticides that are used in a variety of agricultural and household activities. Hepatic clearance of the Type I pyrethroids permethrin and bifenthrin may be a critical determinant of their toxic effect. Rat LD50s reported in the literatur...

Rainfastening of bifenthrine to cotton leaves with selected adjuvants

Treesearch

J. E. Mulrooney; C. D. Elmore

2000-01-01

There are thousands of adjuvants on the market, yet little is known about their effects on the activity of insecticides on plant surfaces. The effects of 11 selected adjuvants on the rainfastness and retention of bifenthrin ([lάJά-(Z)-(±)-(2 methyl[l,l'-biphenyl]-3-yl) methyl 3-(2-chloro-3,3,3-trifluoro-l-propenyl)-2,2-...

Effects of Different Pyrethroids on Landing Behavior of Female Aedes aegypti, Anopheles quadrimaculatus, and Culex quinquefasciatus Mosquitoes (Diptera: Culicidae)

DTIC Science & Technology

2009-03-01

pyrethroid- treated surfacespairedwithadjacentuntreated surfaces.The threepyrethroids testedwerebifenthrin, deltamethrin, and lambda - cyhalothrin . Landing...three pyrethroids tested were bifenthrin deltamethrin, and lambda - cyhalothrin . Landing and resting behavior was video recorded and quanti?ed using...study and tested with the pyrethroids bifenthrin, deltamethrin, and lambda - cyhalothrin . Materials and Methods Mosquitoes. Mosquitoes were reared, as

An analysis of lethal and sublethal interactions among type I and type II pyrethroid pesticide mixtures using standard Hyalella azteca water column toxicity tests.

PubMed

Hoffmann, Krista Callinan; Deanovic, Linda; Werner, Inge; Stillway, Marie; Fong, Stephanie; Teh, Swee

2016-10-01

A novel 2-tiered analytical approach was used to characterize and quantify interactions between type I and type II pyrethroids in Hyalella azteca using standardized water column toxicity tests. Bifenthrin, permethrin, cyfluthrin, and lambda-cyhalothrin were tested in all possible binary combinations across 6 experiments. All mixtures were analyzed for 4-d lethality, and 2 of the 6 mixtures (permethrin-bifenthrin and permethrin-cyfluthrin) were tested for subchronic 10-d lethality and sublethal effects on swimming motility and growth. Mixtures were initially analyzed for interactions using regression analyses, and subsequently compared with the additive models of concentration addition and independent action to further characterize mixture responses. Negative interactions (antagonistic) were significant in 2 of the 6 mixtures tested, including cyfluthrin-bifenthrin and cyfluthrin-permethrin, but only on the acute 4-d lethality endpoint. In both cases mixture responses fell between the additive models of concentration addition and independent action. All other mixtures were additive across 4-d lethality, and bifenthrin-permethrin and cyfluthrin-permethrin were also additive in terms of subchronic 10-d lethality and sublethal responses. Environ Toxicol Chem 2016;35:2542-2549. © 2016 SETAC. © 2016 SETAC.

Efficacy of fipronil for control of yellowjacket wasps in Hawaii Volcanoes National Park

USGS Publications Warehouse

Foote, David; Hanna, Cause; King, Cynthia; Spurr, Eric

2011-01-01

The western yellowjacket wasp (Vespula pensylvanica) invaded Hawai`i’s national parks and refuges following its spread throughout the islands in the late 1970s. The endemic arthropod fauna of Hawai`i is thought to be especially vulnerable to these predacious social Hymenoptera, and methods of wasp control have been a priority for conservation biology in Hawai`i. The efficacy of the insecticide fipronil mixed with minced canned chicken meat for suppression of yellowjacket populations was evaluated in five experimental field trials in Hawai`i Volcanoes National Park between 1999 and 2005. Populations of Vespula were monitored in replicate twoto four- hectare study areas in mesic montane and seasonal submontane forests, before and after application of chicken bait, with and without 0.1% fipronil, and in treatment and nontreatment areas. The bait was applied in hanging bait stations for two to three days. The response of yellowjacket wasp populations was measured using at least three different metrics of abundance including instantaneous counts of wasps at bait stations, wasp traffic rates at Vespula nests, as well as heptyl butyrate trap and/or malaise trap catches in the study areas. All indices of wasp abundance exhibited significant reductions in sites treated with fipronil compared with non-treatment sites with the exception of malaise trapping, where only a limited number of traps were available to be deployed. Wasp traffic ceased at all Vespula nests in sites treated with fipronil within a month after baiting in four of the five trials. The only trial where fipronil failed to terminate yellowjacket nest activity occurred late in the fall when wasps switch from feeding on protein to carbohydrate foods. Based on these data, 0.1% fipronil in chicken bait appears to be an effective tool for suppressing local Vespula yellowjacket populations in the park and other natural areas during the period of peak wasp activity in the summer and early fall months.

Operational note effects of fipronil and lambda-cyhalothrin against larval Anopheles quadrimaculatus and nontarget aquatic mosquito predators in Arkansas small rice plots.

PubMed

Dennett, James A; Bernhardt, John L; Meisch, Max V

2003-06-01

The effects of fipronil and lambda-cyhalothrin, applied at rates labeled for control of the rice water weevil, Lissorhoptrus oryzophilus, on 3 nontarget indigenous insect species in Arkansas rice are described. Three replicates of untreated control checks and fipronil- and lambda-cyhalothrin-treated plots containing 3 sentinel cages each were performed. Ten 4th-stage larvae of Anopheles quadrimaculatus, 10 adult Tropisternus lateralis, or 10 adult Notonecta indica were placed within individual cages in small rice plots treated with ICON 6.2 FS (fipronil) at 0.025 lb active ingredient (AI)/acre (0.028 kg/ha) or KARATEZ 2.08 CS (lambda-cyhalothrin) at 0.03 lb AI/acre (0.033 kg/ha) applied over vegetation and water with a single-boom sprayer. At 24 h after treatment in fipronil plots, significantly higher control of An. quadrimaculatus and T. lateralis (69 and 48% control, respectively) was achieved, compared to N. indica (18%). In lambda-cyhalothrin plots 24 h after treatment, 100% reductions of both T. lateralis and N. indica were highly significant (P < 0.05) from the lower level of control in An. quadrimaculatus (10%). At 48 h after treatment, no significant, differences existed between all species within fipronil plots, with An. quadrimaculatus, T. lateralis, and N. indica obtaining 41, 10, and 7% control, respectively. Significantly higher (P < 0.05) control was obtained in lambda-cyhalothrin plots 48 h after treatment, with 93 and 53% control of T. lateralis and N. indica, respectively, compared to 7% control of An. quadrimaculatus. A marked difference in susceptibility was found between selected nontarget organisms used in this study. When using lambda-cyhalothrin to control adult L. oryzophilus, populations of nontarget beneficial insects, such as T. lateralis and N. indica, could be adversely affected, whereas nontarget pestilent species, such as An. quadrimaculatus, could proliferate. Fipronil achieved higher percentages of control against An. quadrimaculatus, compared to lambda-cyhalothrin, and was less harmful to both nontarget predators.

A method for addressing differences in concentrations of fipronil and three degradates obtained by two different laboratory methods

USGS Publications Warehouse

Crawford, Charles G.; Martin, Jeffrey D.

2017-07-21

In October 2012, the U.S. Geological Survey (USGS) began measuring the concentration of the pesticide fipronil and three of its degradates (desulfinylfipronil, fipronil sulfide, and fipronil sulfone) by a new laboratory method using direct aqueous-injection liquid chromatography tandem mass spectrometry (DAI LC–MS/MS). This method replaced the previous method—in use since 2002—that used gas chromatography/mass spectrometry (GC/MS). The performance of the two methods is not comparable for fipronil and the three degradates. Concentrations of these four chemical compounds determined by the DAI LC–MS/MS method are substantially lower than the GC/MS method. A method was developed to correct for the difference in concentrations obtained by the two laboratory methods based on a methods comparison field study done in 2012. Environmental and field matrix spike samples to be analyzed by both methods from 48 stream sites from across the United States were sampled approximately three times each for this study. These data were used to develop a relation between the two laboratory methods for each compound using regression analysis. The relations were used to calibrate data obtained by the older method to the new method in order to remove any biases attributable to differences in the methods. The coefficients of the equations obtained from the regressions were used to calibrate over 16,600 observations of fipronil, as well as the three degradates determined by the GC/MS method retrieved from the USGS National Water Information System. The calibrated values were then compared to over 7,800 observations of fipronil and to the three degradates determined by the DAI LC–MS/MS method also retrieved from the National Water Information System. The original and calibrated values from the GC/MS method, along with measures of uncertainty in the calibrated values and the original values from the DAI LC–MS/MS method, are provided in an accompanying data release.

Fipronil insecticide: Novel photochemical desulfinylation with retention of neurotoxicity

PubMed Central

Hainzl, Dominik; Casida, John E.

1996-01-01

Fipronil is an outstanding new insecticide for crop protection with good selectivity between insects and mammals. The insecticidal action involves blocking the γ-aminobutyric acid-gated chloride channel with much greater sensitivity of this target in insects than in mammals. Fipronil contains a trifluoromethylsulfinyl moiety that is unique among the agrochemicals and therefore presumably important in its outstanding performance. We find that this substituent unexpectedly undergoes a novel and facile photoextrusion reaction on plants upon exposure to sunlight, yielding the corresponding trifluoromethylpyrazole, i.e., the desulfinyl derivative. The persistence of this photoproduct and its high neuroactivity, resulting from blocking the γ-aminobutyric acid-gated chloride channel, suggest that it may be a significant contributor to the effectiveness of fipronil. In addition, desulfinylfipronil is not a metabolite in mammals, so the safety evaluations must take into account not only the parent compound but also this completely new environmental product. PMID:8917493

Evaluation of cytotoxic effects of fipronil on ovaries of semi-engorged Rhipicephalus sanguineus (Latreille, 1806) (Acari: Ixodidae) tick female.

PubMed

de Oliveira, Patrícia Rosa; Bechara, Gervásio Henrique; Camargo-Mathias, Maria Izabel

2008-07-01

The ovary of the Rhipicephalus sanguineus dog tick female is structurally formed by oocytes in five different stages of development (from I to V) and attached to the gonad by the pedicel. The present study evaluated possible toxic effects of the acaricide fipronil (Frontline) on ovaries of semi-engorged ticks. Sixty partially fed females of R. sanguineus tick were distributed into four groups of 15 specimens each: I--non-treated; II, III and IV--treated with 1, 5 and 10 ppm of fipronil, respectively. The acaricide induced structural changes in the oocytes of individuals of the different treated groups ranging from the presence of a few small vacuoles to cellular death. In conclusion, germinative cells of semi-engorged R. sanguineus tick female are affected by different concentrations of fipronil leading to the reduction of tick fertility.

Fipronil: Toxicity to subterranean termites and dissipation in soils

Treesearch

J. E. Mulrooney; T. L. Wagner; P. D. Gerard

2009-01-01

Fipronil (Termidor 80 WG) was applied to covered and exposed plots at one secondary and four primary USDA Forest Service termiticide test sites in the U.S. Residue analyses and bioassays of soil samples were conducted over 5 y.

Action of the chemical agent fipronil on the reproductive process of semi-engorged females of the tick Rhipicephalus sanguineus (Latreille, 1806) (Acari: Ixodidae). Ultrastructural evaluation of ovary cells.

PubMed

Oliveira, Patrícia Rosa de; Bechara, Gervásio Henrique; Morales, Maria Aparecida Marin; Mathias, Maria Izabel Camargo

2009-06-01

The ovary of the tick Rhipicephalus sanguineus consists of a wall of epithelial cells and a large number of oocytes in five different developmental stages (I-V), which are attached to the wall by a pedicel. The present study provides ultrastructural information on the effects (dose-response) of the acaricide fipronil (Frontline) on ovaries of semi-engorged females of R. sanguineus, as well as it demonstrates some possible defense mechanisms used by oocytes to protect themselves against this chemical agent. Individuals were divided into four groups. Group I was used as control while groups II, III and IV were treated with fipronil at the concentrations of 1, 5 and 10 ppm, respectively. Fipronil at the concentration of 10 ppm had the strongest effect on the development of oocytes. At this concentration, even oocytes that reached the final developmental stage exhibited damaged cell structures. Moreover, the observation in fipronil-treated R. sanguineus ticks of damaged cellular components such as plasmic membrane, mitochondria and protein granules (due to alteration in the protein synthesis), and cellular defense mechanisms such as increase in the amount of cytoplasmic microtubules and large amounts of digestive vacuoles and myelin figures, were only possible by means of ultrastructure.

DBS-platform for biomonitoring and toxicokinetics of toxicants: proof of concept using LC-MS/MS analysis of fipronil and its metabolites in blood

NASA Astrophysics Data System (ADS)

Raju, Kanumuri Siva Rama; Taneja, Isha; Rashid, Mamunur; Sonkar, Ashish Kumar; Wahajuddin, Muhammad; Singh, Sheelendra Pratap

2016-03-01

A simple, sensitive and high throughput LC-MS/MS method was developed and validated for quantification of fipronil, fipronil sulfone and fipronil desulfinyl in rat and human dried blood spots (DBS). DBS samples were prepared by spiking 10 μl blood on DMPK-C cards followed by drying at room temperature. The whole blood spots were then punched from the card and extracted using acetonitrile. The total chromatographic run time of the method was only 2 min. The lower limit of quantification of the method was 0.1 ng/ml for all the analytes. The method was successfully applied to determine fipronil desulfinyl in DBS samples obtained from its toxicokinetic study in rats following intravenous dose (1 mg/kg). In conclusion, the proposed DBS methodology has significant potential in toxicokinetics and biomonitoring studies of environmental toxicants. This microvolume DBS technique will be an ideal tool for biomonitoring studies, particularly in paediatric population. Small volume requirements, minimally invasive blood sampling method, easier storage and shipping procedure make DBS a suitable technique for such studies. Further, DBS technique contributes towards the principles of 3Rs resulting in significant reduction in the number of rodents used and refinement in sample collection for toxicokinetic studies.

Polyoxymethylene passive samplers to assess the effectiveness of biochar by reducing the content of freely dissolved fipronil and ethiprole.

PubMed

Li, Shasha; Wang, Pingping; Liu, Xingang; Wu, Xiaohu; Dong, Fengshou; Xu, Jun; Zheng, Yongquan

2018-07-15

An equilibrium passive sampler based on polyoxymethylene (POM) was used to determine the freely dissolved concentrations (C free ) of fipronil and ethiprole. The sorption equilibrium times of fipronil and ethiprole in POM were 14.2d and 24.0d, respectively. The POM-water partitioning coefficients (logK POM-water ) were 2.6 for fipronil and 1.4 for ethiprole. The method was further used to evaluate the sorption behavior of biochars which produced by pyrolysis of Magnolia wood (Magnolia denudata) at 300°C, 500°C and 700°C. The amounts of target compounds adsorbed increased with increasing pyrolysis temperature of the biochars. Biochars characterized by a low polarity index had better sorption capacity for the target compounds. The additions of biochars to sediment were effective in reducing C free , and the enhancement was found to be more pronounced with high biochar content. C free in sediment with more organic matter was significantly higher after biochar addition. Increasing the sediment-biochar contact time from 7 to 30d resulted in an increase in sorption of the compounds. We conclude that Magnolia wood biochar effectively reduces the content of freely dissolved fipronil and ethiprole content in sediment. Copyright © 2018. Published by Elsevier B.V.

Cross-resistance and synergism bioassays suggest multiple mechanisms of pyrethroid resistance in western corn rootworm populations

PubMed Central

Souza, Dariane; Zukoff, Sarah N.; Meinke, Lance J.; Siegfried, Blair D.

2017-01-01

Recently, resistance to the pyrethroid bifenthrin was detected and confirmed in field populations of western corn rootworm, Diabrotica virgifera virgifera LeConte from southwestern areas of Nebraska and Kansas. As a first step to understand potential mechanisms of resistance, the objectives of this study were i) to assess adult mortality at diagnostic concentration-LC99 to the pyrethroids bifenthrin and tefluthrin as well as DDT, ii) estimate adult and larval susceptibility to the same compounds as well as the organophosphate methyl-parathion, and iii) perform synergism experiments with piperonyl butoxide (PBO) (P450 inhibitor) and S,S,S-tributyl-phosphorotrithioate (DEF) (esterase inhibitor) in field populations. Most of the adult field populations exhibiting some level of bifenthrin resistance exhibited significantly lower mortality to both pyrethroids and DDT than susceptible control populations at the estimated LC99 of susceptible populations. Results of adult dose-mortality bioassays also revealed elevated LC50 values for bifenthrin resistant populations compared to the susceptible control population with resistance ratios ranging from 2.5 to 5.5-fold for bifenthrin, 28 to 54.8-fold for tefluthrin, and 16.3 to 33.0 for DDT. These bioassay results collectively suggest some level of cross-resistance between the pyrethroids and DDT. In addition, both PBO and DEF reduced the resistance ratios for resistant populations although there was a higher reduction in susceptibility of adults exposed to PBO versus DEF. Susceptibility in larvae varied among insecticides and did not correlate with adult susceptibility to tefluthrin and DDT, as most resistance ratios were < 5-fold when compared to the susceptible population. These results suggest that both detoxifying enzymes and target site insensitivity might be involved as resistance mechanisms. PMID:28628635

Stormwater input of pyrethroid insecticides to an urban river.

PubMed

Weston, Donald P; Lydy, Michael J

2012-07-01

The American River flows for nearly 50 km through highly urbanized lands surrounding Sacramento, California, USA. Twenty-three streams, drainage canals, or pumping stations discharge urban runoff to the river, with the cumulative effect of nearly doubling the river's flow during rain events. During winter storms, the water column in the most downstream 13-km reach of the river exhibited toxicity to the standard testing species, Hyalella azteca, in 52% of samples, likely because of the pyrethroid insecticide bifenthrin. The compound is heavily used by professional pest controllers, either as a liquid perimeter treatment around homes or as granules broadcast over landscaped areas. It was found in 11 of 12 runoff sources examined, at concentrations averaging five times the H. azteca 96-h EC50. Quantified inputs of bifenthrin should have been sufficient to attain peak concentrations in the river twice those actually observed, suggesting loss by sedimentation of particulates and pesticide adsorption to the substrate and/or vegetation. Nevertheless, observed bifenthrin concentrations in the river were sufficient to cause water column toxicity, demonstrated during six storms studied over three successive winters. Toxicity and bifenthrin concentrations were greatest when river flow was low (<23 m(3) /s) but persisted even at atypically high flows (585 m(3) /s). Copyright © 2012 SETAC.

Longevity and efficacy of bifenthrin treatment on desert-pattern US military camouflage netting against mosquitoes in a hot-arid environment.

PubMed

Britch, Seth C; Linthicum, Kenneth J; Wynn, Willard W; Aldridge, Robert L; Walker, Todd W; Farooq, Muhammad; Dunford, James C; Smith, Vincent L; Robinson, Cathy A; Lothrop, Branka B; Snelling, Melissa; Gutierrez, Arturo; Wittie, Jeremy; White, Gregory

2011-09-01

The current Department of Defense pest management system does not provide adequate protection from arthropod disease vectors to personnel deployed in support of US military operations. We hypothesized that military camouflage netting, ubiquitous around living and working areas in current US military operations in Africa and the Middle East, treated with a residual pesticide such as bifenthrin may reduce the presence of biting insects and improve the military pest management system. In this study, we examined the longevity and efficacy of bifenthrin applied to camouflage netting material at the maximum label rate of 0.03 liter formulation (7.9% AI) per 92.9 m2 against field populations of mosquitoes in southern California in a hot-arid environment similar to regions of Iraq, Afghanistan, and the Horn of Africa. We showed that bifenthrin treatment of camouflage netting was effective at reducing mosquito populations, predominantly Psorophora columbiae and Aedes vexans, by an average of up to 46% for 56 days, and could cause as much as 40% mortality in Culex quinquefasciatus in laboratory bioassays for nearly 2 months postapplication. These population reductions could translate to commensurate reductions in risk of exposure to mosquito-borne pathogens, and could potentially be effective against sand flies and filth flies.

Efficacy of fipronil in the treatment of feline cheyletiellosis.

PubMed

Scarampella, F; Pollmeier, M; Visser, M; Boeckh, A; Jeannin, P

2005-05-15

The purpose of the present study was to confirm the efficacy of 10% (w/v) fipronil spot-on (Frontline spot-on for cats) in the treatment of feline cheyletiellosis under field conditions. A total of 16 cats of different breeds, sexes, 4 months to 14 years of age and weighing 0.5-6 kg were treated with a single topical application of 10% (w/v) fipronil spot-on according to label directions. The animals were naturally infested with Cheyletiella mites and housed in their normal environment throughout the study. Animals were selected based on clinical signs and infestation was confirmed by demonstration of mites. Mite counts and a clinical assessment of mite infestations (i.e. skin lesions and/or scales) were performed on days 0 and approximately days 14 and 28. Individual counts on day 0 ranged from 1 to 40 mites on individual animals. No mites were detected on cats treated with 10% (w/v) fipronil spot-on (Frontline spot-on for cats) at both post-treatment evaluations. Typical skin lesions and/or scales were present in all animals pre-treatment. In 56% of the cats, the lesions resolved within 14 days after treatment. At the final assessment, 75% cats were free of lesions. Two cats that still had clinical signs on day 28 were suspected of having allergic reactions to food or environmental allergens. The lesions on the remaining two cats could not be related to a specific cause. The efficacy of fipronil in elimination of mites was 100% on each occasion when compared to the pre-treatment count. The results of this study demonstrated that fipronil in a topical formulation is highly effective (100%) for the elimination of an existing Cheyletiella mite infestation under field conditions following a single topical application in cats.

Assessment of the toxic effect of pesticides on honey bee drone fertility using laboratory and semifield approaches: A case study of fipronil.

PubMed

Kairo, Guillaume; Poquet, Yannick; Haji, Haïthem; Tchamitchian, Sylvie; Cousin, Marianne; Bonnet, Marc; Pelissier, Michel; Kretzschmar, André; Belzunces, Luc P; Brunet, Jean-Luc

2017-09-01

Concern about the reproductive toxicity of plant protection products in honey bee reproducers is increasing. Because the reproductive capacity of honey bees is not currently considered during the risk assessment procedure performed during plant protection product registration, it is important to provide methods to assess such potential impairments. To achieve this aim, we used 2 different approaches that involved semifield and laboratory conditions to study the impact of fipronil on drone fertility. For each approach, the drones were reared for 20 d, from emergence to sexual maturity, and exposed to fipronil via a contaminated sugar solution. In both groups, the effects of fipronil were determined by studying life traits and fertility indicators. The results showed that the survival and maturity rates of the drones were better under laboratory conditions than under semifield conditions. Moreover, the drones reared under laboratory conditions produced more seminal fluid. Although these differences could be explained by environmental factors that may vary under semifield conditions, it was found that regardless of the approach used, fipronil did not affect survival rates, maturity rates, or semen volumes, whereas it did affect fertility by inducing a decrease in spermatozoa quantity that was associated with an increase in spermatozoa mortality. These results confirm that fipronil affects drone fertility and support the relevance of each approach for assessing the potential reproductive toxicity of plant protection products in honey bees. Environ Toxicol Chem 2017;36:2345-2351. © 2017 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals, Inc. on behalf of SETAC. © 2017 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals, Inc. on behalf of SETAC.

BIOACCUMULATION, BIOTRANSFORMATION, AND METABOLITE FORMATION OF FIPRONIL AND CHIRAL LEGACY PESTICIDES IN RAINBOW TROUT

EPA Science Inventory

To assess the fate of current-use pesticides it is important to understand their bioaccumulation and biotransformation by aquatic biota. We examined the dietary accumulation and enantioselective biotransformation of the chiral current-use pesticide fipronil, along with a mixture ...

Residue analysis of fipronil and difenoconazole in okra by liquid chromatography tandem mass spectrometry and their food safety evaluation.

PubMed

Hingmire, Sandip; Oulkar, Dasharath P; Utture, Sagar C; Ahammed Shabeer, T P; Banerjee, Kaushik

2015-06-01

A liquid chromatography tandem mass spectrometry (LC-MS/MS) based method is reported for simultaneous analysis of fipronil (plus its metabolites) and difenoconazole residues in okra. The sample preparation method involving extraction with ethyl acetate provided 80-107% recoveries for both the pesticides with precision RSD within 4-17% estimated at the limits of quantification (LOQ, fipronil=1ngg(-1), difenoconazole=5ngg(-1)) and higher fortification levels. In field, both the pesticides dissipated with half-life of 2.5days. The estimated pre-harvest intervals (PHI) for fipronil and difenoconazole were 15 and 19.5days, and 4 and 6.5days at single and double dose of field applications, respectively. Decontamination of incurred residues by washing and different cooking treatments was quite efficient in minimizing the residue load of both the chemicals. Okra samples harvested after the estimated PHIs were found safe for human consumption. Copyright © 2014 Elsevier Ltd. All rights reserved.

Single channel analysis of the blocking actions of BIDN and fipronil on a Drosophila melanogaster GABA receptor (RDL) stably expressed in a Drosophila cell line

PubMed Central

Grolleau, Françoise; Sattelle, David B

2000-01-01

Single channel recordings were obtained from a Drosophila S2 cell line stably expressing the wild-type RDLac Drosophila melanogaster homomer-forming ionotropic GABA receptor subunit, a product of the resistance to dieldrin gene, Rdl. GABA (50 μM) was applied by pressure ejection to outside-out patches from S2-RDL cells at a holding potential of −60 mV. The resulting inward current was completely blocked by 100 μM picrotoxin (PTX). The unitary current-voltage relationship was linear at negative potentials but showed slight inward rectification at potentials more positive than 0 mV. The reversal potential of the current (EGABA=−1.4 mV) was close to the calculated chloride equilibrium potential. The single channel conductance elicited by GABA was 36 pS. A 71 pS conductance channel was also observed when the duration of the pulse, used to eject GABA, was longer than 80 ms. The mean open time distribution of the unitary events was fitted best by two exponential functions suggesting two open channel states. When either 1 μM fipronil or 1 μM BIDN was present in the external saline, the GABA-gated channels were completely blocked. When BIDN or fipronil was applied at a concentration close to the IC50 value for suppression of open probability (281 nM, BIDN; 240 nM, fipronil), the duration of channel openings was shortened. In addition, the blocking action of BIDN resulted in the appearance of a novel channel conductance (17 pS). The effects of co-application of BIDN and fipronil were examined. Co-application of BIDN (300 nM) with various concentrations (100–1000 nM) of fipronil resulted in an additional BIDN-induced dose-dependent reduction of the maximum Po value. Thus both BIDN and fipronil shorten the duration of wild-type RDLac GABA receptor channel openings but appear to act at distinct sites. PMID:10952672

Effects of Fipronil on the EEG of Long Evans Rats

EPA Science Inventory

We have reported that the non-stimulus driven EEG is differentially altered by deltamethrin or permethrin (Lyke and Herr, Toxicologist, 114(S-1):265, 2010). In the current study, we examined the ability to detect changes in EEG activity produced by fipronil, a phenylpyrazole pest...

Fipronil as a larvicide against container-inhabiting mosquito, Aedes albopictus.

USDA-ARS?s Scientific Manuscript database

In the laboratory, Fipronil was tested against laboratory-reared and field-collected early 4th instar Aedes albopictus larvae. The insecticide was also bioassayed for activity against natural field populations of Ae. albopictus inhabiting one-liter capacity stone-made containers in a cemetery, St. A...

Evaluation and comparison of a flumethrin-imidacloprid collar and repeated monthly treatments of fipronil/(s)-methoprene to control flea, Ctenocephalides f. felis, infestations on cats for eight months.

PubMed

Dryden, Michael W; Smith, Vicki; Davis, Wendell L; Settje, Terry; Hostetler, Joe

2016-05-17

This controlled laboratory study was designed to evaluate the efficacy of the 10 % imidacloprid/4.5 % flumethrin collar (Seresto®, Bayer Animal Health) against fleas (Ctenocephalides f. felis) on cats, when compared to fipronil (9.8 %w/w)/(s)-methoprene (11.8 % w/w) topical spot-on formulation (Frontline® Plus for Cats and Kittens, Merial). Thirty cats were randomized into three groups of ten animals based on pre-treatment flea counts: Group 1: imidacloprid/flumethrin collar; Group 2: fipronil/(s)-methoprene topical spot-on and Group 3: non-treated controls. The imidacloprid/flumethrin collars were applied one time on Day 0, while the fipronil/(s)-methoprene spot-on was administered every 30 days from Day 0 through Day 210. Cats were infested with 100 fleas on study days 0, 7, 14, 29, 59, 89, 119, 149, 179, 209 and 239. All flea counts were conducted by combing to remove fleas on post-treatment days 2, 8, 15, 30, 60, 90, 120, 150, 180, 210 and 240. The efficacy of the imidacloprid/flumethrin collar ranged from 98.2 to 100 % for eight months. The efficacy of fipronil/(s)-methoprene spot-on ranged from 68.2 to 99.9 %. Efficacy was < 85 % for fipronil/(s)-methoprene on Days 90, 150 and 210. The flea counts in both treatment groups were significantly fewer than those in the non-treated control group at every post-treatment study day (P < 0.0001). In addition, there were significantly fewer fleas in the imidacloprid/flumethrin collar group when compared to the fipronil/(s)-methoprene group on Days 90, 150 and 210 (P < 0.0001). This study demonstrated that the imidacloprid/flumethrin collar (Seresto®, Bayer Animal Health) maintained excellent ( > 98.2 %) efficacy against fleas on cats for the entire 8 month study. Monthly applications of fipronil/(s)-methoprene (Frontline® Plus for Cats and Kittens, Merial) generally had high, but variable (68.2 to 99.9 %) efficacy over the course of the eight month study. Based on the very high residual efficacy achieved by the imidacloprid/flumethrin collar in this study, veterinarians should expect that this collar will control and eliminate existing flea infestations on cats and in their in-home premises as long as every flea infested host is treated.

Enhanced Ga2O3-photocatalyzed and photochemical degradation of the Fipronil insecticide by UVC irradiation in mixed aqueous/organic media under an inert atmosphere.

PubMed

Hidaka, Hisao; Tsukamoto, Tohru; Mitsutsuka, Yoshihiro; Oyama, Toshiyuki; Serpone, Nick

2015-05-01

Agrochemicals such as the insecticide Fipronil that bear fluoro groups are generally fat-soluble and nearly insoluble in water, so that their photodegradation in a heterogeneous aqueous gallium oxide dispersion presents some challenges. This article examined the photodegradation of this insecticide by solubilizing it through the addition of organic solvents (EtOH, MeOH, THF, 1,4-dioxane and ethylene glycol) to an aqueous medium and then subjecting the insecticide to 254 nm UVC radiation under photocatalytically inert (Ga2O3/N2) and air-equilibrated (Ga2O3/O2) conditions, as well as photochemically in the absence of Ga2O3 but also under inert and air-equilibrated conditions. Defluorination, dechlorination, desulfonation and denitridation of Fipronil were examined in mixed aqueous/organic media (10, 25 and 50 vol% in organic solvent). After 3 h of UVC irradiation (50 vol% mixed media) defluorination with Ga2O3/N2 was ∼65% greater than in aqueous media, and ca. 80% greater than the direct photolysis of Fipronil under inert (N2) conditions; under air-equilibrated conditions both Ga2O3-photocatalyzed and photochemical defluorination were significantly lower than in aqueous media. Dechlorination of Fipronil was ∼160% (Ga2O3/N2) and 140% (photochemically, N2) greater than in aqueous media; under air-equilibrated conditions, both photocatalyzed and photochemical formation of Cl(-) ions in mixed media fell rather short relative to aqueous media. The photocatalyzed (Ga2O3/N2) and photochemical (N2) conversion of the sulfur group in Fipronil to SO4(2(-)) ions was ca. 20% and 30% greater, respectively, in mixed media, while under air-equilibrated conditions photocatalyzed desulfonation was nearly twofold less than in the aqueous phase; direct photolysis showed little variations in mixed media. Denitridation of the nitrogens in Fipronil occurred mostly through the formation of ammonia (as NH4(+)) under all conditions with negligible quantities of NO3(-); again mixed media offered enhanced denitridation, particularly under inert N2 conditions. Time-of-flight electrospray (TOF-MS/ESI(-)) mass spectrometry revealed a fairly large number of intermediates formed in the degradation of Fipronil, particularly under photocatalytic conditions. Only a couple of intermediates were identified in the photodegradation and the presence of Ga2O3 enhanced the complexity of an already cumbersome problem owing to the involvement of organic solvents.

Exposure of native bees foraging in an agricultural landscape to current-use pesticides.

PubMed

Hladik, Michelle L; Vandever, Mark; Smalling, Kelly L

2016-01-15

The awareness of insects as pollinators and indicators of environmental quality has grown in recent years, partially in response to declines in honey bee (Apis mellifera) populations. While most pesticide research has focused on honey bees, there has been less work on native bee populations. To determine the exposure of native bees to pesticides, bees were collected from an existing research area in northeastern Colorado in both grasslands (2013-2014) and wheat fields (2014). Traps were deployed bi-monthly during the summer at each land cover type and all bees, regardless of species, were composited as whole samples and analyzed for 136 current-use pesticides and degradates. This reconnaissance approach provides a sampling of all species and represents overall pesticide exposure (internal and external). Nineteen pesticides and degradates were detected in 54 composite samples collected. Compounds detected in >2% of the samples included: insecticides thiamethoxam (46%), bifenthrin (28%), clothianidin (24%), chlorpyrifos (17%), imidacloprid (13%), fipronil desulfinyl (7%; degradate); fungicides azoxystrobin (17%), pyraclostrobin (11%), fluxapyroxad (9%), and propiconazole (9%); herbicides atrazine (19%) and metolachlor (9%). Concentrations ranged from 1 to 310 ng/g for individual pesticides. Pesticides were detected in samples collected from both grasslands and wheat fields; the location of the sample and the surrounding land cover at the 1000 m radius influenced the pesticides detected but because of a small number of temporally comparable samples, correlations between pesticide concentration and land cover were not significant. The results show native bees collected in an agricultural landscape are exposed to multiple pesticides, these results can direct future research on routes/timing of pesticide exposure and the design of future conservation efforts for pollinators. Published by Elsevier B.V.

Development and validation of a method for fipronil residue determination in ovine plasma using 96-well plate solid-phase extraction and gas chromatography-tandem mass spectrometry.

PubMed

Bichon, E; Richard, C A; Le Bizec, B

2008-08-01

Fipronil, a phenylpyrazole insecticide introduced for pest control on a broad range of crops, undergoes a reinforcement of the regulation within the European Union (2007/52/EC directive) due to its potential effects on environment and human health. In order to assess the plasmatic concentrations of fipronil residues (sulfone, sulfide, fipronil, desulfinyl and amide) in ovine, a methodology based on gas chromatography coupled with tandem mass spectrometry (GC-MS/MS) was developed and validated according to the European standard (2002/657/EC). The proposed method allows a large number of samples to be treated concurrently (n=80) using a reduced sample amounts (0.2 mL), and consents to reach a level of quantification of 0.1 pg microL(-1). The sample preparation consisted of a single solid-phase extraction (SPE) purification on a 96-well plate filled with a styrene-divinyl-benzene phase. Linearity was demonstrated all along the investigated range of concentrations, i.e. from 0.25 to 2000 pg microL(-1), with coefficient of determination (R(2)) from 0.977 to 0.994, depending on target analytes. Calculated decision limit (CCalpha) and detection capability (CCbeta) for fipronil, sulfone and sulphide were in the range 0.05-0.16 and 0.28-0.73 pg microL(-1) respectively.

Impacts of the phenylpyrazole insecticide fipronil on larval fish: time-series gene transcription responses in fathead minnow (Pimephales promelas) following short-term exposure.

PubMed

Beggel, Sebastian; Werner, Inge; Connon, Richard E; Geist, Juergen P

2012-06-01

The utilization of molecular endpoints in ecotoxicology can provide rapid and valuable information on immediate organismal responses to chemical stressors and is increasingly used for mechanistic interpretation of effects at higher levels of biological organization. This study contributes knowledge on the sublethal effects of a commonly used insecticide, the phenylpyrazole fipronil, on larval fathead minnow (Pimephales promelas), utilizing a quantitative transcriptomic approach. Immediately after 24h of exposure to fipronil concentrations of ≥31 μg.L(-1), highly significant changes in gene transcription were observed for aspartoacylase, metallothionein, glucocorticoid receptor, cytochrome P450 3A126 and vitellogenin. Different mechanisms of toxicity were apparent over the course of the experiment, with short-term responses indicating neurotoxic effects. After 6 days of recovery, endocrine effects were observed with vitellogenin being up-regulated 90-fold at 61 μg.L(-1) fipronil. Principal component analysis demonstrated a significant increase in gene transcription changes over time and during the recovery period. In conclusion, multiple mechanisms of action were observed in response to fipronil exposure, and unknown delayed effects would have been missed if transcriptomic responses had only been measured at a single time-point. These challenges can be overcome by the inclusion of multiple endpoints and delayed effects in experimental designs. Copyright © 2012 Elsevier B.V. All rights reserved.

Changes in rate serum bioindicators after single or repeated dosages of fipronil

EPA Science Inventory

Acute exposure to different classes of pesticides produces different patterns of changes in serum bioindicators (Herr et al., Toxicologist, 2013). We now examined profiles of bioindicators after 1 or 14 treatments with 0, 5, or 10 mg/kg/day fipronil (po). Adult male Long-Evans ra...

Effects of a Fipronil Spot-Treatment on field colonies of Coptotermes formosanus (Isoptera: Rhinotermitidae)

USDA-ARS?s Scientific Manuscript database

This field study investigated the colony effect of a Fipronil spot-treatment applied to active infestations of Formosan subterranean termite, Coptotermes formosanus Shiraki. Spot-treatments were applied to a single active independent monitor from each of four colonies in which multiple independent m...

Pesticide residue levels in green beans cultivated in Souss Masa valley (Morocco) after multiple applications of bifenthrin and λ-cyhalothrin.

PubMed

Bouri, M; Salghi, R; Bazzi, Lh; Zarrouk, A; Rios, A; Zougagh, M

2012-09-01

Dissipation of bifenthrin and λ-cyhalothrin pyrethroid insecticides, under environmental conditions, was evaluated on green beans grown in experimental greenhouses (Souss Massa valley, Morocco). Pesticide residues were determined by gas chromatography with micro electron-capture detector (GC-μECD) after dichloromethane extraction and cleanup on florisil phase cartridges. In the case of field experiments, a random block scheme was employed. Each block contained 25 plants in a single row and tests were carried out in triplicates applying pesticides at the recommended doses by the manufacturers. Fruit samples were periodically taken until the end of the preharvest interval (p.i.). The results obtained showed that the p.i of bifenthrin in green bean were 4 days in the winter and 3.5 days in the spring, whereas that for λ-cyhalothrin 8 days was found in the winter and 7.5 days in the spring. Consequently, it is possible to consider the European Union maximum residue limit (EU MRL) values compatible with the proper agricultural practices used for growing green bean in the plastic greenhouse of Souss Massa valley in South Morocco. Bifenthrin had a degradation of first-order kinetics, whereas that of levels for λ-cyhalothrin residue can not be interpreted by the use of a first order model.

Comparing the impacts of sediment-bound bifenthrin on aquatic macroinvertebrates in laboratory bioassays and field microcosms.

PubMed

Boyle, Rhianna L; Hoak, Molly N; Pettigrove, Vincent J; Hoffmann, Ary A; Long, Sara M

2016-11-01

We conducted two laboratory bioassays and two field microcosm exposures with bifenthrin (a synthetic pyrethroid) in order to evaluate the capacity of single-species laboratory bioassays to predict lethal and sublethal impacts on aquatic invertebrates in microcosms. For the laboratory species, Chironomus tepperi, larval survival was reduced by 24% at 53.66µg/g OC, while adult emergence was reduced at concentrations of 33.33µg/g OC and higher, with a 61% decrease at 77.78µg/g OC and no emergence at 126.67µg/g OC. The abundance of several other microcosm taxa was reduced in the microcosms at a similar concentration range (33.33µg/g OC and above), however there was no impact on the abundance of the congeneric species, Chironomus oppositus. The differences in impacts between test systems were potentially due to both differing species sensitivity and the interaction of ambient temperature with bifenthrin toxicity. Bifenthrin also was associated with early emergence of Chironomus sp. in both test systems, at concentrations of 10µg/g OC and higher (laboratory) and 43.90µg/g OC (microcosm), and with a significant decrease in the proportion of C. oppositus males in a microcosm. These findings indicate that while laboratory bioassays accurately predict many impacts in the field, there are some limitations to the predictive capacity of these tests. Copyright © 2016 Elsevier Inc. All rights reserved.

Field trial on the control effect of fipronil bait against German cockroaches

PubMed Central

Ree, Han-Il; Lee, In-Yong; Jeon, Soung-Hoo

2006-01-01

A field trial on the control effect of fipronil poison bait against German cockroaches (Blatella germanica) was carried out at different restaurant types in Sinchon, Seoul, Republic of Korea. Monitoring was performed applying food baited traps for 2 days per week. Reduction rates of German cockroaches by applying fipronil baits were 90.9% at Korean restaurants, 96.4% at Chinese restaurants, and 89.4% in beer hall kitchens after 4 weeks of the treatment. Overall average of the reduction rate was 93.9%. As the natural reduction rate at untreated restaurants was 11.5% after 4 weeks, a correction of the average reduction rate by applying the Abbot formula was 93.1%. PMID:16969066

Effects of an atrazine, metolachlor, and fipronil mixture on Hyalella azteca (Saussure) in a modified backwater wetland

USDA-ARS?s Scientific Manuscript database

We examined the toxicity mitigation efficiency of a hydrologically modified backwater wetland amended with a mixture of three pesticides, atrazine, metolachlor, and fipronil, using 96 h survival bioassays with Hyalella azteca. Significant H. azteca 96 h mortality occurred within the first two hours...

Establishing the discriminating concentration for permethrin and fipronil resistance in Rhipicephalus sanguineus (Latreille) (Acari:Ixodidae), the brown dog tick

USDA-ARS?s Scientific Manuscript database

Rhipicephalus sanguineus (Latreille), the brown dog tick, is a veterinary canine and urban pest. These ticks have been found to develop permethrin resistance and fipronil tolerance, two commonly used acaricides. We developed a discriminating concentration that can be used to rapidly detect permethri...

Effects produced by single and repeated dosages of Fipronil on the EEG of Long Evans Rats

EPA Science Inventory

We have previously reported that various classes of pesticides have different effects on the non- stimulus driven EEG after acute treatment, including fipronil (25 or 50 mg/kg) (Lyke et a!., Toxicologist, 2010, 2011, 2012, 2013). In this study, we compared the effects of single a...

Effect of soil type and exposure duration on mortality and transfer of chlorantraniliprole and fipronil on Formosan subterranean termites (Isoptera: Rhinotermitidae).

PubMed

Gautam, Bal K; Henderson, Gregg

2011-12-01

The uptake and potential transfer of chlorantraniliprole and fipronil by the Formosan subterranean termite, Coptotermes formosanus Shiraki, was investigated in the laboratory by using donor-recipient model bioassays. Two different types of substrates, sandy loam soil (18.6% organic matter) and sand (0.19% organic matter), were used to evaluate how these treated substrates impact the direct mortality and transfer efficiency of the two nonrepellent termiticides tested at different concentrations. Chlorantraniliprole exhibited a more delayed mortality on termites than fipronil in sand. In soil, chlorantraniliprole did not cause higher mortality to either donor or recipient termite at any of the tested concentrations during a 21-d test period when compared with controls. Compared with the controls, a greater number of donors died in the soil treated with fipronil at 14 h postinteraction, and higher death of recipients occurred at 21 d but only in the 60-ppm concentration tested. Our data showed that chlorantraniliprole performed best in substrate with low organic matter against

Evaluation of insecticides for protecting Southwestern ponderosa pines from attack by engraver beetles (Coleoptera: Curculionidae: Scolytinae).

PubMed

DeGomez, Tom E; Hayes, Christopher J; Anhold, John A; McMillin, Joel D; Clancy, Karen M; Bosu, Paul P

2006-04-01

Insecticides that might protect pine trees from attack by engraver beetles (Ips spp.) have not been rigorously tested in the southwestern United States. We conducted two field experiments to evaluate the efficacy of several currently and potentially labeled preventative insecticides for protecting high-value ponderosa pine, Pinus ponderosa Dougl ex. Laws., from attack by engraver beetles. Preventative sprays (0.19% permethrin [Permethrin Plus C]; 0.03, 0.06, and 0.12% bifenthrin [Onyx]; and 1.0 and 2.0% carbaryl [Sevin SL] formulations) and systemic implants (0.875 g per capsule acephate [Acecap] and 0.650 g per capsule dinotefuran) were assessed on bolts (sections of logs) as a surrogate for live trees for a period of 13 mo posttreatment. The pine engraver, Ips pini (Say), was the most common bark beetle found attacking control and treated bolts, but sixspined ips, Ips calligraphus (Germar), and Ips lecontei Swain also were present. After approximately 13 mo posttreatment in one experiment, the spray treatments with 2.0% carbaryl, 0.19% permethrin, and 0.06 or 0.12% bifenthrin prevented Ips attack on the bolts at a protection level of > or = 70%. The acephate and dinotefuran systemic insecticides, and the 0.03% bifenthrin spray, provided inadequate (< or = 36%) protection in this experiment. For the other experiment, sprayed applications of 1.0% carbaryl, 0.19% permethrin, and 0.06% bifenthrin prevented beetle attack at protection levels of > or = 90, > or = 80, and > or = 70%, respectively, when bolts were exposed to Ips beetle attack for approximately 9-15 wk posttreatment. The sprays with 0.19% permethrin and 0.06% bifenthrin also provided > or = 90% protection when bolts were exposed for approximately 15-54 wk posttreatment. We concluded that under the conditions tested, 1.0 and 2.0% carbaryl, 0.19% permethrin, and 0.06 and 0.12% binfenthrin were acceptable preventative treatments for protecting ponderosa pine from successful engraver beetle attack for one entire flight season in the U.S. Southwest.

Morphological alterations induced by boric acid and fipronil in the midgut of worker honeybee (Apis mellifera L.) larvae : Morphological alterations in the midgut of A. mellifera.

PubMed

da Silva Cruz, Aline; da Silva-Zacarin, Elaine C M; Bueno, Odair C; Malaspina, Osmar

2010-04-01

Morphological alterations, by means of histological and ultrastructural analysis, have been used to determine the effects of boric acid and fipronil on midgut tissues of honeybee worker, Apis mellifera L. larvae. In order to observe possible morphological alterations in the midgut, two groups of bioassays were performed. In the first one, the larvae were chronically treated with different concentrations of boric acid added to the food (1.0, 2.5 and 7.5 mg/g). In the second group, the larvae were fed with diets containing different concentrations of fipronil (0.1 and 1 microg/g) and compared with control groups without these chemical compounds. In the first bioassay, the larvae were collected on day 3 and in the second bioassay on day 4, when the mortality rate obtained in the toxicological bioassay was not very high. The larval midguts were removed and processed for morphological analyses using a light and transmission electron microscopy. We observed cytoplasmic vacuolizations, with the absence of autophagic vacuoles, and chromatinic compacting in most of the cells in the groups treated with pesticides. The morphological alterations were far greater in the larvae treated with boric acid than in the larvae treated with fipronil. Our data suggest that the midgut cell death observed was in response to boric acid and fipronil action. This study significantly improves the understanding of the toxicological effect of these insecticides from the ecotoxicological perspective.

Adaptation of in vitro bioassays for the diagnosis of resistance to Fipronil and Ivermectin in R. (B.) microplus

USDA-ARS?s Scientific Manuscript database

R. microplus represents the most important pathological constraint to livestock production in Brazil and Uruguay. The infestation of cattle by ticks is controlled by chemical applications on a regular basis. Fipronil and ivermectin have been widely used in recent years to the benefit of cattle produ...

Effect of vegetation on the longevity, mobility and activity of fipronil applied at the termiticidal rate in laboratory soil columns

Treesearch

Christopher Peterson

2010-01-01

BACKGROUND: Termiticides are applied at concentrations much higher than those used in agricultural settings. The longevity of fipronil has not yet been examined at the rates used for termite control, nor has the compound’s movement in the soil been addressed.

Dissipation and decontamination of bifenthrin residues in tomato (Lycopersicon esculentum Mill).

PubMed

Chauhan, Reena; Monga, Samriti; Kumari, Beena

2012-07-01

A field experiment was conducted at the Research Farm of CCS HAU, Hisar to study the dissipation and decontamination behavior of bifenthrin on tomato crop following the application of 25 g a.i ha(-1) (T(1)) and 50 g a.i ha(-1) (T(2)). Samples were collected periodically on the sampling days after applications. Residues were reached below detectable level of 0.005 mg kg(-1) on 10(th) day after application showing half-life period of 1.83 and 2.05 days at room temperature and 2.02 and 2.32 days under refrigerated condition for single and double dose, respectively. Processing was found effective in reducing the residues of bifenthrin in tomato fruits. Maximum reduction (42.10-45.23 %) was observed by washing + boiling followed by washing (16.66-19.04 %). Reduction was slightly less when samples were stored under refrigerated conditions as compared to room temperature conditions.

Differences in susceptibility of five cladoceran species to two systemic insecticides, imidacloprid and fipronil.

PubMed

Hayasaka, Daisuke; Korenaga, Tomoko; Suzuki, Kazutaka; Sánchez-Bayo, Francisco; Goka, Koichi

2012-03-01

Differences in susceptibility of five cladocerans to the neonicotinoid imidacloprid and the phenyl-pyrazole fipronil, which have been dominantly used in rice fields of Japan in recent years, were examined based on short-term (48-h), semi-static acute immobilization exposure tests. Additionally, we compared the species sensitivity distribution (SSD) patterns of both insecticides between two sets of species: the five tested cladocerans and all other aquatic organisms tested so far, using data from the ECOTOX database of U.S. Environmental Protection Agency (USEPA). The sensitivity of the test species to either imidacloprid or fipronil was consistent, spanning similar orders of magnitude (100 times). At the genus level, sensitivities to both insecticides were in the following descending order: Ceriodaphnia > Moina > Daphnia. A positive relationship was found between body lengths of each species and the acute toxicity (EC(50)) of the insecticides, in particular fipronil. Differences in SSD patterns of imidacloprid were found between the species groups compared, indicating that test cladocerans are much less susceptible than other aquatic species including amphibians, crustaceans, fish, insects, mollusks and worms. However, the SSD patterns for fipronil indicate no difference in sensitivity between cladocerans tested and other aquatic organisms despite the greater exposure, which overestimates the results, of our semi-static tests. From these results, Ceriodaphnia sp. should be considered as more sensitive bioindicators (instead of the standard Daphnia magna) for ecotoxicological assessments of aquatic ecosystems. In addition, we propose that ecotoxicity data associated with differences in susceptibility among species should be investigated whenever pesticides have different physicochemical properties and mode of action.

An update of the Worldwide Integrated Assessment (WIA) on systemic insecticides. Part 1: new molecules, metabolism, fate, and transport.

PubMed

Giorio, Chiara; Safer, Anton; Sánchez-Bayo, Francisco; Tapparo, Andrea; Lentola, Andrea; Girolami, Vincenzo; van Lexmond, Maarten Bijleveld; Bonmatin, Jean-Marc

2017-11-05

With the exponential number of published data on neonicotinoids and fipronil during the last decade, an updated review of literature has been conducted in three parts. The present part focuses on gaps of knowledge that have been addressed after publication of the Worldwide Integrated Assessment (WIA) on systemic insecticides in 2015. More specifically, new data on the mode of action and metabolism of neonicotinoids and fipronil, and their toxicity to invertebrates and vertebrates, were obtained. We included the newly detected synergistic effects and/or interactions of these systemic insecticides with other insecticides, fungicides, herbicides, adjuvants, honeybee viruses, and parasites of honeybees. New studies have also investigated the contamination of all environmental compartments (air and dust, soil, water, sediments, and plants) as well as bees and apicultural products, food and beverages, and the exposure of invertebrates and vertebrates to such contaminants. Finally, we review new publications on remediation of neonicotinoids and fipronil, especially in water systems. Conclusions of the previous WIA in 2015 are reinforced; neonicotinoids and fipronil represent a major threat worldwide for biodiversity, ecosystems, and all the services the latter provide.

Efficacy of fipronil-(S)-methoprene, metaflumizone combined with amitraz, and pyriprole commercial spot-on products in preventing Culex pipiens pipiens from feeding on dogs.

PubMed

Bouhsira, E; Fysikopoulos, A; Franc, M

2009-08-01

A controlled clinical trial was carried out to assess the effectiveness of pyriprole, metaflumizone combined with amitraz, and fipronil-(S)-methoprene commercial spot-on products in preventing adult female Culex pipiens pipiens from feeding on dogs. Twenty-four beagle dogs were tested for their attractiveness to the mosquitoes and ranked accordingly to produce four groups of equivalent sensitivity to mosquitoes; six were treated with the pyriprole spot-on, six with the metaflumizone combined with amitraz spot-on, six with the fipronil-(S)-methoprene spot-on, and six were left untreated. All the dogs were challenged with 50 unfed adult female Culex in cages for one hour seven days before the treatment, and one and seven days after it. The mosquitoes were checked for blood feeding after one hour and for mortality 24 hours after they had been released into the cages. There was a significant reduction in the number of engorged mosquitoes only with the fipronil-(S)-methoprene product and there were significantly more dead mosquitoes with this product and the pyriprole product, but their effects were too small for them to be recommended for use in a dirofilariosis prevention programme.

Simultaneous determination of three pesticides and their metabolites in unprocessed foods using ultraperformance liquid chromatography-tandem mass spectrometry.

PubMed

Rong, Lili; Wu, Xiaohu; Xu, Jun; Dong, Fengshou; Liu, Xingang; Pan, Xinglu; Du, Pengqiang; Wei, Dongmei; Zheng, Yongquan

2018-02-01

We have developed a rapid, multi-compound analytical method for measuring residues of the pesticides thiamethoxam and its metabolite, clothianidin; fipronil and its three metabolites, fipronil sulfone, fipronil sulfide, and fipronil desulfinyl; and pyraclostrobin in unprocessed foods (rice, corn, cucumbers, tomatoes, apples, and bananas) by ultra-performance liquid chromatography coupled to tandem mass spectrometry. Acetonitrile was used as the extraction solvent, and an octadecylsilane-dispersive SPE was used to clean up the analytes, which were then separated through a UPLC HSS T3 column connected to a tandem mass spectrometer via an electrospray ionisation source. The linearity of this method for the target analytes was excellent (R 2  ≥0.990) in the concentration range of 5-1000 μg kg -1 . The average recoveries of the seven compounds at concentrations of 10, 100, and 1000 μg kg -1 from six spiked matrix samples ranged from 73.6 to 110.6%, all with RSD values of ≤19.7%. The limit of quantification was 10 μg kg -1 . The method validated the effectiveness of the method for routine monitoring the residue of these pesticides and their metabolites in foods.

Residue analysis and persistence evaluation of fipronil and its metabolites in cotton using high-performance liquid chromatography-tandem mass spectrometry.

PubMed

Wu, Xiaohu; Yu, Yang; Xu, Jun; Dong, Fengshou; Liu, Xingang; Du, Pengqiang; Wei, Dongmei; Zheng, Yongquan

2017-01-01

A simple residue analytical method based on the QuEChERS approach and high-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) detection was developed for the analysis of fipronil and its three metabolites in cottonseed, cotton plant and soil. The average recoveries of four test compounds from all three matrices were 78.6-108.9% at the level of 0.005 to 0.5 mg/kg, with an RSD in the range of 0.6 to 13.7%. The limit of quantification (LOQ) of the four test compounds ranged from 0.005 to 0.01 mg/kg. The results of the residual dynamics experiments showed that fipronil dissipated rapidly in cotton plants and soil and that oxidation and photolysis were the main degradation pathways. Moreover, the bi-exponential models demonstrated a good fit of the measured data for fipronil in cotton plants and soil, with R2 in the range of 0.8989 to 0.9989. Furthermore, a total of 40 samples of cottonseed from Shandong Province were analyzed, and all of the samples were free from the four test compound residues.

Residue analysis and persistence evaluation of fipronil and its metabolites in cotton using high-performance liquid chromatography-tandem mass spectrometry

PubMed Central

Wu, Xiaohu; Yu, Yang; Xu, Jun; Dong, Fengshou; Liu, Xingang; Du, Pengqiang; Wei, Dongmei; Zheng, Yongquan

2017-01-01

A simple residue analytical method based on the QuEChERS approach and high-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) detection was developed for the analysis of fipronil and its three metabolites in cottonseed, cotton plant and soil. The average recoveries of four test compounds from all three matrices were 78.6–108.9% at the level of 0.005 to 0.5 mg/kg, with an RSD in the range of 0.6 to 13.7%. The limit of quantification (LOQ) of the four test compounds ranged from 0.005 to 0.01 mg/kg. The results of the residual dynamics experiments showed that fipronil dissipated rapidly in cotton plants and soil and that oxidation and photolysis were the main degradation pathways. Moreover, the bi-exponential models demonstrated a good fit of the measured data for fipronil in cotton plants and soil, with R2 in the range of 0.8989 to 0.9989. Furthermore, a total of 40 samples of cottonseed from Shandong Province were analyzed, and all of the samples were free from the four test compound residues. PMID:28291815

Susceptibility of Adult Mosquitoes to Insecticides in Aqueous Sucrose Baits

DTIC Science & Technology

2011-06-01

ingredients representative of five classes of insecticides (pyrethroids, phenylpyroles, pyrroles , neonicotinoids, and macrocyclic lactones) were...a 10% sucrose solution. Active ingredients representative of five classes of insecticides (pyrethroids, phenylpyroles, pyrroles , neonicotinoids, and...Triangle Park NC Pyrrole Chlorfenapyr Phantom® 21.45% BASF, Research Triangle Park NC Neonicotinoid Imidacloprid QuickBayt™ 0.5% Bayer

Sublethal effects of insecticides used in soybean on the parasitoid Trichogramma pretiosum.

PubMed

de Paiva, Ana Clara Ribeiro; Beloti, Vitor Hugo; Yamamoto, Pedro Takao

2018-05-01

To control crop pests, parasitoid wasps of the genus Trichogramma are one alternative to the use of insecticides. Since a wide variety of agrochemicals may be applied to the same crops, it is essential to assess the selectivity of insecticides used for pest control on Trichogramma pretiosum. Information on which insecticides are less harmful to T. pretiosum can improve biological control using this insect, an important tactic in IPM programs for field crops. This study aimed to determine the effects of insecticides on the pupal stage and on the parasitism capacity of T. pretiosum. Lambda-cyhalothrin + thiamethoxam were slightly harmful and chlorpyriphos was moderately harmful to the pupal stage, while acephate, chlorfenapyr and flubendiamide, although considered innocuous, affected the succeeding generations of wasps, with low emergence of F 1 . Chlorfenapyr, chlorpyriphos and lambda-cyhalothrin + thiamethoxam reduced the parasitism, and acephate had a deleterious effect on the generation that contacted the insecticide residue. For an effective IPM program, it is important to apply selective insecticides. Further studies are needed to determine the selectivity of these insecticides under field conditions.

Survival, growth, and body residues of Hyalella azteca (Saussure) exposed to fipronil contaminated sediments from non-vegetated and vegetated microcosms

USDA-ARS?s Scientific Manuscript database

We assessed chronic effects of fipronil and metabolite contaminated sediments from non-vegetated and Thallia dealbata vegetated wetland microcosms on Hyalella azteca during wet and dry exposures. Mean sediment concentrations (ng g-1) ranged from 0.72-1.26, 0.01-0.69, 0.07-0.23, and 0.49-7.87 for fip...

Comparative efficacy on dogs of a single topical treatment with the pioneer fipronil/(S)-methoprene and an oral treatment with spinosad against Ctenocephalides felis

PubMed Central

Beugnet, F.; Doyle, V.; Murray, M.; Chalvet-Monfray, K.

2011-01-01

In the study reported here, the pioneer fipronil/(S)-methoprene topical product (FRONTLINE® PLUS, Merial Limited, Duluth, GA) was compared to the oral spinosad product (COMFORTIS® Elanco, Greenfield, IN) for efficacy against adult fleas and preventing egg production. The product presentations, doses and labelling were the one applicable in the USA. Using a standard protocol, 200 cat fleas of mixed sex were applied to dogs on Days 1, 7, 14, 21, 28, 35, and 42. Dogs were combed to remove fleas 24 hours post-infestation, the fleas were counted, collected, and then reapplied to each dog following completion of their respective count. At 48 hours post-infestation, comb counts were performed and fleas were removed. No fleas were collected from any dog in the fipronil/(S)-methoprene group at any 24 or 48 hours post-infestation assessment throughout the six weeks study, yielding a preventive efficacy of 100%. For the spinosad treatment, efficacy was 100% at 24 hours and 48 hours through Day 16, and thereafter declined. The results observed in the spinosad-treated dogs were highly variable between animals. At the 24 and 48 hours counts following the Day 21 infestation, only five of eight spinosad-treated dogs (62.5%) were flea-free. Following the Day 28 infestation, spinosad efficacy fell to 85% and 89%, for the 24 hours and 48 hours counts, and only two dogs (25%) were flea free, compared to 100% flea-free dogs in the fipronil/(S)-methoprene group. No fleas were collected from the fipronil/(S)- methoprene treated dogs throughout the entire study, therefore, no eggs were collected at any time from any dog in the group. However, in the spinosad group adult fleas were found on dogs starting on Day 21 and by Day 30, 42 eggs were collected from one dog that had 107 adult fleas counted at 48 hours. At Day 37 and Day 49, more than 100 eggs were collected from each dog in the spinosad-treated and control groups. PMID:22091463

Concentration-Response and Residual Activity of Insecticides to Control Herpetogramma phaeopteralis (Lepidoptera: Crambidae) in St. Augustinegrass.

PubMed

Tofangsazi, Nastaran; Cherry, Ron H; Beeson, Richard C; Arthurs, Steven P

2015-04-01

Tropical sod webworm, Herpetogramma phaeopteralis Guenée, is an important pest of warm-season turfgrass in the Gulf Coast states of the United States, the Caribbean Islands, and Central America. Current control recommendations rely on topical application of insecticides against caterpillars. The objective of this study was to generate resistance baseline data of H. phaeopteralis to six insecticide classes. Residual activity of clothianidin, chlorantraniliprole, and bifenthrin was also compared under field conditions in Central Florida. Chlorantraniliprole was the most toxic compound tested (LC50 value of 4.5 ppm), followed by acephate (8.6 ppm), spinosad (31.1 ppm), clothianidin (46.6 ppm), bifenthrin (283 ppm) and Bacillus thuringiensis kurstaki, (342 ppm). In field tests, all compounds at label rates were effective (≥94% mortality of larvae exposed to fresh residues). However, a more rapid decline in activity of clothianidin and bifenthrin was observed compared with chlorantraniliprole. Clothianidin had no statistically detectable activity after 4 wk post-application in spring and the fall, and bifenthrin had no detectable activity after 3 wk in the spring and the fall. However, chlorantraniliprole maintained significant activity (≥84% mortality) compared with other treatments throughout the 5-wk study period. This study provides new information regarding the relative toxicities and persistence of current insecticides used for H. phaeopteralis and other turfgrass caterpillars. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Development, validation, and application of a method for the GC-MS analysis of fipronil and three of its degradation products in samples of water, soil, and sediment.

PubMed

de Toffoli, Ana L; da Mata, Kamilla; Bisinoti, Márcia C; Moreira, Altair B

2015-01-01

A method for the identification and quantification of pesticide residues in water, soil, and sediment samples has been developed, validated, and applied for the analysis of real samples. The specificity was determined by the retention time and the confirmation and quantification of analyte ions. Linearity was demonstrated over the concentration range of 20 to 120 µg L(-1), and the correlation coefficients varied between 0.979 and 0.996, depending on the analytes. The recovery rates for all analytes in the studied matrix were between 86% and 112%. The intermediate precision and repeatability were determined at three concentration levels (40, 80, and 120 µg L(-1)), with the relative standard deviation for the intermediate precision between 1% and 5.3% and the repeatability varying between 2% and 13.4% for individual analytes. The limits of detection and quantification for fipronil, fipronil sulfide, fipronil-sulfone, and fipronil-desulfinyl were 6.2, 3.0, 6.6, and 4.0 ng L(-1) and 20.4, 9.0, 21.6, and 13.0 ng L(-1), respectively. The method developed was used in water, soil, and sediment samples containing 2.1 mg L(-1) and 1.2% and 5.3% of carbon, respectively. The recovery of pesticides in the environmental matrices varied from 88.26 to 109.63% for the lowest fortification level (40 and 100 µg kg(-1)), from 91.17 to 110.18% for the intermediate level (80 and 200 µg kg(-1)), and from 89.09 to 109.82% for the highest fortification level (120 and 300 µg kg(-1)). The relative standard deviation for the recovery of pesticides was under 15%.

Assessment of serum biomarkers in rats after exposure to pesticides of different chemical classes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moser, Virginia C., E-mail: Moser.ginger@epa.gov; Stewart, Nicholas; Freeborn, Danielle L.

There is increasing emphasis on the use of biomarkers of adverse outcomes in safety assessment and translational research. We evaluated serum biomarkers and targeted metabolite profiles after exposure to pesticides (permethrin, deltamethrin, imidacloprid, carbaryl, triadimefon, fipronil) with different neurotoxic actions. Adult male Long–Evans rats were evaluated after single exposure to vehicle or one of two doses of each pesticide at the time of peak effect. The doses were selected to produce similar magnitude of behavioral effects across chemicals. Serum or plasma was analyzed using commercial cytokine/protein panels and targeted metabolomics. Additional studies of fipronil used lower doses (lacking behavioral effects),more » singly or for 14 days, and included additional markers of exposure and biological activity. Biomarker profiles varied in the number of altered analytes and patterns of change across pesticide classes, and discriminant analysis could separate treatment groups from control. Low doses of fipronil produced greater effects when given for 14 days compared to a single dose. Changes in thyroid hormones and relative amounts of fipronil and its sulfone metabolite also differed between the dosing regimens. Most cytokine changes reflected alterations in inflammatory responses, hormone levels, and products of phospholipid, fatty acid, and amino acid metabolism. These findings demonstrate distinct blood-based analyte profiles across pesticide classes, dose levels, and exposure duration. These results show promise for detailed analyses of these biomarkers and their linkages to biological pathways. - Highlights: • Pesticides typical of different classes produced distinct patterns of change in biomarker panels. • Based on the panels used, alterations suggest impacts on immune, metabolism, and homeostasis functions. • Some changes may reflect actions on neurotransmitter systems involved in immune modulation. • Fipronil effects on thyroid and kinetics differed with acute and repeated administration.« less

MicroRNA-155 targets cyb561d2 in zebrafish in response to fipronil exposure.

PubMed

Huang, Hannian; Zhang, Kai; Zhou, Yongyong; Ding, Xianfeng; Yu, Liang; Zhu, Guonian; Guo, Jiangfeng

2016-07-01

MicroRNAs (miRNAs), which are a class of small noncoding RNAs, can modulate the expression of many protein-coding genes when an organism is exposed to an environmental chemical. We previously demonstrated that miR-155 was significantly downregulated in adult zebrafish (Danio rerio) in response to fipronil (5-amino-1-[2,6-dichloro-4-(trifluoromethyl) phenyl]-4-[(trifluoromethyl) sulphinyl]-1H-pyrazole-3-carbonitrile) exposure. However, the regulation of this miRNA's predicted target gene cyb561d2, which is a member of the cytochrome b561 (cyt b561) family involved in electron transfer, cell defence, and chemical stress, has not been experimentally validated to date. In this study, we evaluated the effects of fipronil on miR-155 and cyb561d2 in zebrafish. The expression of miR-155 was downregulated, whereas cyb561d2 was upregulated in both mRNA and protein level in a dose-dependent manner upon stimulation of fipronil. The dual luciferase report assay demonstrated that miR-155 interacted with cyb561d2 3'-untranslated regions (3'-UTR). The expression of cyb561d2 was reduced in both mRNA and protein levels when ZF4 cells were transfected with an miR-155 mimic, whereas its expression levels of both mRNA and protein were increased when endogenous miR-155 was inhibited by transfection with an miR-155 inhibitor. The results improved our understanding of molecular mechanism of toxicity upon fipronil exposure, and presents miR-155 as a potential novel toxicological biomarker for chemical exposure. © 2014 Wiley Periodicals, Inc. Environ Toxicol 31: 877-886, 2016. © 2014 Wiley Periodicals, Inc.

Rainfastness and residual activity of insecticides to control Japanese beetle (Coleoptera: scarabaeidae) in Grapes.

PubMed

Hulbert, Daniel; Isaacs, Rufus; Vandervoort, Christine; Wise, John C

2011-10-01

Field-based bioassays and residue profile analysis were used to determine the relative toxicity, rainfastness, and field degradation over time of five insecticides from five insecticide classes on adult Japanese beetles, Popillia japonica Newman (Coleoptera: Scarabaeidae), in grapes, Vitis labrusca L. Bioassays assessed Japanese beetle condition as alive, knockdown, or immobile when exposed for 24 h or 7-d field-aged residues of phosmet, carbaryl, bifenthrin, thiamethoxam, or indoxacarb after 0, 12.7, or 25.4 mm of rain had been simulated. We found that the two most toxic insecticides to Japanese beetle were phosmet and carbaryl, followed by bifenthrin, thiamethoxam, and then indoxacarb. The efficacy of phosmet decreased because of rainfall, but not because of field aging. The efficacy of carbaryl decreased because of rainfall and field aging. The efficacies of bifenthrin and thiamethoxam were not affected by rainfall but decreased because of field aging. The efficacy of indoxacarb was not affected by rainfall or field aging. This study will help vineyard managers make informed decisions on when reapplications of insecticides are needed with the aim of improving integrated pest management programs.

Comparison of ingestion and topical application of insecticides against the common bed bug, Cimex lectularius (Hemiptera: Cimicidae)

PubMed Central

Sierras, Angela; Schal, Coby

2016-01-01

Background The global prevalence of Cimex lectularius infestations has challenged current intervention efforts, as pyrethroid resistance has become ubiquitous, availability of labeled insecticides for bed bugs is limited, and non-chemical treatment options, such as heat, are often unaffordable. We evaluated representative insecticides toward the goal of developing a novel, ingestible liquid bait for hematophagous arthropods. Results LC50 values were estimated for adult males and first instar nymphs of an insecticide-susceptible strain for abamectin, clothianidin, fipronil and indoxacarb, after ingestion from an in vitro feeder. LD50 values were calculated based on the ingested blood volume. Ingested abamectin, clothianidin and fipronil caused rapid mortality in both life stages. Fipronil was ∼43-fold more effective by ingestion than by topical application. Indoxacarb and its bioactive metabolite decarbomethoxyllated JW062 (DCJW) were ineffective at causing bed bug mortality even at concentrations as high as 1000 ng mL−1 blood. Conclusions Fipronil, clothianidin and abamectin have potential for being incorporated into a liquid bait for bed bug control; indoxacarb and DCJW were not effective. Bed bugs are a good candidate for an ingestible liquid bait because systemic formulations generally require less active ingredient than residual sprays, they remain contained and more effectively target hematophagous arthropods. PMID:27766740

Comparison of ingestion and topical application of insecticides against the common bed bug, Cimex lectularius (Hemiptera: Cimicidae).

PubMed

Sierras, Angela; Schal, Coby

2017-03-01

The global prevalence of Cimex lectularius infestations has challenged current intervention efforts, as pyrethroid resistance has become ubiquitous, availability of labeled insecticides for bed bugs is limited, and non-chemical treatment options, such as heat, are often unaffordable. We evaluated representative insecticides toward the goal of developing a novel, ingestible liquid bait for hematophagous arthropods. LC 50 values were estimated for adult males and first instar nymphs of an insecticide-susceptible strain for abamectin, clothianidin, fipronil and indoxacarb, after ingestion from an artificial feeder. LD 50 values were calculated based on the ingested blood volume. Ingested abamectin, clothianidin and fipronil caused rapid mortality in both life stages. Fipronil was ∼43-fold more effective by ingestion than by topical application. Indoxacarb and its bioactive metabolite decarbomethoxylated JW062 (DCJW) were ineffective at causing bed bug mortality even at concentrations as high as 1000 ng mL -1 blood. Fipronil, clothianidin and abamectin have potential for being incorporated into a liquid bait for bed bug control; indoxacarb and DCJW were not effective. Bed bugs are a good candidate for an ingestible liquid bait because systemic formulations generally require less active ingredient than residual sprays, they remain contained and more effectively target hematophagous arthropods. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

[Comparative efficacy of two topical formulations containing 10% fipronil on the control of Ctenocephalides felis felis on cats].

PubMed

Tancredi, Michelle Godan de Freitas; Correia, Thaís Ribeiro; Ribeiro, Francisco de Assis; Botelho, Maria Clara da Silva Negreiros; Tavares, Pedro Vianna; Scott, Fabio Barbour; Verocai, Guilherme Gomes; Coumendouros, Katherina

2009-01-01

The goal of the present study was to evaluate the comparative efficacy of two topical formulations containing 10% fipronil on the control of Ctenocephalides felis felis on cats. The trial was performed at the Laboratory of Experimental Chemotherapy in Veterinary Parasitology from the Department of Animal Parasitology of the Institute of Veterinary of the Universidade Federal Rural do Rio de Janeiro. Eighteen mixed-breed cats were divided in three groups of six animals each. One group remained without treatment (control). The other groups received as treatment the two topical formulations, a commercial reference and the novel one, both containing 10% fipronil. Treated animals received 0.5 mL of product along their cervical region. Cats were infested on days - 2, +5, +12, +19, +26 and +33. Evaluations were made using the "comb test". The first one was undertaken 4 days after the initial infestation (day +2), and others 48 hours after following infestations (days +7, +14, +21, +28 and + 35). Both tested formulations had satisfactory efficacy until day + 35. No differences were observed comparing the efficacy levels between both formulations throughout the experimental period. The novel topical 10% fipronil formulation presented desirable efficacy on the control of C. f. felis on cats.

Efficacy of a fipronil bait in reducing the number of fleas (Oropsylla spp.) infesting wild black-tailed prairie dogs.

PubMed

Poché, David M; Hartman, Daniel; Polyakova, Larisa; Poché, Richard M

2017-06-01

Bubonic plague (Yersinia pestis) is a deadly zoonosis with black-tailed prairie dogs (Cynomys ludovicianus) as a reservoir host in the United States. Systemic insecticides are a promising means of controlling the vectors, Oropsylla spp. fleas, infesting these prairie dogs, subsequently disrupting the Y. pestis cycle. The objective of this study was to conduct a field trial evaluating the efficacy of a grain rodent bait containing fipronil (0.005%) against fleas infesting prairie dogs. The study was performed in Larimer County, CO, where bait was applied to a treatment area containing a dense prairie dog population, three times over a three-week period. Prairie dogs were captured and combed for fleas during four study periods (pre-, mid-, 1 st post-, and 2 nd post-treatment). Results indicated the use of bait containing fipronil significantly reduced flea burden. The bait containing fipronil was determined to reduce the mean number of fleas per prairie dog >95% for a minimum of 52 days post-initial treatment application and 31 days post-final treatment application. These results suggest the potential for this form of treatment to reduce flea population density on prairie dogs, and subsequently plague transmission, among mammalian hosts across the United States and beyond. © 2017 The Society for Vector Ecology.

Natural enemies of Atta vollenweideri (Hymenoptera: Formicidae) leaf-cutter ants negatively affected by synthetic pesticides, chlorpyrifos and fipronil.

PubMed

Guillade, Andrea C; Folgarait, Patricia J

2014-02-01

In southern South America, Ada vollenweideri Forel (Hymenoptera: Formicidae) is a significant pest of several crops and forestry, also considered to reduce the carrying capacity of pastures. The most usual control method used in Latin America is the application of synthetic pesticides, mainly chlorpyrifos and fipronil. However, no studies have assessed the effects of these agrochemicals on natural enemies of ants. We aimed to evaluate the efficiency of these pesticides on leaf-cutter ants' control and to test their effect on phorid fly parasitoids. Chlorpyrifos failed to exert complete control over ant colonies in the field and was gravely detrimental to specific parasitoids, reducing their percentage of parasitism, pupal survivorship, and adult longevity. Fipronil, however, exerted complete control over the treated colonies. Laboratory tests using both pesticides, either on ants from foraging trails or on pupariae, showed that chlorpyrifos and fipronil decreased larval and pupal survivorship, as well as adult longevity of parasitoids, in comparison to controls. In conclusion, these pesticides will likely affect parasitoids with regard to their reproductive capacity, leading to the decreased levels of natural parasitism observed in the field after treatments. We discuss why neither pesticide should be taken into account for integrated pest management programs.

Efficacy of fipronil, amitraz and (S)-methoprene combination spot-on for dogs against adult dog fleas (Ctenocephalides canis, Curtis, 1826).

PubMed

Bouhsira, Emilie; Yoon, Stephen S; Roques, Martine; Manavella, Coralie; Vermot, Solange; Cramer, Luiz G; Ollagnier, Catherine; Franc, Michel

2011-07-15

A novel spot-on formulation combining fipronil, amitraz and (S)-methoprene (CERTIFECT™, Merial Limited, GA, USA) was evaluated in adult Beagle dogs in a study to determine its adulticidal efficacy against the dog flea (Ctenocephalides canis, Curtis, 1826). Sixteen dogs were randomly allocated to treatment groups: 8 dogs served as untreated controls, and 8 dogs were treated once. Treatment consisted of applying a new combination formulation to deliver at least 6.7mg fipronil/kg body weight (bw), 8.0mg amitraz/kg bw, and 6.0mg (S)-methoprene/kg bw. The combination was designed to enhance the efficacy against ticks of the original fipronil/(S)-methoprene combination. Each dog was infested with 100 adult unfed dog fleas within 24h prior to treatment and then at weekly intervals for 8 weeks after treatment. At 24h after treatment or after each subsequent infestation, each dog was combed thoroughly to remove live fleas to be counted. A single treatment with CERTIFECT provided excellent knock-down of fleas within 24h after treatment and controlled re-infestations for up to 7 weeks (efficacy ≥96.5%, p<0.05). Copyright © 2011 Elsevier B.V. All rights reserved.

Systemic insecticides (neonicotinoids and fipronil): trends, uses, mode of action and metabolites.

PubMed

Simon-Delso, N; Amaral-Rogers, V; Belzunces, L P; Bonmatin, J M; Chagnon, M; Downs, C; Furlan, L; Gibbons, D W; Giorio, C; Girolami, V; Goulson, D; Kreutzweiser, D P; Krupke, C H; Liess, M; Long, E; McField, M; Mineau, P; Mitchell, E A D; Morrissey, C A; Noome, D A; Pisa, L; Settele, J; Stark, J D; Tapparo, A; Van Dyck, H; Van Praagh, J; Van der Sluijs, J P; Whitehorn, P R; Wiemers, M

2015-01-01

Since their discovery in the late 1980s, neonicotinoid pesticides have become the most widely used class of insecticides worldwide, with large-scale applications ranging from plant protection (crops, vegetables, fruits), veterinary products, and biocides to invertebrate pest control in fish farming. In this review, we address the phenyl-pyrazole fipronil together with neonicotinoids because of similarities in their toxicity, physicochemical profiles, and presence in the environment. Neonicotinoids and fipronil currently account for approximately one third of the world insecticide market; the annual world production of the archetype neonicotinoid, imidacloprid, was estimated to be ca. 20,000 tonnes active substance in 2010. There were several reasons for the initial success of neonicotinoids and fipronil: (1) there was no known pesticide resistance in target pests, mainly because of their recent development, (2) their physicochemical properties included many advantages over previous generations of insecticides (i.e., organophosphates, carbamates, pyrethroids, etc.), and (3) they shared an assumed reduced operator and consumer risk. Due to their systemic nature, they are taken up by the roots or leaves and translocated to all parts of the plant, which, in turn, makes them effectively toxic to herbivorous insects. The toxicity persists for a variable period of time-depending on the plant, its growth stage, and the amount of pesticide applied. A wide variety of applications are available, including the most common prophylactic non-Good Agricultural Practices (GAP) application by seed coating. As a result of their extensive use and physicochemical properties, these substances can be found in all environmental compartments including soil, water, and air. Neonicotinoids and fipronil operate by disrupting neural transmission in the central nervous system of invertebrates. Neonicotinoids mimic the action of neurotransmitters, while fipronil inhibits neuronal receptors. In doing so, they continuously stimulate neurons leading ultimately to death of target invertebrates. Like virtually all insecticides, they can also have lethal and sublethal impacts on non-target organisms, including insect predators and vertebrates. Furthermore, a range of synergistic effects with other stressors have been documented. Here, we review extensively their metabolic pathways, showing how they form both compound-specific and common metabolites which can themselves be toxic. These may result in prolonged toxicity. Considering their wide commercial expansion, mode of action, the systemic properties in plants, persistence and environmental fate, coupled with limited information about the toxicity profiles of these compounds and their metabolites, neonicotinoids and fipronil may entail significant risks to the environment. A global evaluation of the potential collateral effects of their use is therefore timely. The present paper and subsequent chapters in this review of the global literature explore these risks and show a growing body of evidence that persistent, low concentrations of these insecticides pose serious risks of undesirable environmental impacts.

Evaluation of the prophylactic effect and curative efficacy of fipronil 1% pour on (Topline) on post-castration scrotal myiasis caused by Cochliomyia hominivorax in cattle.

PubMed

Lima, W S; Malacco, M A F; Bordin, E L; Oliveira, E L

2004-11-10

A field trial was carried out during a summer-fall period on a commercial beef cattle farm in Minas Gerais State, located in the Southeast of Brazil. In order to evaluate the prophylactic effect and the curative efficacy of fipronil in a 1% solution, 200 Zebu crossbred bulls, with ages varying from 20 to 30 months and weights from 233 to 362 kg, were selected. The bulls were assigned by ranked pair to an untreated control group (A) or to a treated group (B), resulting in 100 animals per group. All experimental animals were surgically castrated on day 0, following routine procedures. After castration all animals in the group B were treated with 10 mg/kg bw of a 1% fipronil solution, topically on the dorsal mid-line. The wounds were individually inspected on days: 2, 4, 7, 10, 14, 17, 21, 28 and 35. After castration the animals were naturally exposed to Cochliomyia hominivorax and remained in the same pasture throughout the trial. Among the animals in the control group, 83 were observed to harbor C. hominivorax eggs, with a total of 97 ovipositions, and among those 73 animals had active myiasis. In group B (fipronil 1%), 66 animals showed C. hominivorax eggs, with 92 ovipositions and five animals with active myiasis. Most ovipositions and active myiasis were detected until seven days post-castration for both groups. Wound parasite infestation evidenced bleeding, serous purulent exudation and presence of active C. hominivorax larvae. Treatment with fipronil 1% had a prophylactic effect on scrotal wounds against the development of C. hominivorax larvae in more than 95% of the treated animals for up to 17 days after castration. The treatment showed partial protection of 66% and 50% on days 21 and 28 post-treatment (pt), respectively. Three animals from the control group and one from the treated group showed active screwworms on day 21 pt, and one animal from the treated group and two from the control group also presented C. hominivorax larvae on scrotal wounds on day 28 pt. By the end of the observation period (day 35 pt), the castration wound had healed in all animals. All experimental animals presenting scrotal wounds infested with C. hominivorax larvae were treated with a 1% pour-on formulation of fipronil, on the same day that infestation was observed. Active C. hominivorax larvae were not seen during the monitoring period immediately after treatment. The curative efficacy of fipronil 1% against C. hominivorax larvae infestation in castration wounds was 100%.

Influence of sediment chemistry and sediment toxicity on macroinvertebrate communities across 99 wadable streams of the Midwestern USA

USGS Publications Warehouse

Moran, Patrick W.; Nowell, Lisa H.; Kemble, Nile E.; Mahler, Barbara J.; Waite, Ian R.; Van Metre, Peter C.

2017-01-01

Simultaneous assessment of sediment chemistry, sediment toxicity, and macroinvertebrate communities can provide multiple lines of evidence when investigating relations between sediment contaminants and ecological degradation. These three measures were evaluated at 99 wadable stream sites across 11 states in the Midwestern United States during the summer of 2013 to assess sediment pollution across a large agricultural landscape. This evaluation considers an extensive suite of sediment chemistry totaling 274 analytes (polycyclic aromatic hydrocarbons, organochlorine compounds, polychlorinated biphenyls, polybrominated diphenyl ethers, trace elements, and current-use pesticides) and a mixture assessment based on the ratios of detected compounds to available effects-based benchmarks. The sediments were tested for toxicity with the amphipod Hyalella azteca (28-d exposure), the midge Chironomus dilutus (10-d), and, at a few sites, with the freshwater mussel Lampsilis siliquoidea (28-d). Sediment concentrations, normalized to organic carbon content, infrequently exceeded benchmarks for aquatic health, which was generally consistent with low rates of observed toxicity. However, the benchmark-based mixture score and the pyrethroid insecticide bifenthrin were significantly related to observed sediment toxicity. The sediment mixture score and bifenthrin were also significant predictors of the upper limits of several univariate measures of the macroinvertebrate community (EPT percent, MMI (Macroinvertebrate Multimetric Index) Score, Ephemeroptera and Trichoptera richness) using quantile regression. Multivariate pattern matching (Mantel-like tests) of macroinvertebrate species per site to identified contaminant metrics and sediment toxicity also indicate that the sediment mixture score and bifenthrin have weak, albeit significant, influence on the observed invertebrate community composition. Together, these three lines of evidence (toxicity tests, univariate metrics, and multivariate community analysis) suggest that elevated contaminant concentrations in sediments, in particular bifenthrin, is limiting macroinvertebrate communities in several of these Midwest streams.

Vegetated agricultural drainage ditches for the mitigation of pyrethroid-associated runoff.

PubMed

Bennett, Erin R; Moore, Matthew T; Cooper, Charles M; Smith, Sammie; Shields, F Douglas; Drouillard, Ken G; Schulz, Ralf

2005-09-01

Drainage ditches are indispensable components of the agricultural production landscape. A benefit of these ditches is contaminant mitigation of agricultural storm runoff. This study determined bifenthrin and lambda-cyhalothrin (two pyrethroid insecticides) partitioning and retention in ditch water, sediment, and plant material as well as estimated necessary ditch length required for effective mitigation. A controlled-release runoff simulation was conducted on a 650-m vegetated drainage ditch in the Mississippi Delta, USA. Bifenthrin and lambda-cyhalothrin were released into the ditch in a water-sediment slurry. Samples of water, sediment, and plants were collected and analyzed for pyrethroid concentrations. Three hours following runoff initiation, inlet bifenthrin and lambda-cyhalothrin water concentrations ranged from 666 and 374 microg/L, respectively, to 7.24 and 5.23 microg/L at 200 m downstream. No chemical residues were detected at the 400-m sampling site. A similar trend was observed throughout the first 7 d of the study where water concentrations were elevated at the front end of the ditch (0-25 m) and greatly reduced by the 400-m sampling site. Regression formulas predicted that bifenthrin and lambda-cyhalothrin concentrations in ditch water were reduced to 0.1% of the initial value within 280 m. Mass balance calculations determined that ditch plants were the major sink and/or sorption site responsible for the rapid aqueous pyrethroid dissipation. By incorporating vegetated drainage ditches into a watershed management program, agriculture can continue to decrease potential non-point source threats to downstream aquatic receiving systems. Overall results of this study illustrate that aquatic macrophytes play an important role in the retention and distribution of pyrethroids in vegetated agricultural drainage ditches.

Knock-down and speed of kill of a combination of fipronil and permethrin for the prevention of Ctenocephalides felis flea infestation in dogs.

PubMed

Halos, Lénaïg; Fourie, Josephus J; Fankhauser, Becky; Beugnet, Frederic

2016-02-02

A topical combination of fipronil + permethrin (Frontline Tri-Act/Frontect, Merial) has recently been developed to control fleas, ticks, mosquitoes, sandflies and stable flies on dogs. Two studies were conducted to assess its speed of kill and knock-down effect on Ctenocephalides felis fleas. The combination was compared to either fipronil alone or to a combination of permethrin, dinotefuran, and pyriproxyfen, In each study, 18 dogs were randomly allocated to one of three groups: (Group 1: untreated dog; Group 2: treated once on D0 with the combination of fipronil and permethrin; Group 3: treated once on D0 either with fipronil alone (study 1) or with a combination of permethrin, dinetofuran and pyriproxyfen (study 2)). Each dog was infested with 100 unfed adult C. felis fleas on Days 2 (study 2), 7, 14, 21 and 28. Fleas were collected from dogs at 1 h and 12 h post- infestations (PI) (study 1) or at 2 h and 6 h PI (study 2) to assess efficacy and from collection pans underneath cages 1 h (study 1) or 5 min (study 2) PI to assess knock-down effect. All treated dogs had significantly (p ≤ 0.01) lower flea counts than untreated dogs at every time point in both studies. For a whole month, a significant knock-down effect against infesting fleas is obtained in five minutes PI with the combination of permethrin and fipronil. Complete efficacy (>95%) was achieved in 1 h (study 1) or 2 h (study 2) PI for 14 days and by 6 h PI for all challenges conducted throughout the month. Efficacy remains >85% at 2 h PI for the whole month. A significantly higher efficacy of the fipronil + permethrin combination compared to other treatments was demonstrated at the earliest time points for the month (1 h knock-down effect and insecticidal efficacy compared to fipronil alone; 5 min knock-down effect compared to the combination of permethrin + dinetofuran + pyriproxyfen). The rapid flea knock-down effect and speed of kill demonstrated by the spot on combination of fipronil + permethrin provide a reliable strategy against flea infestations in dogs.

Localized treatments using commercial dust and liquid formulations of fipronil against Coptotermes formosanus (Isoptera: Rhinotermitidae) in the laboratory.

PubMed

Gautam, Bal K; Henderson, Gregg; Wang, Cai

2014-04-01

Use of proper application methods and formulations of termiticides are important to reduce their negative impact to the environment. In this study, we conducted laboratory experiments to determine the effect of localized treatments with commercial dust and liquid formulations of fipronil against Formosan subterranean termites, Coptotermes formosanus Shiraki. The test arena consisted of a specially designed 16-chambered structure with a center chamber connected to 5 foraging chambers that themselves were connected to 10 additional foraging chambers. One peripheral chamber received a liquid or dust treatment and termites were released in the center chamber. Results showed that >91% of the termites were dead within the 9-d test period despite the localized treatment of only 1 foraging chamber. Termites that were still alive after 9 d were transferred to an untreated dish and held for 10 more days. The majority of those termites were dead and the rest were moribund on day 19. Regardless of the specific dish treated, both formulations of fipronil were found to be highly efficacious. Termites did not exhibit repellency to either formulation. Our results suggest that localized (or spot) treatment with either commercially available dust or liquid formulations of fipronil can be a viable option for control of a termite infestation where complete soil drenching is not desirable. © 2013 Institute of Zoology, Chinese Academy of Sciences.

Influence of the RDL A301S mutation in the brown planthopper Nilaparvata lugens on the activity of phenylpyrazole insecticides.

PubMed

Garrood, William T; Zimmer, Christoph T; Gutbrod, Oliver; Lüke, Bettina; Williamson, Martin S; Bass, Chris; Nauen, Ralf; Emyr Davies, T G

2017-10-01

We discovered the A301S mutation in the RDL GABA-gated chloride channel of fiprole resistant rice brown planthopper, Nilaparvata lugens populations by DNA sequencing and SNP calling via RNASeq. Ethiprole selection of two field N. lugens populations resulted in strong resistance to both ethiprole and fipronil and resulted in fixation of the A301S mutation, as well as the emergence of another mutation, Q359E in one of the selected strains. To analyse the roles of these mutations in resistance to phenylpyrazoles, three Rdl constructs: wild type, A301S and A301S+Q359E were expressed in Xenopus laevis oocytes and assessed for their sensitivity to ethiprole and fipronil using two-electrode voltage-clamp electrophysiology. Neither of the mutant Rdl subtypes significantly reduced the antagonistic action of fipronil, however there was a significant reduction in response to ethiprole in the two mutated subtypes compared with the wild type. Bioassays with a Drosophila melanogaster strain carrying the A301S mutation showed strong resistance to ethiprole but not fipronil compared to a strain without this mutation, thus further supporting a causal role for the A301S mutation in resistance to ethiprole. Homology modelling of the N. lugens RDL channel did not suggest implications of Q359E for fiprole binding in contrast to A301S located in transmembrane domain M2 forming the channel pore. Synergist bioassays provided no evidence of a role for cytochrome P450s in N. lugens resistance to fipronil and the molecular basis of resistance to this compound remains unknown. In summary this study provides strong evidence that target-site resistance underlies widespread ethiprole resistance in N. lugens populations. Copyright © 2017 Rothamsted Research Ltd. Published by Elsevier Inc. All rights reserved.

Effects of neonicotinoids and fipronil on non-target invertebrates.

PubMed

Pisa, L W; Amaral-Rogers, V; Belzunces, L P; Bonmatin, J M; Downs, C A; Goulson, D; Kreutzweiser, D P; Krupke, C; Liess, M; McField, M; Morrissey, C A; Noome, D A; Settele, J; Simon-Delso, N; Stark, J D; Van der Sluijs, J P; Van Dyck, H; Wiemers, M

2015-01-01

We assessed the state of knowledge regarding the effects of large-scale pollution with neonicotinoid insecticides and fipronil on non-target invertebrate species of terrestrial, freshwater and marine environments. A large section of the assessment is dedicated to the state of knowledge on sublethal effects on honeybees (Apis mellifera) because this important pollinator is the most studied non-target invertebrate species. Lepidoptera (butterflies and moths), Lumbricidae (earthworms), Apoidae sensu lato (bumblebees, solitary bees) and the section "other invertebrates" review available studies on the other terrestrial species. The sections on freshwater and marine species are rather short as little is known so far about the impact of neonicotinoid insecticides and fipronil on the diverse invertebrate fauna of these widely exposed habitats. For terrestrial and aquatic invertebrate species, the known effects of neonicotinoid pesticides and fipronil are described ranging from organismal toxicology and behavioural effects to population-level effects. For earthworms, freshwater and marine species, the relation of findings to regulatory risk assessment is described. Neonicotinoid insecticides exhibit very high toxicity to a wide range of invertebrates, particularly insects, and field-realistic exposure is likely to result in both lethal and a broad range of important sublethal impacts. There is a major knowledge gap regarding impacts on the grand majority of invertebrates, many of which perform essential roles enabling healthy ecosystem functioning. The data on the few non-target species on which field tests have been performed are limited by major flaws in the outdated test protocols. Despite large knowledge gaps and uncertainties, enough knowledge exists to conclude that existing levels of pollution with neonicotinoids and fipronil resulting from presently authorized uses frequently exceed the lowest observed adverse effect concentrations and are thus likely to have large-scale and wide ranging negative biological and ecological impacts on a wide range of non-target invertebrates in terrestrial, aquatic, marine and benthic habitats.

Methods of analysis by the U.S. Geological Survey National Water Quality Laboratory; a method supplement for the determination of Fipronil and degradates in water by gas chromatography/mass spectrometry

USGS Publications Warehouse

Madsen, James F.; Sandstrom, Mark W.; Zaugg, Steven D.

2002-01-01

A method for the isolation and detemrination of fipronil and four of its degradates has been developed. This method adapts an analytical method created by the U.S. Geological Survey National Water Quality Laboratory in 1995 for the determination of a broad range of high-use pesticides typically found in filtered natural-water samples. In 2000, fipronil and four of its degradates were extracted, analyzed, and validated using this method. The recoveries for these five compounds in reagent-water samples fortified at 1 microgram per liter (ug/L) avereraged 98 percent. Initial method detection limits averaged 0.0029 ug/L. The performance of these five new compounds is consistent with the performance of the compounds in the initial method, making it possible to include them in addition to the other 41 pesticides and pesticide degradates in the original method.

The relationship of metals, bifenthrin, physical habitat metrics, grain size, total organic carbon, dissolved oxygen and conductivity to Hyalella sp. abundance in urban California streams.

PubMed

Hall, Lenwood W; Anderson, Ronald D

2013-01-01

The objectives of this study were to determine the relationship between Hyalella sp. abundance in four urban California streams and the following parameters: (1) 8 bulk metals (As, Cd, Cr, Cu, Pb, Hg, Ni, and Zn) and their associated sediment Threshold Effect Levels (TELs); (2) bifenthrin sediment concentrations; (3) 10 habitat metrics and total score; (4) grain size (% sand, silt and clay); (5) Total Organic Carbon (TOC); (6) dissolved oxygen; and (7) conductivity. California stream data used for this study were collected from Kirker Creek (2006 and 2007), Pleasant Grove Creek (2006, 2007 and 2008), Salinas streams (2009 and 2010) and Arcade Creek (2009 and 2010). Hyalella abundance in the four California streams generally declined when metals concentrations were elevated beyond the TELs. There was also a statistically significant negative relationship between Hyalella abundance and % silt for these 4 California streams as Hyalella were generally not present in silt areas. No statistically significant relationships were reported between Hyalella abundance and metals concentrations, bifenthrin concentrations, habitat metrics, % sand, % clay, TOC, dissolved oxygen and conductivity. The results from this study highlight the complexity of assessing which factors are responsible for determining the abundance of amphipods, such as Hyalella sp., in the natural environment.

Insecticide Resistance in Eggs and First Instars of the Bed Bug, Cimex lectularius (Hemiptera: Cimicidae).

PubMed

Campbell, Brittany E; Miller, Dini M

2015-01-15

Two strains of the common bed bug, Cimex lectularius L., eggs and first instars collected from pyrethroid-resistant adults were evaluated for insecticide resistance and compared to a susceptible strain. Dose-response bioassays were conducted using two insecticide formulations (Temprid: imidacloprid/β-cyfluthrin, and Transport: acetamiprid/ bifenthrin). The lethal concentration (LC50) for the two resistant egg strains exposed to imidacloprid/β-cyfluthrin ranged from 3 to 5-fold higher than susceptible strain eggs. Resistant strain eggs dipped into formulations of acetamiprid/bifenthrin had LC50 values which were significantly greater (39 to 1,080-fold) than susceptible strain eggs. Similar to eggs, resistant strain first instars exposed to residual applications of imidacloprid/β-cyfluthrin had LC50 values ranging from 121 to 493-fold greater than susceptible strain first instars. When resistant strain first instars were treated with acetamiprid/bifenthrin, they had LC50 values that were 99 to >1,900-fold greater than susceptible strain first instars. To determine differences between egg and first instar resistance, stage resistance ratios (SRR) were compared between the two stages. There was little difference between the egg and first instar stages, indicated by small SRR values ranging from 1.1 to 10.0. This study suggests that insecticide resistance is expressed early during bed bug development.

Insecticide Resistance in Eggs and First Instars of the Bed Bug, Cimex lectularius (Hemiptera: Cimicidae)

PubMed Central

Campbell, Brittany E.; Miller, Dini M.

2015-01-01

Two strains of the common bed bug, Cimex lectularius L., eggs and first instars collected from pyrethroid-resistant adults were evaluated for insecticide resistance and compared to a susceptible strain. Dose-response bioassays were conducted using two insecticide formulations (Temprid: imidacloprid/β-cyfluthrin, and Transport: acetamiprid/bifenthrin). The lethal concentration (LC50) for the two resistant egg strains exposed to imidacloprid/β-cyfluthrin ranged from 3 to 5-fold higher than susceptible strain eggs. Resistant strain eggs dipped into formulations of acetamiprid/bifenthrin had LC50 values which were significantly greater (39 to 1,080-fold) than susceptible strain eggs. Similar to eggs, resistant strain first instars exposed to residual applications of imidacloprid/β-cyfluthrin had LC50 values ranging from 121 to 493-fold greater than susceptible strain first instars. When resistant strain first instars were treated with acetamiprid/bifenthrin, they had LC50 values that were 99 to >1,900-fold greater than susceptible strain first instars. To determine differences between egg and first instar resistance, stage resistance ratios (SRR) were compared between the two stages. There was little difference between the egg and first instar stages, indicated by small SRR values ranging from 1.1 to 10.0. This study suggests that insecticide resistance is expressed early during bed bug development. PMID:26463070

Occurrence and potential sources of pyrethroid insecticides in stream sediments from seven U.S. metropolitan areas

USGS Publications Warehouse

Kuivila, Kathryn; Hladik, Michelle; Ingersoll, Christopher G.; Kemble, Nile E.; Moran, Patrick W.; Calhoun, Daniel L.; Nowell, Lisa H.; Gilliom, Robert J.

2012-01-01

A nationally consistent approach was used to assess the occurrence and potential sources of pyrethroid insecticides in stream bed sediments from seven metropolitan areas across the United States. One or more pyrethroids were detected in almost half of the samples, with bifenthrin detected the most frequently (41%) and in each metropolitan area. Cyhalothrin, cypermethrin, permethrin, and resmethrin were detected much less frequently. Pyrethroid concentrations and Hyalella azteca mortality in 28-d tests were lower than in most urban stream studies. Log-transformed total pyrethroid toxic units (TUs) were significantly correlated with survival and bifenthrin was likely responsible for the majority of the observed toxicity. Sampling sites spanned a wide range of urbanization and log-transformed total pyrethroid concentrations were significantly correlated with urban land use. Dallas/Fort Worth had the highest pyrethroid detection frequency (89%), the greatest number of pyrethroids (4), and some of the highest concentrations. Salt Lake City had a similar percentage of detections but only bifenthrin was detected and at lower concentrations. The variation in pyrethroid concentrations among metropolitan areas suggests regional differences in pyrethroid use and transport processes. This study shows that pyrethroids commonly occur in urban stream sediments and may be contributing to sediment toxicity across the country.

A probabilistic risk assessment for deployed military personnel after the implementation of the "Leishmaniasis Control Program" at Tallil Air Base, Iraq.

PubMed

Schleier, Jerome J; Davis, Ryan S; Barber, Loren M; Macedo, Paula A; Peterson, Robert K D

2009-05-01

Leishmaniasis has been of concern to the U.S. military and has re-emerged in importance because of recent deployments to the Middle East. We conducted a retrospective probabilistic risk assessment for military personnel potentially exposed to insecticides during the "Leishmaniasis Control Plan" (LCP) undertaken in 2003 at Tallil Air Base, Iraq. We estimated acute and subchronic risks from resmethrin, malathion, piperonyl butoxide (PBO), and pyrethrins applied using a truck-mounted ultra-low-volume (ULV) sprayer and lambda-cyhalothrin, cyfluthrin, bifenthrin, chlorpyrifos, and cypermethrin used for residual sprays. We used the risk quotient (RQ) method for our risk assessment (estimated environmental exposure/toxic endpoint) and set the RQ level of concern (LOC) at 1.0. Acute RQs for truck-mounted ULV and residual sprays ranged from 0.00007 to 33.3 at the 95th percentile. Acute exposure to lambda-cyhalothrin, bifenthrin, and chlorpyrifos exceeded the RQ LOC. Subchronic RQs for truck-mounted ULV and residual sprays ranged from 0.00008 to 32.8 at the 95th percentile. Subchronic exposures to lambda-cyhalothrin and chlorpyrifos exceeded the LOC. However, estimated exposures to lambda-cyhalothrin, bifenthrin, and chlorpyrifos did not exceed their respective no observed adverse effect levels.

Acute toxicity of fipronil to the stingless bee Scaptotrigona postica Latreille.

PubMed

Jacob, Cynthia Renata Oliveira; Soares, Hellen Maria; Carvalho, Stephan Malfitano; Nocelli, Roberta Cornélio Ferreira; Malaspina, Osmar

2013-01-01

Fipronil is an insecticide widely used to control a great number of pests, thus the aim of this study was to determine the lethal dose and lethal concentration (LD(50) and LC(50)) of this insecticide to the stingless bees Scaptotrigona postica Latreille, 1807. The LD(50) and LC(50) values obtained after 24 h of exposition were of 0.54 ng a.i./bee and 0.24 ng a.i./μL diet, respectively. These values were considered highly toxic to stingless bees.

Assessment of Potential Sublethal Effects of Various Insecticides on Key Biological Traits of The Tobacco Whitefly, Bemisia tabaci

PubMed Central

He, Yuxian; Zhao, Jianwei; Zheng, Yu; Weng, Qiyong; Biondi, Antonio; Desneux, Nicolas; Wu, Kongming

2013-01-01

The tobacco whitefly Bemisia tabaci is one of the most devastating pests worldwide. Current management of B. tabaci relies upon the frequent applications of insecticides. In addition to direct mortality by typical acute toxicity (lethal effect), insecticides may also impair various key biological traits of the exposed insects through physiological and behavioral sublethal effects. Identifying and characterizing such effects could be crucial for understanding the global effects of insecticides on the pest and therefore for optimizing its management in the crops. We assessed the effects of sublethal and low-lethal concentrations of four widely used insecticides on the fecundity, honeydew excretion and feeding behavior of B. tabaci adults. The probing activity of the whiteflies feeding on treated cotton seedlings was recorded by an Electrical Penetration Graph (EPG). The results showed that imidacloprid and bifenthrin caused a reduction in phloem feeding even at sublethal concentrations. In addition, the honeydew excretions and fecundity levels of adults feeding on leaf discs treated with these concentrations were significantly lower than the untreated ones. While, sublethal concentrations of chlorpyrifos and carbosulfan did not affect feeding behavior, honeydew excretion and fecundity of the whitefly. We demonstrated an antifeedant effect of the imidacloprid and bifenthrin on B. tabaci, whereas behavioral changes in adults feeding on leaves treated with chlorpyrifos and carbosulfan were more likely caused by the direct effects of the insecticides on the insects' nervous system itself. Our results show that aside from the lethal effect, the sublethal concentration of imidacloprid and bifenthrin impairs the phloem feeding, i.e. the most important feeding trait in a plant protection perspective. Indeed, this antifeedant property would give these insecticides potential to control insect pests indirectly. Therefore, the behavioral effects of sublethal concentrations of imidacloprid and bifenthrin may play an important role in the control of whitefly pests by increasing the toxicity persistence in treated crops. PMID:23494876

Wide spread cross resistance to pyrethroids in Aedes aegypti (L.) from Veracruz State Mexico

PubMed Central

Flores, Adriana E.; Ponce, Gustavo; Silva, Brenda G.; Gutierrez, Selene M.; Bobadilla, Cristina; Lopez, Beatriz; Mercado, Roberto; Black, William C.

2014-01-01

Seven F1 strains of Aedes aegypti (L.) were evaluated by bottle bioassay for resistance to the pyrethroids d-phenothrin, permethrin, deltamethrin, λ-cyalothrin, bifenthrin, cypermethrin, α-cypermethrin and z-cypermethrin. The New Orleans strain was used as a susceptible control. Mortality rates after a 1h exposure and following a 24h recovery period were determined. The resistance ratio between the 50% knockdown values (RRKC50) of the F1 and New Orleans strains indicated high levels of knockdown resistance (kdr). The RRKC50 with α-cypermethrin varied from 10–100 among strains indicating high levels of kdr. Most of the strains had moderate resistance to d-phenothrin. Significant but much lower levels of resistance were detected for λ–cyalothrin, permethrin and cypermethrin. For z-cypermethrin and bifenthrin, only one strain exhibited resistance with RRKC50 values of 10- and 21-fold, respectively. None of the strains showed RRKC50 >10 with deltamethrin, and moderate resistance was seen in three strains, while the rest were susceptible. Mosquitoes from all strains exhibited some recovery from all pyrethroids except d-phenothrin. Regression analysis was used to analyze the relationship between RRLC50 and RRKC50. Both were highly correlated (R2 = 0.84 – 0.97) so that the slope could be used to determine how much additional pyrethroid was needed to insure lethality. Slopes ranged from 0.875 for d-phenothrin (RRLC50 ≃ RRKC50) to 8.67 for λ–cyalothrin (~8.5 fold more insecticide needed to kill). Both RRLC50 and RRKC50 values were highly correlated for all pyrethroids except bifenthrin indicating strong cross resistance. Bifenthrin appears to be an alternative pyrethroid without strong cross resistance that could be used as an alternative to the current widespread use of permethrin in Mexico. PMID:23786088

Toxicity of nine insecticides on four natural enemies of Spodoptera exigua

PubMed Central

Liu, Yongqiang; Li, Xiangying; Zhou, Chao; Liu, Feng; Mu, Wei

2016-01-01

Spodoptera exigua, which feeds on various crops worldwide, has natural enemies that are susceptible to the insecticides used against S. exigua. We investigate the toxicity and residue risk of 9 insecticides on the development of H. axyridis, C. sinica, S. manilae and T. remus. S. manilae and T. remus adults were sensitive to all 9 insecticides (LC50 less than 2.75 mg a.i. liter−1), while H. axyridis and C. sinica adults were less sensitive (LC50 between 6 × 10−5 mg a.i. liter−1 and 78.95 mg a.i. liter−1). Emamectin benzoate, spinosad, indoxacarb, alpha-cypermethrin, chlorfenapyr and chlorantraniliprole showed no toxicity on H. axyridis, C. sinica, S. manilae and T. remus pupae with the recommended field concentrations. The risk analysis indicated that chlorantraniliprole is harmless to larvae of four natural enemies and adult of H. axyridis, C. sinica and S. manilae. Emamectin benzoate and spinosad had higher safety to the development of H. axyridis, C. sinica, S. manilae and T. remus with the risk duration less than 4d. Indoxacarb, tebufenozide, chlorfenapyr, methomyl, alpha-cypermethrin and chlorpyrifos showed dangerously toxic and long risk duration on S. manilae and T. remus adults. PMID:27958333

Induction of Amyloid-β42 Production by Fipronil and Other Pyrazole Insecticides.

PubMed

Cam, Morgane; Durieu, Emilie; Bodin, Marion; Manousopoulou, Antigoni; Koslowski, Svenja; Vasylieva, Natalia; Barnych, Bogdan; Hammock, Bruce D; Bohl, Bettina; Koch, Philipp; Omori, Chiori; Yamamoto, Kazuo; Hata, Saori; Suzuki, Toshiharu; Karg, Frank; Gizzi, Patrick; Haber, Vesna Erakovic; Bencetic Mihaljevic, Vlatka; Tavcar, Branka; Portelius, Erik; Pannee, Josef; Blennow, Kaj; Zetterberg, Henrik; Garbis, Spiros D; Auvray, Pierrick; Gerber, Hermeto; Fraering, Jeremy; Fraering, Patrick C; Meijer, Laurent

2018-01-01

Generation of amyloid-β peptides (Aβs) by proteolytic cleavage of the amyloid-β protein precursor (AβPP), especially increased production of Aβ42/Aβ43 over Aβ40, and their aggregation as oligomers and plaques, represent a characteristic feature of Alzheimer's disease (AD). In familial AD (FAD), altered Aβ production originates from specific mutations of AβPP or presenilins 1/2 (PS1/PS2), the catalytic subunits of γ-secretase. In sporadic AD, the origin of altered production of Aβs remains unknown. We hypothesize that the 'human chemical exposome' contains products able to favor the production of Aβ42/Aβ43 over Aβ40 and shorter Aβs. To detect such products, we screened a library of 3500 + compounds in a cell-based assay for enhanced Aβ42/Aβ43 production. Nine pyrazole insecticides were found to induce a β- and γ-secretase-dependent, 3-10-fold increase in the production of extracellular Aβ42 in various cell lines and neurons differentiated from induced pluripotent stem cells derived from healthy and FAD patients. Immunoprecipitation/mass spectrometry analyses showed increased production of Aβs cleaved at positions 42/43, and reduced production of peptides cleaved at positions 38 and shorter. Strongly supporting a direct effect on γ-secretase activity, pyrazoles shifted the cleavage pattern of another γ-secretase substrate, alcadeinα, and shifted the cleavage of AβPP by highly purified γ-secretase toward Aβ42/Aβ43. Focusing on fipronil, we showed that some of its metabolites, in particular the persistent fipronil sulfone, also favor the production of Aβ42/Aβ43 in both cell-based and cell-free systems. Fipronil administered orally to mice and rats is known to be metabolized rapidly, mostly to fipronil sulfone, which stably accumulates in adipose tissue and brain. In conclusion, several widely used pyrazole insecticides enhance the production of toxic, aggregation prone Aβ42/Aβ43 peptides, suggesting the possible existence of environmental "Alzheimerogens" which may contribute to the initiation and propagation of the amyloidogenic process in sporadic AD.

Use of electroencephalography (EEG) to assess CNS changes produced by pesticides with different modes of action: Effects of permethrin, deltamethrin, fipronil, imidacloprid, carbaryl, and triadimefon

DOE Office of Scientific and Technical Information (OSTI.GOV)

Freeborn, Danielle L., E-mail: Freeborn.danielle@epa.gov; McDaniel, Katherine L., E-mail: McDaniel.kathy@epa.gov; Moser, Virginia C., E-mail: Moser.ginger@epa.gov

The electroencephalogram (EEG) is an apical measure, capable of detecting changes in brain neuronal activity produced by internal or external stimuli. We assessed whether pesticides with different modes of action produced different changes in the EEG of adult male Long–Evans rats. The EEG was recorded using two montages (visual cortex referenced to the cerebellum and to the frontal cortex) in unrestrained rats at the time of peak behavioral effects. Pesticides included: permethrin and deltamethrin (Type I and Type II pyrethroids; 2 h), fipronil (single and repeated doses; phenylpyrazole; 6 h), imidacloprid (neonicotinoid; 2 h), carbaryl (carbamate; 0.5 h), and triadimefonmore » (triazole; 1 h), using dosages that produced approximately an ED{sub 30} or an ED{sub 50}–ED{sub 80} change in motor activity. Permethrin (43, 100 mg/kg) increased amplitudes or areas (delta, alpha, or gamma bands) in the EEG. Deltamethrin (2.5, 5.5 mg/kg) reduced the amplitudes or areas of the delta, theta, alpha, beta, and gamma bands, but the changes were not dose-related. A single treatment with fipronil (25, 50 mg/kg, but not 5, 10 mg/kg) decreased gamma band area. Additional changes in the delta, theta, and gamma bands were observed when fipronil (5, 10 mg/kg) was administered for 14 days. Imidacloprid (50, 100 mg/kg) did not alter the EEG. Carbaryl (10, 50 mg/kg) decreased theta area, and decreased delta and increased beta frequency. Triadimefon (75, 150 mg/kg) produced minimal changes in the EEG. The results show that the EEG is affected differently by approximately equipotent doses of pesticides with different modes of action. - Highlights: • Pesticides with different modes of action have different effects on in vivo rodent EEG. • The EEG was also changed differently after single vs. repeated treatment with fipronil. • The data suggest that EEG may be used as an apical measure for detecting chemical effects on the central nervous system.« less

Efficacy of a novel topical fipronil, (S)-methoprene, eprinomectin and praziquantel combination against naturally acquired intestinal nematode and cestode infections in cats.

PubMed

Knaus, Martin; Abu-Madi, Marawan A; Ibarra-Velarde, Froylán; Kok, Dawie J; Kusi, Ilir; Postoli, Rezart; Chester, S Theodore; Rosentel, Joseph; Alva, Roberto; Irwin, Jennifer; Visser, Martin; Winter, Renate; Rehbein, Steffen

2014-04-28

The efficacy of a novel topical combination formulation of fipronil, (S)-methoprene, eprinomectin and praziquantel against naturally acquired intestinal nematode and cestode infections in cats was evaluated in seven negative control, blinded studies. Cats were selected based on a pre-treatment faecal examination indicating a patent infection with at least hookworms (two studies), Toxocara ascarids (one study), taeniid cestodes (two studies) or Dipylidium cestodes (two studies). In each study, cats were assigned randomly to blocks of two animals each, based on decreasing pre-treatment body weight and were randomly allocated to one of two groups of six to 12 cats: untreated (control) or treated with topical fipronil (8.3%, w/v), (S)-methoprene (10%, w/v), eprinomectin (0.4%, w/v) and praziquantel (8.3%, w/v) (BROADLINE(®), Merial) at 0.12 mL/kg body weight (providing a minimum of 10mg fipronil+12 mg S-methoprene+0.5mg eprinomectin+10mg praziquantel per kg body weight). The topical treatment was administered directly on the skin in the midline of the neck in a single spot once on Day 0. For parasite recovery and count, cats were euthanized humanely and necropsied seven or ten days after treatment. A single treatment with the novel topical combination product provided 91% efficacy against Ancylostoma braziliense, ≥ 99% efficacy against Ancylostoma tubaeforme, and >97% efficacy against Toxocara cati. Similarly, excellent efficacy was established against Taenia taeniaeformis, Dipylidium caninum and Diplopylidium spp. as demonstrated by >97% and up to 100% reductions of cestode counts in the treated cats when compared to the untreated controls (P<0.01). All cats accepted the treatment well based on health observations post-treatment and daily health observations. No adverse experiences or other health problems were observed throughout the studies. The results of this series of controlled studies demonstrated high efficacy and excellent acceptability of the novel topical combination formulation of fipronil, (S)-methoprene, eprinomectin and praziquantel against a broad range of feline intestinal nematode and cestode infections. Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.

Efficacy of a Novel Topical Combination of Fipronil 9.8% and (S)-Methoprene 8.8% against Ticks and Fleas in Naturally Infested Dogs.

PubMed

Nambi, Ayyanampakkam Pandurangan; Rathi, Badal; S, Kavitha; Dudhatra, Ghanshyam; Yamini, Hamsa S; Ali Bhat, Abid

2016-01-01

The efficacy of a novel topical combination of fipronil 9.8% (w/v) and (S)-methoprene 8.8% (w/v) (Fiprofort® Plus) was tested against ticks and fleas in naturally infested dogs. A total of fifty dogs were allocated in the study with ticks infestation (n = 35) and fleas infestation (n = 15). On day 0, thirty-five tick and fifteen flea infested dogs received the test formulation, a combination of fipronil 9.8% (w/v) and (S)-methoprene 8.8% (w/v) spot-on solution. Ticks and flea counts were taken on days 0 (pretreatment) and 3, 7, 14, 21, 28, and 35 after treatment. Blood samples were collected for evaluation of haematological parameters on days 0 (pretreatment) and 7, 21, and 35 after treatment. All the adult ticks and fleas collected were identified as Rhipicephalus sanguineus and Ctenocephalides felis, respectively. The efficacy of spot-on formulation against ticks was 34.00% (day 3), 53.14% (day 7), 62.71% (day 14), 65.48% (day 21), 59.80% (day 28), and 58.82% (day 35), whereas against fleas it was 38.00% (day 3), 64.34% (day 7), 89.67% (day 14), 95.40% (day 21), 100.00% (day 28), and 100.00% (day 35). Haematological parameters for ticks and fleas infested dogs were statistically nonsignificant as compared to control. The combination of fipronil and (S)-methoprene eliminated the existing ticks and fleas infestation and prevented the dogs from flea and tick infestation for four weeks.

Control of flea populations in a simulated home environment model using lufenuron, imidacloprid or fipronil.

PubMed

Jacobs, D E; Hutchinson, M J; Ryan, W G

2001-03-01

Control strategies were evaluated over a 6-month period in a home simulation model comprising a series of similar carpeted pens, housing matched groups of six cats, in which the life-cycle of the flea Ctenocephalides felis felis Bouche (Siphonaptera: Pulicidae) had been established. Additional adult fleas were placed on the cats at intervals to mimic acquisition of extraneous fleas from outside the home. Treatment strategies included a single subcutaneous deposition of injectable lufenuron supported by initial treatments with a short-acting insecticidal spray, or monthly topical applications of imidacloprid or fipronil. An untreated control group indicated that conditions were suitable for flea replication and development. Controls had to be combed on 18 occasions to remove excessive flea burdens and two developed allergic reactions. Lufenuron cats were combed once and required two insecticidal treatments in the first month to achieve control. Even so, small flea burdens were constantly present thereafter. Imidacloprid and fipronil treatments appeared to give virtually complete control throughout. Single fleas were found on imidacloprid cats on two occasions, whereas none were recovered from fipronil cats at any time after the first treatment. Tracer cats were used to monitor re-infestation rates at the end of the trial period. Small numbers of host-seeking fleas were demonstrated in all treatment pens, indicating that total eradication had not been accomplished. It is concluded that the home environment simulation model incorporating tracer animals could provide a powerful tool for studying flea population dynamics under controlled conditions but improved techniques are needed for quantifying other off-host life-cycle stages.

Development and validation of an ultra performance liquid chromatography Q-Exactive Orbitrap mass spectrometry for the determination of fipronil and its metabolites in tea and chrysanthemum.

PubMed

Chen, Hongping; Gao, Guanwei; Liu, Pingxiang; Pan, Meiling; Chai, Yunfeng; Liu, Xin; Lu, Chengyin

2018-04-25

A fast, sensitive and reliable method for the determination of fipronil and its metabolites in tea and chrysanthemum was developed using a modified QuEChERS technique and an ultra performance liquid chromatography Q-Exactive Orbitrap mass spectrometry. The mixture of adsorbents containing primary secondary amine (PSA), octadecylsilane (C 18 ) and carbon nanotubes (CNTs), was used as QuEChERS adsorbents. The use of mass resolution at 70000 full width at half maximum (FWHM) and narrow mass windows at 5 ppm achieved high selectivity and repeatability. Satisfactory linearity with correlative coefficient (R 2 ) higher than 0.996 was achieved for all compounds. Recoveries at three levels (2, 10 and 50 μg kg -1 ) ranged from 86% to 112%, while the intra- and inter-day accuracies were less than 15%. Limits of quantification for fipronil and its metabolites were 2 μg kg -1 , which fulfils the requirement of maximum residue limits formulated by European Union and Japan. Copyright © 2017 Elsevier Ltd. All rights reserved.

Contact toxicity and residual effects of selected insecticides against the adult Paederus fuscipes (Coleoptera: Staphylinidae).

PubMed

Bong, Lee-Jin; Neoh, Kok-Boon; Jaal, Zairi; Lee, Chow-Yang

2013-12-01

The contact toxicity of four insecticide formulations (deltamethrin, fipronil, fenitrothion, and imidacloprid) applied on three different substrates (tile, plywood, and concrete) against the adult rove beetle, Paederus fuscipes Curtis, was evaluated. The relative order of speed of killing effects was as follows: deltamethrin > imidacloprid > fipronil > fenitrothion. Although deltamethrin showed the fastest action against P. fuscipes, the recovery rate of rove beetles at 48 h posttreatment was moderate (approximately 25%) on the tile surface to high (approximately 80%) on the plywood surface. Thus, it is likely that the insects did not pick up the lethal dose especially on porous surfaces. In contrast, fipronil demonstrated delayed toxicity that might promote maximal uptake by the insects. More than 80% mortality was registered for tile and plywood surfaces up to 4 wk after exposure. High mortality (almost 100%) was recorded for imidacloprid-exposed P. fuscipes at 48 h posttreatment, but only on the tile surface. Among the four insecticides tested, fenitrothion was the least effective against P. fuscipes because low percentage to no mortality was recorded in the fenitrothion treatment.

Validation of an off line solid phase extraction liquid chromatography-tandem mass spectrometry method for the determination of systemic insecticide residues in honey and pollen samples collected in apiaries from NW Spain.

PubMed

García-Chao, María; Agruña, María Jesús; Flores Calvete, Gonzalo; Sakkas, Vasilis; Llompart, María; Dagnac, Thierry

2010-07-05

The use of pesticides to protect crops against plagues and insects is one of the most important ways to assure agricultural quality and productivity. However, bad application practices may cause the contamination of different environmental compartments and animal species, as a consequence of migration or accumulation of those compounds. Fipronil, imidacloprid and thiametoxam are systemic or systemic-like insecticides widely used in maize crops. Their heavy action in the nervous system of target insects also means a high toxicity to non-target pollinator insects such as honey bees which can get in touch with them through pollen and nectar during foraging activities. These insecticides have even been suspected to cause a significant decrease of honeybee colonies that has been observed in many countries since the past decade. Since September 1st 2008, the European Commission set new MRLs in food and feed of plant and animal origin. The pesticides included in this study have MRLs in honey and pollen between 10 and 50 ng g(-1). In the present work, an analytical method was developed with the aim of determining residues of fipronil and some of its metabolites (fipronil sulfone, fipronil sulfide, fipronil desulfinyl and fipronil carboxamide), thiamethoxam and imidacloprid in honey and pollen samples. The extraction optimization was performed using a Doehlert experimental design by studying two factors, the mixture and the ratio of solvents used. Prior to the extraction procedure, raw hive samples containing honey, pollen and wax were centrifuged at 4000 rpm. The upper solid material was removed, and 1 g of the lower phase was mixed with 3 mL of the optimized mixture of methanol/water (10/90). The extract was passed through a florisil cartridge and the target compounds were eluted with methanol and analysed by LC-MS/MS in selective reaction monitoring (SRM) mode. The method was validated according to the guidelines included in the SANCO/10684/2009 document and the ISO 11843 standard for the following parameters: decision limit (CCalpha), detection capability (CCbeta), recovery, repeatability and reproducibility at 0.5, 1 and 1.5 folds the MRLs. Ion suppression/enhancement effects into the ion source were also assessed. The CCbeta values were included between 0.83 and 4.83 ng g(-1), well below the current MRLs. The validated method was applied to the determination of the target pesticides in 91 samples collected in colonies from 73 apiaries of NW Spain (two sampling campaigns during 2008). None of the target insecticides were detected among all the collected samples. Copyright 2010 Elsevier B.V. All rights reserved.

Laboratory degradation rates of 11 pyrethroids under aerobic and anaerobic conditions.

PubMed

Meyer, Brian N; Lam, Chung; Moore, Sean; Jones, Russell L

2013-05-22

Degradation of 11 pyrethroids was measured over approximately 100 days in three sediment/water systems under aerobic and anaerobic conditions at 25 °C in the dark. The three California sediments represented a range of textures and organic matter. Test compounds were bifenthrin, cypermethrin, ζ-cypermethrin, cyfluthrin, β-cyfluthrin, deltamethrin, esfenvalerate, fenpropathrin, γ-cyhalothrin, λ-cyhalothrin, and permethrin. A non-standard design was employed to keep conditions essentially the same for all compounds. The test compounds were applied as two test mixtures (six active ingredients per mixture, with bifenthrin common to both) at approximately 50 μg of test compound/kg of sediment (dry weight). Extracts of sediment/water were cleaned up by solid-phase extraction, concentrated, and analyzed by gas chromatography/mass spectrometry (except deltamethrin) against matrix-matched standards, with cyfluthrin-d6 as an internal standard. Deltamethrin was analyzed by liquid chromatography/tandem mass spectrometry using deltamethrin-phenoxy-(13)C6 as an internal standard. Similar degradation rates of bifenthrin and for related isomeric compounds (e.g., cyfluthrin and β-cyfluthrin) were generally measured in both mixtures for each sediment. First-order half-lives under aerobic conditions ranged from 2.9 to greater than 200 days, with a median value of 18 days. Under anaerobic conditions, the range was from 20 to greater than 200 days, with a median value of 70 days.

Contaminants in stream sediments from seven United States metropolitan areas: part I: distribution in relation to urbanization

USGS Publications Warehouse

Nowell, Lisa H.; Moran, Patrick W.; Gilliom, Robert J.; Calhoun, Daniel L.; Ingersoll, Christopher G.; Kemble, Nile E.; Kuivila, Kathryn; Phillips, Patrick J.

2013-01-01

Organic contaminants and trace elements were measured in bed sediments collected from streams in seven metropolitan study areas across the United States to assess concentrations in relation to urbanization. Polycyclic aromatic hydrocarbons, polychlorinated biphenyls, organochlorine pesticides, the pyrethroid insecticide bifenthrin, and several trace elements were significantly related to urbanization across study areas. Most contaminants (except bifenthrin, chromium, nickel) were significantly related to the total organic carbon (TOC) content of the sediments. Regression models explained 45–80 % of the variability in individual contaminant concentrations using degree of urbanization, sediment-TOC, and study-area indicator variables (which represent the combined influence of unknown factors, such as chemical use or release, that are not captured by available explanatory variables). The significance of one or more study-area indicator variables in all models indicates marked differences in contaminant levels among some study areas, even after accounting for the nationally modeled effects of urbanization and sediment-TOC. Mean probable effect concentration quotients (PECQs) were significantly related to urbanization. Trace elements were the major contributors to mean PECQs at undeveloped sites, whereas organic contaminants, especially bifenthrin, were the major contributors at highly urban sites. Pyrethroids, where detected, accounted for the largest share of the mean PECQ. Part 2 of this series (Kemble et al. 2012) evaluates sediment toxicity to amphipods and midge in relation to sediment chemistry.

Effects of several pyrethroids on hepatic cytochrome P450 activities in rats.

PubMed

Abdou, Rania; Sasaki, Kazuaki; Khalil, Waleed; Shah, Syed; Murasawa, Youhei; Shimoda, Minoru

2010-04-01

Four commonly used pyrethroids (permethrin, bifenthrin, ethofenprox, and fenpropathrin) were orally administered to Sprague-Dawley rats for 5 days to study their effects on the liver cytochrome P450 (CYP) activities. Also Michaelis-Menten kinetics of the metabolic reactions catalyzed by liver CYPs were examined after adding these pyrethroids to the assay system to investigate their possible inhibitory effects on liver CYPs activities. These reactions included ethoxyresorufin O-deethylation, tolbutamide hydroxylation, bufuralol 1'-hydroxylation, and midazolam 4-hydroxylation, for CYP1A, 2C, 2D, and 3A activities, respectively. Results showed that oral administration of bifenthrin and ethofenprox highly induced CYP1A. The most potent inhibitors for CYP1A were fenpropathrin and cis-permethrin with K(i) values of 3.71 & 3.87 microM, respectively. CYP2D was slightly inhibited by both of fenpropathrin and cis-permethrin (K(i) values were 307.32 & 632.23 microM, respectively). On the other hand, none of CYP2C or 3A was inhibited by the tested pyrethroids. Since CYP1A may relate to biotransformation of many chemicals to reactive metabolites, bifenthrin and ethofenprox may potentiate mutagenicity of the chemicals through their inducing effects on CYP 1A. As permethrin and fenpropathrin were potent inhibitor for CYP1A, they may result in substantial accumulation of some chemicals. The resultant accumulation may lead to fatal toxicities in some case.

Differential Expression Profile of lncRNAs from Primary Human Hepatocytes Following DEET and Fipronil Exposure

PubMed Central

Wallace, Andrew D.; Hodgson, Ernest; Roe, R. Michael

2017-01-01

While the synthesis and use of new chemical compounds is at an all-time high, the study of their potential impact on human health is quickly falling behind, and new methods are needed to assess their impact. We chose to examine the effects of two common environmental chemicals, the insect repellent N,N-diethyl-m-toluamide (DEET) and the insecticide fluocyanobenpyrazole (fipronil), on transcript levels of long non-protein coding RNAs (lncRNAs) in primary human hepatocytes using a global RNA-Seq approach. While lncRNAs are believed to play a critical role in numerous important biological processes, many still remain uncharacterized, and their functions and modes of action remain largely unclear, especially in relation to environmental chemicals. RNA-Seq showed that 100 µM DEET significantly increased transcript levels for 2 lncRNAs and lowered transcript levels for 18 lncRNAs, while fipronil at 10 µM increased transcript levels for 76 lncRNAs and decreased levels for 193 lncRNAs. A mixture of 100 µM DEET and 10 µM fipronil increased transcript levels for 75 lncRNAs and lowered transcript levels for 258 lncRNAs. This indicates a more-than-additive effect on lncRNA transcript expression when the two chemicals were presented in combination versus each chemical alone. Differentially expressed lncRNA genes were mapped to chromosomes, analyzed by proximity to neighboring protein-coding genes, and functionally characterized via gene ontology and molecular mapping algorithms. While further testing is required to assess the organismal impact of changes in transcript levels, this initial analysis links several of the dysregulated lncRNAs to processes and pathways critical to proper cellular function, such as the innate and adaptive immune response and the p53 signaling pathway. PMID:28991164

Use of electroencephalography (EEG) to assess CNS changes produced by pesticides with different modes of action: effects of permethrin, deltamethrin, fipronil, imidacloprid, carbaryl, and triadimefon.

PubMed

Freeborn, Danielle L; McDaniel, Katherine L; Moser, Virginia C; Herr, David W

2015-01-15

The electroencephalogram (EEG) is an apical measure, capable of detecting changes in brain neuronal activity produced by internal or external stimuli. We assessed whether pesticides with different modes of action produced different changes in the EEG of adult male Long-Evans rats. The EEG was recorded using two montages (visual cortex referenced to the cerebellum and to the frontal cortex) in unrestrained rats at the time of peak behavioral effects. Pesticides included: permethrin and deltamethrin (Type I and Type II pyrethroids; 2 h), fipronil (single and repeated doses; phenylpyrazole; 6 h), imidacloprid (neonicotinoid; 2 h), carbaryl (carbamate; 0.5 h), and triadimefon (triazole; 1 h), using dosages that produced approximately an ED30 or an ED50-ED80 change in motor activity. Permethrin (43, 100 mg/kg) increased amplitudes or areas (delta, alpha, or gamma bands) in the EEG. Deltamethrin (2.5, 5.5 mg/kg) reduced the amplitudes or areas of the delta, theta, alpha, beta, and gamma bands, but the changes were not dose-related. A single treatment with fipronil (25, 50 mg/kg, but not 5, 10 mg/kg) decreased gamma band area. Additional changes in the delta, theta, and gamma bands were observed when fipronil (5, 10 mg/kg) was administered for 14 days. Imidacloprid (50, 100 mg/kg) did not alter the EEG. Carbaryl (10, 50 mg/kg) decreased theta area, and decreased delta and increased beta frequency. Triadimefon (75, 150 mg/kg) produced minimal changes in the EEG. The results show that the EEG is affected differently by approximately equipotent doses of pesticides with different modes of action. Published by Elsevier Inc.

Continuous low-level aquatic monitoring (CLAM) samplers for pesticide contaminant screening in urban runoff: Analytical approach and a field test case.

PubMed

Ensminger, Michael P; Vasquez, Martice; Tsai, Hsing-Ju; Mohammed, Sarah; Van Scoy, A; Goodell, Korena; Cho, Gail; Goh, Kean S

2017-10-01

Monitoring of surface waters for organic contaminants is costly. Grab water sampling often results in non-detects for organic contaminants due to missing a pulse event or analytical instrumentation limitations with a small sample size. Continuous Low-Level Aquatic Monitoring (CLAM) samplers (C.I.Agent ® Solutions) continually extract and concentrate organic contaminants in surface water onto a solid phase extraction disk. Utilizing CLAM samplers, we developed a broad spectrum analytical screen for monitoring organic contaminants in urban runoff. An intermediate polarity solid phase, hydrophobic/lipophilic balance (HLB), was chosen as the sorbent for the CLAM to target a broad range of compounds. Eighteen urban-use pesticides and pesticide degradates were targeted for analysis by LC/MS/MS, with recoveries between 59 and 135% in laboratory studies. In field studies, CLAM samplers were deployed at discrete time points from February 2015 to March 2016. Half of the targeted chemicals were detected with reporting limits up to 90 times lower than routine 1-L grab samples with good precision between field replicates. In a final deployment, CLAM samplers were compared to 1-L water samples. In this side-by-side comparison, imidacloprid, fipronil, and three fipronil degradates were detected by the CLAM sampler but only imidacloprid and fipronil sulfone were detected in the water samples. However, concentrations of fipronil sulfone and imidacloprid were significantly lower with the CLAM and a transient spike of diuron was not detected. Although the CLAM sampler has limitations, it can be a powerful tool for development of more focused and informed monitoring efforts based on pre-identified targets in the field. Copyright © 2017 Elsevier Ltd. All rights reserved.

Compatibility of endoparasitoid Hyposoter didymator (Hymenoptera: Ichneumonidae) protected stages with five selected insecticides.

PubMed

Medina, P; Morales, J J; Budia, F; Adan, A; Del Estal, P; Viñuela, E

2007-12-01

Hyposoter didymator (Thunberg) (Hymenoptera: Ichneumonidae) is a koinobiont endoparasitoid that emerges from the parasitization of economically important noctuid pests. H. didymator also is considered one of the most important native biocontrol agents of noctuids in Spain. Side effects of five insecticides with very different modes of action (fipronil, imidacloprid, natural pyrethrins + piperonyl butoxide, pymetrozine, and triflumuron) at the maximum field recommended rate in Spain were evaluated on H. didymator parasitizing Spodoptera littoralis (Boisduval) larvae and pupae of the endoparasitoid. Parasitized larvae were topically treated or ingested treated artificial diet. Parasitoid cocoons were topically treated. Host mortality when parasitized larvae were treated, as well as further development of the parasitoid surviving (e.g., percentage of cocoons spun, adult emergence, hosts attacked, and numbered progeny) were determined. Toxicity after treatment of parasitized larvae differed depending on the mode of exposure and insecticide. Fipronil was always highly toxic; imidacloprid killed all host insects by ingestion, but it was less toxic to both host and parasitoids, when administered topically; natural pyrethrins + piperonyl butoxide and triflumuron showed differing degrees of toxicity, and pymetrozine was harmless. Parasitoid cocoons provided effective protection against all the insecticides, except fipronil.

Drone exposure to the systemic insecticide Fipronil indirectly impairs queen reproductive potential

NASA Astrophysics Data System (ADS)

Kairo, Guillaume; Provost, Bertille; Tchamitchian, Sylvie; Ben Abdelkader, Faten; Bonnet, Marc; Cousin, Marianne; Sénéchal, Jacques; Benet, Pauline; Kretzschmar, André; Belzunces, Luc P.; Brunet, Jean-Luc

2016-08-01

A species that requires sexual reproduction but cannot reproduce is doomed to extinction. The important increasing loss of species emphasizes the ecological significance of elucidating the effects of environmental stressors, such as pesticides, on reproduction. Despite its special reproductive behavior, the honey bee was selected as a relevant and integrative environmental model because of its constant and diverse exposure to many stressors due to foraging activity. The widely used insecticide Fipronil, the use of which is controversial because of its adverse effects on honey bees, was chosen to expose captive drones in hives via syrup contaminated at 0.1 μg/L and gathered by foragers. Such environmental exposure led to decreased spermatozoa concentration and sperm viability coupled with an increased sperm metabolic rate, resulting in drone fertility impairment. Subsequently, unexposed queens inseminated with such sperm exhibited fewer spermatozoa with lower viability in their spermatheca, leaving no doubt about the detrimental consequences for the reproductive potential of queens, which are key for colony sustainability. These findings suggest that pesticides could contribute to declining honey bee populations through fertility impairment, as exemplified by Fipronil. More broadly, reproductive disorders should be taken into consideration when investigating the decline of other species.

Design of a New Glutamine-Fipronil Conjugate with α-Amino Acid Function and its Uptake by A. thaliana Lysine Histidine Transporter 1 ( AtLHT1).

PubMed

Jiang, Xunyuan; Xie, Yun; Ren, Zhanfu; Ganeteg, Ulrika; Lin, Fei; Zhao, Chen; Xu, Hanhong

2018-06-26

Creating novel pesticides with phloem-mobility is essential for controlling insects in vascular tissue and root, and conjugating existing pesticides with amino acid is an effective approach. In order to obtain highly phloem-mobile candidate for efficient pesticide, an electro-neutral L-glutamine-fipronil conjugate (L-GlnF) retaining α-amino acid function was designed and synthesized to fit the substrate specificity of amino acid transporter. Cotyledon uptake and phloem loading tests with Ricinus communis have verified that L-GlnF was phloem mobile, and its phloem mobility was higher than its enantiomer D-GlnF and other previously reported amino acid-fipronil conjugates. Inhibition experiments then suggested that the uptake of L-GlnF was, at least partially, mediated by active transport mechanism. This inference was further strengthened by assimilation experiments with Xenopus oocytes and genetically modified Arabidopsis thaliana, which showed direct correlation between the uptake of L-GlnF and expression of amino acid transporter AtLHT1. Thus, conjugation with L-Gln appears to be a potential strategy to ensure the uptake of pesticides via endogenous amino acid transport system.

Postapplication Fipronil Exposure Following Use on Pets.

PubMed

Cochran, R C; Yu, Liu; Krieger, R I; Ross, J H

2015-01-01

Fipronil is a pyrazole acaricide and insecticide that may be used for insect, tick, lice, and mite control on pets. Residents' short-term and long-term postapplication exposures to fipronil, including secondary environmental exposures, were estimated using data from chemical-specific studies. Estimations of acute (24-h) absorbed doses for residents were based on U.S. Environmental Protection Agency (U.S. EPA) 2012 standard operating procedures (SOPs) for postapplication exposure. Chronic exposures were not estimated for residential use, as continuous, long-term application activities were unlikely to occur. Estimated acute postapplication absorbed doses were as high as 0.56 μg/kg-d for toddlers (1-2 yr) in households with treated pets based on current U.S. EPA SOPs. Acute toddler exposures estimated here were fivefold larger in comparison to adults. Secondary exposure from the household environment in which a treated pet lives that is not from contacting the pet, but from contacting the house interior to which pet residues were transferred, was estimated based on monitoring socks worn by pet owners. These secondary exposures were more than an order of magnitude lower than those estimated from contacting the pet and thus may be considered negligible.

Drone exposure to the systemic insecticide Fipronil indirectly impairs queen reproductive potential.

PubMed

Kairo, Guillaume; Provost, Bertille; Tchamitchian, Sylvie; Ben Abdelkader, Faten; Bonnet, Marc; Cousin, Marianne; Sénéchal, Jacques; Benet, Pauline; Kretzschmar, André; Belzunces, Luc P; Brunet, Jean-Luc

2016-08-23

A species that requires sexual reproduction but cannot reproduce is doomed to extinction. The important increasing loss of species emphasizes the ecological significance of elucidating the effects of environmental stressors, such as pesticides, on reproduction. Despite its special reproductive behavior, the honey bee was selected as a relevant and integrative environmental model because of its constant and diverse exposure to many stressors due to foraging activity. The widely used insecticide Fipronil, the use of which is controversial because of its adverse effects on honey bees, was chosen to expose captive drones in hives via syrup contaminated at 0.1 μg/L and gathered by foragers. Such environmental exposure led to decreased spermatozoa concentration and sperm viability coupled with an increased sperm metabolic rate, resulting in drone fertility impairment. Subsequently, unexposed queens inseminated with such sperm exhibited fewer spermatozoa with lower viability in their spermatheca, leaving no doubt about the detrimental consequences for the reproductive potential of queens, which are key for colony sustainability. These findings suggest that pesticides could contribute to declining honey bee populations through fertility impairment, as exemplified by Fipronil. More broadly, reproductive disorders should be taken into consideration when investigating the decline of other species.

Drone exposure to the systemic insecticide Fipronil indirectly impairs queen reproductive potential

PubMed Central

Kairo, Guillaume; Provost, Bertille; Tchamitchian, Sylvie; Ben Abdelkader, Faten; Bonnet, Marc; Cousin, Marianne; Sénéchal, Jacques; Benet, Pauline; Kretzschmar, André; Belzunces, Luc P.; Brunet, Jean-Luc

2016-01-01

A species that requires sexual reproduction but cannot reproduce is doomed to extinction. The important increasing loss of species emphasizes the ecological significance of elucidating the effects of environmental stressors, such as pesticides, on reproduction. Despite its special reproductive behavior, the honey bee was selected as a relevant and integrative environmental model because of its constant and diverse exposure to many stressors due to foraging activity. The widely used insecticide Fipronil, the use of which is controversial because of its adverse effects on honey bees, was chosen to expose captive drones in hives via syrup contaminated at 0.1 μg/L and gathered by foragers. Such environmental exposure led to decreased spermatozoa concentration and sperm viability coupled with an increased sperm metabolic rate, resulting in drone fertility impairment. Subsequently, unexposed queens inseminated with such sperm exhibited fewer spermatozoa with lower viability in their spermatheca, leaving no doubt about the detrimental consequences for the reproductive potential of queens, which are key for colony sustainability. These findings suggest that pesticides could contribute to declining honey bee populations through fertility impairment, as exemplified by Fipronil. More broadly, reproductive disorders should be taken into consideration when investigating the decline of other species. PMID:27549030

Sediment-associated pesticides in an urban stream in Guangzhou, China: implication of a shift in pesticide use patterns.

PubMed

Li, Huizhen; Sun, Baoquan; Lydy, Michael J; You, Jing

2013-04-01

Pesticide use patterns in China have changed in recent years; however, the study of the environmental fate of current-use pesticides (CUPs) and their ecotoxicological significance in aquatic ecosystems is limited. In the present study, sediments were collected from an urban stream in the Chinese city of Guangzhou. Sediment-associated legacy organochlorine pesticides and CUPs-including organophosphates, pyrethroids, fipronil, and abamectin-were analyzed. Additionally, the relative toxicity of the sediments was evaluated with 10-d bioassays using Chironomus dilutus. Fifteen of 16 sediments collected from the stream were acutely toxic to C. dilutus, with 81% of the samples causing 100% mortality. Abamectin, fipronil, and pyrethroids (mainly cypermethrin) were identified as the principal contributors to the noted toxicity in the midges, with median predicted toxic units of 1.63, 1.63, and 1.03, respectively. Sediments taken from downstream sites, where residential and industrial regions were located, had elevated CUP concentrations and sediment toxicity compared with upstream sites. The present study is the first of its kind to link sediment CUPs, fipronil, and abamectin concentrations with toxicity in urban streams in China with a focus on shifting pesticide usage patterns. Copyright © 2013 SETAC.

A field trial of a fixed combination of permethrin and fipronil (Effitix®) for the treatment and prevention of flea infestation in dogs living with sheep.

PubMed

Chatzis, Manolis K; Psemmas, Dimitris; Papadopoulos, Elias; Navarro, Christelle; Saridomichelakis, Manolis N

2017-04-28

A large number of fleas parasitize dogs living with sheep in Greece. The primary aim of this randomized, blinded, placebo-controlled trial was to examine the efficacy of a permethrin-fipronil combination (Effitix ® ) for the treatment and prevention of flea infestation in dogs living with sheep and the secondary aim was to examine the efficacy of this intervention on flea infestation, pruritus and skin lesions of the people in contact with these dogs. Thirty dogs living with sheep and infested by at least 10 fleas and all 80 sheep living on the same premises were randomly allocated into equal groups. Group A dogs were treated three times, every 4 weeks, with a spot-on containing 54.5% permethrin and 6.1% fipronil, group A sheep were treated, on the same days, with a pour-on containing 1% deltamethrin, whereas group B dogs were sham-treated and group B sheep were placebo-treated. Flea counting was performed at the beginning of the trial (day 0) and after 14, 28, 56 and 84 days and the first five fleas from each animal were used for species identification. At the same time points, flea infestation, pruritus and skin lesions of the people in contact with the dogs were assessed. The percentage of dogs with zero flea counts was significantly higher in group A than in group B on days 14, 28, 56 and 84 and flea counts were significantly lower in group A dogs than in group B dogs at the same time points. The percent efficacy of the permethrin-fipronil combination was higher than 78% (arithmetic means) or than 96% (geometric means) throughout the study. No adverse reactions were recorded. Between the two flea species found on dogs, Ctenocephalides canis was predominant over C. felis. Flea-infected sheep were not found at the beginning or during the study and no significant changes in flea infestation, pruritus and skin lesions of the people in contact with the dogs were witnessed throughout the study. A spot-on solution containing 54.5% permethrin and 6.1% fipronil is safe and effective for the treatment and prevention of C. canis and C. felis infestations in dogs living with sheep.

miRNA-216 and miRNA-499 target cyb561d2 in zebrafish in response to fipronil exposure.

PubMed

Zhou, Yongyong; Huang, Hannian; Zhang, Kai; Ding, Xianfeng; Jia, Longlue; Yu, Liang; Zhu, Guonian; Guo, Jiangfeng

2016-07-01

MicroRNA (miRNA) can regulate the expression of its target gene by mediating mRNA cleavage or by translational repression at a post-transcriptional level. Usually, one miRNA may regulate many genes as its targets, while one gene may also be targeted by many miRNAs. We previously demonstrated that cyb561d2, whose protein product is involved in cell defense, and chemical stress, is targeted by miR-155 in adult zebrafish (Danio rerio) when exposed to fipronil (5-amino-1-[2,6-dichloro-4-(trifluoromethyl) phenyl]-4-[(trifluoromethyl) sulphinyl]-1H-pyrazole-3-carbonitrile). Microcosm Targets prediction showed that the cyb561d2 gene is also highly possibly targeted by miR-194a, miR-216b, miR-429, and miR-499. These interactions need to be further validated experimentally. In this study, we evaluated the effects of fipronil on miR-194a, miR-216b, miR-429, miR-499 and cyb561d2 in zebrafish and investigated whether these four miRNAs could regulate the expression of cyb561d2 in both mRNA and protein levels. The expression of cyb561d2 was upregulated in both mRNA and protein level in a dose-dependent manner upon stimulation of fipronil, and miR-216b and miR-499 were downregulated concurrently, whereas there was no significant changes were observed in the expression level of miR-194a and miR-429. The dual luciferase report assay demonstrated that miR-216b and miR-499 interacted with cyb561d2 3'-untranslated regions (3'-UTR), miR-194a and miR-429 did not stimulate degradation of cyb561d2 mRNA. The expression of cyb561d2 was reduced in both mRNA and protein level when ZF4 cells were transfected with miR-499 mimic, whereas expression level of both mRNA and protein was increased when endogenous miR-499 was inhibited by transfection with miR-499 inhibitor. Likewise, the mRNA and protein level of cyb561d2 was affected by treatment with the mimics and the inhibitor of miR-216b. In contrast, when ZF4 cells were transfected with a mimic of miR-194a or miR-429, the expression of cyb561d2 mRNA was not significantly changed. As a result, cyb561d2 is targeted by miR-155, miR-216b and miR-499 upon fipronil exposure, and miR-194a and miR-429 can not target cyb561d2. The expression pattern of these 3 miRNAs presents novel fipronil responses that could be used as a toxicological biomarker. Copyright © 2016 Elsevier B.V. All rights reserved.

75 FR 51040 - Issuance of an Experimental Use Permit by the State of Florida

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-18

... determine if the addition of mosquito ovitrap strips (Trap-N-Kill\\TM\\), impregnated with bifenthrin to existing mosquito management practices, will significantly reduce the abundance of the dengue mosquito...

Identification and expression profiles of nine glutathione S-transferase genes from the important rice phloem sap-sucker and virus vector Laodelphax striatellus (Fallén) (Hemiptera: Delphacidae).

PubMed

Zhou, Wen-Wu; Li, Xi-Wang; Quan, Yin-Hua; Cheng, Jiaan; Zhang, Chuan-Xi; Gurr, Geoff; Zhu, Zeng-Rong

2012-09-01

Glutathione S-transferases (GSTs) have received considerable attention in insects for their roles in insecticide resistance. Laodelphax striatellus (Fallén) is a serious rice pest. L. striatellus outbreaks occur frequently throughout eastern Asia. A key problem in controlling this pest is its rapid adaptation to numerous insecticides. In this research, nine cDNAs encoding GSTs in L. striatellus were cloned and characterised. The cloned GSTs of L. striatellus belonged to six cytosolic classes and a microsomal subgroup. Exposure to sublethal concentrations of each of the six insecticides, DDT, chlorpyrifos, fipronil, imidacloprid, buprofezin and beta-cypermethrin, quickly induced (6 h) up-expression of LsGSTe1. The expression of LsGSTs2 was increased by chlorpyrifos, fipronil and beta-cypermethrin. Furthermore, exposure of L. striatellus to fipronil, imidacloprid, buprofezin and beta-cypermethrin increased the expression of the LsGSTm gene after 24 or 48 h. This work is the first identification of GST genes from different GST groups in Auchenorrhyncha species and their induction characteristics with insecticide types and time. The elevated expression of GST genes induced by insecticides might be related to the enhanced tolerance of this insect to insecticides and xenobiotics. Copyright © 2012 Society of Chemical Industry.

Efficacy of a topical application of Certifect® (fipronil 6.26% w/v, amitraz 7.48% w/v, (S)-methoprene 5.63% w/v) for the treatment of canine generalized demodicosis.

PubMed

Fourie, Josephus; Dumont, Pascal; Halos, Lénaïg; Beugnet, Frederic; Pollmeier, Matthias

2013-01-01

The efficacy of the treatment with Certifect ® (containing fipronil 6.26% w/v, amitraz 7.48% w/v, (S)-methoprene 5.63% w/v) applied topically was assessed in 18 dogs diagnosed with clinical generalized demodicosis. Three treatment regimens were compared over a 3-month period. Starting at Day 0, dogs were treated monthly (group 1) or every two weeks (group 2) with the combination of fipronil, amitraz, and (S)-methoprene or with monthly topical applications of the combination of amitraz and metaflumizone (group 3, reference treatment). Clinical examinations including deep skin scrapings were performed every month in order to evaluate the resolution of clinical signs and the reduction in mite counts. On Day 84, the percentage reduction of mite counts in group 1 was 99.8%, whereas no Demodex canis could be detected in groups 2 and 3 (i.e. 100% parasitological efficacy). As a result of the Demodex mite count reduction, the skin condition of the dogs improved significantly in all groups. This study illustrates, that both monthly and bi-weekly treatments with Certifect were effective in treating dogs with generalized demodicosis over a 3-month period. © J. Fourie et al., published by EDP Sciences, 2013.

Efficacy of a topical application of Certifect® (fipronil 6.26% w/v, amitraz 7.48% w/v, (S)-methoprene 5.63% w/v) for the treatment of canine generalized demodicosis

PubMed Central

Fourie, Josephus; Dumont, Pascal; Halos, Lénaïg; Beugnet, Frederic; Pollmeier, Matthias

2013-01-01

The efficacy of the treatment with Certifect ® (containing fipronil 6.26% w/v, amitraz 7.48% w/v, (S)-methoprene 5.63% w/v) applied topically was assessed in 18 dogs diagnosed with clinical generalized demodicosis. Three treatment regimens were compared over a 3-month period. Starting at Day 0, dogs were treated monthly (group 1) or every two weeks (group 2) with the combination of fipronil, amitraz, and (S)-methoprene or with monthly topical applications of the combination of amitraz and metaflumizone (group 3, reference treatment). Clinical examinations including deep skin scrapings were performed every month in order to evaluate the resolution of clinical signs and the reduction in mite counts. On Day 84, the percentage reduction of mite counts in group 1 was 99.8%, whereas no Demodex canis could be detected in groups 2 and 3 (i.e. 100% parasitological efficacy). As a result of the Demodex mite count reduction, the skin condition of the dogs improved significantly in all groups. This study illustrates, that both monthly and bi-weekly treatments with Certifect were effective in treating dogs with generalized demodicosis over a 3-month period. PMID:24256940

Impact of fipronil on the mushroom bodies of the stingless bee Scaptotrigona postica.

PubMed

Jacob, Cynthia R O; Soares, Hellen M; Nocelli, Roberta C F; Malaspina, Osmar

2015-01-01

Studies on stingless bees are scarce, and little is known about these insects, especially regarding the effects of contamination by neurotoxic insecticides, which can cause damage to important structures of the insect brain. This study evaluated the morphological changes in the intrinsic neurons of the protocerebral mushroom bodies (Kenyon cells) of the stingless bee Scaptotrigona postica after exposure to different doses of fipronil, using light microscopy and transmission electron microscopy. This region of the brain was selected for analysis because of its importance as a sensory integration centre. In both oral and topical treatments, Kenyon cells presented pyknotic profiles, suggesting cell death. Statistical analysis showed significant differences among doses and exposure times. Transmission electron microscopy revealed changes in the nucleus and cellular organelles. Depending on the dose, the characteristics observed suggested apoptotosis or necrosis. This study demonstrates the toxic effects of fipronil. An increase in the number of pyknotic profiles of Kenyon cells of mushroom bodies was observed even at the sublethal doses of 0.27 ng AI bee(-1) and 0.24 ng AI µL(-1) in the topical and oral treatments respectively. Also, differences in the number of pyknotic profiles were dose and time dependent. © 2014 Society of Chemical Industry.

Field-relevant doses of the systemic insecticide fipronil and fungicide pyraclostrobin impair mandibular and hypopharyngeal glands in nurse honeybees (Apis mellifera).

PubMed

Zaluski, Rodrigo; Justulin, Luis Antonio; Orsi, Ricardo de Oliveira

2017-11-09

Global decreases in bee populations emphasize the importance of assessing how environmental stressors affect colony maintenance, especially considering the extreme task specialization observed in honeybee societies. Royal jelly, a protein secretion essential to colony nutrition, is produced by nurse honeybees, and development of bee mandibular glands, which comprise a reservoir surrounded by secretory cells and hypopharyngeal glands that are shaped by acini, is directly associated with production of this secretion. Here, we examined individual and combined effects of the systemic fungicide pyraclostrobin and insecticide fipronil in field-relevant doses (850 and 2.5 ppb, respectively) on mandibular and hypopharyngeal glands in nurse honeybees. Six days of pesticide treatment decreased secretory cell height in mandibular glands. When pyraclostrobin and fipronil were combined, the reservoir volume in mandibular glands also decreased. The total number of acini in hypopharyngeal glands was not affected, but pesticide treatment reduced the number of larger acini while increasing smaller acini. These morphological impairments appeared to reduce royal jelly secretion by nurse honeybees and consequently hampered colony maintenance. Overall, pesticide exposure in doses close to those experienced by bees in the field impaired brood-food glands in nurse honeybees, a change that could negatively influence development, survival, and colony maintenance.

Comparative Effectiveness of Insecticides for Use Against the House Fly (Diptera: Muscidae): Determination of Resistance Levels on a Malaysian Poultry Farm.

PubMed

Ong, Song-Quan; Ahmad, Hamdan; Jaal, Zairi; Rus, Adanan Che

2016-02-01

In this study, the toxicology of two commercial larvicides--cyromazine (Neporex 50SP) and ChCy (combination of chlorpyrifos and cypermethrin, Naga 505)--and five commercial adulticides--thiamethoxam (Agita 10WG), cyfluthrin (Responsar WP), lambda-cyhalothrin (Icon 2.8EC), fipronil (Regent 50SC), and imidacloprid (Toxilat 10WP)--was examined against the WHO/VCRU (World Health Organization/ Vector Control Research Unit) susceptible strain and the AYTW (Ayer Tawar) field strain of house fly, Musca domestica L. These pesticides were administered topically, in the diet, or as a dry residue treatment on plywood. Probit analysis using at least five concentrations and the concentration that was lethal to 50% (LC(50)) of the organisms was applied to compare the toxicology and resistance levels of the AYTW population to different insecticides. In the larvicide laboratory study, ChCy was more effective than cyromazine, with a significantly lower LC(50) value when administered topically or in the diet, although the AYTW population was susceptible to both larvicides with a resistance ratio (RR) <10. For the adulticide laboratory study, cyfluthrin and fipronil exhibited the lowest LC50 values of the adulticides, indicating that they are both effective at controlling adult flies, although lambda-cyhalothrin showed moderate resistance (RR = 11.60 by topical application; 12.41 by plywood treatment). Further investigation of ChCy, cyromazine, cyfluthrin, and fipronil under field conditions confirmed that ChCy and cyromazine strikingly reduced larval density, and surprisingly, ChCy also exhibited adulticidal activity, which significantly reduced adult fly numbers compared with the control group. Cyfluthrin and fipronil were also confirmed to be effective, with a significant reduction in adult fly numbers compared with the control group. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Assessment of the efficacy of a topical combination of fipronil-permethrin (Frontline Tri-Act®/Frontect®) against egg laying and adult emergence of the cat flea (Ctenocephalides felis) in dogs

PubMed Central

Beugnet, Frédéric; Halos, Lénaïg; Lebon, Wilfried; Liebenberg, Julian

2016-01-01

This study was conducted to assess the prevention of egg laying and the inhibition of the emergence of the cat flea (Ctenocephalides felis) resulting from the application of a combination of fipronil and permethrin (Frontline Tri-Act®/Frontect®, Merial) on dogs. Sixteen healthy dogs were included after pre-treatment live flea counts and randomly allocated to two groups. Eight dogs served as untreated controls and 8 dogs were treated on Day 0 and Day 30 with topical application of fipronil/permethrin at the minimum dose of 6.76 mg/kg fipronil and 50.48 mg/kg permethrin. On days −2, 7, 21, 28, 42 and 56, each dog was infested with 100 fleas. Flea eggs were collected from each dog in individual trays from 12 to 36 h after treatment or each flea re-infestation. All fleas were removed by combing and counted 36 h after treatment or infestations. The collected eggs were counted and incubated for 28 days for larval development and adult emergence assessment. The curative efficacy of Frontline Tri-Act®/Frontect® against adult fleas 36 h after treatment was 95.3% and the efficacy remained 100% after subsequent flea infestations for 8 weeks. Compared to the control group, the treatment reduced egg laying by 84.5% within 36 h after first treatment and was 99.9%, 100%, 100%, 100%, 100% on collection days 7, 21, 29, 43 and 57, respectively. Frontline Tri-Act®/Frontect® reduced by 28.7% the emergence of new adult fleas from eggs laid during the 48 h of pre-treatment infestation. The inhibition of adult emergence from incubated flea eggs could not be assessed after flea re-infestation in the treated group as no eggs were collected. PMID:27991415

Fate of organohalogens in US wastewater treatment plants and estimated chemical releases to soils nationwide from biosolids recycling.

PubMed

Heidler, Jochen; Halden, Rolf U

2009-12-01

This study examined the occurrence in wastewater of 11 aromatic biocides, pesticides and degradates, and their fate during passage through US treatment plants, as well as the chemical mass contained in sewage sludge (biosolids) destined for land application. Analyte concentrations in wastewater influent, effluent and sludge from 25 facilities in 18 US states were determined by liquid chromatography electrospray (tandem) mass spectrometry. Dichlorocarbanilide, fipronil, triclocarban, and triclosan were found consistently in all sample types. Dichlorophene, hexachlorophene, and tetrachlorocarbanilide were detected infrequently only, and concentrations of the phenyl urea pesticides diflubenzuron, hexaflumuron, and linuron were below the limit of detection in all matrixes. Median concentrations (+/-95% confidence interval) of quantifiable compounds in influent ranged from 4.2 +/- 0.8 microg L(-1) for triclocarban to 0.03 +/- 0.01 microg L(-1) for fipronil. Median concentrations in effluent were highest for triclocarban and triclosan (0.23 +/- 0.08 and 0.07 +/- 0.04 microg L(-1), respectively). Median aqueous-phase removal efficiencies (+/-95% CI) of activated sludge treatment plants decreased in the order of: triclosan (96 +/- 2%) > triclocarban (87 +/- 7%) > dichlorocarbanilide (55 +/- 20%) > fipronil (18 +/- 22%). Median concentrations of organohalogens were typically higher in anaerobically than in aerobically digested sludges, and peaked at 27 600 +/- 9600 and 15 800 +/- 8200 microg kg(-1) for triclocarban and triclosan, respectively. Mass balances obtained for three primary pesticides in six activated sludge treatment plants employing anaerobic digestion suggested a decreasing overall persistence from fipronil (97 +/- 70%) to triclocarban (87 +/- 29%) to triclosan (28 +/- 30%). Nationwide release of the investigated organohalogens to agricultural land via municipal sludge recycling and into surface waters is estimated to total 258 000 +/- 110 00 kg year(-1) (mean +/- 95% confidence interval), with most of this mass derived from antimicrobial consumer products of daily use. This study addresses some of the data gaps identified by the National Research Council in its 2002 study on standards and practices of biosolids application on land.

[Determination of eight pesticide residues in tea by liquid chromatography-tandem mass spectrometry and its uncertainty evaluation].

PubMed

Hu, Beizhen; Cai, Haijiang; Song, Weihua

2012-09-01

A method was developed for the determination of eight pesticide residues (fipronil, imidacloprid, acetamiprid, buprofezin, triadimefon, triadimenol, profenofos, pyridaben) in tea by liquid chromatography-tandem mass spectrometry. The sample was extracted by accelerated solvent extraction with acetone-dichloromethane (1:1, v/v) as solvent, and the extract was then cleaned-up with a Carb/NH2 solid phase extraction (SPE) column. The separation was performed on a Hypersil Gold C, column (150 mm x 2. 1 mm, 5 microm) and with the gradient elution of acetonitrile and 0. 1% formic acid. The eight pesticides were determined in the modes of electrospray ionization (ESI) and multiple reaction monitoring (MRM). The analytes were quantified by matrix-matched internal standard method for imidacloprid and acetamiprid, by matrix-matched external standard method for the other pesticides. The calibration curves showed good linearity in 1 - 100 microg/L for fipronil, and in 5 -200 microg/L for the other pesticides. The limits of quantification (LOQs, S/N> 10) were 2 p.g/kg for fipronil and 10 microg/kg for the other pesticides. The average recoveries ranged from 75. 5% to 115.0% with the relative standard deviations of 2.7% - 7.7% at the spiked levels of 2, 5, 50 microg/kg for fipronil and 10, 50, 100 microg/kg for the other pesticides. The uncertainty evaluation for the results was carried out according to JJF 1059-1999 "Evaluation and Expression of Uncertainty in Measurement". Items constituting measurement uncertainty involved standard solution, weighing of sample, sample pre-treatment, and the measurement repeatability of the equipment were evaluated. The results showed that the measurement uncertainty is mainly due to sample pre-treatment, standard curves and measurement repeatability of the equipment. The method developed is suitable for the conformation and quantification of the pesticides in tea.

Potential of contact insecticides to control Xyleborus glabratus (Coleoptera: Curculionidae), a vector of laurel wilt disease in avocados.

PubMed

Carrillo, Daniel; Crane, Jonathan H; Peña, Jorge E

2013-12-01

Xyleborus glabratus Eichhoff (Coleoptera: Curculionidae: Scolytinae) is an invasive ambrosia beetle that vectors laurel wilt, a new disease that threatens avocado and other species in the Lauraceae Family. The lethal concentrations (LC50 & 90) of nine commercial insecticides to X. glabratus were determined by using a bolt-dip bioassay. Different formulations of bifenthrin, permethrin, fenpropathrin, z-cypermethrin + bifenthrin, 1-cyhalothrin + thiamethoxam, malathion, chlorpyrifos, carbaryl, and methomyl were tested. Four concentrations of each insecticide were tested (0.5, 0.1, 0.03, and 0.01 of the label rate) and with water as a control. Beetles were exposed to treated bolts and mortality registered 48 h later. After 2 wk, bolts were destructively sampled to determine the number of beetles that constructed galleries and were alive inside the wood. Probit analysis was used to determine the LC50 & 90. Six pesticides were applied directly to the trunk and limbs of avocado trees in a commercial grove. Limbs of treated trees were cut weekly after the application and exposed to X. glabratus to determine the number of beetles boring into the logs. The toxicity of pesticides to X. glabratus was greatly reduced 2 wk after application. Among the tested pesticides, malathion and z-cypermethrin + bifenthrin provided the best suppression of X. glabratus. Among the insecticides registered for use in avocado, fenpropathrin and malathion were the most effective in protecting trees from attack by X. glabratus. Other pesticides that are currently not registered for use in avocados could be useful for managing this ambrosia beetle.

Formulating nanoparticles by flash nanoprecipitation for drug delivery and sustained release

NASA Astrophysics Data System (ADS)

Liu, Ying

This dissertation provides a fundamental understanding of the process for generating nanoparticles with controlled size distribution and of predicting nanoparticle stability for drug delivery and sustained release. We developed and characterized a novel technology to generate organic and inorganic nanoparticles protected by biocompatible and biodegradable polymers with precisely controlled size and size distribution. Computational fluid mechanics (CFD) together with experimental results provided details of the micromixing in the mixer. The particle size dependence on Reynolds number and supersaturation was illustrated. The study of the fundamental mass transfer phenomena leading to Ostwald ripening enables quantitative prediction of the time evolution of nanoparticles with monodistribution and relatively broader multi-distribution using beta-carotene and polystyrene-b-poly(ethylene oxide) (PS-b-PEO) as a model system. Negatively charged latex particles were used to exam the attachment of the diblock copolymer, PS-b-PEO, on the surface. The stability provided by the Columbic repulsion was replaced by steric stabilization. The attachment of the block copolymers on the surface of the colloids depends on the flow field, i.e. Reynolds number, of the mixing process. The slow degradation of poly(epsilon-caprolactone) (PCL) and poly(gamma-methyl-epsilon-caprolactone) (PMCL) was demonstrated. The slow degradation ensures long-term stability and long-term blood circulation of the polymeric nanoparticles. As a practical application, we formulate the anti-tuberculosis drug, rifampicin, into nanoparticles by conjugation to other hydrophobic molecules (such as vitamin E, PCL and 2-ethylhexyl vinyl ether) by pH sensitive cleavable chemical bonds to increase the drug loading, return stability of the nanoparticle suspension, and control drug release. The in vitro release profiles were provided by using HPLC and E.coli growth inhibition on LB agar plates. The prodrug nanoparticle suspensions were spray dried to form low density porous micro-particles for the purpose of aerosol drug delivery. The simultaneous encapsulation of imaging agents and therapeutic agents provides a method for studying the fate of nanoparticles and for medical imaging with treatment. As another example, bifenthrin nanoparticle suspensions with various stabilizers were formulated. The pesticide, bifenthrin, was used to test whether nanoparticles provided an advantage in increasing the effectiveness of pesticide formulations. Larvae mortality with the application of nanoparticle suspension was about 2.5 times of the mortality with the application of bifenthrin mineral oil solution. Nanoparticles at very low bifenthrin concentration showed sustained release for fourteen days.

Efficacy in cats of a novel topical combination of fipronil, (S)-methoprene, eprinomectin, praziquantel, against induced infestations of Echinococcus multilocularis.

PubMed

Tielemans, Eric; Manavella, Coralie; Visser, Martin; Theodore Chester, S; Rosentel, Joseph

2014-04-28

Although foxes are the main reservoir of Echinococcus multilocularis, it is recognized that dogs and cats also may become infected. In cats the infection and egg production rates are usually low. Nevertheless, cats are a potential source of transmission of E. multilocularis. Due to the high human medical significance of E. multilocularis infection, it is important in endemic areas that owned cats are dewormed regularly. This paper presents the efficacy results of a new topical formulation, Broadline(®) (Merial) tested against E. multilocularis infection in cats. Two blinded laboratory studies were conducted to evaluate this novel topical combination of fipronil, (S)-methoprene, eprinomectin, and praziquantel against E. multilocularis. In each study, purpose-bred cats were assigned randomly to two treatment groups of 10 cats each: one untreated control group and one group treated at the minimum therapeutic dose of 0.12 mL/kg bodyweight to deliver 10mg fipronil, 12 mg (S)-methoprene, 0.5mg eprinomectin and 10mg praziquantel/kg bodyweight. The cats were inoculated orally with E. multilocularis protoscolices, 22 or 23 days before treatment. Based on necropsy and intestinal worm count, 8 or 11 days after treatment, the two studies confirmed 100% efficacy of Broadline(®) against adult E. multilocularis. Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.

In vitro tests to establish LC50 and discriminating concentrations for fipronil against Rhipicephalus (Boophilus) microplus (Acari: Ixodidae) and their standardization.

PubMed

Castro-Janer, E; Rifran, L; Piaggio, J; Gil, A; Miller, R J; Schumaker, T T S

2009-05-26

Laboratory test was carried out on larvae and adults of the cattle tick, Rhipicephalus (Boophilus) microplus, to determine fipronil toxicity. Adult immersion test (AIT, N=26), larval immersion test (LIT, N=71) and larval packet test (LPT, N=41) were standardized using susceptible strain (Mozo). Dose-response curves were compared with a fipronil resistant strain. Four variables were analyzed from AIT results: mortality, weight of eggs on day 7 and on day 14, index of fertility, and index of fecundity. For larval test, dose mortality curves were analyzed. In spite of the high LC(50) variability, all variables determined for AIT were appropriate to discriminate both strains. AIT and LIT had more sensitivity than LPT, with larger resistance factors. It was used two times LC(99.9) as discriminating doses (DCs) following FAO suggestion. For mortality by AIT, LIT and LPT the DCs were estimated: 4.98ppm, 7.64ppm and 2365.8ppm, respectively, for Mozo strain. DCs mortality values estimated for resistant strain by AIT, LIT and LPT were: 6.96x10(5)ppm, 343.26ppm and 5.7x10(3)ppm, respectively and their respective resistant factors were: 202.4, 5.36 and 1.52. Protocols for AIT, LIT and LPT have been presented in this paper.

Correlation of tissue concentrations of the pyrethroid bifenthrin with neurotoxicity in the rat

EPA Science Inventory

Pyrethroids are neurotoxic insecticides used in a variety of agricultural and household products. Due to the phase-out oforganophosphate pesticides, the use of pyrethroids has increased. The potential for human exposure to pyrethroids has prompted pharmacodynamic and pharmacokine...

Evaluation of various soaking agents as a novel tool for pesticide residues mitigation from cauliflower (Brassica oleracea var. botrytis).

PubMed

Abdullah; Randhawa, Muhammad Atif; Asghar, Ali; Pasha, Imran; Usman, Rabia; Shamoon, Muhammad; Bhatti, Muhammad Arslan; Irshad, Muhammad Asim; Ahmad, Naveed

2016-08-01

The increasing use of pesticides for boosting the yield of agricultural crops also impart toxic residues which ultimately extend to numerous physiological disorders upon consumption. The present study was designed as an effort to assess the reduction potential of various chemical solutions and to minimize the pesticide residues in cauliflower ( Brassica oleracea var. botrytis ). The samples were soaked in various solutions along with tap water to mitigate pesticide residues. Afterwards, the extracted supernatant was passed through column containing anhydrous sodium sulfate trailed by activated carbon for clean-up. Eluents were first evaporated and then completely dried under gentle stream of Nitrogen. Finally, the residues were determined using gas chromatography equipped with electron capture detector (GC-ECD). Results revealed the highest reduction of endosulfan, bifenthrin and cypermethrin residues with acetic acid (10 %) was 1.133 ± 0.007 (41 %), 0.870 ± 0.022 (60 %) and 0.403 ± 0.003 (75 %), respectively among the tested solutions. However, simple tap water treatment also resulted in 0.990 ± 0.02 (12 %), 1.323 ± 0.015 (14 %) and 1.274 ± 0.002 (21 %) elimination of endosulfan, bifenthrin and cypermethrin residues, respectively. Moreover, among various solutions, acetic acid depicted maximum reduction potential followed by citric acid, hydrogen peroxide, sodium chloride and sodium carbonate solutions. The percent reduction by various solutions ranged from 12 to 41, 14 to 60 and 21 to 75 % for the elimination of endosulfan, bifenthrin and cypermethrin residues, respectively.

Impact of Pesticide Resistance on Toxicity and Tolerance of Hostplant Phytochemicals in Amyelois Transitella (Lepidoptera: Pyralidae)

PubMed Central

Bagchi, Vikram A.; Siegel, Joel P.; Demkovich, Mark R.; Zehr, Luke N.; Berenbaum, May R.

2016-01-01

For some polyphagous insects, adaptation to phytochemically novel plants can enhance resistance to certain pesticides, but whether pesticide resistance expands tolerance to phytochemicals has not been examined. Amyelois transitella Walker (navel orangeworm) is an important polyphagous pest of nut and fruit tree crops in California. Bifenthrin resistance, partially attributable to enhanced cytochrome P450 (P450)-mediated detoxification, has been reported in an almond-infesting population exposed to intense pesticide selection. We compared the toxicity of bifenthrin and three phytochemicals–chlorogenic acid, and the furanocoumarins xanthotoxin and bergapten–to three strains of A. transitella: pyrethroid-resistant R347 (maintained in the laboratory for ∼10 generations), fig-derived FIG (in the laboratory for ∼25 generations), and CPQ–a laboratory strain derived from almonds ∼40 years ago). Whereas both Ficus carica (fig) and Prunus dulcis (almond) contain chlorogenic acid, furanocoumarins occur only in figs. Both R347 and FIG exhibited 2-fold greater resistance to the three phytochemicals compared with CPQ; surprisingly, bifenthrin resistance was highest in FIG. Piperonyl butoxide, a P450 synergist, increased toxicity of all three phytochemicals only in CPQ, implicating alternate tolerance mechanisms in R347 and FIG. To test the ability of the strains to utilize novel hostplants directly, we compared survival on diets containing seeds of Wisteria sinensis and Prosopis pallida, two non-host Fabaceae species; survival of FIG was highest and survival of R347 was lowest. Our results suggest that, while P450-mediated pesticide resistance enhances tolerance of certain phytochemicals in this species, it is only one of multiple biochemical adaptations associated with acquiring novel hostplants. PMID:27620560

Pesticide concentrations in water and sediment and associated invertebrate toxicity in Del Puerto and Orestimba Creeks, California, 2007-2008.

PubMed

Ensminger, Michael; Bergin, Rick; Spurlock, Frank; Goh, Kean S

2011-04-01

The California's San Joaquin River and its tributaries including Orestimba (ORC) and Del Puerto (DPC) Creeks are listed on the 2006 US EPA Clean Water Act §303(d) list for pesticide impairment. From December 2007 through June 2008, water and sediment samples were collected from both creeks in Stanislaus County to determine concentrations of organophosphorus (OP) and pyrethroid insecticides and to identify toxicity to Ceriodaphnia dubia and Hyalella azteca. OPs were detected in almost half (10 of 21) of the water samples, at concentrations from 0.005 to 0.912 μg L(-1). Diazinon was the most frequently detected OP, followed by chlorpyrifos and dimethoate. Two water samples were toxic to C. dubia; based on median lethal concentrations (LC50), chlorpyrifos was likely the cause of this toxicity. Pyrethroids were detected more frequently in sediment samples (18 detections) than in water samples (three detections). Pyrethroid concentrations in water samples ranged from 0.005 to 0.021 μg L(-1). These concentrations were well below reported C. dubia LC50s, and toxicity was not observed in laboratory bioassays. Cyfluthrin, bifenthrin, esfenvalerate, and λ-cyhalothrin were detected in sediment samples at concentrations ranging from 1.0 to 74.4 ng g(-1), dry weight. At DPC, all but one sediment sample caused 100% toxicity to H. azteca. Based on estimated toxicity units (TUs), bifenthrin was likely responsible for this toxicity and λ-cyhalothrin also contributed. At ORC, survival of H. azteca was significantly reduced in four of the 11 sediment samples. However, pyrethroids were detected in only two of these samples. Based on TUs, bifenthrin and λ-cyhalothrin likely contributed to the toxicity.

Toxicity of seven foliar insecticides to four insect parasitoids attacking citrus and cotton pests.

PubMed

Prabhaker, Nilima; Morse, J G; Castle, S J; Naranjo, S E; Henneberry, T J; Toscano, N C

2007-08-01

Laboratory studies were carried out to compare the toxicity of seven foliar insecticides to four species of adult beneficial insects representing two families of Hymenoptera: Aphelinidae (Aphytis melinus Debach, Eretmocerus eremicus Rose & Zolnerowich, and Encarsiaformosa Gahan) and Mymaridae (Gonatocerus ashmeadi Girault) that attack California red scale, Aonidiella aurantii (Maskell); sweetpotato whitefly, Bemisia tabaci (Gennadius) (both E. eremicus and E. formosa); and glassy-winged sharpshooter, Homalodisca vitripennis (Germar), respectively. Insecticides from four pesticide classes were evaluated using a petri dish bioassay technique across a range of concentrations to develop dosage-mortality regressions. Insecticides tested included acetamiprid (neonicotinoid); chlorpyrifos (organophosphate); bifenthrin, cyfluthrin, and fenpropathrin (pyrethroids); and buprofezin and pyriproxyfen (insect growth regulators [IGRs]). Chlorpyrifos was consistently the most toxic pesticide to all four species of beneficial insects tested based on LC50 values recorded 24 h posttreatment compared with 48-h LC50 values with the neonicotinoid and pyrethroids or 96 h with the IGRs. Among the three pyrethroids, fenpropathrin was usually less toxic (except similar toxicity to A. melinus) than was cyfluthrin, and it was normally less toxic (except similar toxicity with E. formosa) than was bifenthrin. Acetamiprid was generally less toxic than bifenthrin (except similar toxicity with G. ashmeadi). The IGRs buprofezin and pyriproxyfen were usually less toxic than the contact pesticides, but we did not test for possible impacts on female fecundity. For all seven pesticides tested, A. melinus was the most susceptible parasitoid of the four test species. The data presented here will provide pest managers with specific information on the compatibility of select insecticides with natural enemies attacking citrus and cotton, Gossypium hirsutum L., pests.

Effects of Insecticides and Fungicides Commonly Used in Tomato Production on Phytoseiulus persimilis (Acari: Phtyoseiidae).

PubMed

Ditillo, J L; Kennedy, G G; Walgenbach, J F

2016-12-01

The twospotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae), is an important pest of tomatoes in North Carolina. Resident populations of the predatory mite Phytoseiulus persimilis have recently been detected on field-grown tomatoes in central North Carolina, and potentially can be a useful biological control agent against T. urticae Laboratory bioassays were used to assess lethal and reproductive effects of 10 insecticides and five fungicides commonly used in commercial tomato production (chlorantraniliprole, spinetoram, permethrin, imidacloprid, dimethoate, dinotefuran, thiamethoxam, bifenthrin, fenpropathrin, lambda-cyhalothrin, azoxystrobin, chlorothalonil, boscalid, cyazofamid, and mancozeb) on P. persimilis adult females and eggs. Insecticides were tested using concentrations equivalent to 1×, 0.5×, and 0.1× of the recommended field rates. Fungicides were tested at the 1× rate only. Dimethoate strongly impacted P. persimilis with high adult mortality, reduced fecundity, and reduced hatch of eggs laid by treated adults, particularly at high concentrations. The pyrethroids lambda-cyhalothrin, bifenthrin, and fenpropathrin were associated with repellency and reproductive effects at high concentrations. Bifenthrin additionally caused increased mortality at high concentrations. Chlorantraniliprole, dinotefuran, and permethrin did not significantly affect mortality or reproduction. Imidacloprid significantly reduced fecundity and egg viability, but was not lethal to adult P. persimilis Thiamethoxam negatively impacted fecundity at the 1× rate. There were no negative effects associated with fungicide exposure with the exception of mancozeb, which impacted fecundity. Field trials were conducted to explore the in vivo impacts of screened insecticides on P. persimilis populations in the field. Field trials supported the incompatibility of dimethoate with P. persimilis populations. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Impact of Pesticide Resistance on Toxicity and Tolerance of Hostplant Phytochemicals in Amyelois Transitella (Lepidoptera: Pyralidae).

PubMed

Bagchi, Vikram A; Siegel, Joel P; Demkovich, Mark R; Zehr, Luke N; Berenbaum, May R

2016-01-01

For some polyphagous insects, adaptation to phytochemically novel plants can enhance resistance to certain pesticides, but whether pesticide resistance expands tolerance to phytochemicals has not been examined. Amyelois transitella Walker (navel orangeworm) is an important polyphagous pest of nut and fruit tree crops in California. Bifenthrin resistance, partially attributable to enhanced cytochrome P450 (P450)-mediated detoxification, has been reported in an almond-infesting population exposed to intense pesticide selection. We compared the toxicity of bifenthrin and three phytochemicals-chlorogenic acid, and the furanocoumarins xanthotoxin and bergapten-to three strains of A. transitella: pyrethroid-resistant R347 (maintained in the laboratory for ∼10 generations), fig-derived FIG (in the laboratory for ∼25 generations), and CPQ-a laboratory strain derived from almonds ∼40 years ago). Whereas both Ficus carica (fig) and Prunus dulcis (almond) contain chlorogenic acid, furanocoumarins occur only in figs. Both R347 and FIG exhibited 2-fold greater resistance to the three phytochemicals compared with CPQ; surprisingly, bifenthrin resistance was highest in FIG. Piperonyl butoxide, a P450 synergist, increased toxicity of all three phytochemicals only in CPQ, implicating alternate tolerance mechanisms in R347 and FIG. To test the ability of the strains to utilize novel hostplants directly, we compared survival on diets containing seeds of Wisteria sinensis and Prosopis pallida, two non-host Fabaceae species; survival of FIG was highest and survival of R347 was lowest. Our results suggest that, while P450-mediated pesticide resistance enhances tolerance of certain phytochemicals in this species, it is only one of multiple biochemical adaptations associated with acquiring novel hostplants. © The Author 2016. Published by Oxford University Press on behalf of the Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Magnetic solid-phase extraction of heterocyclic pesticides in environmental water samples using metal-organic frameworks coupled to high performance liquid chromatography determination.

PubMed

Ma, Jiping; Wu, Gege; Li, Shuang; Tan, Weiqiang; Wang, Xiaoyan; Li, Jinhua; Chen, Lingxin

2018-06-08

A simple method of magnetic solid-phase extraction (MSPE) coupled to high performance liquid chromatography (HPLC) was developed for the simultaneous extraction and determination of four kinds of heterocyclic pesticides (carbendazim, triadimefon, chlorfenapyr and fenpyroximate) in environmental water samples. Magnetic metal-organic frameworks (MOFs) of type MOF-5 were prepared and used as adsorbents of MSPE. Several main parameters influencing MSPE efficiency were investigated, including amount of magnetic MOF-5, sample solution pH, extraction time, salt concentration, type and volume of desorption solvents and desorption time. Under optimal conditions, the MSPE-HPLC method presented fast simple separation and analysis, and excellent linearity in the range of 0.3-500.0 μg/L for carbendazim and triadimefon, and 0.1-500.0 μg/L for chlorfenapyr and fenpyroximate, with correlation coefficients (r) higher than 0.9992. High sensitivity with limits of detection and quantification ranging from 0.04-0.11 μg/L and 0.13-0.35 μg/L, respectively, were achieved, as well as good precision with relative standard deviations of 2.98-7.11% (intra-day) and 3.31-7.12% (inter-day). Furthermore, the method was successfully applied to reservoir and Yellow River water samples, and satisfactory recoveries at three spiked concentration levels were between 80.20% and 108.33%.The magnetic MOF-5 composites based MSPE followed by HPLC proved promising for convenient and efficient determination of heterocyclic pesticides in environmental water samples. Copyright © 2018 Elsevier B.V. All rights reserved.

Comparison of subacute effects of two types of pyrethroid insecticides using metabolomics methods.

PubMed

Miao, Jiyan; Wang, Dezhen; Yan, Jin; Wang, Yao; Teng, Miaomiao; Zhou, Zhiqiang; Zhu, Wentao

2017-11-01

In this study, 1 H NMR based metabolomics analysis, LC-MS/MS based serum metabolomics and histopathology techniques were used to investigate the toxic effects of subacute exposure to two types of pyrethroid insecticides bifenthrin and lambda-cyhalothrin in mice. Metabolomic analysis of tissues extracts and serum showed that these two types of pyrethroid insecticides resulted in alterations of metabolites in the liver, kidney and serum of mice. Based on the altered metabolites, several significant pathways were identified, which are associated with gut microbial metabolism, lipid metabolism, nucleotide catabolism, tyrosine metabolism and energy metabolism. The results showed that bifenthrin and lambda-cyhalothrin have similarities in disruption of metabolic pathways in kidney, indicating that the toxicological mechanisms of these two types of insecticides have some likeness to each other. This study may provide novel insight into revealing differences of toxicological mechanisms between these two types of pyrethroid insecticides. Copyright © 2017 Elsevier Inc. All rights reserved.

Spatial and Temporal Distribution of Current-Use Pesticides in Atmospheric Particulate Matter in Houston, Texas.

PubMed

Clark, Adelaide E; Yoon, Subin; Sheesley, Rebecca J; Usenko, Sascha

2016-12-01

The atmospheric concentrations of seven current-use pesticides in particulate matter were determined at four locations throughout the Houston metropolitan area in TSP and PM 2.5 samples from September 2013. Atmospheric concentrations in both TSP and PM 2.5 ranged from below method detection limits (MDLs) to nearly 1100 pg m -3 . The three compounds most frequently detected above MDLs were chlorothalonil, bifenthrin, and λ-cyhalothrin. Atmospheric chlorothalonil concentrations were above 800 pg m -3 in several TSP samples, but

Direct Detection of Potential Pyrethroids in Yangtze River via an Imprinted Multilayer Phosphorescence Probe.

PubMed

Chen, Li; Lv, Xiaodong; Dai, Jiangdong; Sun, Lin; Huo, Pengwei; Li, Chunxiang; Yan, Yongsheng

2018-01-01

A novel tailored multilayer probe for monitoring potential pyrethroids in the Yangtze River was proposed. The room-temperature phosphorescence method was applied to realize a detection strategy that is superior to the fluorescence method. Efficient Mn-doped ZnS quantum dots with uniform size of 4.6 nm were firstly coated with a mesoporous silica to obtain a suitable intermediate transition layer, then an imprinted layer containing bifenthrin specific recognition sites was anchored. Characterizations verified the multilayer structure convincingly and the detection process relied on the electron transfer-induced fluorescence quenching mechanism. Optional detection time and standard detection curve were obtained within a concentration range from 5.0 to 50 μmol L -1 . The stability was verified to be good after 12 replicates. Feasibility of the probe was proved by monitoring water samples from the Zhenjiang reach of the Yangtze River. The probe offers promise for direct bifenthrin detection in unknown environmental water with an accurate and stable phosphorescence analysis strategy.

A test house study of pesticides and pesticide degradation products following an indoor application.

PubMed

Starr, J M; Gemma, A A; Graham, S E; Stout, D M

2014-08-01

Preexisting pesticide degradates are a concern for pesticide biomonitoring studies as exposure to them may result in overestimation of pesticide exposure. The purpose of this research was to determine whether there was significant formation and movement, of pesticide degradates over a 5-week period in a controlled indoor setting after insecticide application. Movement of the pesticides during the study was also evaluated. In a simulated crack and crevice application, commercially available formulations of fipronil, propoxur, cis/trans-permethrin, and cypermethrin were applied to a series of wooden slats affixed to the wall in one room of an unoccupied test house. Floor surface samples were collected through 35 days post-application. Concentrations of the pesticides and the following degradates were determined: 2-iso-propoxyphenol, cis/trans 3-(2,2-dichlorovinyl)-3-3-dimethyl-(1-cyclopropane) carboxylic acid, 3-phenoxybenzoic acid, fipronil sulfone, fipronil sulfide, and fipronil desulfinyl. Deltamethrin, which had never been applied, and chlorpyrifos, which had been applied several years earlier, and their degradation products, cis-3-(2,2-dibromovinyl)-2,2-dimethylcyclopropane-1-carboxylic acid, and, 3,5,6-trichloro-2-pyridinol, respectively, were also measured. Propoxur was the only insecticide with mass movement away from the application site. There was no measurable formation or movement of the degradates. However, all degradates were present at low levels in the formulated product. These results indicate longitudinal repetitive sampling of indoor degradate levels during short-term studies, is unnecessary. Exposure to preexisting pesticide degradates may inflate estimates of exposure in biomonitoring studies where these compounds are used as biomarkers. To date, there is no published information on formation of pesticide degradates following an indoor application. We found that the study pesticides have low rates of degradation and are unlikely to be a significant factor affecting results of short-term (weeks) biomonitoring studies. Therefore, relatively few indoor samples are needed to estimate background levels of degradation products resulting from a recent pesticide application. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.

Fate of Organohalogens in U.S. Wastewater Treatment Plants and Estimated Chemical Releases to Soils Nationwide from Biosolids Recycling

PubMed Central

Heidler, Jochen; Halden, Rolf U.

2009-01-01

This study examined the occurrence in wastewater of 11 aromatic biocides, pesticides and degradates, and their fate during passage through U.S. treatment plants, as well as the chemical mass contained in sewage sludge (biosolids) destined for land application. Analyte concentrations in wastewater influent, effluent and sludge from 25 facilities in 18 U.S. states were determined by liquid chromatography electrospray (tandem) mass spectrometry. Dichlorocarbanilide, fipronil, triclocarban, and triclosan were found consistently in all sample types. Dichlorophene, hexachlorophene, and tetrachlorocarbanilide were detected infrequently only, and concentrations of the phenyl urea pesticides diflubenzuron, hexaflumuron, and linuron were below the limit of detection in all matrixes. Median concentrations (± 95% confidence interval) of quantifiable compounds in influent ranged from 4.2 ± 0.8 µg L−1 for triclocarban to 0.03 ± 0.01 µg L−1 for fipronil. Median concentrations in effluent were highest for triclocarban and triclosan (0.23 ± 0.08 and 0.07 ± 0.04 µg L−1, respectively). Median aqueous-phase removal efficiencies (± 95% CI) of activated sludge treatment plants decreased in the order of: triclosan (96 ± 2%) > triclocarban (87 ± 7%) > dichlorocarbanilide (55 ± 20%) > fipronil (18 ± 22%). Median concentrations of organohalogens were typically higher in anaerobically than in aerobically digested sludges, and peaked at 27,600 ± 9,600 and 15,800 ± 8,200 µg kg−1 for triclocarban and triclosan, respectively. Mass balances obtained for three primary pesticides in six activated sludge treatment plants employing anaerobic digestion suggested a decreasing overall persistence from fipronil (97 ± 70%) to triclocarban (87 ± 29%) to triclosan (28 ± 30%). Nationwide release of the investigated organohalogens to agricultural land via municipal sludge recycling and into surface waters is estimated to total 258,000 ± 110,00 kg yr−1 (mean ± 95% confidence interval), with most of this mass derived from antimicrobial consumer products of daily use. This study addresses some of the data gaps identified by the National Research Council in its 2002 study on standards and practices of biosolids application on land. PMID:20024018

Repellent and insecticidal efficacy of a new combination of fipronil and permethrin against the main vector of canine leishmaniosis in Europe (Phlebotomus perniciosus).

PubMed

Dumont, Pascal; Fankhauser, Becky; Bouhsira, Emilie; Lienard, Emmanuel; Jacquiet, Philippe; Beugnet, Frederic; Franc, Michel

2015-01-27

Two successive laboratory experiments (A and B) were conducted to confirm the efficacy of a new fipronil and permethrin combination to repel and kill Phlebotomus perniciosus sandflies when applied once topically on dogs. Due to the difficulty to get enough available dogs and sandflies in one run, the study was divided into 2 experiments which had exactly the same design, and were conducted at the same place, with the same technicians. They compared dogs treated with a combination containing 67.6 mg/mL fipronil + 504.8 mg/mL permethrin (Frontect/Frontline Tri-Act, Merial) to untreated dogs. The treatments were applied topically once on Day 0. Sandfly exposures were performed on Days 1, 7, 14, 21 and 29 with 80 P. perniciosus female sandflies. After 60 min, sandflies were assessed for vitality and engorgement status. Live sandflies were kept in an insectary and observed for mortality counts 4 h after the exposure period ended. Percent sandfly repellency on treated dogs was 98.2, 98.5, 99.2, 90.9 and 90.3%, for Days 1, 7, 14, 21, and 29, respectively. There was a significant difference (p ≤ 0.05) between the treated and control groups in both experiments and for the pooled data on every assessment day. Insecticidal efficacy on treated dogs at 4 h post-exposure on Days 1, 7, 14, 21 and 29 was 98.7, 99.7, 96.8, 93.4, and 78.9%, respectively. There was a significant difference between the treated and control groups for live sandflies observed at 4 h post-exposure for all assessment days (p < 0.05). A single topical administration of a new combination of fipronil and permethrin demonstrated a significant repellent effect (i.e., > 80%) against P. perniciosus which lasted for 29 days after application. The repellent effect was accompanied by a significant insecticidal effect on sandflies. The results suggest that in endemic areas, the application of the fipronil-permethrin combination could be integrated into canine leishmaniosis prevention program.

IN VIVO DERMAL ABSORPTION OF PYRETHROID PESTICIDES IN THE RAT

EPA Science Inventory

The potential for exposure to pyrethroid pesticides has risen recently because of their increased agricultural and residential use. The objective of this study was to examine the in vivo dermal absorption of bifenthrin, deltamethrin and cis-permethrin in the rat. Hair on...

77 FR 56782 - Bifenthrin; Pesticide Tolerances

Federal Register 2010, 2011, 2012, 2013, 2014

2012-09-14

..., hay. Interregional Research Project Number 4 (IR-4) requested these tolerances under the Federal Food... OCSPP test guidelines referenced in this document electronically, please go to http://www.epa.gov/ocspp and select ``Test Methods and Guidelines.'' C. How can I file an objection or hearing request? Under...

In vivo dermal absorption of pyrethroid pesticides in the rat.

EPA Science Inventory

The potential for exposure to pyrethroid pesticides has risen recently because of their increased use. The objective of this study was to examine the in vivo dermal absorption of bifenthrin, deltamethrin and permethrin in the rat. Hair on the dorsal side of anesthetized adult m...

BLOOD AND BRAIN CONCENTRATIONS OF BIFENTHRIN CORRELATE WITH DECREASED MOTOR ACTIVITY INDEPENDENT OF TIME OF EXPOSURE

EPA Science Inventory

Pyrethroids are neurotoxic insecticides used in a variety of agricultural and household activities. Due to the phase-out of organophosphate pesticides, the use of pyrethroids has increased. The potential for human exposure to pyrethroids has prompted pharmacodynamic and pharmac...

77 FR 63829 - Product Cancellation Order for Certain Pesticide Registrations

Federal Register 2010, 2011, 2012, 2013, 2014

2012-10-17

.... 053883-00259 Termini 9.1 SC... Fipronil. CO080003 Endura Fungicide. Boscalid. MD080002 Ridomil Gold Copper hydroxide Copper. D-Alanine, N-(2,6- dimethylphenyl)-N- (methoxyacetyl)-, methyl ester. OR000023...

Effects of insecticides chlorpyrifos, emamectin benzoate and fipronil on Spodoptera litura might be mediated by OBPs and CSPs.

PubMed

Lin, X; Jiang, Y; Zhang, L; Cai, Y

2017-12-04

Spodoptera litura is a widespread polyphagous insect pest that can develop resistance and cross-resistance to insecticides, making it difficult to control. Insecticide exposure has previously been linked with induction of specific olfactory-related proteins, including some chemosensory proteins (CSPs) and odorant-binding proteins (OPBs), which may disrupt detection of environmental factors and reduce fitness. However, functional evidence supporting insecticide and OBPs/CSPs mediation remains unknown. Here we fed male S. litura moths with sucrose water containing one of three insecticides, chlorpyrifos, emamectin benzoate or fipronil, and used real-time quantitative polymerase chain reaction and RNAi to investigate OBPs and CSPs expression and their correlations with survival. Chlorpyrifos and emamectin benzoate increased expression of 78% of OBPs, plus 63 and 56% of CSP genes, respectively, indicating a major impact on these gene families. RNAi knockdown of SlituCSP18, followed by feeding with chlorpyrifos or fipronil, decreased survival rates of male moths significantly compared with controls. Survival rate also decreased significantly with the downregulation of SlituOBP9 followed by feeding with chlorpyrifos. Thus, although these three insecticides had different effects on OBP and CSP gene expression, we hypothesize that SlituOBPs and SlituCSPs might mediate their effects by increasing their expression levels to improve survival. Moreover, the differential response of S. litura male moths to the three insecticides indicated the potential specificity of chlorpyrifos affect SlituCSP18 and SlituOBP9 expression.

Distribution of pesticides in dust particles in urban environments.

PubMed

Richards, Jaben; Reif, Ruben; Luo, Yuzhuo; Gan, Jay

2016-07-01

In regions with a mild climate, pesticides are often used around homes for pest control. Recent monitoring studies have linked pesticide use in residential areas to aquatic toxicity in urban surface water ecosystems, and suggested dust particles on paved surfaces as an important source of pesticides. To test the hypothesis that dust on hard surfaces is a significant source of pesticides, we evaluated spatial and temporal patterns of current-use insecticides in Southern California, and further explored their distribution as a function of particle sizes. Pyrethroid insecticides were detected in dust from the driveway, curb gutter and street at 53.5-94.8%, with median concentrations of 1-46 ng g(-1). Pyrethroid residues were uniformly distributed in areas adjacent to a house, suggesting significant redistribution. The total levels of pyrethroids in dust significantly (p < 0.01) decreased from October to February, suggesting rainfalls as a major mechanism to move pesticide residues offsite. Fipronil as well as its degradation products, were detected at 50.6-75.5%, and spatial and temporal patterns of fipronil residues suggested rapid transformations of fipronil to its biologically active intermediates. Moreover, pyrethroids were found to be enriched in fine particles that have a higher mobility in runoff than coarse particles. Results from this study highlight the widespread occurrence of pesticides in outdoor dust around homes and the potential contribution to downstream surface water contamination via rain-induced runoff. Copyright © 2016 Elsevier Ltd. All rights reserved.

Critical electrolyte concentration of silk gland chromatin of the sugarcane borer Diatraea saccharalis, induced using agrochemicals.

PubMed

Santos, S A; Fermino, F; Moreira, B M T; Araujo, K F; Falco, J R P; Ruvolo-Takasusuki, M C C

2014-09-29

The sugarcane borer Diatraea saccharalis is widely known as the main pest of sugarcane crop, causing increased damage to the entire fields. Measures to control this pest involve the use of chemicals and biological control with Cotesia flavipes wasps. In this study, we evaluated the insecticides fipronil (Frontline; 0.0025%), malathion (Malatol Bio Carb; 0.4%), cipermetrina (Galgotrin; 10%), and neem oil (Natuneem; 100%) and the herbicide nicosulfuron (Sanson 40 SC; 100%) in the posterior region silk glands of 3rd- and 5th-instar D. saccharalis by studying the variation in the critical electrolyte concentration (CEC). Observations of 3rd-instar larvae indicated that malathion, cipermetrina, and neem oil induced increased chromatin condensation that may consequently disable genes. Tests with fipronil showed no alteration in chromatin condensation. With the use of nicosulfuron, there was chromatin and probable gene decompaction. In the 5th-instar larvae, the larval CEC values indicated that malathion and neem oil induced increased chromatin condensation. The CEC values for 5th-instar larvae using cipermetrina, fipronil, and nicosulfuron indicated chromatin unpacking. These observations led us to conclude that the quantity of the pesticide does not affect the mortality of these pests, can change the conformation of complexes of DNA, RNA, and protein from the posterior region of silk gland cells of D. saccharalis, activating or repressing the expression of genes related to the defense mechanism of the insect and contributing to the selection and survival of resistant individuals.

Chemical induced behavioral responses in anopheles minimus and Anopheles harrisoni in Thailand

USDA-ARS?s Scientific Manuscript database

Behavioral responses of female mosquitoes representing two species in the Minimus Complex exposed to an operational field dose of bifenthrin or DEET (N,N-diethyl-m-toluamide) were described using an excito-repellency test system. Two test populations of An. minimus, one from the field (Tak Provinc...

In vitro and in vivo experimental data for pyrethroid pharmacokinetic models: the case of bifenthrin

EPA Science Inventory

Pyrethroids are a class of neurotoxic synthetic pesticides. Exposure to pyrethroids has increased due to declining use of other classes of pesticides. Our studies are focused on generating in vitro and in vivo data for the development of pharmacokinetic models for pyrethroids. Us...

In vitro metabolic clearance of pyrethroid pesticides by rat and human hepatic microsomes and cytochrome P450 isoforms

EPA Science Inventory

Species differences in the intrinsic clearance (CL_int) and the enzymes involved in the metabolism of pyrethroid pesticides were examined in rat and human hepatic microsomes. The pyrethroids bifenthrin, S-bioallethrin, bioresmethrin, β-cyfluthrin, cypermethrin, cis-per...

Susceptibility of field populations of the diamondback moth, Plutella xylostella, to a selection of insecticides in Central China.

PubMed

Zhang, Shuzhen; Zhang, Xiaolei; Shen, Jun; Mao, Kaikai; You, Hong; Li, Jianhong

2016-09-01

The diamondback moth (DBM), Plutella xylostella (L.) (Lepidoptera: Plutellidae), is a globally distributed and important economic pest. Chemical control is the primary approach to regulate populations of this pest. However, resistance to insecticides evolves following heavy and frequent use. Therefore, the insecticide resistance in field populations of P. xylostella collected from Central China from 2013 to 2014 was determined with a leaf-dipping method. Based on the results of the monitoring, P. xylostella has developed high levels of resistance to beta-cypermethrin (resistance ratio=69.76-335.76-fold), Bt (WG-001) (RR=35.43-167.36), and chlorfluazuron (RR=13.60-104.95) and medium levels of resistance to chlorantraniliprole (RR=1.19-14.26), chlorfenapyr (RR=4.22-13.44), spinosad (RR=5.89-21.45), indoxacarb (RR=4.01-34.45), and abamectin (RR=23.88-95.15). By contrast, the field populations of P. xylostella remained susceptible to or developed low levels of resistance to diafenthiuron (RR=1.61-8.05), spinetoram (RR=0.88-2.35), and cyantraniliprole (RR=0.4-2.15). Moreover, the LC50 values of field populations of P. xylostella were highly positively correlated between chlorantraniliprole and cyantraniliprole (r=0.88, P=0.045), chlorantraniliprole and spinosad (r=0.66, P=0.039), spinosad and diafenthiuron (r=0.57, P=0.0060), and chlorfenapyr and diafenthiuron (r=0.51, P=0.016). Additionally, the activities of detoxification enzymes in field populations of P. xylostella were significantly positively correlated with the log LC50 values of chlorantraniliprole and spinosad. The results of this study provide an important base for developing effective and successful strategies to manage insecticide resistance in P. xylostella. Copyright © 2016 Elsevier B.V. All rights reserved.

Lethal and sublethal effects of insecticides on Engytatus varians (Heteroptera: Miridae), a predator of Tuta absoluta (Lepidoptera: Gelechiidae).

PubMed

Pérez-Aguilar, Daniel Alberto; Soares, Marianne Araújo; Passos, Luis Clepf; Martínez, Ana Mabel; Pineda, Samuel; Carvalho, Geraldo Andrade

2018-06-19

The mirid Engytatus varians (Distant) is a promising biological control agent of the tomato borer, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), one of the most destructive pests of tomato (Solanum lycopersicum L.). The effects of five insecticides commonly used on tomato crops in Brazil were evaluated on E. varians in laboratory and semifield conditions. Glass Petri dish with residues of chlorfenapyr, thiamethoxam, and abamectin caused ˃90% mortality in both stages of the predator 72 h post-treatment, except imidacloprid that caused 78% of nymphs mortality. Teflubenzuron caused 24 and 66% mortality on adults and nymphs, respectively. The offspring of females derived from treated nymphs with teflubenzuron was significantly lower than the control but not when females were treated as adults. Longevity of males derived from nymphs treated with teflubenzuron was significantly reduced, but no effects were observed on females. When males and females were treated as adults with teflubenzuron there were no effects on their longevity. In the greenhouse-aged tomato plants, the 2 h-old residues of thiamethoxam, chlorfenapyr, and abamectin caused more than 70% of mortality of third instar of E. varians at 72 h post-treatment, 12 day-old residues of all three compounds caused a mortality lower than 30%. These data suggest that teflubenzuron can be associated with releases of E. varians adults, while the use of other evaluated pesticides should be avoided in this situation. Although, the low persistence of these products indicate that their spraying and later releases of E. varians adults on tomato crops are a possible strategy to control T. absoluta.

Parasite-insecticide interactions: a case study of Nosema ceranae and fipronil synergy on honeybee

PubMed Central

Aufauvre, Julie; Biron, David G.; Vidau, Cyril; Fontbonne, Régis; Roudel, Mathieu; Diogon, Marie; Viguès, Bernard; Belzunces, Luc P.; Delbac, Frédéric; Blot, Nicolas

2012-01-01

In ecosystems, a variety of biological, chemical and physical stressors may act in combination to induce illness in populations of living organisms. While recent surveys reported that parasite-insecticide interactions can synergistically and negatively affect honeybee survival, the importance of sequence in exposure to stressors has hardly received any attention. In this work, Western honeybees (Apis mellifera) were sequentially or simultaneously infected by the microsporidian parasite Nosema ceranae and chronically exposed to a sublethal dose of the insecticide fipronil, respectively chosen as biological and chemical stressors. Interestingly, every combination tested led to a synergistic effect on honeybee survival, with the most significant impacts when stressors were applied at the emergence of honeybees. Our study presents significant outcomes on beekeeping management but also points out the potential risks incurred by any living organism frequently exposed to both pathogens and insecticides in their habitat. PMID:22442753

Using a Novel Sediment Exposure to Determine the Effects of Bifenthin on Marine Benthic Communities

EPA Science Inventory

Bifenthrin is a widely used pyrethroid insecticide that affects animal sodium ion channels in the peripheral and central nervous system of target and non-target species, eventually causing paralysis. It is a suspected human carcinogen and has been banned for use in the European U...

A comparative analysis of resistance testing methods in Aedes albopictus (Diptera: Culicidae) from St. Johns County, Florida

USDA-ARS?s Scientific Manuscript database

Aedes albopictus Skuse (Diptera: Culicidae) was tested for resistance to permethrin, bifenthrin, and malathion using Centers for Disease Control and Prevention (CDC) bottle bioassays and topical toxicology assays on adults and larval bioassays. Eggs were collected from 3 locations across St. Johns C...

Reducing Sand Fly Numbers in Leishmania Endemic Regions in Kenya with Insecticide Treated Camouflage Screening

USDA-ARS?s Scientific Manuscript database

Current US military operations in deserts face persistent threats from sand flies that transmit human Leishmania. Methods to reduce the risk of human infection from leishmaniasis by reducing the number of sand fly vectors were investigated in Kenya. Bifenthrin treated and un-treated camouflage netti...

Effective Subcritical Butane Extraction of Bifenthrin Residue in Black Tea.

PubMed

Zhang, Yating; Gu, Lingbiao; Wang, Fei; Kong, Lingjun; Qin, Guangyong

2017-03-30

As a natural and healthy beverage, tea is widely enjoyed; however, the pesticide residues in tea leaves affect the quality and food safety. To develop a highly selective and efficient method for the facile removal of pesticide residues, the subcritical butane extraction (SBE) technique was employed, and three variables involving temperature, time and extraction cycles were studied. The optimum SBE conditions were found to be as follows: extraction temperature 45 °C, extraction time 30 min, number of extraction cycles 1, and in such a condition that the extraction efficiency reached as high as 92%. Further, the catechins, theanine, caffeine and aroma components, which determine the quality of the tea, fluctuated after SBE treatment. Compared with the uncrushed leaves, pesticide residues can more easily be removed from crushed leaves, and the practical extraction efficiency was 97%. These results indicate that SBE is a useful method to efficiently remove the bifenthrin, and as appearance is not relevant in the production process, tea leaves should first be crushed and then extracted in order that residual pesticides are thoroughly removed.

Efficacy of dinotefuran-pyriproxyfen, dinotefuran-pyriproxyfen-permethrin and fipronil-(S)-methoprene topical spot-on formulations to control flea populations in naturally infested pets and private residences in Tampa, FL.

PubMed

Dryden, Michael W; Payne, Patricia A; Vicki, Smith; Riggs, Breanne; Davenport, Jacob; Kobuszewski, Denise

2011-12-15

Thirteen cats and 7 dogs living in 14 homes were treated topically with either a dinotefuran (22%, w/w)/pyriproxyfen (3.00%, w/w) (DP) or dinotefuran (4.95%, w/w)/pyriproxyfen (0.44%, w/w)/permethrin (36.08%, w/w) (DPP) topical spot-on, respectively. Twenty cats and 7 dogs living in 16 homes were treated topically with either a fipronil (9.8%, w/w)/(S)-methoprene (11.8%, w/w) or fipronil (9.8%, w/w)/(S)-methoprene (8.8%, w/w) topical spot-on (FM), respectively. All products were applied according to label directions by study investigators on day 0 and again between days 28 and 30. Flea populations on pets were assessed using visual area counts and premise flea infestations were assessed using intermittent-light flea traps on days 0, 7, 14, 21, 28-30, 40-45, and 54-60. A single application of the DP-DPP and FM formations reduced flea populations by 87.35% and 88.44%, respectively within 7 days. Following two monthly applications of either the DP-DPP or FM formulations, pet flea burdens were reduced by 95.24% and 95.47%, respectively. Flea numbers in the indoor-premises were also markedly reduced by days 54-60, with 98.05% and 96.15% reductions in intermittent-light flea trap counts in the DP-DPP or FM treatment groups, respectively. Copyright © 2011 Elsevier B.V. All rights reserved.

Repellent and insecticidal efficacy of a new combination of fipronil and permethrin against three mosquito species (Aedes albopictus, Aedes aegypti and Culex pipiens) on dogs.

PubMed

Fankhauser, Becky; Dumont, Pascal; Hunter, James S; McCall, John W; Kaufmann, Christian; Mathis, Alexander; Young, David R; Carroll, Scott P; McCall, Scott; Chester, S Theodore; Soll, Mark D

2015-01-30

Three laboratory studies were conducted to assess the repellent and insecticidal efficacy of a combination of fipronil and permethrin (Frontline Tri- Act/Frontect) against three mosquito species (Aedes albopictus, Aedes aegypti and Culex pipiens) on dogs. In each study, 16 healthy adult dogs were allocated to two groups. Eight dogs were treated with the new topical spot-on combination of fipronil and permethrin on Day 0 and the other eight dogs served as untreated controls. Each dog was exposed to mosquitoes on Days 1, 7, 14, 21 and 28 (and also on Day 35 in the A. aegypti study). After a 1-h exposure period, all mosquitoes were counted and categorized as live or dead and fed or non-fed. Live mosquitoes were kept in an insectary and observed for mortality counts 4, 24 and 48 h post-exposure (PE) for Aedes spp. and 24 and 48 h PE for C. pipiens. Repellency and insecticidal efficacies were defined as the percent reduction in the number of fed and live mosquitoes, respectively, in the treated group as compared to the untreated control group. Repellency against A. albopictus was ≥93.4% through Day 21 and 86.9% on Day 28. It was ≥91.0% through Day 35 against A. aegypti and ≥90.4% through Day 28 against C. pipiens. Insecticidal efficacy against A. albopictus was ≥97.1% at 24 h PE from Day 7 to Day 28. It was ≥98.0% for the first 3 weeks and still 75.7% on Day 35 against A. aegypti at 24 h PE. For C. pipiens, insecticidal efficacy ranged from 93.8% (Day 7) to 30.9% (Day 28) at 48 h PE. A single topical administration of the combination of fipronil and permethrin provides repellency against mosquitoes on dogs for at least 4 weeks. The product may therefore significantly reduce the potential for the transmission of vector-borne pathogens through the inhibition of mosquito feeding, as well as the discomfort associated with mosquito bites. Moreover, mosquito mortality was induced by contact with the treated dogs, which could aid in the control of mosquitoes, and hence the control of mosquito-borne diseases, in the local vicinity of treated dogs.

Electrospun and functionalized PVDF/PAN nanocatalyst-loaded composite for dechlorination and photodegradation of pesticides in contaminated water.

PubMed

Nthumbi, Richard M; Ngila, Jane C

2016-10-01

A novel approach for the electrospinning and functionalization of nanocatalyst-loaded polyvinylidene fluoride/polyacrylonitrile (PVDF/PAN) composite grafted with acrylic acid (AA; which form polyacrylic acid (PAA) brush) and decorated with silver (Ag/PAN/PVDF-g-PAA-TiO 2 /Fe-Pd) designed for the dechlorination and photodegradation of pesticides was carried out. PAN was used both as a nitrogen dopant as well as a co-polymer. Smooth nanofibers were obtained by electrospinning a solution of 12:2 wt.% PVDF/PAN blend using dimethylformamide (DMF) as solvent. The nanofibers were grafted with AA by free-radical polymerization using 2,2'azobis(2-methylpropionitrile) (AIBN) as initiator. Both bimetallic iron-palladium (Fe-Pd) and titania (TiO 2 ) nanoparticles (NP) were anchored on the grafted nanofibers via the carboxylate groups by in situ and ex situ synthesis. The Fe-Pd and nitrogen-doped TiO 2 nanoparticles were subsequently used for dechlorination and oxidation of target pollutants (dieldrin, chlorpyrifos, diuron, and fipronil) to benign products. Structural and chemical characterizations of the composites were done using various techniques. These include surface area and porosity analyzer (ASAP) using the technique by Brunner Emmett Teller (BET), Fourier transform infrared (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscope (TEM) analyses were done. After dechlorination, the transformation products (TPs) for dieldrin, chlorpyrifos, diuron, and fipronil were obtained and identified using two-dimensional gas chromatography (time-of-flight) with a mass spectrometer detector (GCxGC-TOFMS). Analysis of total organic carbon (TOC) was carried out and used to extrapolate percentage mineralization. Experimental results showed that dechlorination efficiencies of 96, 93, 96, and 90 % for 1, 2, 2, and 3 h treatment period were respectively achieved for 5 ppm solutions of dieldrin, chlorpyrifos, diuron, and fipronil. The dechlorination of dieldrin, diuron, and fipronil follows first-order kinetics while that of chlorpyrifos followed pseudo-first order. Mineralization performance of 34 to 45 % were recorded when Fe-Pd was used, however upon electrospinning, doping, and grafting (Ag/PAN/PVDF-g-PAA-TiO 2 /Fe-Pd composite); it significantly increased to 99.9999 %. This composite reveals great potential for dechlorination and mineralization of pesticides in contaminated water.

Trends in pesticide concentrations in urban streams in the United States, 1992-2008

USGS Publications Warehouse

Ryberg, Karen R.; Vecchia, Aldo V.; Martin, Jeffrey D.; Gilliom, Robert J.

2010-01-01

Pesticide concentration trends in streams dominated by urban land use were assessed using data from 27 urban streams sampled as part of the U.S. Geological Survey National Water-Quality Assessment Program. The sites were divided into four regions, Northeast, South, Midwest, and West, to examine possible regional patterns. Three partially overlapping 9-year periods (1992-2000, 1996-2004, and 2000-2008) were examined for eight herbicides and one degradation product (simazine, prometon, atrazine, deethylatrazine, metolachlor, trifluralin, pendimethalin, tebuthiuron, and Dacthal), and five insecticides and two degradation products (chlorpyrifos, malathion, diazinon, fipronil, fipronil sulfide, desulfinylfipronil, and carbaryl). The data were analyzed for trends in concentration using a parametric regression model with seasonality, flow-related variability, and trend, called SEAWAVE-Q. The SEAWAVE-Q model also was used to generate estimated daily concentration percentiles for each analysis period to provide a summary of concentration magnitudes. For herbicides, the largest 90th percentiles of estimated concentrations for simazine were in the South, prometon at some sites in all of the regions, atrazine and deethylatrazine in the South and Midwest, metolachlor in the Midwest and a few sites in the South, pendimethalin at scattered sites in all of the regions, and tebuthiuron in the South and a few sites in the Midwest and West. For insecticides, the largest 90th percentiles of estimated concentrations for diazinon and carbaryl were distributed among various sites in all regions (especially during 1996-2004), and fipronil at isolated sites in all of the regions during 2000-2008. Trend analysis results for the herbicides indicated many significant trends, both upward and downward, with varying patterns depending on period, region, and herbicide. Overall, deethylatrazine showed the most consistent pattern of upward trends, especially in the Northeast (2000-2008), South (1996-2004 and 2000-2008), and Midwest (1996-2004 and 2000-2008). Other herbicides showed less consistent upward trends, including simazine in the South (1996-2004), prometon in the Midwest (2000-2008), and atrazine in the South (1996-2004). The most consistent downward trends were for simazine in the Northeast and Midwest (1996-2004), prometon in the Northeast and Midwest (1996-2004) and West (1996-2004 and 2000-2008), and tebuthiuron in the South (1996-2004 and 2000-2008) and West (2000-2008). Strong similarity existed between the trends for atrazine and deethylatrazine during 1996-2004. During 2000-2008, however, there were mixed upward and downward trends in atrazine and predominantly upward trends in deethylatrazine. Ten sites with a downward trend in atrazine were paired with an upward trend in deethylatrazine and for three of these sites (1 in the South and 2 in the Midwest) both opposing trends were significant. Opposing trends showing a decrease in atrazine and an increase in deethylatrazine may indicate that decreases in atrazine from surface runoff are being offset in some cases by increases in deethylatrazine from groundwater for the latter analysis period. Trend results for insecticides indicated widespread significant downward trends for chlorpyrifos (especially 1996-2004), diazinon (1996-2004 and 2000-2008), and malathion (especially 1996-2004); widespread significant upward trends for fipronil and its degradation products (2000-2008); and mostly nonsignificant trends for carbaryl (1996-2004 and 2000-2008). The downward trends for chlorpyrifos and diazinon were consistent with the regulatory phaseout of residential uses of these insecticides and the upward trends for fipronil and its degradation products were consistent with its introduction in 1996 and subsequent increasing use as a possible substitute for chlorpyrifos and diazinon. The downward trends in malathion may be caused by voluntary substitution of pyrethroids or fipronil for malathio

75 FR 13281 - Fipronil; Receipt of Application for Emergency Exemption, Solicitation of Public Comment

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-19

... or otherwise protected through regulations.gov or e- mail. The regulations.gov website is an... files should avoid the use of special characters, any form of encryption, and be free of any defects or...

Efficacy of two insecticides for protecting loblolly pines (Pinus taeda L.) from subcortical beetles (Coleoptera: Curculionidae and Cerambycidae)

Treesearch

Jordon L. Burke; James L. Hanula; Scott Horn; Jackson P. Audley; Kamal JK. Gandhi

2012-01-01

Tests were conducted on two insecticides (carbaryl and bifenthrin) for excluding subcortical beetles (Coleoptera: Curculionidae and Cerambycidae) from loblolly pine trees (Pinus taeda L.). Two trap designs (single- and double-pane windows) and two trapping heights (1.5 and 4m) were also evaluated for maximizing beetle catches.

Longevity and efficacy of bifenthrin treatment on desert-pattern U.S. military camouflage netting against mosquitoes in a hot-arid environment

USDA-ARS?s Scientific Manuscript database

Personnel deployed in support of US military operations will benefit from additions to the current Department of Defense pest management system. A recent study showed that residual insecticide treatment of woodland pattern US military camouflage netting was long lasting and effective at reducing mos...

Persistence and efficacy of termiticides used in preconstruction treatments to soil in Mississippi

Treesearch

J.E. Mulrooney; M.K. Davis; T.L. Wagner; R.L. Ingram

2006-01-01

Laboratory and field studies were conducted to determine the persistence and efficacy of termiticides used as preconstruction treatments against subterranean termites. Bifenthrin (0.067%), chlorpyrifos (0.75%), and imidacloprid (0.05%) ( [AI]; wt:wt) were applied to soil beneath a monolithic concrete slab at their minimum labeled rates. Soil samples were taken from...

Insecticides evaluated as regulatory immersion treatments to eliminate third-instar Japanese beetles (Coleoptera: Scarabaeidae) from small-diameter field-grown nursery plants

USDA-ARS?s Scientific Manuscript database

Japanese beetles, Popillia japonica Newman, are a quarantine issue for nursery shipments to certain U.S. states. The Domestic Japanese Beetle Harmonization Plan (DJHP) allows balled and burlapped (B&B) root ball immersion in chlorpyrifos or bifenthrin for P. japonica certification. Study objective...

Effects of the insecticide fipronil on reproductive endocrinology in the fathead minnow

EPA Science Inventory

Gamma aminobutyric acid (GABA) and GABA receptors play an important role in neuroendocrine regulation in fish. Disruption of the GABAergic system by environmental contaminants could interfere with normal regulation of the hypothalamic pituitary gonadal (HPG) axis, leading to imp...

Visceral Leishmaniasis on the Indian Subcontinent: Modelling the Dynamic Relationship between Vector Control Schemes and Vector Life Cycles.

PubMed

Poché, David M; Grant, William E; Wang, Hsiao-Hsuan

2016-08-01

Visceral leishmaniasis (VL) is a disease caused by two known vector-borne parasite species (Leishmania donovani, L. infantum), transmitted to man by phlebotomine sand flies (species: Phlebotomus and Lutzomyia), resulting in ≈50,000 human fatalities annually, ≈67% occurring on the Indian subcontinent. Indoor residual spraying is the current method of sand fly control in India, but alternative means of vector control, such as the treatment of livestock with systemic insecticide-based drugs, are being evaluated. We describe an individual-based, stochastic, life-stage-structured model that represents a sand fly vector population within a village in India and simulates the effects of vector control via fipronil-based drugs orally administered to cattle, which target both blood-feeding adults and larvae that feed on host feces. Simulation results indicated efficacy of fipronil-based control schemes in reducing sand fly abundance depended on timing of drug applications relative to seasonality of the sand fly life cycle. Taking into account cost-effectiveness and logistical feasibility, two of the most efficacious treatment schemes reduced population peaks occurring from April through August by ≈90% (applications 3 times per year at 2-month intervals initiated in March) and >95% (applications 6 times per year at 2-month intervals initiated in January) relative to no control, with the cumulative number of sand fly days occurring April-August reduced by ≈83% and ≈97%, respectively, and more specifically during the summer months of peak human exposure (June-August) by ≈85% and ≈97%, respectively. Our model should prove useful in a priori evaluation of the efficacy of fipronil-based drugs in controlling leishmaniasis on the Indian subcontinent and beyond.

Phenylpyrazole insecticide fipronil induces male infertility in the estuarine meiobenthic crustacean Amphiascus tenuiremis.

PubMed

Cary, Tawnya L; Chandler, G Thomas; Volz, David C; Walse, Spencer S; Ferry, John L

2004-01-15

Copepods are the most abundant arthropods on earth and are often the most important secondary producers in estuarine/marine food webs. The new GABA (gamma-aminobutyric acid)-disrupting insecticide fipronil (FP) induces unique sex-specific reproductive dysfunction in male meiobenthic copepods, leading to trans-generational population depression at environmentally realistic concentrations (0.63 microg/L). Using a newly developed 96-well microplate lifecycle bioassay, more than 700 individual Stage-I juveniles were reared to adulthood in as short as 12 days in only 200 microL of control (CTL) or 0.63 microg-FP/L seawater solution. Individual virgin male: female pairs were then cross-mated for all possible combinations within and across rearing treatments and allowed to mate for an additional 12 days in CTL or 0.63 microg-FP/L solution. FP at 0.63 microg/L caused no significant lethality to any mating combinations but evoked 73% or 89% inhibition of reproduction when FP-reared males were mated with either a control- or FP-reared female in FP solution, respectively. In contrast, when CTL-reared males were mated with FP-reared females in FP solution, there was no difference in reproductive success compared to FP-free controls. When FP-reared males were mated with either female group in FP-free solution, these mating pairs displayed a 3-day delay in time to brood sac extrusion but ultimately did reproduce. As fipronil (1) has a high K(ow), (2) is persistent in sediments where meiobenthic copepods live, and (3) has been detected in estuarine waters >0.7 microg/L, it may pose high risk to copepod production in estuarine systems.

The novel isoxazoline ectoparasiticide lotilaner (Credelio™): a non-competitive antagonist specific to invertebrates γ-aminobutyric acid-gated chloride channels (GABACls).

PubMed

Rufener, Lucien; Danelli, Vanessa; Bertrand, Daniel; Sager, Heinz

2017-11-01

The isoxazolines are a novel class of parasiticides that are potent inhibitors of γ-aminobutyric acid (GABA)-gated chloride channels (GABACls) and, to a lesser extent, of inhibitory glutamate-gated chloride channels (GluCls). Lotilaner (Credelio™), a novel representative of this chemical class, is currently evaluated for its excellent ectoparasiticide properties. In this study, we investigated the molecular mode of action and pharmacology of lotilaner. We report the successful gene identification, cDNA cloning and functional expression in Xenopus oocytes of Drosohpila melanogaster (wild type and dieldrin/fipronil-resistant forms), Lepeophtheirus salmonis (an ectoparasite copepod crustacean of salmon), Rhipicephalus microplus and Canis lupus familiaris GABACls. Automated Xenopus oocyte two-electrode voltage clamp electrophysiology was used to assess GABACls functionality and to compare ion channel inhibition by lotilaner with that of established insecticides addressing GABACls as targets. In these assays, we demonstrated that lotilaner is a potent non-competitive antagonist of insects (fly) GABACls. No cross-resistance with dieldrin or fipronil resistance mutations was detected, suggesting that lotilaner might bind to a site at least partly different from the one bound by known GABACl blockers. Using co-application experiments, we observed that lotilaner antagonism differs significantly from the classical open channel blocker fipronil. We finally confirmed for the first time that isoxazoline compounds are not only powerful antagonists of GABACls of acari (ticks) but also of crustaceans (sea lice), while no activity on a dog GABA A receptor was observed up to a concentration of 10 μM. Together, these results demonstrate that lotilaner is a non-competitive antagonist specific to invertebrate's γ-aminobutyric acid-gated chloride channels (GABACls). They contribute to our understanding of the mode of action of this new ectoparasiticide compound.

FIPRONIL-INDUCED MALE INFERTILITY IN THE MEIOBENTHIC HARPACTICOID COPEPOD, AMPHIASCUS TENUIREMIS. (R827397)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

Broflanilide: A meta-diamide insecticide with a novel mode of action.

PubMed

Nakao, Toshifumi; Banba, Shinichi

2016-02-01

Broflanilide is a meta-diamide [3-benzamido-N-(4-(perfluoropropan-2-yl)phenyl)benzamide] that exhibits high larvicidal activity against Spodoptera litura. It has been suggested that broflanilide is metabolized to desmethyl-broflanilide and that it acts as a noncompetitive resistant-to-dieldrin (RDL) γ-aminobutyric acid (GABA) receptor antagonist. The binding site of desmethyl-broflanilide was demonstrated to be distinct from that of conventional noncompetitive antagonists such as fipronil. It has been proposed that the site of action for desmethyl-broflanilide is close to G336 in the M3 region of the Drosophila RDL GABA receptor. However, although the site of action for desmethyl-broflanilide appears to overlap with that of macrocyclic lactones, different modes of actions have been demonstrated for desmethyl-broflanilide and the macrocyclic lactones. The mechanisms underlying the high selectivity of meta-diamides are also discussed in this review. Broflanilide is expected to become a prominent insecticide because it is effective against pests with resistance to cyclodienes and fipronil. Copyright © 2015 Elsevier Ltd. All rights reserved.

Evaluation of a Localized Treatment Technique Using Three Ready-to-Use Products Against the Drywood Termite Incisitermes snyderi (Kalotermitidae) in Naturally Infested Lumber

PubMed Central

Hickman, Robert; Forschler, Brian T.

2012-01-01

Twenty-one boards infested with drywood termites were examined for activity using a Termatrac® motion detector. Termite galleries were identified using a Resistograph drill and treated with one of three ready-to-use (RTU) products. Results indicated that the Termatrac was excellent at locating termite activity but provided 9.5% false negatives. The Resistograph located termite galleries with an average of 4.6 ± 2.7 holes drilled to find at least one gallery in a board. Treatments included three formulations and two active ingredients; a foam (imidacloprid), a dry (fipronil) and an experimental formulation in a pressurized can (fipronil). All treatments provided evidence for a reduction in mean termite populations per board compared to the control. Two treatments provided evidence of elimination of infestation but no formulation eliminated infestations in every board that was treated. The concept of local treatment for drywood termite control is discussed relative to our results. PMID:26467947

Effect of paste processing on residue levels of imidacloprid, pyraclostrobin, azoxystrobin and fipronil in winter jujube.

PubMed

Peng, Wei; Zhao, Liuwei; Liu, Fengmao; Xue, Jiaying; Li, Huichen; Shi, Kaiwei

2014-01-01

The changes of imidacloprid, pyraclostrobin, azoxystrobin and fipronil residues were studied to investigate the carryover of pesticide residues in winter jujube during paste processing. A multi-residue analytical method for winter jujube was developed based on the QuEChERS approach. The recoveries for the pesticides were between 87.5% and 116.2%. LODs ranged from 0.002 to 0.1 mg kg(-1). The processing factor (Pf) is defined as the ratio of pesticide residue concentration in the paste to that in winter jujube. Pf was higher than 1 for the removal of extra water, and other steps were generally less than 1, indicating that the whole process resulted in lower pesticide residue levels in paste. Peeling would be the critical step for pesticide removal. Processing factors varied among different pesticides studied. The results are useful to address optimisation of the processing techniques in a manner that leads to considerable pesticide residue reduction.

Evidence of field-evolved resistance to bifenthrin in western corn rootworm (Diabrotica virgifera virgifera LeConte) populations in western Nebraska and Kansas

USDA-ARS?s Scientific Manuscript database

Pyrethroid insecticides are widely used to control larvae or adult western corn rootworm, a key pest of corn in the United States. In response to reports of reduced efficacy of pyrethroids in WCR management programs in southwestern areas of Nebraska and Kansas the present research was designed to es...

Determination of Pyrethroids in Tea Brew by GC-MS Combined with SPME with Multiwalled Carbon Nanotube Coated Fiber.

PubMed

Ren, Dongxia; Sun, Chengjun; Ma, Guanqun; Yang, Danni; Zhou, Chen; Xie, Jiayu; Li, Yongxin

2018-01-01

A new method has been developed to simultaneously determine 7 pyrethroid residues in tea brew using gas chromatography-mass spectrometry (GC-MS) combined with solid phase microextraction (SPME) with multiwalled carbon nanotubes (MWCNTs) coated fiber. The MWCNTs coated fiber of SPME was homemade by using stainless steel wire as coating carrier and polyacrylonitrile (PAN) solution as adhesive glue. Under the optimized conditions, a good linearity was shown for bifenthrin, fenpropathrin, permethrin, and cyfluthrin in 1-50 ng mL -1 and for cypermethrin, fenvalerate, and deltamethrin in 5-50 ng mL -1 . The correlation coefficients were in the range of 0.9948-0.9999. The average recoveries of 7 pyrethroids were 94.2%-107.3% and the relative standard deviations (RSDs) were less than 15%. The detection limit of the method ranged from 0.12 to 1.65 ng mL -1 . The tea brew samples made from some commercial tea samples were analyzed. Among them, bifenthrin, fenpropathrin, and permethrin were found. The results show that the method is rapid and sensitive and requires low organic reagent consumption, which can be well used for the detection of the pyrethroids in tea brew.

MSPD procedure for determining buprofezin, tetradifon, vinclozolin, and bifenthrin residues in propolis by gas chromatography-mass spectrometry.

PubMed

dos Santos, Thaíse Fernanda Santana; Aquino, Adriano; Dórea, Haroldo Silveira; Navickiene, Sandro

2008-03-01

A simple and effective extraction method based on matrix solid-phase dispersion (MSPD) was developed to determine bifenthrin, buprofezin, tetradifon, and vinclozolin in propolis using gas chromatography-mass spectrometry in selected ion monitoring mode (GC-MS, SIM). Different method conditions were evaluated, for example type of solid phase (C(18), alumina, silica, and Florisil), the amount of solid phase and eluent (n-hexane, dichloromethane, dichloromethane-n-hexane (8:2 and 1:1, v/v) and dichloromethane-ethyl acetate (9:1, 8:2 and 7:3, v/v)). The best results were obtained using 0.5 g propolis, 1.0 g silica as dispersant sorbent, 1.0 g Florisil as clean-up sorbent, and dichloromethane-ethyl acetate (9:1, v/v) as eluting solvent. The method was validated by analysis of propolis samples fortified at different concentration levels (0.25 to 1.0 mg kg(-1)). Average recoveries (four replicates) ranged from 67% to 175% with relative standard deviation between 5.6% and 12.1%. Detection and quantification limits ranged from 0.05 to 0.10 mg kg(-1) and 0.15 to 0.25 mg kg(-1) propolis, respectively.

Evaluation of diamide insecticides co-applied with other agrochemicals at various times to manage Ostrinia nubilalis in processing snap bean.

PubMed

Huseth, Anders S; Groves, Russell L; Chapman, Scott A; Nault, Brian A

2015-12-01

Multiple applications of pyrethroid insecticides are used to manage European corn borer, Ostrinia nubilalis Hübner, in snap bean, but new diamide insecticides may reduce application frequency. In a 2 year small-plot study, O. nubilalis control was evaluated by applying cyantraniliprole (diamide) and bifenthrin (pyrethroid) insecticides at one of three phenological stages (bud, bloom and pod formation) of snap bean development. Co-application of these insecticides with either herbicides or fungicides was also examined as a way to reduce the total number of sprays during a season. Cyantraniliprole applications timed either during bloom or during pod formation controlled O. nubilalis better than similar timings of bifenthrin. Co-applications of insecticides with fungicides controlled O. nubilalis as well as insecticide applications alone. Insecticides applied either alone or with herbicides during bud stage did not control this pest. Diamides are an alternative to pyrethroids for the management of O. nubilalis in snap bean. Adoption of diamides by snap bean growers could improve the efficiency of production by reducing the number of sprays required each season. © 2015 Society of Chemical Industry.

Two-dimensional coordination polymer matrix for solid-phase extraction of pesticide residues from plant Cordia salicifolia.

PubMed

de Carvalho, Pedro Henrique Viana; Barreto, Alysson Santos; Rodrigues, Marcelo O; Prata, Vanessa de Menezes; Alves, Péricles Barreto; de Mesquita, Maria Eliane; Alves, Severino; Navickiene, Sandro

2009-06-01

The 2D coordination polymer (infinity[Gd(DPA)(HDPA)]) was tested for extraction of acephate, chlorpropham, pirimicarb, bifenthrin, tetradifon, and phosalone from the medicinal plant Cordia salicifolia, whose extracts are commercialized in Brazil as diuretic, appetite suppressant, and weight loss products, using GC/MS, SIM. Considering that there are no Brazilian regulations concerning maximum permissible pesticide residue concentrations in medicinal herbs, recovery experiments were carried out (seven replicates), at two arbitrary fortification levels (0.5 and 1.0 mg/kg), resulting in recoveries in range of 20 to 107.7% and SDRSDs were between 5.6 and 29.1% for infinity[Gd(DPA)(HDPA)] sorbent. Detection and quantification limits for herb ranged from 0.10 to 0.15 mg/kg and from 0.15 to 0.25 mg/kg, respectively, for the different pesticides studied. The developed method is linear over the range assayed, 0.5-10.0 microg/mL, with correlation coefficients ranging from 0.9975 to 0.9986 for all pesticides. Comparison between infinity[Gd(DPA)(HDPA)] sorbent and conventional sorbent (neutral alumina) showed similar performance of infinity[Gd(DPA)(HDPA)] polymeric sorbent for three (bifenthrin, tetradifon, and phosalone) out of six pesticides tested.

Urban and agricultural sources of pyrethroid insecticides to the Sacramento-San Joaquin Delta of California.

PubMed

Weston, Donald P; Lydy, Michael J

2010-03-01

While studies have documented the presence of pyrethroid insecticides at acutely toxic concentrations in sediments, little quantitative data on sources exist. Urban runoff, municipal wastewater treatment plants and agricultural drains in California's Sacramento-San Joaquin River Delta were sampled to understand their importance as contributors of these pesticides to surface waters. Nearly all residential runoff samples were toxic to the amphipod, Hyalella azteca, and contained pyrethroids at concentrations exceeding acutely toxic thresholds, in many cases by 10-fold. Toxicity identification evaluation data were consistent with pyrethroids, particularly bifenthrin and cyfluthrin, as the cause of toxicity. Pyrethroids passed through secondary treatment systems at municipal wastewater treatment facilities and were commonly found in the final effluent, usually near H. azteca 96-h EC(50) thresholds. Agricultural discharges in the study area only occasionally contained pyrethroids and were also occasional sources of toxicity related to the organophosphate insecticide chlorpyrifos. Discharge of the pyrethroid bifenthrin via urban stormwater runoff was sufficient to cause water column toxicity in two urban creeks, over at least a 30 km reach of the American River, and at one site in the San Joaquin River, though not in the Sacramento River.

Acute triadimefon-induced changes in the EEG of Long-Evans Rats

EPA Science Inventory

We have reported that the non-stimulus driven EEG is altered differently by acute treatment with deltamethrin, permethrin, fipronil, or imidacloprid (Lyke and Herr, Lyke et al., Toxicologist, 2010, 2011, 2012) in non-restrained animals. In the current study, we examined the abili...

Risks of large-scale use of systemic insecticides to ecosystem functioning and services.

PubMed

Chagnon, Madeleine; Kreutzweiser, David; Mitchell, Edward A D; Morrissey, Christy A; Noome, Dominique A; Van der Sluijs, Jeroen P

2015-01-01

Large-scale use of the persistent and potent neonicotinoid and fipronil insecticides has raised concerns about risks to ecosystem functions provided by a wide range of species and environments affected by these insecticides. The concept of ecosystem services is widely used in decision making in the context of valuing the service potentials, benefits, and use values that well-functioning ecosystems provide to humans and the biosphere and, as an endpoint (value to be protected), in ecological risk assessment of chemicals. Neonicotinoid insecticides are frequently detected in soil and water and are also found in air, as dust particles during sowing of crops and aerosols during spraying. These environmental media provide essential resources to support biodiversity, but are known to be threatened by long-term or repeated contamination by neonicotinoids and fipronil. We review the state of knowledge regarding the potential impacts of these insecticides on ecosystem functioning and services provided by terrestrial and aquatic ecosystems including soil and freshwater functions, fisheries, biological pest control, and pollination services. Empirical studies examining the specific impacts of neonicotinoids and fipronil to ecosystem services have focused largely on the negative impacts to beneficial insect species (honeybees) and the impact on pollination service of food crops. However, here we document broader evidence of the effects on ecosystem functions regulating soil and water quality, pest control, pollination, ecosystem resilience, and community diversity. In particular, microbes, invertebrates, and fish play critical roles as decomposers, pollinators, consumers, and predators, which collectively maintain healthy communities and ecosystem integrity. Several examples in this review demonstrate evidence of the negative impacts of systemic insecticides on decomposition, nutrient cycling, soil respiration, and invertebrate populations valued by humans. Invertebrates, particularly earthworms that are important for soil processes, wild and domestic insect pollinators which are important for plant and crop production, and several freshwater taxa which are involved in aquatic nutrient cycling, were all found to be highly susceptible to lethal and sublethal effects of neonicotinoids and/or fipronil at environmentally relevant concentrations. By contrast, most microbes and fish do not appear to be as sensitive under normal exposure scenarios, though the effects on fish may be important in certain realms such as combined fish-rice farming systems and through food chain effects. We highlight the economic and cultural concerns around agriculture and aquaculture production and the role these insecticides may have in threatening food security. Overall, we recommend improved sustainable agricultural practices that restrict systemic insecticide use to maintain and support several ecosystem services that humans fundamentally depend on.

Efficacy against nematode and cestode infections and safety of a novel topical fipronil, (S)-methoprene, eprinomectin and praziquantel combination product in domestic cats under field conditions in Europe.

PubMed

Rehbein, Steffen; Capári, Balazs; Duscher, Georg; Keidane, Dace; Kirkova, Zvezdelina; Petkevičius, Saulius; Rapti, Dhimiter; Wagner, Annegret; Wagner, Thomas; Chester, S Theodore; Rosentel, Joseph; Tielemans, Eric; Visser, Martin; Winter, Renate; Kley, Katrin; Knaus, Martin

2014-04-28

A novel topical combination product (BROADLINE(®), Merial) composed of fipronil, (S)-methoprene, eprinomectin and praziquantel was evaluated for safety and efficacy against nematode and cestode infections in domestic cats. The study comprised a multi-centre, positive control, blinded, field study, using a randomized block design based on order of presentation for allocation. In total 196 client-owned cats, confirmed as positive for naturally acquired infections of nematodes and/or cestodes by pre-treatment faecal examination, were studied in seven countries in Europe. Pre-treatment faecal examination revealed the presence of Toxocara, hookworm, Capillaria and/or spirurid nematode infections in 129, 73, 33 or 1 cat(s), respectively; infections with taeniid and Dipylidium cestodes were demonstrated in 39 and 17 cats, respectively. Cats were allocated randomly to one of two treatments in a ratio of 2, topical fipronil (8.3%, w/v), (S)-methoprene (10%, w/v), eprinomectin (0.4%, w/v) and praziquantel (8.3%, w/v) (BROADLINE(®), Merial; 130 cats); and 1, topical PROFENDER(®) Spot-On (Bayer; 66 cats) and treated once on Day 0. For evaluation of efficacy, two faecal samples were collected, one prior to treatment (Day -4 ± 4 days) and one at the end of the study (Day 14 ± 5 days). These were examined for fecal forms of nematode and cestode parasites. For evaluation of safety, cats were examined by a veterinarian before treatment and at the end of the study, and cat owners recorded the health status of their cats daily until the end of the study. For cats treated with Broadline(®), the efficacy was >99.9%, 100%, and 99.6% for Toxocara, hookworms, and Capillaria, respectively; and the efficacy was >99.9%, >99.9%, and 98.5%, respectively, for the cats treated with Profender(®) (p<0.001 for all nematodes and both treatments). Efficacy was 100% for both cestodes for both treatments (p<0.001). No treatment related adverse experiences were observed throughout the study. For both treatments, every cat that completed the study was given a safety score of 'excellent' for both local and systemic evaluations. The topical combination product of fipronil, (S)-methoprene, eprinomectin and praziquantel was shown to have an excellent safety profile and demonstrated high levels of efficacy when administered once as topical solution to cats infected with nematodes and cestodes under field conditions. Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.

Comparison of storm intensity and application timing on modeled transport and fate of six contaminants.

PubMed

Chiovarou, Erica D; Siewicki, Thomas C

2008-01-15

Hundreds, if not thousands, of fish kills and kills of other aquatic organisms occur following storms in the US each year, but they are difficult to quantify, investigate, or manage due to the transient nature of major storms and the other priorities following them. Methods are needed to better understand the causes of these kills. The Pesticide Root Zone Model and the Exposure Analysis Modeling System were used to compare risk to resident biota in estuarine headwaters in two locations under various conditions. Contaminants were selected using a landuse-based preliminary risk assessment approach. Atrazine, fipronil, and imidacloprid were compared for potential impacts on important prey species, including copepods and grass shrimp, in Lake Bethel in Volusia County, Florida. Carbaryl, diquat dibromide, and fluoranthene were compared for potential impacts on salmon and other aquatic species in Johnson Creek, near Portland, Oregon. Predictions of contaminant concentrations in groundwater runoff, surface water, benthic sediments, and pelagic biota tissue were obtained based upon watershed characteristics, storm types, and contaminant chemistry and application. For all six contaminants, the simulated concentrations were highest following the 100-yr storms and lowest following the 2-yr storms. Aqueous concentrations ranged between 84 and 2100% higher in 100-yr compared to two-yr storms. Most atrazine and carbaryl concentrations were highest if applied one day before the storm while fipronil, imidacloprid, and diquat dibromide were highest if applied 16 days prior to the storm. Carbaryl and fluoranthene concentrations were highest in the forested segment of the watershed while diquat dibromide concentrations were highest in the agricultural segment. In Florida simulations, groundwater and surface water concentrations generally were highest for atrazine, followed by imidacloprid, and then fipronil. Atrazine poses the highest risk to algae and copepods due to its mobility and high allowable application rates. Fipronil and imidacloprid, though highly toxic, were not predicted to occur at high enough concentrations to pose a risk. In Oregon simulations, groundwater and surface water concentrations generally were highest for carbaryl, followed by fluoranthene, and then diquat dibromide. For salmonids, fluoranthene poses a higher risk than carbaryl, whereas it is unlikely that diquat dibromide will affect salmonids in this system. For crustaceans, carbaryl poses the greatest risk, followed by fluoranthene. Diquat dibromide was determined to pose little risk. These tests demonstrate the use of preliminary risk assessment, along with transport and fate modeling, to characterize risks to aquatic organisms without the need for in situ chemical measurements.

Preliminary efficacy investigations of oral fipronil against Anopheles arabiensis when administered to Zebu cattle (Bos indicus) under field conditions.

PubMed

Poché, Richard M; Githaka, Naftaly; van Gool, Frans; Kading, Rebekah C; Hartman, Daniel; Polyakova, Larisa; Abworo, Edward Okoth; Nene, Vishvanath; Lozano-Fuentes, Saul

2017-12-01

Globally, malaria remains one of the most important vector-borne diseases despite the extensive use of vector control, including indoor residual spraying (IRS) and insecticide-treated nets (ITNs). These control methods target endophagic vectors, whereas some malaria vectors, such as Anopheles arabiensis, preferentially feed outdoors on cattle, making it a complicated vector to control using conventional strategies. Our study evaluated whether treating cattle with a capsule containing the active ingredient (AI) fipronil could reduce vector density and sporozoite rates, and alter blood feeding behavior, when applied in a small-scale field study. A pilot field study was carried out in the Samia District, Western Kenya, from May to July 2015. Four plots, each comprised of 50 huts used for sleeping, were randomly designated to serve as control or treatment. A week before cattle treatment, baseline mosquito collections were performed inside the houses using mechanical aspirators. Animals in the treatment (and buffer) were administered a single oral application of fipronil at ∼0.5mg/kg of body weight. Indoor mosquito collections were performed once a week for four weeks following treatment. Female mosquitoes were first identified morphologically to species complex, followed by PCR-based methods to obtain species identity, sporozoite presence, and the host source of the blood meal. All three species of anophelines found in the study area (An. gambiae s.s., An. arabiensis, An. funestus s.s.) were actively transmitting Plasmodium falciparum during the study period. The indoor resting density of An. arabiensis was significantly reduced in treatment plot one at three weeks post-treatment (T1) (efficacy=89%; T1 density=0.08, 95% credibility intervals [0.05, 0.10]; control plot density=0.78 [0.22, 0.29]) and at four weeks post-treatment (efficacy=64%; T1 density=0.16 [0.08, 0.14]; control plot density=0.48 [0.17, 0.22]). The reduction of An. arabiensis mosquitoes captured in the treatment plot two was higher: zero females were collected after treatment. The indoor resting density of An. gambiae s.s. was not significantly different between the treatment (T1, T2) and their corresponding control plots (C1, C2). An. funestus s.s. showed an increase in density over time. The results of this preliminary study suggest that treating cattle orally with fipronil, to target exophagic and zoophagic malaria vectors, could be a valuable control strategy to supplement existing vector control interventions which target endophilic anthropophilic species. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

IMIDACLOPRID PRODUCES MINIMAL CHANGES IN THE EEG OF LONG-EVANS RATS

EPA Science Inventory

We have reported that the non-stimulus driven EEG is differentially altered by deltamethrin or permethrin (Lyke and Herr, Toxicologist, 114(S-1) :265, 2010) as well as fipronil (Lyke and Herr, Toxicologist, 120(S-2) :290, 2011). In the current study, we examined the ability to de...

MARINE MESOCOSM ESTIMATES OF TOXICITY USING THE INSECTICIDE FIPRONIL AND A TYPICAL SOUTHEASTERN SALT MARSH. (R827397)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

FIPRONIL (ICON) EFFECTS ON COPEPOD SURVIVAL, DEVELOPMENT, AND REPRODUCTIVE SUCCESS IN A MICROPLATE-BASED LIFE-CYCLE SCREENING ASSAY. (R827397)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

THE ROLE OF DISSOLVED ORGANIC MATTER, NITRATE, AND BICARBONATE IN THE PHOTOLYSIS OF AQUEOUS FIPRONIL. (R827397)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

77 FR 25716 - Fipronil; Receipt of Applications for Emergency Exemptions, Solicitation of Public Comment

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-01

... pesticide manufacturer. Potentially affected entities may include, but are not limited to: Crop production (NAICS code 111). Animal production (NAICS code 112). Food manufacturing (NAICS code 311). Pesticide... your concerns and suggest alternatives. vii. Explain your views as clearly as possible, avoiding the...

Efficiency of a modified backwater wetland in trapping a pesticide mixture

USDA-ARS?s Scientific Manuscript database

The pesticide trapping efficiency of a modified backwater wetland amended with a mixture of three pesticides, atrazine, S-metolachlor, and fipronil, using a simulated runoff event, was examined. The 700 m long, 25 m wide wetland, located along the Coldwater River in Tunica County, Mississippi, USA,...

Pesticide trapping efficiency of a modified backwater wetland using a simulated runoff event

USDA-ARS?s Scientific Manuscript database

This study examined the trapping efficiency of a modified backwater wetland amended with a mixture of three pesticides, atrazine, metolachlor, and fipronil, using a simulated runoff event. The 700 m long, 25 m wide wetland, located along the Coldwater River in Tunica County, Mississippi, was modifie...

Permethrin Induces Overexpression of Cytochrome c Oxidase Subunit 3 in Aedes aegypti

USDA-ARS?s Scientific Manuscript database

Using quantitative PCR (QPCR), the relative transcriptional levels of cytochrome c oxidase subunit 3 (CO3) were studied in Aedes aegypti (L.) in response to treatments with acetone, permethrin, or fipronil. The transcriptional levels of CO3 were significantly (p <0.05) higher in acetone-treated Ae. ...

Truncated transcripts of nicotinic acetylcholine subunit gene bdalpha6 are associated with spinosad resistance in Bactrocera dorsalis

USDA-ARS?s Scientific Manuscript database

We investigated spinosad resistance mechanisms of a Bactocera dorsalis strain from Taiwan. Resistance levels were 901-fold, and there was no cross resistance against imidacloprid or fipronil Combined biochemical and synergistic data indicated that target site insensitivity is the major resistance co...

Determination of metabolic resistance mechanisms in pyrethroid-resistant and fipronil-tolerant brown dog ticks

USDA-ARS?s Scientific Manuscript database

Rhipicephalus sanguineus (Latreille) (Ixodida: Ixodidae) is a three-host dog tick found worldwide that is able to complete its’ entire lifecycle indoors. Options for the management of R. sanguineus are limited and its’ control relies largely on only a few acaricidal active ingredients. Previous stud...

Synergy between dinotefuran and fipronil against the cat flea (Ctenocephalides felis): improved onset of action and residual speed of kill in adult cats.

PubMed

Delcombel, Romain; Karembe, Hamadi; Nare, Bakela; Burton, Audrey; Liebenberg, Julian; Fourie, Josephus; Varloud, Marie

2017-07-19

The cat flea, Ctenocephalides felis felis (C. felis), is a cosmopolitan hematophagous ectoparasite, and is considered to be the most prevalent flea species in both Europe and the USA. Clinical signs frequently associated with flea bites include pruritus, dermatitis and in severe cases even pyodermatitis and alopecia. Ctenocephalides felis is also a vector for several pathogens and is an intermediate host for the cestode Dipylidium caninum. Treatment of cats with a fast-acting pulicide, that is persistently effective in protecting the animal against re-infestation, is therefore imperative to their health. In addition, a rapid onset of activity ("speed of kill") may also reduce the risks of disease transmission and flea allergic dermatitis. The aim of this study was to evaluate the in vitro insecticidal activity and potential synergism between dinotefuran and fipronil against C. felis. A further aim was to evaluate the onset of activity and residual speed of kill of the combination in vivo on cats artificially infested with C. felis. In the first study, the insecticidal activity of dinotefuran and fipronil separately and dinotefuran/fipronil (DF) in combination, at a fixed ratio (2:1), was evaluated using an in vitro coated-vial bioassay. In the second study, the onset of activity against existing flea infestations and residual speed of kill of DF against artificial flea infestations on cats was assessed in vivo. Onset of activity against existing flea infestations was assessed in terms of knock-down effect within 2 h post-treatment and onset of speed of kill assessed at 3 h, 6 h and 12 h post-treatment. Residual speed of kill was evaluated 6 h and 48 h after infestation, over a period of six weeks post-treatment. In vitro results revealed that the DF combination was synergistic and more potent against fleas than either compound alone. The combination also proved effective when tested in vivo. Efficacy was > 97% [geometric mean (GM) and arithmetic mean (AM)] at 3 h after treatment, and ≥ 99.8% (GM and AM) at 6 h and 12 h post-treatment. At 6 h after flea re-infestations, the efficacy of DF remained ≥ 90.8% (GM and AM) for up to 28 days, and at 42 days post-treatment persistent efficacy was still ≥ 54.3% (GM and AM). At 48 h after flea re-infestations, DF remained almost fully effective for up to 28 days, with efficacies ≥ 99.4% (GM and AM) and was persistently ≥ 93.0% (GM and AM) effective for up to 42 days post-treatment. The combination of dinotefuran and fipronil in a single formulation exhibited strong synergistic insecticidal activity against C. felis in vitro, and also proved effective on artificially infested cats. This activity had a rapid onset that persisted for 6 weeks against re-infestations of C. felis on cats. The rapid curative insecticidal effect was observed as early as 3 h after treatment, and as early as 6 h after re-infestations for up to 6 weeks post-treatment. The insecticidal activity profile of DF makes it an optimal candidate for the protection of cats against flea infestations, and possibly also associated diseases.

40 CFR 180.442 - Bifenthrin; tolerances for residues.

Code of Federal Regulations, 2012 CFR

2012-07-01

... Cattle, meat 0.5 Coriander, dried leaves 25 Coriander, leaves 6.0 Coriander, seed 5.0 Corn, field, forage..., undelinted seed 0.5 Eggplant 0.05 Egg 0.05 Fruit, citrus, group 10 0.05 Goat, fat 1.0 Goat, meat byproducts 0....05 Poultry, meat 0.05 Radish, tops 4.5 Rapeseed, seed 0.05 Sheep, fat 1.0 Sheep, meat byproducts 0.1...

40 CFR 180.442 - Bifenthrin; tolerances for residues.

Code of Federal Regulations, 2014 CFR

2014-07-01

..., leaves 6.0 Coriander, seed 5.0 Corn, field, forage 3.0 Corn, field, grain 0.05 Corn, field, stover 5.0... husk removed 0.05 Corn, sweet, stover 5.0 Cotton, undelinted seed 0.5 Eggplant 0.05 Egg 0.05 Fruit..., seed 0.05 Sheep, fat 1.0 Sheep, meat byproducts 0.1 Sheep, meat 0.5 Soybean, hulls 0.50 Soybean...

40 CFR 180.442 - Bifenthrin; tolerances for residues.

Code of Federal Regulations, 2013 CFR

2013-07-01

..., leaves 6.0 Coriander, seed 5.0 Corn, field, forage 3.0 Corn, field, grain 0.05 Corn, field, stover 5.0... husk removed 0.05 Corn, sweet, stover 5.0 Cotton, undelinted seed 0.5 Eggplant 0.05 Egg 0.05 Fruit..., seed 0.05 Sheep, fat 1.0 Sheep, meat byproducts 0.1 Sheep, meat 0.5 Soybean, hulls 0.50 Soybean...

40 CFR 180.442 - Bifenthrin; tolerances for residues.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Cattle, meat 0.5 Coriander, dried leaves 25 Coriander, leaves 6.0 Coriander, seed 5.0 Corn, field, forage..., undelinted seed 0.5 Eggplant 0.05 Egg 0.05 Fruit, citrus, group 10 0.05 Goat, fat 1.0 Goat, meat byproducts 0....05 Poultry, meat 0.05 Radish, tops 4.5 Rapeseed, seed 0.05 Sheep, fat 1.0 Sheep, meat byproducts 0.1...

Effectiveness of bifenthrin (Onyx) and carbaryl (Sevin SL) for protecting individual, high-value conifers from bark beetle attack (Coleoptera: Curculionidae: Scolytinae) in the Western United States

Treesearch

Christopher J. Fettig; Kurt K. Allen; Robert R. Borys; John Christopherson; Christopher P. Dabney; Thomas J. Eager; Kenneth E. Gibson; Elizabeth G. Hebertson; Daniel F. Long; A. Steven Munson; Patrick J. Shea; Sheri L. Smith; Michael I. Haverty

2006-01-01

High-value trees, such as those located in residential, recreational, or administrative sites, are particularly susceptible to bark beetle (Coleoptera: Curculionidae: Scolytinae) attack as a result of increased amounts of stress associated with drought, soil compaction, mechanical injury, or vandalism. Tree losses in these unique environments generally have a...

Single and combination insecticides evaluated as regulatory immersion treatments to eliminate third-instar Japanese beetle (Coleoptera: Scarabaeidae) from small diameter field-grown and containerized nursery plants

USDA-ARS?s Scientific Manuscript database

Japanese beetles, Popillia japonica Newman, are a nursery regulatory pest. Immersion of field-grown plants harvested as balled and burlapped (B&B) or container plants grown in pine bark substrates in a solution of chlorpyrifos or bifenthrin is allowed for certification in the Domestic Japanese Beet...

Physical and chemical properties of pyrethroids.

PubMed

Laskowski, Dennis A

2002-01-01

The physical and chemical properties of the pyrethroids bifenthrin, cyfluthrin, cypermethrin (also zetacypermethrin), deltamethrin, esfenvalerate (also fenvalerate), fenpropathrin, lambda-cyhalothrin (also cyhalothrin), permethrin, and tralomethrin have been reviewed and summarized in this paper. Physical properties included molecular weight, octanol-water partition coefficient, vapor pressure, water solubility, Henry's law constant, fish biocencentration factor, and soil sorption, desorption, and Freundlich coefficients. Chemical properties included rates of degradation in water as a result of hydrolysis, photodecomposition, aerobic or anaerobic degradation by microorganisms in the absence of light, and also rates of degradation in soil incubated under aerobic or anaerobic conditions. Collectively, the pyrethroids display a highly nonpolar nature of low water solubility, low volatility, high octanol-water partition coefficients, and have high affinity for soil and sediment particulate matter. Pyrethroids have low mobility in soil and are sorbed strongly to the sediments of natural water systems. Although attracted to living organisms because of their nonpolar nature, their capability to bioconcentrate is mitigated by their metabolism and subsequent elimination by the organisms. In fish, bioconcentration factors (BCF) ranged from 360 and 6000. Pyrethroids in water solution tend to be stable at acid and neutral pH but [table: see text] become increasingly susceptible to hydrolysis at pH values beyond neutral. Exceptions at higher pH are bifenthrin (stable), esfenvalerate (stable), and permethrin (half-life, 240 d). Pyrethroids vary in susceptibility to sunlight. Cyfluthrin and tralomethrin in water had half-lives of 0.67 and 2.5 d; lambda-cyhalothrin, esfenvalerate, deltamethrin, permethrin, and cypermethrin were intermediate with a range of 17-110 d; and bifenthrin and fenpropathrin showed the least susceptibility with half-lives of 400 and 600 d, respectively. Pyrethroids on soil can also undergo photolysis, often at rates similar to that in water. Half-lives ranged from 5 to 170 d. [table: see text] Pyrethroids are degradable in soils with half-lives ranging from 3 to 96 d aerobically, and 5 to 430 d anaerobically. For those pyrethroids studied in water (cypermethrin, deltamethrin, esfenvalerate, fenpropathrin, and lambda-cyhalothrin), aerobic and anaerobic degradation often continued at rates similar to that displayed in soil.

Evaluation of two least toxic integrated pest management programs for managing bed bugs (Heteroptera: Cimicidae) with discussion of a bed bug intercepting device.

PubMed

Wang, Changlu; Gibb, Timothy; Bennett, Gary W

2009-05-01

The cost and effectiveness of two bed bug (Cimex lectularius L.) integrated pest management (IPM) programs were evaluated for 10 wk. Sixteen bed bug-infested apartments were chosen from a high-rise low-income apartment building. The apartments were randomly divided into two treatment groups: diatomaceous earth dust-based IPM (D-IPM) and chlorfenapyr spray-based IPM (S-IPM). The initial median (minimum, maximum) bed bug counts (by visual inspection) of the two treatment groups were 73.5 (10, 352) and 77 (18, 3025), respectively. A seminar and an educational brochure were delivered to residents and staff. It was followed by installing encasements on mattresses and box springs and applying hot steam to bed bug-infested areas in all 16 apartments. Diatomaceous earth dust (Mother Earth-D) was applied in the D-IPM group 2 d after steaming. In addition, bed bug-intercepting devices were installed under legs of infested beds or sofas or chairs to intercept bed bugs. The S-IPM group only received 0.5% chlorfenapyr spray (Phantom) after the nonchemical treatments. All apartments were monitored bi-weekly and retreated when necessary. After 10 wk, bed bugs were eradicated from 50% of the apartments in each group. Bed bug count reduction (mean +/- SEM) was 97.6 +/- 1.6 and 89.7 +/- 7.3% in the D-IPM and S-IPM groups, respectively. Mean treatment costs in the 10-wk period were $463 and $482 per apartment in the D-IPM and S-IPM groups, respectively. Bed bug interceptors trapped an average of 219 +/- 135 bed bugs per apartment in 10 wk. The interceptors contributed to the IPM program efficacy and were much more effective than visual inspections in estimating bed bug numbers and determining the existence of bed bug infestations.

FIPRONIL EFFECTS ON ESTUARINE COPEPOD (AMPHIASCUS TENUIREMIS) DEVELOPMENT, FERTILITY, AND REPRODUCTION: A RAPID LIFE-CYCLE ASSAY IN 96-WELL MICROPLATE FORMAT. (R827397)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

AN INTEGRATION OF COPEPOD-BASED BAFS, LIFECYCLE TOXICITY TESTING, AND ENDOCRINE DISRUPTION METHODOLOGIES FOR RAPID POPULATION-LEVEL RISK ASSESSMENT OF PERSISTENT BIOACCUMULATIVE TOXICANTS

EPA Science Inventory

Extensive multi-generational microplate culturing (copepod hatching stage through two broods) experiments were completed with the POPs lindane, DDD and fipronil sulfide.  Identical tandem microplate experiments were run concurrently to yield sufficient copepod biomass for li...

40 CFR 180.517 - Fipronil; tolerances for residues.

Code of Federal Regulations, 2010 CFR

2010-07-01

...)-(trifluoromethyl)sulfinyl]-1H-pyrazole-3-carbonitrile) and its metabolites 5-amino-1-[2,6-dichloro-4-(trifluoromethyl)phenyl]-4-[(trifluoromethyl) sulfonyl]-1H-pyrazole-3-carbonitrile and 5-amino-1-[2,6-dichloro-4-(trifluoromethyl) phenyl]-4-[(trifluoromethyl)thio]-1H-pyrazole-3-carbonitrile and its photodegradate 5-amino-1-(2...

Varying termiticide application rate and volume affect initial soil penetration

Treesearch

Christopher Peterson

2010-01-01

The initial soil penetration of Premise 75 and Termidor SC, containing imidacloprid and fipronil, respectively, were tested in laboratory columns of five different soils. Three combinations of application concentration and volume were used: double the recommended active ingredient concentration at one half the recommended volume (DR), the full concentration and volume...

78 FR 23557 - Fipronil; Receipt of Application for Emergency Exemptions, Solicitation of Public Comment

Federal Register 2010, 2011, 2012, 2013, 2014

2013-04-19

... your concerns and suggest alternatives. vii. Explain your views as clearly as possible, avoiding the... population who, as a result of their location, cultural practices, or other factors, may have atypical or... that an emergency situation exists based upon three factors: A severe increase in cabbage maggot...

Using paired soil and house dust samples in an in vitro assay to assess the post ingestion bioaccessibility of sorbed fipronil

EPA Science Inventory

For children, ingestion of soils and house dusts can be an important exposure pathway for regulated organic compounds. Following ingestion, the extent to which compounds desorb and become bioaccessible is a critical determinant of systemic adsorption.We characterized the physicoc...

Lethal and sublethal effects of selected insecticides and an insect growth regulator on the boll weevil (Coleoptera: Curculionidae) ectoparasitoid Catolaccus grandis (Hymenoptera: Pteromalidae).

PubMed

Elzen, G W; Maldonado, S N; Rojas, M G

2000-04-01

A laboratory culture of Catolaccus grandis (Burks), an ectoparasitoid of the boll weevil, Anthonomus grandis grandis Boheman, was exposed to lethal and sublethal doses of insecticides and an insect growth regulator using a spray chamber bioassay. Materials tested were azinphos-methyl, endosulfan, fipronil, malathion, cyfluthrin, dimethoate, spinosad, methyl parathion, acephate, oxamyl, and tebufenozide. At full rates, spinosad was significantly less toxic to female C. grandis than other treatments except endosulfan. Fipronil and malathion were significantly more toxic to females than other treatments. Most of the chemicals tested were highly toxic to male C. grandis; spinosad was least toxic. At reduced rates, most of 4 selected chemicals tested were low in toxicity to C. grandis; however, a reduced rate of malathion was significantly more toxic to females than other treatments. No C. grandis pupae developed from parasitism during a 24-h treatment period with malathion or spinosad. The sex ratio of progeny from sprayed adults appeared to be unaffected by the treatments.

Estimating terrestrial amphibian pesticide body burden through dermal exposure.

PubMed

Van Meter, Robin J; Glinski, Donna A; Hong, Tao; Cyterski, Mike; Henderson, W Matthew; Purucker, S Thomas

2014-10-01

Dermal exposure presents a potentially significant but understudied route for pesticide uptake in terrestrial amphibians. Our study measured dermal uptake of pesticides of varying hydrophobicity (logKow) in frogs. Amphibians were indirectly exposed to one of five pesticide active ingredients through contact with contaminated soil: imidacloprid (logKow = 0.57), atrazine (logKow = 2.5), triadimefon (logKow = 3.0), fipronil (logKow = 4.11) or pendimethalin (logKow = 5.18). All amphibians had measurable body burdens at the end of the exposure in concentrations ranging from 0.019 to 14.562 μg/g across the pesticides tested. Atrazine produced the greatest body burdens and bioconcentration factors, but fipronil was more permeable to amphibian skin when application rate was considered. Soil partition coefficient and water solubility were much better predictors of pesticide body burden, bioconcentration factor, and skin permeability than logKow. Dermal uptake data can be used to improve risk estimates of pesticide exposure among amphibians as non-target organisms. Copyright © 2014 Elsevier Ltd. All rights reserved.

Detection of pesticides in active and depopulated beehives in Uruguay.

PubMed

Pareja, Lucía; Colazzo, Marcos; Pérez-Parada, Andrés; Niell, Silvina; Carrasco-Letelier, Leonidas; Besil, Natalia; Cesio, María Verónica; Heinzen, Horacio

2011-10-01

The influence of insecticides commonly used for agricultural purposes on beehive depopulation in Uruguay was investigated. Honeycombs, bees, honey and propolis from depopulated hives were analyzed for pesticide residues, whereas from active beehives only honey and propolis were evaluated. A total of 37 samples were analyzed, representing 14,800 beehives. In depopulated beehives only imidacloprid and fipronil were detected and in active beehives endosulfan, coumaphos, cypermethrin, ethion and chlorpyrifos were found. Coumaphos was present in the highest concentrations, around 1,000 μg/kg, in all the propolis samples from active beehives. Regarding depopulated beehives, the mean levels of imidacloprid found in honeycomb (377 μg/kg, Standard Deviation: 118) and propolis (60 μg/kg, Standard Deviation: 57) are higher than those described to produce bee disorientation and fipronil levels detected in bees (150 and 170 μg/kg) are toxic per se. The other insecticides found can affect the global fitness of the bees causing weakness and a decrease in their overall productivity. These preliminary results suggest that bees exposed to pesticides or its residues can lead them in different ways to the beehive.

Effectiveness of bifenthrin (Onyx™) and carbaryl (Sevin® SL) for protecting individual, high-value trees from bark beetle attack (Coleoptera: Curculionidae: Scolytinae) in the western United States

Treesearch

Christopher J. Fettig; Kurt K. Allen; Robert R. Borys; John Christopherson; Christopher P. Dabney; Thomas J. Eager; Kenneth E. Gibson; Elizabeth G. Hebertson; Daniel F. Long; A. Steven Munson; Patrick J. Shea; Sheri L. Smith; Michael I. Haverty

2006-01-01

High-value trees, such as those located in residential, recreational, or administrative sites, are particularly susceptible to bark beetle (Coleoptera: Curculionidae: Scolytinae) attack as a result of increased amounts of stress associated with drought, soil compaction, mechanical injury, or vandalism. Tree losses in these unique environments generally have a...

Evaluation of sunlight-exposed pyrethroid-treated netting for the control of face fly and housefly (Diptera: Muscidae).

PubMed

Peck, George W; Ferguson, Holly J; LePage, Jane T; Hebert, Vincent R; O'Neal, Sally D; Walsh, Douglas B

2014-01-01

Face flies, Musca autumnalis De Geer (Diptera: Muscidae), and houseflies, Musca domestica L. (Diptera: Muscidae), have a significant impact on livestock and dairy production throughout North America. Pyrethroid insecticide efficacy can be affected by exposure to direct sunlight, and the rate of photodegradation is substrate and formulation dependent. Insecticide-treated netting (ITN) is finding new applications in crop and livestock production systems. A baseline study using long-duration no-choice assays has been carried out to gauge the effectiveness of ITN treated with β-cyfluthrin, λ-cyhalothrin and bifenthrin on face flies and houseflies. After 12 weeks in direct sunlight, ITN treated with β-cyfluthrin was still highly insecticidal to face flies and houseflies, producing 100% mortality in petri dish assays. However, sunlight reduced the insecticidal activity of λ-cyhalothrin, with 3% of face flies and 50% of houseflies surviving after exposure to ITN that had been deployed for 10 weeks. Insecticidal activity was greatly reduced on bifenthrin-treated netting, with 20% of face flies and 50% of houseflies surviving in assays with netting deployed for only 3 weeks. With careful choice of the pyrethroid applied, treated netting could be an important component of livestock integrated pest management programs focused on sustainable practices. © 2013 Society of Chemical Industry.

Disruption of the hormonal network and the enantioselectivity of bifenthrin in trophoblast: maternal-fetal health risk of chiral pesticides.

PubMed

Zhao, Meirong; Zhang, Ying; Zhuang, Shulin; Zhang, Quan; Lu, Chengsheng; Liu, Weiping

2014-07-15

Endocrine-disrupting chemicals (EDCs) can interfere with normal hormone signaling to increase health risks to the maternal-fetal system, yet few studies have been conducted on the currently used chiral EDCs. This work tested the hypothesis that pyrethroids could enantioselectively interfere with trophoblast cells. Cell viability, hormone secretion, and steroidogenesis gene expression of a widely used pyrethroid, bifenthrin (BF), were evaluated in vitro, and the interactions of BF enantiomers with estrogen receptor (ER) were predicted. At low or noncytotoxic concentrations, both progesterone and human chorionic gonadotropin secretion were induced. The expression levels of progesterone receptor and human leukocyte antigen G genes were significantly stimulated. The key regulators of the hormonal cascade, GnRH type-I and its receptor, were both upregulated. The expression levels of selected steroidogenic genes were also significantly altered. Moreover, a consistent enantioselective interference of hormone signaling was observed, and S-BF had greater effects than R-BF. Using molecular docking, the enantioselective endocrine disruption of BF was predicted to be partially due to enantiospecific ER binding affinity. Thus, BF could act through ER to enantioselectively disturb the hormonal network in trophoblast cells. These converging results suggest that the currently used chiral pesticides are of significant concern with respect to maternal-fetal health.

Acaricidal and repellent effects of Cnidium officinale-derived material against Dermanyssus gallinae (Acari: Dermanyssidae).

PubMed

Kim, Hyun Kyung; Lee, Seung Ju; Hwang, Bang-Yeon; Yoon, Jong Ung; Kim, Gil-Hah

2018-04-01

The acaricidal activity of a methanolic extract and fractions from the rhizome of Cnidium officinale against Dermanyssus gallinae adults was investigated. The C. officinale methanolic extract exhibited 100% acaricidal activity after 48 h of treatment at a dose of 4000 ppm. The acaricidal constituents of the plant were sequentially partitioned with several solvents and then purified using silica gel column chromatography and high-performance liquid chromatography. Gas chromatography-mass spectrometry and nuclear magnetic resonance spectroscopy revealed (Z)-ligustilide as a constituent of C. officinale. Acaricidal activity was examined in three experimental tests (spray, fumigation and contact), with the spraying method being the most effective. The methanolic extract of C. officinale showed both contact and fumigant activities, though only fumigant activity was observed with (Z)-ligustilide. The fumigant effects of the methanolic extract and (Z)-ligustilide caused 86.5 and 62.6% mortality, respectively, of D. gallinae adults at 48 h. Among (Z)-ligustilide, acaricides (bifenthrin, cypermethrin and spinosad) and butylidenephthalide, bifenthrin displayed the highest acaricidal activity, and the activity of butylidenephthalide was 2.3-fold higher than that of (Z)-ligustilide. These results suggest that C. officinale-derived material can be used for the development of a control agent for D. gallinae.

Simultaneous biodegradation of bifenthrin and chlorpyrifos by Pseudomonas sp. CB2.

PubMed

Zhang, Qun; Li, Shuhuai; Ma, Chen; Wu, Nancun; Li, Chunli; Yang, Xinfeng

2018-05-04

The degradation of bifenthrin (BF) and chlorpyrifos (CP), either together or individually, by a bacterial strain (CB2) isolated from activated sludge was investigated. Strain CB2 was identified as belonging to genus Pseudomonas based on the morphological, physiological, and biochemical characteristics and a homological analysis of the 16S rDNA sequence. Strain CB2 has the potential to degrade BF and CP, either individually or in a mixture. The optimum conditions for mixture degradation were as follows: OD 600nm = 0.5; incubation temperature = 30°C; pH = 7.0; BF-CP mixture (10 mg L -1 of each). Under these optimal conditions, the degradation rate constants (and half-lives) were 0.4308 d -1 (1.61 d) and 0.3377 d -1 (2.05 d) for individual BF and CP samples, respectively, and 0.3463 d -1 (2.00 d) and 0.2931 d -1 (2.36 d) for the BF-CP mixture. Major metabolites of BF and CP were 2-methyl-3-biphenylyl methanol and 3,5,6-trichloro-2-pyridinol, respectively. No metabolite bioaccumulation was observed. The ability of CB2 to efficiently degrade BF and CP, particularly in a mixture, may be useful in bioremediation efforts.

GLC-3: a novel fipronil and BIDN-sensitive, but picrotoxinin-insensitive, L-glutamate-gated chloride channel subunit from Caenorhabditis elegans

PubMed Central

Horoszok, Lucy; Raymond, Valérie; Sattelle, David B; Wolstenholme, Adrian J

2001-01-01

We report the cloning and expression of a novel Caenorhabditis elegans polypeptide, GLC-3, with high sequence identity to previously cloned L-glutamate-gated chloride channel subunits from nematodes and insects. Expression of glc-3 cRNA in Xenopus oocytes resulted in the formation of homo-oligomeric L-glutamate-gated chloride channels with robust and rapidly desensitizing currents, an EC50 of 1.9±0.03 mM and a Hill coefficient of 1.5±0.1. GABA, glycine, histamine and NMDA all failed to activate the GLC-3 homo-oligomer at concentrations of 1 mM. The anthelminthic, ivermectin, directly and irreversibly activated the L-glutamate-gated channel with an EC50 of 0.4±0.02 μM. The GLC-3 channels were selective for chloride ions, as shown by the shift in the reversal potential for L-glutamate-gated currents after the reduction of external Cl− from 107.6 to 62.5 mM. Picrotoxinin failed to inhibit L-glutamate agonist responses at concentrations up to 1 mM. The polycyclic dinitrile, 3,3-bis-trifluoromethyl-bicyclo[2,2,1]heptane-2,2-dicarbonitrile (BIDN), completely blocked L-glutamate-induced chloride currents recorded from oocytes expressing GLC-3 with an IC50 of 0.2±0.07 μM. The phenylpyrazole insecticide, fipronil, reversibly inhibited L-glutamate-gated currents recorded from the GLC-3 receptor with an IC50 of 11.5±0.11 μM. In this study, we detail the unusual antagonist pharmacology of a new GluCl subunit from C. elegans. Unlike all other native and recombinant nematode GluCl reported to date, the GLC-3 receptor is insensitive to picrotoxinin, but is sensitive to two other channel blockers, BIDN and fipronil. Further study of this receptor may provide insights into the molecular basis of non-competitive antagonism by these compounds. PMID:11250875

Efficacy of a novel topical combination of fipronil, amitraz and (S)-methoprene for treatment and control of induced infestations with four North American tick species (Dermacentor variabilis, Ixodes scapularis, Amblyomma americanum and Amblyomma maculatum) on dogs.

PubMed

Baker, Christine F; Hunter, James S; McCall, John W; Young, David R; Hair, Jakie A; Everett, William R; Yoon, Stephen S; Irwin, Jennifer P; Young, Stephanie L; Cramer, Luiz G; Pollmeier, Matthias G; Prullage, Joseph B

2011-07-15

Five laboratory studies were conducted to confirm that a single topical dose of the novel combination of fipronil, amitraz and (S)-methoprene, CERTIFECT™ (Merial Limited, GA, USA), is efficacious for the rapid control of pre-existing infestations and the prevention of new infestations with Ixodes scapularis, Dermacentor variabilis, Amblyomma americanum and Amblyomma maculatum for at least 28 days on dogs. In each study, 8 male and 8 female purpose-bred, laboratory beagles were randomly assigned to one of two study groups (treated and untreated). Starting on the day before treatment, each dog was infested weekly with about 30 or 50 ticks, depending on the study. Treatment with the novel combination rapidly eliminated pre-existing infestations and controlled weekly re-infestations for at least 28 days. Pre-existing infestations with all four tick species were rapidly and effectively reduced, with post-treatment therapeutic efficacies ranging from 91.7 to 99.5% within 18-48 h post treatment. Amblyomma maculatum numbers were significantly (p<0.05) reduced on treated dogs from the first tick counts as early as 6h post-treatment. All subsequent infestations with each of the 4 tick species were quickly disrupted, with prophylactic efficacies greater than 90% within 18-48 h post-infestation for at least a full month. Because the combination of fipronil, amitraz and (S)-methoprene quickly starts disrupting and killing ixodid ticks within hours of treatment, with similar high levels of efficacy maintained for at least 28 days in these and other studies, the authors conclude that a single topical treatment with CERTIFECT may prevent the transmission of most infectious agents carried by ixodid ticks for at least one month. Copyright © 2011 Elsevier B.V. All rights reserved.

Use of Electroencephalography (EEG) to Assess CNS Changes Produced by Pesticides with different Modes of Action: Effects of Permethrin, Deltamethrin, Fipronil, Imidacloprid, Carbaryl, and Triadimefon

EPA Science Inventory

The electroencephalogram (EEG) is an apical measure, capable of detecting changes in brain neuronal activity produced by internal or external stimuli. We assessed whether pesticides with different modes of action produced different changes in the EEG of adult male Long-Evans rats...

Enantiomeric separation of type I and type II pyrethroid insecticides with different chiral stationary phases by reversed-phase high-performance liquid chromatography.

PubMed

Zhang, Ping; Yu, Qian; He, Xiulong; Qian, Kun; Xiao, Wei; Xu, Zhifeng; Li, Tian; He, Lin

2018-04-01

The enantiomeric separation of type I (bifenthrin, BF) and type II (lambda-cyhalothrin, LCT) pyrethroid insecticides on Lux Cellulose-1, Lux Cellulose-3, and Chiralpak IC chiral columns was investigated by reversed-phase high-performance liquid chromatography. Methanol/water or acetonitrile/water was used as mobile phase at a flow rate of 0.8 mL/min. The effects of chiral stationary phase, mobile phase composition, column temperature, and thermodynamic parameters on enantiomer separation were carefully studied. Bifenthrin got a partial separation on Lux Cellulose-1 column and baseline separation on Lux Cellulose-3 column, while LCT enantiomers could be completely separated on both Lux Cellulose-1 and Lux Cellulose-3 columns. Chiralpak IC provided no separation ability for both BF and LCT. Retention factor (k) and selectivity factor (α) decreased with the column temperature increasing from 10°C to 40°C for both BF and LCT enantiomers. Thermodynamic parameters including ∆H and ∆S were also calculated, and the maximum R s were not always obtained at lowest temperature. Furthermore, the quantitative analysis methods for BF and LCT enantiomers in soil and water were also established. Such results provide a new approach for pyrethroid separation under reversed-phase condition and contribute to environmental risk assessment of pyrethroids at enantiomer level. © 2017 Wiley Periodicals, Inc.

The consequences of sublethal exposure to insecticide on the survivorship and mobility of Halyomorpha halys (Hemiptera: Pentatomidae).

PubMed

Morrison, William R; Poling, Brittany; Leskey, Tracy C

2017-02-01

The direct lethal effects of conventional and organic insecticides have been investigated thoroughly for all life stages of Halyomorpha halys. However, the sublethal effects of insecticides on the behavior of H. halys have not been well documented. Our aims were to evaluate the impact of a brief 5 min exposure to residues of bifenthrin, dinotefuran, methomyl, thiamethoxam and thiamethoxam + λ-cyhalothrin on survivorship, horizontal and vertical movement, and flight capacity of adult H. halys under laboratory conditions. Over half of the insecticide-exposed adults were classified as affected, moribund or dead after the 5 min exposure, compared with only 6% of the adults in the water-only control. We found that the horizontal movement, vertical climbing and flight capacity of adults exposed to insecticides were decreased by 20-60% overall relative to the water-only control. The most lethal insecticide was bifenthrin. Many insecticide-exposed H. halys adults retained significant mobility and flight capacity, with flight most pronounced immediately after exposure. These results suggest that brief exposure periods to efficacious insecticides will result in high dispersal and low mortality. Therefore, management strategies that enhance the retention of H. halys on insecticide-coated surfaces should be considered to ensure that adults are exposed to a lethal dose of insecticide. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Global occurrence of pyrethroid insecticides in sediment and the associated toxicological effects on benthic invertebrates: An overview.

PubMed

Li, Huizhen; Cheng, Fei; Wei, Yanli; Lydy, Michael J; You, Jing

2017-02-15

Pyrethroids are the third most applied group of insecticides worldwide and are extensively used in agricultural and non-agricultural applications. Pyrethroids exhibit low toxicity to mammals, but have extremely high toxicity to fish and non-target invertebrates. Their high hydrophobicity, along with pseudo-persistence due to continuous input, indicates that pyrethroids will accumulate in sediment, pose long-term exposure concerns to benthic invertebrates and ultimately cause significant risk to benthic communities and aquatic ecosystems. The current review synthesizes the reported sediment concentrations of pyrethroids and associated toxicity to benthic invertebrates on a global scale. Geographically, the most studied area was North America, followed by Asia, Europe, Australia and Africa. Pyrethroids were frequently detected in both agricultural and urban sediments, and bifenthrin and cypermethrin were identified as the main contributors to toxicity in benthic invertebrates. Simulated hazard quotients (HQ) for sediment-associated pyrethroids to benthic organisms ranged from 10.5±31.1 (bifenthrin) to 41.7±204 (cypermethrin), suggesting significant risk. The current study has provided evidence that pyrethroids are not only commonly detected in the aquatic environment, but also can cause toxic effects to benthic invertebrates, and calls for better development of accurate sediment quality criteria and effective ecological risk assessment methods for this emerging class of insecticides. Copyright © 2016 Elsevier B.V. All rights reserved.

Detection of resistance, cross-resistance, and stability of resistance to new chemistry insecticides in Bemisia tabaci (Homoptera: Aleyrodidae).

PubMed

Basit, Muhammad; Saeed, Shafqat; Saleem, Mushtaq Ahmad; Denholm, Ian; Shah, Maqbool

2013-06-01

Resistance levels in whitefly, Bemisia tabaci (Gennadius) collections from cotton and sunflower (up to four districts) for five neonicotinoids and two insect growth regulators (IGRs) were investigated for two consecutive years. Based on the LC50(s), all collections showed slight to moderate levels of resistance for the tested insecticides compared with the laboratory susceptible population. The data also indicated that cotton and sunflower collections had similar resistance levels. In comparison (four collections), Vehari collections showed higher resistance for acetamiprid, thiacloprid, and nitenpyram compared with those of others. Average resistance ratios for acetamiprid, thiacloprid, and nitenpyram ranged from 5- to 13-, 4- to 8-, and 9- to 13-fold, respectively. Multan and Vehari collections also exhibited moderate levels (9- to 16-fold) of resistance to buprofezin. Furthermore, toxicity of neonicotinoids against immature stages was equal to that of insect growth regulators. The data also suggested that resistance in the field populations was stable. After selection for four generations with bifenthrin (G1 to G4), resistance to bifenthrin increased to 14-fold compared with the laboratory susceptible population. Selection also increased resistance to fenpropathrin, lambdacyhalothrin, imidacloprid, acetamiprid, and diafenthuron. Cross-resistance and stability of resistance in the field populations is of some concern. Rotation of insecticides having no cross-resistance and targeting the control against immature stages may control the resistant insects, simultaneously reducing the selection pressure imposed.

An overview comparing results from two decades of monitoring for pesticides in the Nation’s streams and rivers, 1992-2001 and 2002-2011

USGS Publications Warehouse

Stone, Wesley W.; Gilliom, Robert J.; Martin, Jeffrey D.

2014-01-01

This report provides an overview of the U.S. Geological Survey National Water-Quality Assessment program and National Stream Quality Accounting Network findings for pesticide occurrence in U.S. streams and rivers during 2002–11 and compares them to findings for the previous decade (1992–2001). In addition, pesticide stream concentrations were compared to Human Health Benchmarks (HHBs) and chronic Aquatic Life Benchmarks (ALBs). The comparisons between the decades were intended to be simple and descriptive. Trends over time are being evaluated separately in a series of studies involving rigorous trend analysis. During both decades, one or more pesticides or pesticide degradates were detected more than 90 percent of the time in streams across all types of land uses. For individual pesticides during 2002–11, atrazine (and degradate, deethylatrazine), carbaryl, fipronil (and degradates), metolachlor, prometon, and simazine were detected in streams more than 50 percent of the time. In contrast, alachlor, chlorpyrifos, cyanazine, diazinon, EPTC, Dacthal, and tebuthiuron were detected less frequently in streams during the second decade than during the first decade. During 2002–11, only one stream had an annual mean pesticide concentration that exceeded an HHB. In contrast, 17 percent of agriculture land-use streams and one mixed land-use stream had annual mean pesticide concentrations that exceeded HHBs during 1992–2001. The difference between the first and second decades in terms of percent of streams exceeding HHBs was attributed to regulatory changes. During 2002–11, nearly two-thirds of agriculture land-use streams and nearly one-half of mixed land-use streams exceeded chronic ALBs. For urban land use, 90 percent of the streams exceeded a chronic ALB. Fipronil, metolachlor, malathion, cis-permethrin, and dichlorvos exceeded chronic ALBs for more than 10 percent of the streams. For agriculture and mixed land-use streams, the overall percent of streams that exceeded a chronic ALB was very similar between the decades. For urban land-use streams, the percent of streams exceeding a chronic ALB during 2002–11 nearly doubled that seen during 1992–2001. The reason for this difference was the inclusion of fipronil monitoring during the second decade. Across all land-use streams, the percent of streams exceeding a chronic ALB for fipronil during 2002–11 was greater than all other insecticides during both decades. The percent of streams exceeding a chronic ALB for metolachlor, chlorpyrifos, diazinon, malathion, and carbaryl decreased from the first decade to the second decade. The results of the 2002–11 summary and comparison to 1992–2001 are consistent with the results from more rigorous trend analysis of pesticide stream concentrations for individual streams in various regions of the U.S.

Environmental Factors Affecting Efficacy of Bifenthrin-Treated Vegetation for Mosquito Control

DTIC Science & Technology

2009-01-01

and Surgeoner 1983, Ander- son et al. 1991, Perich et al. 1993, Cilek and Hallmon 2006), lambda cyhalothrin (Trout et al. 2007, Cilek and Hallmon 2008...insecticide treatment. Leaves were sampled 1–2 days before treatment, on the day of treatment, and at weeks 1, 2, 4, 6, and 7. All plants were watered ...were divided into 2 groups: those with no rainfall and those with heavy rainfall characteris- tic for June–September in north central Florida. Water

Toxicity of four veterinary pharmaceuticals on the survival and reproduction of Folsomia candida in tropical soils.

PubMed

Zortéa, Talyta; Segat, Julia C; Maccari, Ana Paula; Sousa, José Paulo; Da Silva, Aleksandro S; Baretta, Dilmar

2017-04-01

This study aimed to evaluate the effect of veterinary pharmaceuticals (VPs) used to control endo- and ectoparasites in ruminants, on the survival and reproduction of the collembolan species Folsomia candida. Standard ecotoxicological tests were conducted in Tropical Artificial Soil and the treatments consisted of increasing dosages of four commercial products with different active ingredients: ivermectin, fipronil, fluazuron and closantel. Ecotoxicological effects were related to the class and mode of action of the different compounds. Fipronil and ivermectin were the most toxic compounds causing a significant reduction in the number of juveniles at the lowest doses tested (LOEC reprod values of 0.3 and 0.2 mg kg -1 of dry soil, respectively) and similar low EC 50 values (fipronil: 0.19 mg kg -1 dry soil, CL 95% 0.16-0.22; ivermectin: 0.43 mg kg -1 dry soil, CL 95% 0.09-0.77), although the effects observed in the former compound were possibly related to a low adult survival (LC 50 of 0.62 mg kg -1 dry soil; CL 95% : 0.25-1.06). For the latter compound no significant lethal effects were observed. Fluazuron caused an intermediate toxicity (EC 50 of 3.07 mg kg -1 dry soil, CL 95% : 2.26-3.87), and also here a decrease in adult survival could explain the effects observed at reproduction. Closantel, despite showing a significant reduction on the number of juveniles produced, no dose-response relationship nor effects higher than 50% were observed. Overall, all tested compounds, especially ivermectin, when present in soil even at sub-lethal concentrations, can impair the reproduction of collembolans and possibly other arthropods. However, the actual risk to arthropod communities should be further investigated performing tests under a more realistic exposure (e.g., by testing the dung itself as the contaminated matrix) and by deriving ecotoxicologically relevant exposure concentration in soil derived from the presence of cattle dung. Copyright © 2017 Elsevier Ltd. All rights reserved.

A Locomotor Deficit Induced by Sublethal Doses of Pyrethroid and Neonicotinoid Insecticides in the Honeybee Apis mellifera.

PubMed

Charreton, Mercédès; Decourtye, Axel; Henry, Mickaël; Rodet, Guy; Sandoz, Jean-Christophe; Charnet, Pierre; Collet, Claude

2015-01-01

The toxicity of pesticides used in agriculture towards non-targeted organisms and especially pollinators has recently drawn the attention from a broad scientific community. Increased honeybee mortality observed worldwide certainly contributes to this interest. The potential role of several neurotoxic insecticides in triggering or potentiating honeybee mortality was considered, in particular phenylpyrazoles and neonicotinoids, given that they are widely used and highly toxic for insects. Along with their ability to kill insects at lethal doses, they can compromise survival at sublethal doses by producing subtle deleterious effects. In this study, we compared the bee's locomotor ability, which is crucial for many tasks within the hive (e.g. cleaning brood cells, feeding larvae…), before and after an acute sublethal exposure to one insecticide belonging to the two insecticide classes, fipronil and thiamethoxam. Additionally, we examined the locomotor ability after exposure to pyrethroids, an older chemical insecticide class still widely used and known to be highly toxic to bees as well. Our study focused on young bees (day 1 after emergence) since (i) few studies are available on locomotion at this stage and (ii) in recent years, pesticides have been reported to accumulate in different hive matrices, where young bees undergo their early development. At sublethal doses (SLD48h, i.e. causing no mortality at 48 h), three pyrethroids, namely cypermethrin (2.5 ng/bee), tetramethrin (70 ng/bee), tau-fluvalinate (33 ng/bee) and the neonicotinoid thiamethoxam (3.8 ng/bee) caused a locomotor deficit in honeybees. While the SLD48h of fipronil (a phenylpyrazole, 0.5 ng/bee) had no measurable effect on locomotion, we observed high mortality several days after exposure, an effect that was not observed with the other insecticides. Although locomotor deficits observed in the sublethal range of pyrethroids and thiamethoxam would suggest deleterious effects in the field, the case of fipronil demonstrates that toxicity evaluation requires information on multiple endpoints (e.g. long term survival) to fully address pesticides risks for honeybees. Pyrethroid-induced locomotor deficits are discussed in light of recent advances regarding their mode of action on honeybee ion channels and current structure-function studies.

A Locomotor Deficit Induced by Sublethal Doses of Pyrethroid and Neonicotinoid Insecticides in the Honeybee Apis mellifera

PubMed Central

Charreton, Mercédès; Decourtye, Axel; Henry, Mickaël; Rodet, Guy; Sandoz, Jean-Christophe; Charnet, Pierre; Collet, Claude

2015-01-01

The toxicity of pesticides used in agriculture towards non-targeted organisms and especially pollinators has recently drawn the attention from a broad scientific community. Increased honeybee mortality observed worldwide certainly contributes to this interest. The potential role of several neurotoxic insecticides in triggering or potentiating honeybee mortality was considered, in particular phenylpyrazoles and neonicotinoids, given that they are widely used and highly toxic for insects. Along with their ability to kill insects at lethal doses, they can compromise survival at sublethal doses by producing subtle deleterious effects. In this study, we compared the bee’s locomotor ability, which is crucial for many tasks within the hive (e.g. cleaning brood cells, feeding larvae…), before and after an acute sublethal exposure to one insecticide belonging to the two insecticide classes, fipronil and thiamethoxam. Additionally, we examined the locomotor ability after exposure to pyrethroids, an older chemical insecticide class still widely used and known to be highly toxic to bees as well. Our study focused on young bees (day 1 after emergence) since (i) few studies are available on locomotion at this stage and (ii) in recent years, pesticides have been reported to accumulate in different hive matrices, where young bees undergo their early development. At sublethal doses (SLD48h, i.e. causing no mortality at 48h), three pyrethroids, namely cypermethrin (2.5 ng/bee), tetramethrin (70 ng/bee), tau-fluvalinate (33 ng/bee) and the neonicotinoid thiamethoxam (3.8 ng/bee) caused a locomotor deficit in honeybees. While the SLD48h of fipronil (a phenylpyrazole, 0.5 ng/bee) had no measurable effect on locomotion, we observed high mortality several days after exposure, an effect that was not observed with the other insecticides. Although locomotor deficits observed in the sublethal range of pyrethroids and thiamethoxam would suggest deleterious effects in the field, the case of fipronil demonstrates that toxicity evaluation requires information on multiple endpoints (e.g. long term survival) to fully address pesticides risks for honeybees. Pyrethroid-induced locomotor deficits are discussed in light of recent advances regarding their mode of action on honeybee ion channels and current structure-function studies. PMID:26659095

Development and validation of modified QuEChERS method coupled with LC-MS/MS for simultaneous determination of cymiazole, fipronil, coumaphos, fluvalinate, amitraz, and its metabolite in various types of honey and royal jelly.

PubMed

Zheng, Weijia; Park, Jin-A; Abd El-Aty, A M; Kim, Seong-Kwan; Cho, Sang-Hyun; Choi, Jeong-Min; Yi, Hee; Cho, Soo-Min; Ramadan, Amer; Jeong, Ji Hoon; Shim, Jae-Han; Shin, Ho-Chul

2018-01-01

Over the past few decades, honey products have been polluted by different contaminants, such as pesticides, which are widely applied in agriculture. In this work, a modified EN - quick, easy, cheap, effective, rugged, and safe (QuEChERS) extraction method was developed for the simultaneous quantification of pesticide residues, including cymiazole, fipronil, coumaphos, fluvalinate, amitraz, and its metabolite 2,4-dimethylaniline (2,4-DMA), in four types of honey (acacia, wild, chestnut, and manuka) and royal jelly. Samples were buffered with 0.2M dibasic sodium phosphate (pH 9), and subsequently, acetonitrile was employed as the extraction solvent. A combination of primary secondary amine (PSA) and C18 sorbents was used for purification prior to liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI + /MS-MS) analysis. The estimated linearity measured at six concentration levels presented good correlation coefficients (R 2 )≥0.99. The recovery, calculated from three different spiking levels, was 62.06-108.79% in honey and 67.58-106.34% in royal jelly, with an RSD<12% for all the tested compounds. The matrix effect was also evaluated, and most of the analytes presented signal enhancement. The limits of quantification (LOQ) ranged between 0.001 and 0.005mg/kg in various samples. These are considerably lower than the maximum residue limits (MRL) set by various regulatory authorities. A total of 43 market (domestic and imported) samples were assayed for method application. Among the tested samples, three samples were tested positive (i.e. detected and quantified) only for cymiazole residues. The residues in the rest of the samples were detected but not quantified. We concluded that the protocol developed in this work is simple and versatile for the routine quantification of cymiazole, 2,4-DMA, fipronil, coumaphos, amitraz, and fluvalinate in various types of honey and royal jelly. Copyright © 2017 Elsevier B.V. All rights reserved.

Ecotoxicological Study of Insecticide Effects on Arthropods in Common Bean

PubMed Central

de Barros, Emerson Cristi; Ventura, Hudson Vaner; Gontijo, Pablo Costa; Pereira, Renata Ramos; Picanço, Marcelo Coutinho

2015-01-01

Arthropods are an important group of macroorganisms that work to maintain ecosystem health. Despite the agricultural benefits of chemical control against arthropod pests, insecticides can cause environmental damage. We examined the effects of one and two applications of the insecticides chlorfenapyr (0.18 liters a.i. ha-1) and methamidophos (0.45 liters a.i. ha-1), both independently and in combination, on arthropods in plots of common bean. The experiment was repeated for two growing seasons. Principal response curve, richness estimator, and Shannon–Wiener diversity index analyses were performed. The insecticides generally affected the frequency, richness, diversity, and relative abundance of the arthropods. In addition, the arthropods did not experience recovery after the insecticide applications. The results suggest that the insecticide impacts were sufficiently drastic to eliminate many taxa from the studied common bean plots. PMID:25700537

Solid-phase Microextraction (SPME) with Stable Isotope Calibration for Measuring Bioavailability of Hydrophobic Organic Contaminants

PubMed Central

Cui, Xinyi; Bao, Lianjun; Gan, Jay

2014-01-01

Solid-phase microextraction (SPME) is a biomimetic tool ideally suited for measuring bioavailability of hydrophobic organic compounds (HOCs) in sediment and soil matrices. However, conventional SPME sampling requires the attainment of equilibrium between the fiber and sample matrix, which may take weeks or months, greatly limiting its applicability. In this study, we explored the preloading of polydimethylsiloxane fiber with stable isotope labeled analogs (SI-SPME) to circumvent the need for long sampling time, and evaluated the performance of SI-SPME against the conventional equilibrium SPME (Eq-SPME) using a range of sediments and conditions. Desorption of stable isotope-labeled analogs and absorption of PCB-52, PCB-153, bifenthrin and cis-permethrin were isotropic, validating the assumption for SI-SPME. Highly reproducible preloading was achieved using acetone-water (1:4, v/v) as the carrier. Compared to Eq-SPME that required weeks or even months, the fiber concentrations (Cf) under equilibrium could be reliably estimated by SI-SPME in 1 d under agitated conditions or 20 d under static conditions in spiked sediments. The Cf values predicted by SI-SPME were statistically identical to those determined by Eq-SPME. The SI-SPME method was further applied successfully to field sediments contaminated with PCB 52, PCB 153, and bifenthrin. The increasing availability of stable isotope labeled standards and mass spectrometry nowadays makes SI-SPME highly feasible, allowing the use of SPME under non-equilibrium conditions with much shorter or flexible sampling time. PMID:23930601

Insecticide resistance of adults and nymphs of Asian citrus psyllid populations from Apatzingán Valley, Mexico.

PubMed

Pardo, Saúl; Martínez, Ana M; Figueroa, José I; Chavarrieta, Juan M; Viñuela, Elisa; Rebollar-Alviter, Ángel; Miranda, Mario A; Valle, Javier; Pineda, Samuel

2018-01-01

Control of the Asian citrus psyllid Diaphorina citri Kuwayama, the most important pest of citrus worldwide, is based on the use of insecticides, though unsatisfactory results have recently been reported. In this study, insecticide resistance of D. citri to three insecticides (bifenthrin, malathion, and chlorpyrifos) was examined. Three populations (designated Dci-CParácuaro, Dci-El Junco, and Dci-Antúnez) of both adults and fourth-instar D. citri individuals were collected in 2014 at two different times and on one occasion, respectively, from three locations (Crucero de Parácuaro, El Junco, and Antúnez). These locations represent the major commercial Mexican lemon production areas in the Apatzingán Valley in the state of Michoacán, Mexico. The three populations of D. citri adults and fourth-instar nymphs at the different collection times showed low levels of resistance (≤7-fold) to bifenthrin, but were very resistant to malathion (≤345- and ≤432-fold for adults and fourth instars, respectively) and chlorpyrifos (≤2435- and ≤1424-fold for adults and fourth instars, respectively). Resistance levels to the tested insecticides were highly variable but homogeneous among seasons and localities. Resistance management programmes that include crop sanitation, use of biological and cultural control practices, and rotation of insecticide classes should be established, particularly in areas where D. citri has developed resistance to malathion and chlorpyrifos. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Evaluation of barrier treatments on native vegetation in a southern California desert habitat.

PubMed

Britch, Seth C; Linthicum, Kenneth J; Wynn, Wayne W; Walker, Todd W; Farooq, Muhammad; Smith, Vincent L; Robinson, Cathy A; Lothrop, Branka B; Snelling, Melissa; Gutierrez, Arturo; Lothrop, Hugh D

2009-06-01

Treating perimeters with residual insecticides for protection from mosquito vectors has shown promise. These barrier treatments are typically evaluated in temperate or tropical areas using abundant vegetation as a substrate. However, there is an emerging interest to develop this technology to protect deployed US troops in extreme desert environments with sparse vegetation. We used a remote desert area in the Coachella Valley, California, to 1) evaluate bifenthrin barrier treatments on native xeric vegetation and 2) compare treatments applied with electrostatic and conventional spray technologies. Through a combination of laboratory bioassays on treated and control vegetation sampled at specific intervals over 63 days, synchronized with field surveillance of mosquitoes, we measured the temporal pattern of bioactivity of bifenthrin barriers under natural hot, dry, and dusty desert conditions. Regardless of spray technology, mosquito catch in treated plots was about 80% lower than the catch in control plots 1 day after treatment. This reduction in mosquito numbers in treated plots declined each week after treatment but remained at about 40% lower than control plots after 28 days. Field data were corroborated by results from bioassays that showed significantly higher mosquito mortality on treated vegetation over controls out to 28 days postspray. We concluded that barrier treatments in desert environments, when implemented as part of a suite of integrated control measures, may offer a significant level of protection from mosquitoes for deployed troops. Given the comparable performance of the tested spray technologies, we discuss considerations for choosing a barrier treatment sprayer for military scenarios.

Suspended particles only marginally reduce pyrethroid toxicity to the freshwater invertebrate Gammarus pulex (L.) during pulse exposure.

PubMed

Rasmussen, Jes Jessen; Cedergreen, Nina; Kronvang, Brian; Andersen, Maj-Britt Bjergager; Nørum, Ulrik; Kretschmann, Andreas; Strobel, Bjarne Westergaard; Hansen, Hans Christian Bruun

2016-04-01

Current ecotoxicological research on particle-associated pyrethroids in freshwater systems focuses almost exclusively on sediment-exposure scenarios and sediment-dwelling macroinvertebrates. We studied how suspended particles influence acute effects of lambda-cyhalothrin and bifenthrin on the epibenthic freshwater amphipod Gammarus pulex (L.) using brief pulse exposures followed by a 144 h post exposure recovery phase. Humic acid (HA) and the clay mineral montmorillonite (MM) were used as model sorbents in environmentally realistic concentrations (5, 25 and 125 mg L(-1)). Mortality of G. pulex was recorded during the post exposure recovery phase and locomotor behavior was measured during exposure to lambda-cyhalothrin. We found that HA in concentrations ≥25 mg L(-1) adsorbed the majority of pyrethroids but only reduced mortality of G. pulex up to a factor of four compared to pyrethroid-only treatments. MM suspensions adsorbed a variable fraction of pyrethroids (10% for bifenthrin and 70% for lambda-cyhalothrin) but did not significantly change the concentration-response relationship compared to pure pyrethroid treatments. Behavioral responses and immobilisation rate of G. pulex were reduced in the presence of HA, whereas behavioral responses and immobilisation rate were increased in the presence of MM. This indicates that G. pulex was capable of sensing the bioavailable fraction of lambda-cyhalothrin. Our results imply that suspended particles reduce to only a limited extent the toxicity of pyrethroids to G. pulex and that passive uptake of pyrethroids can be significant even when pyrethroids are adsorbed to suspended particles.

Effects of metals on enantioselective toxicity and biotransformation of cis-bifenthrin in zebrafish.

PubMed

Yang, Ye; Ji, Dapeng; Huang, Xin; Zhang, Jianyun; Liu, Jing

2017-08-01

Co-occurrence of pyrethroids and metals in watersheds previously has been reported to pose great risk to aquatic species. Pyrethroids are a class of chiral insecticides that have been shown to have enantioselective toxicity and biotransformation. However, the influence of metals on enantioselectivity of pyrethroids has not yet been evaluated. In the present study, the effects of cadmium (Cd), copper (Cu), and lead (Pb) on the enantioselective toxicity and metabolism of cis-bifenthrin (cis-BF) were investigated in zebrafish at environmentally relevant concentrations. The addition of Cd, Cu, or Pb significantly increased the mortality of zebrafish in racemate and R-enantiomer of cis-BF-treated groups. In rac-cis-BF- or 1R-cis-BF-treated groups, the addition of Cd, Cu, or Pb caused a decrease in enantiomeric fraction (EF) and an increased ratio of R-enantiomer residues in zebrafish. In 1S-cis-BF-treated groups, coexposure to Cd led to a lower EF and decreased residue levels of S-enantiomer. In addition, coexposure to the 3 metals resulted in different biodegradation characteristics of each enantiomer accompanied with differential changes in the expression of cytochrome P450 (CYP)1, CYP2, and CYP3 genes, which might be responsible for the enantioselective biodegradation of cis-BF in zebrafish. These results suggest that the influence of coexistent metals should be considered in the ecological risk assessment of chiral pyrethroids in aquatic environments. Environ Toxicol Chem 2017;36:2139-2146. © 2017 SETAC. © 2017 SETAC.

Pyrethroid-Resistance Level Affects Performance of Larvicides and Adulticides From Different Insecticide Classes in Populations of Listronotus maculicollis (Coleoptera: Curculionidae).

PubMed

Koppenhöfer, Albrecht M; Kostromytska, Olga S; Wu, Shaohui

2018-05-25

The annual bluegrass weevil, Listronotus maculicollis Kirby (Coleoptera: Curculionidae), is a major pest of golf course turf in eastern North America with widespread insecticide resistance. This study examined the effect of pyrethroid-resistance level on the efficacy of adulticides and larvicides from different insecticide classes commonly used for L. maculicollis management through greenhouse and field studies. The tested populations had previously been determined to be susceptible, moderately resistant, resistant, and highly resistant to the pyrethroid bifenthrin. Targeting adults, efficacy was significantly reduced for bifenthrin against the highly resistant population and for the spinosyn spinosad and the oxadizine indoxacarb against the resistant and highly resistant populations. Efficacy of the organophosphate chlorpyrifos was not significantly reduced. No adulticide provided significant control of resistant and highly resistant populations. Targeting larvae, the efficacy of spinosad and the anthranilic diamide cyantraniliprole was marginally reduced against the highly resistant population. Significant reductions in efficacy and no significant control were observed for indoxacarb against the highly resistant population and for the neonicotinoid clothianidin, the anthranilic diamide chlorantraniliprole, and the organophosphate trichlorfon against the resistant and highly resistant populations. Our findings lay the groundwork for management recommendations for populations with different resistance levels. Generally, synthetic insecticide applications should be minimized with greater use of larvicides supplemented with nonchemical control alternatives. The remaining effective larvicides should be rotated using cyantraniliprole, spinosad, and indoxacarb against resistant and cyantraniliprole and spinosad against highly resistant populations.

Responses of striped stem borer, Chilo suppressalis (Lepidoptera: Pyralidae), from Taiwan to a range of insecticides.

PubMed

Cheng, Xuan; Chang, Cheng; Dai, Shu-Mei

2010-07-01

Information on the insecticide susceptibility of striped stem borer, Chilo suppressalis (Walker), is essential for an effective pest management programme. An early detection of resistance development can prompt the modification of current control methods and increase the lifespan of insecticides through the rotation of chemicals with different modes of action. In this study, the susceptibility of this pest in Taiwan to four classes of insecticides has been examined. Over 1000-fold resistance to carbofuran was detected in C. suppressalis collected from Chiayi and Changhua prefectures, with estimated LC(50) values of > 3 mg cm(-2). In addition, 61-fold resistance to cartap was found in the Chiayi population. On the other hand, all tested populations of rice stem borer were still relatively susceptible to chlorpyrifos, fipronil and permethrin, with LC(50) values ranging from 30 to 553 ng cm(-2). Chilo suppressalis populations collected from the central parts of Taiwan have a higher degree of resistance to the tested insecticides than those from northern areas. The occurrence of high resistance to carbofuran in the Chiayi and Changhua areas suggests that this compound should be replaced with chemicals having a different mode of action, such as chlorpyrifos, fipronil and permethrin, to which low cross-resistance has been detected. Copyright (c) 2010 Society of Chemical Industry.

Evaluation of Liquid and Bait Insecticides against the Dark Rover Ant (Brachymyrmex patagonicus)

PubMed Central

Miguelena, Javier G.; Baker, Paul B.

2014-01-01

Dark rover ants (Brachymyrmex patagonicus, Mayr) are an exotic ant species native to South America that has recently spread through the southern US. We evaluated the residual activity of three liquid insecticides (indoxacarb, fipronil and lambda-cyhalothrin) as potential barrier treatments against these ants. The factors we considered include the use of a porous or non-porous surface, a short or long exposure time and the changes in insecticide activity after treatment during a 90 day period. We also tested the effect of baits containing three different active ingredients (imidacloprid, sodium tetraborate and indoxacarb) on colony fragments of this species for a 15 day period. Both lambda-cyhalothrin® and indoxacarb® resulted in high levels of ant mortality up to 90 days after application. The results of exposure to fipronil® resembled those from the control treatment. Application of insecticides on a porous surface and the shorter exposure time generally resulted in greater ant survival. Of the baits tested, only the imidacloprid based one decreased ant survival significantly during the evaluation period. Within three days, the imidacloprid bait produced over 50% mortality which increased to over 95% by the end of the experiment. Results from the other two bait treatments were not significantly different from the control. PMID:26462943

Efficacy of a novel topical combination of fipronil, amitraz and (S)-methoprene for treatment and control of induced infestations of brown dog ticks (Rhipicephalus sanguineus) on dogs.

PubMed

Hunter, James S; Baggott, Derek; Everett, William R; Fourie, Josephus J; Cramer, Luiz G; Yoon, Stephen S; Collidor, Nadia; Mallouk, Yasmina; Lee, Lorne; Blair, Jeffrey; Prullage, Joseph B

2011-07-15

Four laboratory studies were conducted to demonstrate that a single topical dose of a novel spot-on combination containing fipronil, amitraz and (S)-methoprene (CERTIFECT™, Merial Limited, GA, USA) is efficacious against the brown dog tick, Rhipicephalus sanguineus. In each study, 6-8 male and 6-8 female purpose-bred, laboratory mongrels, terrier cross or Beagles were randomly assigned to one of two study groups (treated and untreated), based on pre-treatment parasite counts. Starting on the day before treatment, each dog was infested weekly with 50 ticks. Ticks were thumb counted at various time points after treatment and weekly infestations starting as early as 6h and continued at 12, 18 and 24h depending on the study. Ticks were removed and counted at 48 h after treatment and weekly infestations. CERTIFECT provided rapid and excellent control of pre-existing and newly acquired infestations of R. sanguineus with efficacy as high as 93% within the first 12h after a single topical treatment. Excellent control (>96%) of R. sanguineus as early as 18 h, following post treatment infestations was maintained for at least 35 days. Copyright © 2011 Elsevier B.V. All rights reserved.

Efficacy of a topical combination of fipronil, (S)-methoprene, eprinomectin and praziquantel (Broadline(®)) against naturally acquired infections with cestodes of the genus Joyeuxiella in cats.

PubMed

Schuster, Rolf K; Mustafa, Murad Basheer; Baskar, Jagadeesan Vijay; Rosentel, Joseph; Chester, S Theodore; Knaus, Martin

2016-07-01

Cats are host to dipylidiid cestodes of the genera Diplopylidium, Dipylidium and Joyeuxiella. Broadline(®), a topical broad-spectrum combination parasiticide containing fipronil (8.3 % w/v), (S)-methoprene (10 % w/v), eprinomectin (0.4 % w/v) and the cestocide praziquantel (8.3 % w/v), has previously been shown to be efficacious against Dipylidium caninum and Diplopylidium spp. in cats. To evaluate its efficacy against Joyeuxiella species, a blinded clinical efficacy study was conducted according to GCP. All cats had evidence for naturally acquired dipylidiid cestode infection as confirmed by pre-treatment examination. Cats were allocated randomly to two groups of 13 cats each based on bodyweight: Control (untreated) and Broadline(®) at 0.12 mL/kg bodyweight administered once topically. Based on the comparison of helminth counts in the treated and untreated cats seven days post treatment, Broadline(®) demonstrated >99 % efficacy (p < 0.01) against mature J. fuhrmanni and J. pasqualei, with 11 and 13 of the untreated cats harbouring 1 to 102 or 2 to 95 cestodes, respectively. In addition, parasite counts indicated 95.9 % efficacy (p = 0.006) against the rictularoid nematode Pterygodermatites cahirensis.

Insecticide resistance and diminished secondary kill performance of bait formulations against German cockroaches (Dictyoptera: Blattellidae)

PubMed Central

Ko, Alexander E.; Bieman, Donald N.; Schal, Coby; Silverman, Jules

2015-01-01

BACKGROUND Bait formulations are considered the most effective method for reducing German cockroach infestations. An important property of some bait formulations is secondary kill, whereby active ingredient is translocated in insect-produced residues throughout the cockroach population, especially affecting relatively sedentary early instar nymphs. RESULTS Blattella germanica was collected from a location where baits containing hydramethylnon, fipronil, or indoxacarb became ineffective, and these AIs were topically applied to adult males. Results revealed the first evidence for hydramethylnon resistance, moderate resistance to fipronil and extremely high resistance to indoxacarb. Insecticide residues excreted by field-collected males that ingested commercial baits effectively killed nymphs of an insecticide-susceptible laboratory strain of B. germanica but failed to kill most nymphs of the field-collected strain. CONCLUSIONS We report three novel findings: 1) The first evidence for hydramethylnon resistance in any insect; 2) extremely high levels of indoxacarb resistance in a field population; and 3) reduced secondary mortality in an insecticide-resistant field-collected strain of B. germanica. We suggest that while secondary mortality is considered to be advantageous in cockroach interventions, the ingestion of sublethal doses of AI by nymphs may select for high insecticide resistance by increasing the frequency of AI resistance alleles within the population. PMID:26689433

Evidence for a separate mechanism of toxicity for the Type I and the Type II pyrethroid insecticides.

PubMed

Breckenridge, Charles B; Holden, Larry; Sturgess, Nicholas; Weiner, Myra; Sheets, Larry; Sargent, Dana; Soderlund, David M; Choi, Jin-Sung; Symington, Steve; Clark, J Marshall; Burr, Steve; Ray, David

2009-11-01

Neurotoxicity and mechanistic data were collected for six alpha-cyano pyrethroids (beta-cyfluthrin, cypermethrin, deltamethrin, esfenvalerate, fenpropathrin and lambda-cyhalothrin) and up to six non-cyano containing pyrethroids (bifenthrin, S-bioallethrin [or allethrin], permethrin, pyrethrins, resmethrin [or its cis-isomer, cismethrin] and tefluthrin under standard conditions. Factor analysis and multivariate dissimilarity analysis were employed to evaluate four independent data sets comprised of (1) fifty-six behavioral and physiological parameters from an acute neurotoxicity functional observatory battery (FOB), (2) eight electrophysiological parameters from voltage clamp experiments conducted on the Na(v)1.8 sodium channel expressed in Xenopus oocytes, (3) indices of efficacy, potency and binding calculated for calcium ion influx across neuronal membranes, membrane depolarization and glutamate released from rat brain synaptosomes and (4) changes in chloride channel open state probability using a patch voltage clamp technique for membranes isolated from mouse neuroblastoma cells. The pyrethroids segregated into Type I (T--syndrome-tremors) and Type II (CS syndrome--choreoathetosis with salivation) groups based on FOB data. Of the alpha-cyano pyrethroids, deltamethrin, lambda-cyhalothrin, cyfluthrin and cypermethrin arrayed themselves strongly in a dose-dependent manner along two factors that characterize the CS syndrome. Esfenvalerate and fenpropathrin displayed weaker response profiles compared to the non-cyano pyrethroids. Visual clustering on multidimensional scaling (MDS) maps based upon sodium ion channel and calcium influx and glutamate release dissimilarities gave similar groupings. The non-cyano containing pyrethroids were arrayed in a dose-dependent manner along two different factors that characterize the T-syndrome. Bifenthrin was an outlier when MDS maps of the non-cyano pyrethroids were based on sodium ion channel characteristics and permethrin was an outlier when the MDS maps were based on calcium influx/glutamate release potency. Four of six alpha-cyano pyrethroids (lambda-cyfluthrin, cypermethrin, deltamethrin and fenpropathrin) reduced open chloride channel probability. The R-isomers of lambda-l-cyhalothrin reduced open channel probability whereas the S-isomers, antagonized the action of the R-isomers. None of the non-cyano pyrethroids reduced open channel probability, except bioallethrin, which gave a weak response. Overall, based upon neurotoxicity data and the effect of pyrethroids on sodium, calcium and chloride ion channels, it is proposed that bioallethrin, cismethrin, tefluthrin, bifenthrin and permethrin belong to one common mechanism group and deltamethrin, lambda-cyhalothrin, cyfluthrin and cypermethrin belong to a second. Fenpropathrin and esfenvalerate occupy an intermediate position between these two groups.

Evaluation of a New Spraying Machine for Barrier Treatment and Penetration of Bifenthrin on Vegetation Against Mosquitoes

DTIC Science & Technology

2015-03-01

one at the University of Florida Veterinary Entomology Laboratory (UF- VEL). Leaf samples for both laboratories were collected together. All samples...Mulla’s formula (Mulla et al. 1971): % reduction 5 100 2 (C1/T1 3 T2/C2) 3 100. The C1 variable was the mean number of mosquitoes from the control site...statistical analysis was performed using JMP 11.1 software (SAS Insti- tute Inc., Cary, NC). Treatment mortality was corrected with Abbott’s formula

Distribution and risk assessment of 82 pesticides in Jiulong River and estuary in South China.

PubMed

Zheng, Senllin; Chen, Bin; Qiu, Xiaoyan; Chen, Meng; Ma, Zhiyuan; Yu, Xingguang

2016-02-01

To discover the distribution and risk of pesticides in Jiulong River and estuary, the residues of 102 pesticides were analyzed in water, sediment and clam samples collected from 35 sites in different seasons. A total number of 82 pesticides were detected and the occurrence and the risk to human and fish were assessed. Most of pesticides with high frequency were medium or low toxic except for DDTs. DDTs were the significant contaminant and the widely used dicofol was the new source of DDTs. The spatial and seasonal variation of pesticide distribution was linked with the distribution of orchards and farmlands. Health risk from river water consumption was low (RQ < 0.1) while that from clam consumption was medium (RQ = 0.84). Pesticides in water posed great risk to fish and among the 76 water samples analyzed, 65 of them showed high risk (RQ > 1) and 6 showed medium risk (0.1 ≤ QR < 1). The single chemical posed high risk to fish included DDTs, triazophos, fenvalerate, bifenthrin and cyfluthrin, and those showed medium risk included dicofol, butachlor, isocarbophos, terbufos and cyhalothrin. There were 14 single pesticides detected with concentration above 100 ng L(-1) in this study and the pesticide with the highest concentration was procymidone (3904 ng L(-1)). Further experiments illustrated that procymidone could disrupt the expression of vitellogenin in the estuarine fish even at environmental concentrations. DDTs, dicofol, triazophos, isocarbophos, terbufos, cyfluthrin, bifenthrin, fenvalerate, cyhalothrin, butachlor and procymidone have become the significant pesticides and should be considered in aquatic ecosystem risk management. Copyright © 2015 Elsevier Ltd. All rights reserved.

Lethal and Sublethal Impacts of Acaricides on Tamarixia radiata (Hemiptera: Eulophidae), an Important Ectoparasitoid of Diaphorina citri (Hemiptera: Liviidae).

PubMed

Lira, A C S; Zanardi, O Z; Beloti, V H; Bordini, G P; Yamamoto, P T; Parra, J R P; Carvalho, G A

2015-10-01

The use of synthetic acaricides for management of pest mites may alter the efficacy of the ectoparasitoid Tamarixia radiata (Waterston) in biological control of Diaphorina citri Kuwayama, the vector of the bacteria associated with huanglongbing (HLB) in citrus orchards. We evaluated the toxicity of 16 acaricides that are recommended for the control of citrus-pest mites to T. radiata. Acrinathrin, bifenthrin, carbosulfan, and fenpropathrin caused high acute toxicity and were considered harmful (mortality >77%) to T. radiata. Abamectin, diflubenzuron, etoxazole, fenbutatin oxide, fenpyroximate, flufenoxuron, hexythiazox, propargite, spirodiclofen, and sulfur caused low acute toxicity and affected the parasitism rate and emergence rate of adults (F1 generation), and were considered slightly harmful to T. radiata. Dicofol and pyridaben did not affect the survival and action of the ectoparasitoid, and were considered harmless. In addition to its acute toxicity, carbosulfan caused mortality higher than 25% for >30 d after application, and was considered persistent. Acrinathrin, bifenthrin, fenpropathrin, fenpyroximate, propargite, and sulfur caused mortalities over 25% until 24 d after application and were considered moderately persistent; abamectin was slightly persistent, and fenbutatin oxide was short lived. Our results suggest that most acaricides used to control pest mites in citrus affect the density and efficacy of T. radiata in the biological control of D. citri. However, further evaluations are needed in order to determine the effect of these products on this ectoparasitoid under field conditions. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Endocrine-Disrupting Effects of Pesticides through Interference with Human Glucocorticoid Receptor.

PubMed

Zhang, Jianyun; Zhang, Jing; Liu, Rui; Gan, Jay; Liu, Jing; Liu, Weiping

2016-01-05

Many pesticides have been identified as endocrine-disrupting chemicals (EDCs) due to their ability to bind sex-steroid hormone receptors. However, little attention has been paid to the ability of pesticides to interfere with other steroid hormone receptors such as glucocorticoid receptor (GR) that plays a critical role in metabolic, endocrine, immune, and nervous systems. In this study, the glucocorticoidic and antiglucocorticoidic effects of 34 pesticides on human GR were investigated using luciferase reporter gene assay. Surprisingly, none of the test chemicals showed GR agonistic activity, but 12 chemicals exhibited apparent antagonistic effects. Bifenthrin, λ-cyhalothrin, cypermethrin, resmethrin, o,p'-DDT, p,p'-DDT, methoxychlor, ethiofencarb, and tolylfluanid showed remarkable GR antagonistic properties with RIC20 values lower than 10(-6) M. The disruption of glucocorticoid-responsive genes in H4IIE and J774A.1 cells was further evaluated on these 12 GR antagonists. In H4IIEcells, four organochlorine insecticides, bifenthrin, and 3-PBA decreased cortisol-induced PEPCK gene expression, while o,p'-DDT and methoxychlor inhibited cortisol-stimulated Arg and TAT gene expression. Cypermethrin and tolyfluanid attenuated cortisol-induced TAT expression. In J774A.1 cells, λ-cyhalothrin, resmethrin, 3-PBA, o,p'-DDT, p,p'-DDT, p,p'-DDE, methoxychlor- and tolylfluanid-reduced cortisol-stimulated GILZ expression. Furthermore, molecular docking simulation indicated that different interactions may stabilize the binding between molecules and GR. Our findings suggest that comprehensive screening and evaluation of GR antagonists and agonists should be considered to better understand the health and ecological risks of man-made chemicals such as pesticides.

Sustainable management tactics for control of Phyllotreta cruciferae (Coleoptera: Chrysomelidae) on canola in Montana.

PubMed

Reddy, Gadi V P; Tangtrakulwanich, Khanobporn; Miller, John H; Ophus, Victoria L; Prewett, Julie

2014-04-01

The crucifer flea beetle, Phyllotreta cruciferae (Goeze) (Coleoptera: Chrysomelidae), has recently emerged as a serious pest of canola (Brassica napus L.) in Montana. The adult beetles feed on canola leaves, causing many small holes that stunt growth and reduce yield. In 2013, damage to canola seedlings was high (approximately 80%) in many parts of Montana, evidence that when flea beetles emerge in large numbers, they can quickly destroy a young canola crop. In the current study, the effectiveness of several biopesticides was evaluated and compared with two insecticides (deltamethrin and bifenthrin) commonly used as foliar sprays as well as seed treatment with an imidacloprid insecticide for the control of P. cruciferae under field conditions in 2013. The biopesticides used included an entomopathogenic nematode (Steinernema carpocapsae), two entomopathogenic fungi (Beauveria bassiana and Metarhizium brunneum), neem, and petroleum spray oils. The control agents were delivered in combination or alone in a single or repeated applications at different times. The plant-derived compound neem (azadirachtin), petroleum spray oil, and fatty acids (M-Pede) only showed moderate effect, although they significantly reduced leaf injuries caused by P. cruciferae and resulted in higher canola yield than the untreated control. Combined use of B. bassiana and M. brunneum in two repeated applications and bifenthrin in five applications were most effective in reducing feeding injuries and improving yield levels at both trial locations. This indicates that entomopathogenic fungi are effective against P. cruciferae, and may serve as alternatives to conventional insecticides or seed treatments in managing this pest.

Enantioselective disruption of the endocrine system by Cis-Bifenthrin in the male mice.

PubMed

Jin, Yuanxiang; Wang, Jiangcong; Pan, Xiuhong; Miao, Wenyu; Lin, Xiaojian; Wang, Linggang; Fu, Zhengwei

2015-07-01

Bifenthrin (BF), as a chiral pyrethroid, is widely used to control field and household pests in China. At present, the commercial BF is a mixed compound containing cis isomers (cis-BF) including two enantiomers of 1R-cis-BF and 1S-cis-BF. In the present study, the two individual cis-BF enantiomers were separated by a preparative supercritical fluid chromatography. Then, four week-old adolescent male ICR mice were orally administered 1R-cis-BF and 1S-cis-BF separately daily for 3 weeks at doses of 0, 7.5 and 15 mg/kg/day, respectively. Results showed that the transcription status of some genes involved in cholesterol synthesis and transport as well as testosterone (T) synthesis in the testes were influenced by cis-BF enantiomers. Especially, we observed that the transcription status of key genes on the pathway of T synthesis including cytochrome P450 cholesterol side-chain cleavage enzyme (P450scc) and cytochrome P450 17α-hydroxysteroid dehydrogenase (P45017α)) were selectively altered in the testis of mice when treated with 1S-cis-BF, suggesting that it is the possible reason to explain why the lower serum T concentration in 1S-cis-BF treated group. Taken together, it concluded that both of the cis-BF enantiomers have the endocrine disruption activities, while 1S-cis-BF was higher than 1R-cis-BF in mice when exposed during the puberty. The data was helpful to understand the toxicity of cis-BF in mammals under enantiomeric level. © 2014 Wiley Periodicals, Inc.

Efficacy of fipronil for protecting individual pines from mortality attributed to attack by western pine beetle and mountain pine beetle (Coleoptera: Curculionidae, Scolytinae)

Treesearch

C.J. Fettig; A.S. Munson; C.I. Jorgenson; D.M. and Grosman

2010-01-01

Bark beetles (Coleoptera: C~rculionidae, Scolytinae) are commonly recognized as important tree mortality agents in coniferous forests of the western U.S. Most species feed on the phloem and cambium, or xylem tissue of woody plants; and a few are recognized as the most destructive of all forest insect pests. The last decade has seen elevated levels of bark beetle caused...

Protective effects of rosuvastatin and vitamin E against fipronil-mediated oxidative damage and apoptosis in rat liver and kidney.

PubMed

Abdel-Daim, Mohamed M; Abdeen, Ahmed

2018-04-01

Fipronil (FPN) is a phenylpyrazole insecticide that is extensively used in agriculture and veterinary applications. However, FPN is also a potent environmental toxicant to animals and humans. Therefore, the current study aimed to investigate the protective role of rosuvastatin (ROSU) and vitamin E (Vit E) against FPN-induced hepatorenal toxicity in albino rats. Seven groups with eight rats each were used for this purpose; these groups included the control vehicle group that received corn oil, the Vit E group (1000 mg/kg, orally), the ROSU group (10 mg/kg, orally), the FPN group (20 mg/kg, orally), the FPN-ROSU group, the FPN-Vit E group, and the FPN-Vit E-ROSU group. The results revealed that FPN significantly increased serum levels of alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, lactate dehydrogenase, cholesterol, urea, and creatinine. In addition, there were substantial increases in the liver and kidney contents of malondialdehyde and nitric oxide, along with significant decreases in glutathione, superoxide dismutase, catalase, and glutathione peroxidase. FPN also caused histological changes and increased the expression of caspase-3 in the liver and kidney tissues. However, administration of ROSU and Vit E alone or in combination ameliorated the FPN-induced oxidative damage and apoptosis, possibly through their antioxidant properties. Copyright © 2018 Elsevier Ltd. All rights reserved.

Identification of the Rdl mutation in laboratory and field strains of the cat flea, Ctenocephalides felis (Siphonaptera: Pulicidae).

PubMed

Bass, Chris; Schroeder, Iris; Turberg, Andreas; Field, Linda M; Williamson, Martin S

2004-12-01

In many insect species, resistance to cyclodiene insecticides is caused by amino acid substitutions at a single residue (A302) within the M2 transmembrane region of the gamma-aminobutyric acid (GABA) receptor sub-unit termed Rdl (resistance to dieldrin). These mutations (A302S and A302G) have also been shown to confer varying levels of cross-resistance to fipronil, a phenylpyrazole insecticide with a similar mode of action to cyclodienes. To investigate the possible occurrence of these mutations in the cat flea, Ctenocephalides felis (Bouché), a 176-bp fragment of the cat flea Rdl gene, encompassing the mutation site, was PCR amplified and sequenced from nine laboratory flea strains. The A302S mutation was found in eight of the nine strains analysed, although the relative frequency of the mutant allele varied between strains. Only one strain (R6) was found to be homozygous for the S302 allele in all the individuals tested, and this correlated with previous reports of low-level fipronil resistance in this strain. A PCR-based diagnostic assay, capable of screening individual fleas for this mutation, was developed and used to survey a range of fleas collected at random from veterinary clinics in the UK and USA. The A302S mutation was present at a high frequency in these domestic pet populations. 2004 Society of Chemical Industry.

Synergistic interactions between a variety of insecticides and an ergosterol biosynthesis inhibitor fungicide in dietary exposures of bumble bees (Bombus terrestris L.).

PubMed

Raimets, Risto; Karise, Reet; Mänd, Marika; Kaart, Tanel; Ponting, Sally; Song, Jimao; Cresswell, James E

2018-03-01

In recent years, concern has been raised over honey bee colony losses, and also among wild bees there is evidence for extinctions and range contractions in Europe and North America. Pesticides have been proposed as a potential cause of this decline. Bees are exposed simultaneously to a variety of agrochemicals, which may cause synergistically detrimental impacts, which are incompletely understood. We investigated the toxicity of the fungicide imazalil in mixture with four common insecticides: fipronil (phenylpyrazoid), cypermethrin (pyrethroid), thiamethoxam, and imidacloprid (neonicotinoids). Ergosterol biosynthesis inhibitor (EBI) fungicides like imazalil can inhibit P450 detoxification systems in insects and therefore fungicide - insecticide co-occurrence might produce synergistic toxicity in bees. We assessed the impact of dietary fungicide - insecticide mixtures on the mortality and feeding rates of laboratory bumble bees (Bombus terrestris L.). Regarding mortality, imazalil synergised the toxicity of fipronil, cypermethrin and thiamethoxam, but not imidacloprid. We found no synergistic effects on feeding rates. Our findings suggest that P450-based detoxification processes are differentially important in mitigating the toxicity of certain insecticides, even those of the same chemical class. Our evidence that cocktail effects can arise in bumble bees should extend concern about the potential impacts of agrochemical mixtures to include wild bee species in farmland. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Model methodology for estimating pesticide concentration extremes based on sparse monitoring data

USGS Publications Warehouse

Vecchia, Aldo V.

2018-03-22

This report describes a new methodology for using sparse (weekly or less frequent observations) and potentially highly censored pesticide monitoring data to simulate daily pesticide concentrations and associated quantities used for acute and chronic exposure assessments, such as the annual maximum daily concentration. The new methodology is based on a statistical model that expresses log-transformed daily pesticide concentration in terms of a seasonal wave, flow-related variability, long-term trend, and serially correlated errors. Methods are described for estimating the model parameters, generating conditional simulations of daily pesticide concentration given sparse (weekly or less frequent) and potentially highly censored observations, and estimating concentration extremes based on the conditional simulations. The model can be applied to datasets with as few as 3 years of record, as few as 30 total observations, and as few as 10 uncensored observations. The model was applied to atrazine, carbaryl, chlorpyrifos, and fipronil data for U.S. Geological Survey pesticide sampling sites with sufficient data for applying the model. A total of 112 sites were analyzed for atrazine, 38 for carbaryl, 34 for chlorpyrifos, and 33 for fipronil. The results are summarized in this report; and, R functions, described in this report and provided in an accompanying model archive, can be used to fit the model parameters and generate conditional simulations of daily concentrations for use in investigations involving pesticide exposure risk and uncertainty.

Heterologous expression of Helicoverpa armigera cytochrome P450 CYP6B7 in Pichia pastoris and interactions of CYP6B7 with insecticides.

PubMed

Zhao, Chunqing; Song, Genmiao; Duan, Hongxia; Tang, Tao; Wang, Chen; Qiu, Lihong

2017-09-01

Previous studies indicated that constitutive over-expression of cytochrome P450 CYP6B7 was involved in fenvalerate resistance in Helicoverpa armigera. In this study, the CYP6B7 gene from H. armigera (namely HaCYP6B7), was heterologously expressed in Pichia pastoris GS115. A vector pPICZA-HaCYP6B7 was constructed and transformed into P. pastoris GS115, the transformant of pPICZA-HaCYP6B7-GS115 was then cultured and induced by 1% (v/v) methanol and the heterologous expression of HaCYP6B7 protein in P. pastoris was confirmed by SDS-PAGE and western blot. Microsomes containing the expressed HaCYP6B7 showed activities against model substrate p-nitroanisole and 7-ethoxycoumarin, with p-nitroanisole O-demethylation (PNOD) and 7-ethoxycoumarin O-deethylation (ECOD) activities of 15.66- and 4.75-fold of the control, respectively. Moreover, it showed degradation activities against the insecticides bifenthrin, fenvalerate and chlorpyrifos, with clearance activities of 6.88-, 1.49- and 2.27-fold of the control, respectively. The interactions of HaCYP6B7 with insecticides were further confirmed by molecular docking in silico with binding scores of 5.450, 5.295 and 2.197 between putative HaCYP6B7 protein and bifenthrin, fenvalerate and chlorpyrifos, respectively. The results of present study provided more direct and important evidence on the role of HaCYP6B7 conferring pyrethroid resistance in H. armigera. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Mechanism of Resistance Acquisition and Potential Associated Fitness Costs in Amyelois transitella (Lepidoptera: Pyralidae) Exposed to Pyrethroid Insecticides.

PubMed

Demkovich, Mark; Siegel, Joel P; Higbee, Bradley S; Berenbaum, May R

2015-06-01

The polyphagous navel orangeworm, Amyelois transitella (Walker) (Lepidoptera: Pyralidae), is the most destructive pest of nut crops, including almonds and pistachios, in California orchards. Management of this insect has typically been a combination of cultural controls and insecticide use, with the latter increasing substantially along with the value of these commodities. Possibly associated with increased insecticide use, resistance has been observed recently in navel orangeworm populations in Kern County, California. In studies characterizing a putatively pyrethroid-resistant strain (R347) of navel orangeworm, susceptibility to bifenthrin and β-cyfluthrin was compared with that of an established colony of susceptible navel orangeworm. Administration of piperonyl butoxide and S,S,S-tributyl phosphorotrithioate in first-instar feeding bioassays with the pyrethroids bifenthrin and β-cyfluthrin produced synergistic effects and demonstrated that cytochrome P450 monooxygenases and carboxylesterases contribute to resistance in this population. Resistance is therefore primarily metabolic and likely the result of overexpression of specific cytochrome P450 monooxygenases and carboxylesterase genes. Resistance was assessed by median lethal concentration (LC50) assays and maintained across nine generations in the laboratory. Life history trait comparisons between the resistant strain and susceptible strain revealed significantly lower pupal weights in resistant individuals reared on the same wheat bran-based artificial diet across six generations. Time to second instar was greater in the resistant strain than the susceptible strain, although overall development time was not significantly different between strains. Resistance was heritable and may have an associated fitness cost, which could influence the dispersal and expansion of resistant populations in nut-growing areas in California. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Toxicity of six insecticides to predatory mite Amblyseius cucumeris (Oudemans) (Acari: Phytoseiidae) in- and off-field.

PubMed

Cheng, Shenhang; Lin, Ronghua; Zhang, Nan; Yuan, Shankui; Zhou, Xinxin; Huang, Jian; Ren, Xiaodong; Wang, Shoushan; Jiang, Hui; Yu, Caihong

2018-06-22

Amblyseius cucumeris (Oudemans) is a beneficial non-target arthropod (NTA) and a key predator of tetranychid mites in integrated pest management (IPM) programs across China. Evaluating the toxic effects of insecticides on such predatory mites is essential for the success and development of IPM. We tested six insecticides to determine the risk of neonicotinoid insecticide toxicity to predatory mites, using the 'open glass plate method' and adult female A. cucumeris in a "worst case laboratory exposure" scenario. A 48-h toxicity test was performed using the hazard quotient (HQ) approach to evaluate the risk of each insecticide. The LR 50 values (application rate that caused 50% mortality) of acetamiprid, thiamethoxam, imidacloprid, and dinotefuran were 76.4, 104.5, 84.9, and 224.6 g active ingredient (a.i.) ha -1 , respectively, with in-field HQ values of 0.40, 1.28, 0.49, and 0.82, respectively. The HQ values were lower than the trigger value of 2, and were consistent with off-field values. The risks of the four neonicotinoid insecticides to adult female A. cucumeris were acceptable in two exposure scenarios in field and off field. The 48-h LR 50 values for bifenthrin and malathion were 0.008 and 0.062 g. a.i. ha -1 , respectively, which were much lower than the recommended field application rates. The HQ values were much higher than the trigger values for both in- and off-field, indicating that the risks of these two insecticides were unacceptable. Bifenthrin and malathion posed an extremely high risk to the test species, and their use should be restricted to reduce risks to the field with augmentative releases of A. cucumeris. Copyright © 2018 Elsevier Inc. All rights reserved.

Pyrethroids in chicken eggs from commercial farms and home production in Rio de Janeiro: Estimated daily intake and diastereomeric selectivity.

PubMed

Parente, Cláudio E T; Lestayo, Julliana; Guida, Yago S; Azevedo-Silva, Claudio E; Torres, João Paulo M; Meire, Rodrigo O; Malm, Olaf

2017-10-01

In this study, pyrethroids were determined in chicken eggs from commercial farm (n = 60) and home egg production (n = 30). These pyrethroids were investigated: bifenthrin, phenothrin, permethrin, cyfluthrin, cypermethrin and fenvalerate, including most diastereomers. Quantification was done using GC-MS in a negative chemical ionization mode. Pyrethroids residues were found in 79% of the analyzed samples. Cypermethrin presented the highest occurrence, being quantified in 62 samples (69%) in concentrations (lipid weight - l w.) varying between 0.29 and 6408 ng g -1 , followed by phenothrin (24%), 21-3910 ng g -1 , permethrin (14%), 2.96-328 ng g -1 , and bifenthrin (11%), 3.77-16.7 ng g -1 . Cyfluthrin and fenvalerate were not detected. Home-produced eggs had a higher occurrence of pyrethroids (97%), with a greater predominance of phenothrin. In commercial production, 70% of the samples presented pyrethroid residues (predominantly cypermethrin). This is the first report about the presence of pyrethroids in home-produced eggs and the first description of a selectivity pattern with the predominance of cis diastereomers in chicken eggs. In general, estimated daily intake does not present a risk to human consumption, according to Brazilian and international standards (FAO/WHO). However, one third of the samples (30 eggs) had concentrations above the maximum residue limits (MRLs). The maximum cypermethrin concentration was 66 times the MRL, while the maximum phenothrin concentration was 11 times the limit. Further studies about transfer dynamics, bioaccumulation and metabolic degradation of stereoisomers are required, as well as determining if this selectivity pattern in food can increase consumer's health risk. Copyright © 2017 Elsevier Ltd. All rights reserved.

Pyrethroid insecticide concentrations and toxicity in streambed sediments and loads in surface waters of the San Joaquin Valley, California, USA

USGS Publications Warehouse

Domagalski, Joseph L.; Weston, Donald P.; Zhang, Minghua; Hladik, Michelle L.

2010-01-01

Pyrethroid insecticide use in California, USA, is growing, and there is a need to understand the fate of these compounds in the environment. Concentrations and toxicity were assessed in streambed sediment of the San Joaquin Valley of California, one of the most productive agricultural regions of the United States. Concentrations were also measured in the suspended sediment associated with irrigation or storm‐water runoff, and mass loads during storms were calculated. Western valley streambed sediments were frequently toxic to the amphipod, Hyalella azteca, with most of the toxicity attributable to bifenthrin and cyhalothrin. Up to 100% mortality was observed in some locations with concentrations of some pyrethroids up to 20 ng/g. The western San Joaquin Valley streams are mostly small watersheds with clay soils, and sediment‐laden irrigation runoff transports pyrethroid insecticides throughout the growing season. In contrast, eastern tributaries and the San Joaquin River had low bed sediment concentrations (<1 ng/g) and little or no toxicity because of the preponderance of sandy soils and sediments. Bifenthrin, cyhalothrin, and permethrin were the most frequently detected pyrethroids in irrigation and storm water runoff. Esfenvalerate, fenpropathrin, and resmethrin were also detected. All sampled streams contributed to the insecticide load of the San Joaquin River during storms, but some compounds detected in the smaller creeks were not detected in the San Joaquin River. The two smallest streams, Ingram and Hospital Creeks, which had high sediment toxicity during the irrigation season, accounted for less than 5% of the total discharge of the San Joaquin River during storm conditions, and as a result their contribution to the pyrethroid mass load of the larger river was minimal. 

Lambda-Cyhalothrin Resistance in the Lady Beetle Eriopis connexa (Coleoptera: Coccinellidae) Confers Tolerance to Other Pyrethroids.

PubMed

Torres, J B; Rodrigues, A R S; Barros, E M; Santos, D S

2015-02-01

Pyrethroid insecticides are widely recommended to control insect defoliators but lack efficacy against most aphid species. Thus, conserving aphid predators such as the lady beetle Eriopis connexa (Germar) is important to pest management in crop ecosystems that require pyrethroid sprays. In a greenhouse, early fourth-instar larvae and 5-day-old adults from susceptible (S) and resistant (R) E. connexa populations were caged on lambda-cyhalothrin-treated cotton plants, after which survival and egg production (for those caged at adult stage) were assessed. In the laboratory, similar groups were subjected to dried residues and topical treatment with one of eight pyrethroids (alpha-cypermethrin, bifenthrin, deltamethrin, esfenvalerate, fenpropathrin, permethrin, zeta-cypermethrin, and lambda-cyhalothrin), the organophosphate methidathion, or water and wetting agent. After caging on treated cotton terminals, 66% of the R-population larvae survived to adulthood, compared with 2% of those from the S-population. At 12 d after caging at adult stage under the same conditions, 64% of the females from the R-population survived and laid eggs, compared with 100% mortality and no oviposition for the S-females. In trials involving dried insecticide residues, gain in survival based on the survival difference (percentage for R-population minus percentage for S-population) across all tested pyrethroids varied from 3 to 63% for larvae and from 3 to 70% for adults. In trials involving topical sprays of the tested pyrethroids, survival differences ranged from 36 to 96% for larvae and from 21 to 82% for adults. Fenpropathrin and bifenthrin were the least and most toxic, respectively. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Actions of Agonists, Fipronil and Ivermectin on the Predominant In Vivo Splice and Edit Variant (RDLbd, I/V) of the Drosophila GABA Receptor Expressed in Xenopus laevis Oocytes

PubMed Central

Suwanmanee, Siros; Buckingham, Steven David; Biggin, Philip; Sattelle, David

2014-01-01

Ionotropic GABA receptors are the targets for several classes of insecticides. One of the most widely-studied insect GABA receptors is RDL (resistance to dieldrin), originally isolated from Drosophila melanogaster. RDL undergoes alternative splicing and RNA editing, which influence the potency of GABA. Most work has focussed on minority isoforms. Here, we report the first characterisation of the predominant native splice variant and RNA edit, combining functional characterisation with molecular modelling of the agonist-binding region. The relative order of agonist potency is GABA> muscimol> TACA> β-alanine. The I/V edit does not alter the potency of GABA compared to RDLbd. Docking calculations suggest that these agonists bind and activate RDLbdI/V through a similar binding mode. TACA and β-alanine are predicted to bind with lower affinity than GABA, potentially explaining their lower potency, whereas the lower potency of muscimol and isoguvacine cannot be explained structurally from the docking calculations. The A301S (resistance to dieldrin) mutation reduced the potency of antagonists picrotoxin, fipronil and pyrafluprole but the I/V edit had no measurable effect. Ivermectin suppressed responses to GABA of RDLbdI/V, RDLbd and RDLbdI/VA301S. The dieldrin resistant variant also showed reduced sensitivity to Ivermectin. This study of a highly abundant insect GABA receptor isoform will help the design of new insecticides. PMID:24823815

Minireview: Mode of action of meta-diamide insecticides.

PubMed

Nakao, Toshifumi; Banba, Shinichi

2015-06-01

Meta-diamides [3-benzamido-N-(4-(perfluoropropan-2-yl)phenyl)benzamides] are a distinct class of RDL GABA receptor noncompetitive antagonists showing high insecticidal activity against Spodoptera litura. The mode of action of the meta-diamides was demonstrated to be distinct from that of conventional noncompetitive antagonists (NCAs) such as fipronil, picrotoxin, lindane, dieldrin, and α-endosulfan. It was suggested that meta-diamides act at or near G336 in the M3 region of the Drosophila RDL GABA receptor. Although the site of action of the meta-diamides appears to overlap with that of macrocyclic lactones including avermectins and milbemycins, differential effects of mutations on the actions of the meta-diamides and the macrocyclic lactones were observed. Molecular modeling studies revealed that the meta-diamides may bind to an inter-subunit pocket near G336 in the Drosophila RDL GABA receptor better when in the closed state, which is distinct from the NCA-binding site, which is in a channel formed by M2s. In contrast, the macrocyclic lactones were suggested to bind to an inter-subunit pocket near G336 in the Drosophila RDL GABA receptor when in the open state. Furthermore, mechanisms underlying the high selectivity of meta-diamides are discussed. This minireview highlights the unique features of novel meta-diamide insecticides and demonstrates why meta-diamides are anticipated to become prominent insecticides that are effective against pests resistant to cyclodienes and fipronil. Copyright © 2014 Elsevier Inc. All rights reserved.

The impact of restrictions on neonicotinoid and fipronil insecticides on pest management in maize, oilseed rape and sunflower in eight European Union regions†

PubMed Central

Castañera, Pedro; Alonso‐Prados, José Luis; Gómez‐Barbero, Manuel; Rodríguez‐Cerezo, Emilio

2017-01-01

Abstract BACKGROUND In 2013, the European Commission restricted the use of three neonicotinoids (clothianidin, imidacloprid and thiamethoxam) and the pyrazole fipronil, which are widely used to control early‐season pests. Here, we used original farm survey data to examine the impact of the restrictions on pest management practices in eight regional case studies including maize, oilseed rape and sunflower in seven European Union (EU) countries. RESULTS In four case studies, farmers switched to using untreated seeds as no alternative seed treatments were available. In three case studies, farmers switched to using unrestricted neonicotinoid‐ or pyrethroid‐treated seeds. In five case studies, farmers increased the use of soil or foliar treatments, with pyrethroids as the principal insecticide class. Other changes in pest management practices ranged from increased sowing density to more frequent scouting for pests. Many farmers perceived that the time, cost and amount of insecticides required to protect crops increased, along with pest pressure. Alternative seed treatments were mostly perceived as being less effective than the restricted seed treatments. CONCLUSION Farmers generally relied on alternative seed treatments or more soil/foliar treatments in the first growing season after the restrictions took effect. Further study is required to assess the effectiveness and sustainability of these alternatives compared with the restricted insecticides. © 2017 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. PMID:28842940

Comparisons of toxic baits for controlling the cockroach, Blattella germanica: attractiveness and feeding stimulation.

PubMed

Durier, V; Rivault, C

2000-12-01

Female German cockroaches, Blattella germanica (L.) (Dictyoptera: Blattellidae) and nymphs (stages 1, 3 and 6) were used to test the attractiveness and the feeding stimulation of several commercial gel formulations of insecticide food baits in laboratory binary choice tests. The four toxic gel baits tested were: 'Avert' (0.05% abamectin=avermectin B1), 'Drax' (33.3% boric acid), 'Goliath' (0.05% fipronil) and 'Maxforce' (2.15% hydramethylnon). The attractiveness of a bait was estimated by the number of cockroaches that chose it first, and by their tendency to change to it secondarily. Feeding stimulation was estimated by the mean duration of feeding bouts and total duration of food intake. Variability of these factors was assessed in relation to age of cockroaches and to age of baits. With a few exceptions, cockroach age did not affect performance in any of these tests. Attractiveness to B. germanica ranked 'Goliath' gel higher than 'Avert', 'Drax' and 'Maxforce' gels, whether or not the active ingredient fipronil was present in 'Goliath' gel. Feeding stimulation ranked 'Avert' and 'Maxforce' gels higher than 'Goliath' gel, and 'Drax' gel was inferior. With ageing up to 3 months, the feeding stimulation power of 'Goliath' and 'Maxforce' gels increased, whereas that of 'Avert' fluctuated. Assuming that all types of bait effectively kill cockroaches once ingested, these results illustrate the importance of behavioural observations on bait efficiency and show that ranking of these different food baits varies in relation to the parameter analysed.

Overview of pesticide residues in stored pollen and their potential effect on bee colony (Apis mellifera) losses in Spain.

PubMed

Bernal, J; Garrido-Bailón, E; Del Nozal, M J; González-Porto, A V; Martín-Hernández, R; Diego, J C; Jiménez, J J; Bernal, J L; Higes, M

2010-12-01

In the last decade, an increase in honey bee (Apis mellifera L.) colony losses has been reported in several countries. The causes of this decline are still not clear. This study was set out to evaluate the pesticide residues in stored pollen from honey bee colonies and their possible impact on honey bee losses in Spain. In total, 1,021 professional apiaries were randomly selected. All pollen samples were subjected to multiresidue analysis by gas chromatography-mass spectrometry (MS) and liquid chromatography-MS; moreover, specific methods were applied for neonicotinoids and fipronil. A palynological analysis also was carried out to confirm the type of foraging crop. Pesticide residues were detected in 42% of samples collected in spring, and only in 31% of samples collected in autumn. Fluvalinate and chlorfenvinphos were the most frequently detected pesticides in the analyzed samples. Fipronil was detected in 3.7% of all the spring samples but never in autumn samples, and neonicotinoid residues were not detected. More than 47.8% of stored pollen samples belonged to wild vegetation, and sunflower (Heliantus spp.) pollen was only detected in 10.4% of the samples. A direct relation between pesticide residues found in stored pollen samples and colony losses was not evident accordingly to the obtained results. Further studies are necessary to determine the possible role of the most frequent and abundant pesticides (such as acaricides) and the synergism among them and with other pathogens more prevalent in Spain.

Ecotoxicological effects of the insecticide fipronil in Brazilian native stingless bees Melipona scutellaris (Apidae: Meliponini).

PubMed

de Morais, Cássio Resende; Travençolo, Bruno Augusto Nassif; Carvalho, Stephan Malfitano; Beletti, Marcelo Emílio; Vieira Santos, Vanessa Santana; Campos, Carlos Fernando; de Campos Júnior, Edimar Olegário; Pereira, Boscolli Barbosa; Carvalho Naves, Maria Paula; de Rezende, Alexandre Azenha Alves; Spanó, Mário Antônio; Vieira, Carlos Ueira; Bonetti, Ana Maria

2018-09-01

Melipona scutellaris Latreille, 1811 (Hymenoptera, Apidae) is a pollinator of various native and cultivated plants. Because of the expansion of agriculture and the need to ensure pest control, the use of insecticides such as fipronil (FP) has increased. This study aimed to evaluate the effects of sublethal doses of FP insecticide on M. scutellaris at different time intervals (6, 12, and 24 h) after exposure, via individually analyzed behavioral biomarkers (locomotor activity, behavioral change) as well as the effect of FP on different brain structures of bees (mushroom bodies, antennal cells, and optic cells), using sub-individual cell biomarkers (heterochromatin dispersion, total nuclear and heterochromatic volume). Forager bees were collected when they were returning to the nest and were exposed to three different concentrations of FP (0.40, 0.040, and 0.0040 ng a.i/bee) by topical application. The results revealed a reduction in the mean velocity, lethargy, motor difficulty, paralysis, and hyperexcitation in all groups of bees treated with FP. A modification of the heterochromatic dispersion pattern and changes in the total volume of the nucleus and heterochromatin were also observed in the mushroom bodies (6, 12, and 24 h of exposure) and antennal lobes (6 and 12 h) of bees exposed to 0.0040 ng a.i/bee (LD 50/100 ). FP is toxic to M. scutellaris and impairs the essential functions required for the foraging activity. Copyright © 2018 Elsevier Ltd. All rights reserved.

The role of Rdl in resistance to phenylpyrazoles in Drosophila melanogaster.

PubMed

Remnant, Emily J; Morton, Craig J; Daborn, Phillip J; Lumb, Christopher; Yang, Ying Ting; Ng, Hooi Ling; Parker, Michael W; Batterham, Philip

2014-11-01

Extensive use of older generation insecticides may result in pre-existing cross-resistance to new chemical classes acting at the same target site. Phenylpyrazole insecticides block inhibitory neurotransmission in insects via their action on ligand-gated chloride channels (LGCCs). Phenylpyrazoles are broad-spectrum insecticides widely used in agriculture and domestic pest control. So far, all identified cases of target site resistance to phenylpyrazoles are based on mutations in the Rdl (Resistance to dieldrin) LGCC subunit, the major target site for cyclodiene insecticides. We examined the role that mutations in Rdl have on phenylpyrazole resistance in Drosophila melanogaster, exploring naturally occurring variation, and generating predicted resistance mutations by mutagenesis. Natural variation at the Rdl locus in inbred strains of D. melanogaster included gene duplication, and a line containing two Rdl mutations found in a highly resistant line of Drosophila simulans. These mutations had a moderate impact on survival following exposure to two phenylpyrazoles, fipronil and pyriprole. Homology modelling suggested that the Rdl chloride channel pore contains key residues for binding fipronil and pyriprole. Mutagenesis of these sites and assessment of resistance in vivo in transgenic lines showed that amino acid identity at the Ala(301) site influenced resistance levels, with glycine showing greater survival than serine replacement. We confirm that point mutations at the Rdl 301 site provide moderate resistance to phenylpyrazoles in D. melanogaster. We also emphasize the beneficial aspects of testing predicted mutations in a whole organism to validate a candidate gene approach. Copyright © 2014 Elsevier Ltd. All rights reserved.

Exposure to sub-acute doses of fipronil and buprofezin in combination or alone induces biochemical, hematological, histopathological and genotoxic damage in common carp (Cyprinus carpio L.).

PubMed

Qureshi, Irfan Zia; Bibi, Asia; Shahid, Sana; Ghazanfar, Madiha

2016-10-01

Use of pesticides or insecticides can be highly toxic to aquatic life forms due to leaching and agricultural runoff, rains or flood. Fipronil (FP) is a GABA receptor inhibitor, while buprofezin (BPFN) is an insect growth regulator. Presently, we exposed groups of aquaria acclimated carp fish (Cyprinus carpio) for 96h to sub-lethal concentrations of fipronil (400μgL(-1); 9.15×10(-7)molL(-1)) and buprofezin (BPFN, 100mgL(-1); 1.072×10(-6)molL(-1)) singly or in combination. The extent of damage was assessed at biochemical, hematological, molecular biological and histopathological level. Results obtained in treated fish were compared statistically with those of control non-treated fish and also among treatment groups. Significance level was p<0.05. Compared to control, serum total protein and globulin concentrations decreased significantly (p<0.0001) in fish treated with FP; while albumin concentration remained unaltered with all treatments. Glucose concentration decreased significantly (p<0.002) in fish treated with FP. In contrast, combined FP+BPFN treatment and BPFN treatment caused insignificant elevation of glucose concentration. Hematological assessment demonstrated significant decrease in red blood cell and thrombocyte counts, hemoglobin concentration and hematocrit percent; while white blood cell count showed an increase in all treatment groups (p<0.0001). Blood smears from pesticide treated fish revealed aberrant erythrocyte morphologies which included necrosis, micronuclear formation and hyperchromatosis. DNA laddering assay carried out on whole blood demonstrated excessive smear formation in combined FP+BPFN and BPFN treatment groups but no smear formation was noticeable in FP treated fish. Compared to control, whole blood DNA content increased significantly in the combined FP+BPFN and BPFN treatment groups (p<0.001 and p<0.009). With all treatments histopathological changes observed in the gills were: epithelial uplifting and necrosis of lamellae, lamellar atrophy, disruption of cartilaginous core, fusion and disorganization of lamellae and telangiectasia. In liver these were: karyorrhexis, hepatocellular hypertrophy, nuclear hypertrophy, melanomacrophage aggregates and central vein contraction, while in the kidney: deterioration of glomerulus and dilatation of Bowman's space, dilatation of renal tubules, thyroidisation, altered tubular lumen, nuclear hypertrophy, cellular atrophy, and cellular necrosis were the outcome. Our study revealed that FP and BPFN produce highly toxic effects on fish when given in combination or singly. To our knowledge, this is the first report on toxicity caused by FP and BPFN in single and combined state. Copyright © 2016 Elsevier B.V. All rights reserved.

Does the Clock Make the Poison? Circadian Variation in Response to Pesticides

PubMed Central

Hooven, Louisa A.; Sherman, Katherine A.; Butcher, Shawn; Giebultowicz, Jadwiga M.

2009-01-01

Background Circadian clocks govern daily physiological and molecular rhythms, and putative rhythms in expression of xenobiotic metabolizing (XM) genes have been described in both insects and mammals. Such rhythms could have important consequences for outcomes of chemical exposures at different times of day. To determine whether reported XM gene expression rhythms result in functional rhythms, we examined daily profiles of enzyme activity and dose responses to the pesticides propoxur, deltamethrin, fipronil, and malathion. Methodology/Principal Findings Published microarray expression data were examined for temporal patterns. Male Drosophila were collected for ethoxycoumarin-O-deethylase (ECOD), esterase, glutathione-S-transferase (GST), and, and uridine 5′-diphosphoglucosyltransferase (UGT) enzyme activity assays, or subjected to dose-response tests at four hour intervals throughout the day in both light/dark and constant light conditions. Peak expression of several XM genes cluster in late afternoon. Significant diurnal variation was observed in ECOD and UGT enzyme activity, however, no significant daily variation was observed in esterase or GST activity. Daily profiles of susceptibility to lethality after acute exposure to propoxur and fipronil showed significantly increased resistance in midday, while susceptibility to deltamethrin and malathion varied little. In constant light, which interferes with clock function, the daily variation in susceptibility to propoxur and in ECOD and UGT enzyme activity was depressed. Conclusions/Significance Expression and activities of specific XM enzymes fluctuate during the day, and for specific insecticides, the concentration resulting in 50% mortality varies significantly during the day. Time of day of chemical exposure should be an important consideration in experimental design, use of pesticides, and human risk assessment. PMID:19649249

Investigation of pharmaceuticals, personal care products and endocrine disrupting chemicals in a tropical urban catchment and the influence of environmental factors.

PubMed

You, Luhua; Nguyen, Viet Tung; Pal, Amrita; Chen, Huiting; He, Yiliang; Reinhard, Martin; Gin, Karina Yew-Hoong

2015-12-01

Previous studies showed the presence of multiple emerging organic contaminants (EOCs) in urban surface waters of Singapore even though there are no obvious direct wastewater discharges. In this study, we investigated the occurrence and distribution of 17 pharmaceuticals and personal care products (PPCPs) and endocrine disruptive compounds (EDCs) in a tropical urban catchment of Singapore. Monthly samples were collected from a reservoir and its 5 upstream tributaries during a 16-month period. Analysis of samples showed all sites had measurable PPCP and EDC concentrations, with caffeine (33.9-2980 ng/L), salicylic acid (5-838 ng/L), acetaminophen (<4-485.5 ng/L), BPA (<2-919.5 ng/L) and DEET (13-270 ng/L) being the most abundant. Marked differences in concentrations of target analytes between the reservoir and upstream tributaries were observed, and were tentatively attributed to the spatial differences in source inputs, water dilution capacity as well as natural attenuation of EOCs. Significant correlations between EOCs and conductivity, dissolved oxygen, chlorophyll a, turbidity, nutrients and cumulative precipitation were observed. These factors appeared to affect the distribution and attenuation of EOCs, depending on their physicochemical properties. Rainfall also influenced the temporal distribution of caffeine, BPA, triclosan, fipronil and DEET in the reservoir. Ecological risk assessment showed that caffeine, acetaminophen, estrone, BPA, triclosan and fipronil may warrant further survey. In particular, BPA levels exceeded the literature-based Predicted No-Effect Concentration (PNEC) value, highlighting the need for source control and/or water remediation in this urban catchment. Copyright © 2015 Elsevier B.V. All rights reserved.

The impact of restrictions on neonicotinoid and fipronil insecticides on pest management in maize, oilseed rape and sunflower in eight European Union regions.

PubMed

Kathage, Jonas; Castañera, Pedro; Alonso-Prados, José Luis; Gómez-Barbero, Manuel; Rodríguez-Cerezo, Emilio

2018-01-01

In 2013, the European Commission restricted the use of three neonicotinoids (clothianidin, imidacloprid and thiamethoxam) and the pyrazole fipronil, which are widely used to control early-season pests. Here, we used original farm survey data to examine the impact of the restrictions on pest management practices in eight regional case studies including maize, oilseed rape and sunflower in seven European Union (EU) countries. In four case studies, farmers switched to using untreated seeds as no alternative seed treatments were available. In three case studies, farmers switched to using unrestricted neonicotinoid- or pyrethroid-treated seeds. In five case studies, farmers increased the use of soil or foliar treatments, with pyrethroids as the principal insecticide class. Other changes in pest management practices ranged from increased sowing density to more frequent scouting for pests. Many farmers perceived that the time, cost and amount of insecticides required to protect crops increased, along with pest pressure. Alternative seed treatments were mostly perceived as being less effective than the restricted seed treatments. Farmers generally relied on alternative seed treatments or more soil/foliar treatments in the first growing season after the restrictions took effect. Further study is required to assess the effectiveness and sustainability of these alternatives compared with the restricted insecticides. © 2017 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. © 2017 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Multiple resistance to acaricides in field populations of Rhipicephalus microplus from Rio Grande do Sul state, Southern Brazil.

PubMed

Klafke, Guilherme; Webster, Anelise; Dall Agnol, Bruno; Pradel, Endrigo; Silva, Jeniffer; de La Canal, Luiz Henrique; Becker, Marcelo; Osório, Mateus Felipe; Mansson, Melanie; Barreto, Rafael; Scheffer, Ramon; Souza, Ugo Araújo; Corassini, Vivian Bamberg; Dos Santos, Julsan; Reck, José; Martins, João Ricardo

2017-01-01

Acaricide resistance is a major obstacle to the control of Rhipicephalus microplus. Historically, the indiscriminate use of chemical compounds has contributed to the selection of populations resistant to different classes of acaricides. Therefore, multiple acaricide resistance is an important threat to the chemical control of the cattle tick. To investigate the occurrence and extent of multiple resistance to acaricides in Southern Brazil we performed larval tests with cypermethrin, chlorpyriphos, amitraz, fipronil and ivermectin on 104 cattle tick field samples from different ranches in Rio Grande do Sul, between the years 2013 and 2015. Adult immersion tests with a commercial formulation mixture of chlorpyriphos and cypermethrin were performed on 75 samples. Four levels of resistance were established according to the mortality of larvae: Level I: mortality between 82% and 95%; Level II: mortality between 57% and 82%; Level III: mortality between 25% and 57%; and Level IV: mortality lower than 25%. Resistance to cypermethrin was detected in 98.08% of the samples evaluated, mostly at resistance level IV. The frequency of samples resistant to amitraz, chlorpyriphos, ivermectin and fipronil was 76.92%, 60.58%, 60.58% and 53.85% respectively. Multiple resistance to three or more compounds was found in 78.85% of the samples. The results obtained in this study are alarming and reveal a new scenario for the challenge of tick control using chemicals. This is an issue of high importance to cattle production systems where this tick is responsible for a high economic impact. Copyright © 2016 Elsevier GmbH. All rights reserved.

Behavioral Effects and Tunneling Responses of Eastern Subterranean Termites (Isoptera: Rhinotermitidae) Exposed to Chlorantraniliprole-Treated Soils.

PubMed

Saran, Raj K; Ziegler, Melissa; Kudlie, Sara; Harrison, Danielle; Leva, David M; Scherer, Clay; Coffelt, Mark A

2014-10-01

Intrinsic toxicities of chlorantraniliprole, fipronil, and imidacloprid were evaluated with topical applications on worker termites. Worker termites were exposed to substrates treated with formulated chlorantraniliprole to study contact toxicity, tunneling, and postexposure behaviors. The intrinsic toxicities (LD50, ng/termite) of chlorantraniliprole (1.25, 0.96, and 0.44) and fipronil (0.12, 0.11, and 0.13) at 11 d were similar for workers from three termite colonies. Imidacloprid toxicity (LD50) values were highly variable among the workers from three different colonies, values at 11 d ranging from 0.7 to 75 ng/termite. Termite workers exposed to sand and soils treated with chlorantraniliprole at 50 ppm exhibited delayed mortality and, for most of the exposure times, it took >5 d to observe 90-100% mortality in termite workers. Exposure to chlorantraniliprole-treated sand (50 ppm) for as little as 1 min stopped feeding and killed 90-100% of the workers. Tunneling (≈ 2 h) in different soil types treated with chlorantraniliprole at 50 ppm, even those with high organic matter (6.3%) and clay content (30%), caused immediate feeding cessation in worker termites and mortality in the next 7-14 d. Worker termites exposed for 1 and 60 min to sand treated with chlorantraniliprole (50 ppm) were able to walk normally for 4 h after exposure in most cases. Delayed toxicity, increased aggregation, and grooming were observed in exposed termites and discussed in the context of horizontal transfer effects within termite colonies. © 2014 Entomological Society of America.

Cross-resistance of bisultap resistant strain of Nilaparvata lugens and its biochemical mechanism.

PubMed

Ling, Shanfeng; Zhang, Runjie

2011-02-01

The resistant (R) strain of the planthopper Nilaparvata lugens (Stål) selected for bisultap resistance displayed 7.7-fold resistance to bisultap and also had cross-resistance to nereistoxin (monosultap, thiocyclam, and cartap), chlorpyrifos, dimethoate, and malathion but no cross-resistance to buprofezin, imidacloprid, and fipronil. To find out the biochemical mechanism of resistance to bisultap, biochemical assay was done. The results showed that cytochrome P450 monooxygenases (P450) activity in R strain was 2.71-fold that in susceptible strain (S strain), in which the changed activity for general esterase (EST) was 1.91 and for glutathione S-transferases only 1.32. Piperonyl butoxide (PBO) could significantly inhibit P450 activity (percentage of inhibition [PI]: 37.31%) in the R strain, with ESTs PI = 16.04% by triphenyl phosphate (TPP). The results also demonstrated that diethyl maleate had no synergism with bisultap. However, PBO displayed significant synergism in three different strains, and the synergism increased with resistance (S strain 1.42, Lab strain, 2.24 and R strain, 3.23). TPP also showed synergism for three strains, especially in R strain (synergistic ratio = 2.47). An in vitro biochemical study and in vivo synergistic study indicated that P450 might be play important role in the biochemical mechanism of bisultap resistance and that esterase might be the important factor of bisultap resistance. Acetylcholinesterase (AChE) insensitivity play important role in bisultap resistance. We suggest that buprofezin, imidacloprid, and fipronil could be used in resistance management programs for N. lugens via alternation and rotation with bisultap.

Development of virtual bait stations to control Argentine ants (Hymenoptera: Formicidae) in environmentally sensitive habitats.

PubMed

Choe, Dong-Hwan; Vetter, Richard S; Rust, Michael K

2010-10-01

A novel bait station referred to as a virtual bait station was developed and tested against field populations of the invasive Argentine ant, Linepithema humile (Mayr) (Hymenoptera: Formicidae), at White Beach, Camp Pendleton, in Oceanside, CA. White Beach is a nesting habitat for an endangered seabird, the California least tern (Sterna antillarum browni Mearns). The beach is heavily infested with Argentine ants, one of the threats for the California least tern chicks. Conventional pest control strategies are prohibited because of the existence of the protected bird species and the site's proximity to the ocean. The bait station consisted of a polyvinyl chloride pipe that was treated on the inside with fipronil insecticide at low concentrations to obtain delayed toxicity against ants. The pipe was provisioned with an inverted bottle of 25% sucrose solution, then capped, and buried in the sand. Foraging ants crossed the treated surface to consume the sucrose solution. The delayed toxicity of fipronil deposits allowed the ants to continue foraging on the sucrose solution and to interact with their nestmates, killing them within 3-5 d after exposure. Further modification of the bait station design minimized the accumulation of dead ants in the sucrose solution, significantly improving the longevity and efficacy of the bait station. The virtual bait station exploits the foraging behavior of the ants and provides a low impact approach to control ants in environmentally sensitive habitats. It excluded all insects except ants, required only milligram quantities of toxicant, and eliminated the problem of formulating toxicants into aqueous sugar baits.

Diverse Neurotoxicants Target the Differentiation of Embryonic Neural Stem Cells into Neuronal and Glial Phenotypes

PubMed Central

Slotkin, Theodore A.; Skavicus, Samantha; Card, Jennifer; Levin, Edward D.; Seidler, Frederic J.

2016-01-01

The large number of compounds that need to be tested for developmental neurotoxicity drives the need to establish in vitro models to evaluate specific neurotoxic endpoints. We used neural stem cells derived from rat neuroepithelium on embryonic day 14 to evaluate the impact of diverse toxicants on their ability to differentiate into glia and neurons: a glucocorticoid (dexamethasone), organophosphate insecticides (chlorpyrifos, diazinon, parathion), insecticides targeting the GABAA receptor (dieldrin, fipronil), heavy metals (Ni2+, Ag+), nicotine and tobacco smoke extract. We found three broad groupings of effects. One diverse set of compounds, dexamethasone, the organophosphate pesticides, Ni2+ and nicotine, suppressed expression of the glial phenotype while having little or no effect on the neuronal phenotype. The second pattern was restricted to the pesticides acting on GABAA receptors. These compounds promoted the glial phenotype and suppressed the neuronal phenotype. Notably, the actions of compounds eliciting either of these differentiation patterns were clearly unrelated to deficits in cell numbers: dexamethasone, dieldrin and fipronil all reduced cell numbers, whereas organophosphates and Ni2+ had no effect. The third pattern, shared by Ag+ and tobacco smoke extract, clearly delineated cytotoxicity, characterized major cell loss with suppression of differentiation into both glial and neuronal phenotypes; but here again, there was some selectivity in that glia were suppressed more than neurons. Our results, from this survey with diverse compounds, point to convergence of neurotoxicant effects on a specific “decision node” that controls the emergence of neurons and glia from neural stem cells. PMID:27816694

Effect of subacute poisoning with bifenthrin on locomotor activity, memory retention, haematological, biochemical and histopathological parameters in mice.

PubMed

Nieradko-Iwanicka, B; Borzecki, A; Jodlowska-Jedrych, B

2015-02-01

Bifenthrin (BIF) is a pyrethroid (PYR) insecticide. The target point for PYR's toxic action are voltage sensitive sodium channels in the central nervous system (CNS). Intoxication with PYRs results in motor activity impairment and death in insects. Although PYRs are considered to be safe for mammals, there were numerous cases of pyrethroid poisoning in humans, animals and pets described. The general population is chronically exposed to PYRs via grain products, dust and indoor air. Therefore new questions arise: whether PYRs act in a dose-additive fashion in the course of subacute poisoning, are there other target organs (but brain) for BIF and if there is one common mechanism of its' toxic action in different organs. The objective of this work was to characterize the effect of BIF at the doses of 4 or 8 mg/kg injected intraperitoneally (i.p.) daily for 28 consecutive days on memory and motor activity, hematological, biochemical and histopathological parameters in mice. BIF at the doses of 8 mg/kg or 4 mg/kg of body mass was administered i.p. daily to the mice for 28 consecutive days. Motor function was measured on day 1, 7, 14 and 28 and memory retention was tested in a passive avoidance task on day 2, 7, 14 and 28. BIF significantly impaired memory retention on day 2. BIF decreased locomotor activity at every stage of the experiment in a single dose depending manner. No behavioral cumulative effect was observed. Subacute poisoning with the higher dose of BIF caused anaemia, elevated white blood cell count (WBC), elevated alanine transaminase (ALT), superoxide dismuthase (SOD), and decreased glutathione peroxidase (GPx) activity. Lymphocyte infiltrates were visualized in the livers. subacute poisoning with BIF decreases locomotor activity in a single dose proportionate manner. BIF damages also the liver and alters blood morphology. The possible common mechanism of these effects can be oxidative stress.

Magnetic solid-phase extraction of five pyrethroids from environmental water samples followed by ultrafast liquid chromatography analysis.

PubMed

Yu, Xi; Sun, Ying; Jiang, Chunzhu; Sun, Xiumin; Gao, Yan; Wang, Yuanpeng; Zhang, Hanqi; Song, Daqian

2012-08-30

In this study, the polystyrene-coated magnetic nanoparticles (MNPs/PSt) were successfully prepared and characterized by Fourier transform infrared spectroscopy, transmission electron microscopy and vibrating sample magnetometry. The as-prepared MNPs/PSt were used as the adsorbent in magnetic solid phase extraction of five pyrethroids, including lambda-cyhalothrin, deltamethrin, esfenvalerate, permethrin, bifenthrin, in environmental water samples. The five pyrethroids were determined by ultra fast liquid chromatography-ultraviolet spectrometry. The influencing factors, including amount of MNPs/Pst, extraction time, pH value, type and volume of desorption solvent and desorption time, were examined and optimized. The extraction recoveries obtained with merely 50mg of MNPs/Pst were very satisfactory. The whole extraction process could be completed within 0.5h. The MNPs/PSt can be reused after an easy washing process. Thus, a simple, green, economical, time saving and effective method for pyrethroids analysis in environmental water samples was established. A high enrichment factor of 500 was achieved and the limits of detection for lambda-cyhalothrin, deltamethrin, esfenvalerate, permethrin, bifenthrin were 0.015±0.001 ng mL(-1), 0.012±0.001 ng mL(-1), 0.026±0.001 ng mL(-1), 0.020±0.001 ng mL(-1), 0.013±0.001 ng mL(-1), respectively. Recoveries obtained by analyzing spiked water samples at three concentration levels (0.100±0.001 ng mL(-1), 1.000±0.001 ng mL(-1), 10.000±0.001 ng mL(-1)) were between 78.97±8.38% and 96.05±8.38%. The standard curves for the five pyrethroids showed good linearity with the correlation coefficients in the range of 0.9994-0.9999. The intra-day and inter-day precision were satisfactory with the RSDs in the range of 2.05-5.52% and 2.73-8.38%, respectively. Copyright © 2012 Elsevier B.V. All rights reserved.

Assessing the transport potential of polymeric nanocapsules developed for crop protection.

PubMed

Petosa, Adamo Riccardo; Rajput, Faraz; Selvam, Olivia; Öhl, Carolin; Tufenkji, Nathalie

2017-03-15

Nanotechnology is increasingly important in the agricultural sector, with novel products being developed to heighten crop yields and increase pesticide efficacy. Herein, the transport potential of different polymeric nanocapsules (nCAPs) developed as pesticide delivery vehicles was assessed in model soil systems. The nCAPs examined are (i) poly(acrylic acid)-based (nCAP1), (ii) poly(methacrylic acid)-ran-poly(ethyl acrylate) copolymer-based (nCAP2), (iii) poly(methacrylic acid-ran-styrene) copolymer-based (nCAP3), and (iv) poly(methacrylic acid-ran-butylmethacrylate)-based (nCAP4). nCAP mobility was examined in columns packed with agricultural loamy sand saturated with artificial porewater containing Ca 2+ and Mg 2+ cations (10 mM ionic strength, pH 6 and 8). Furthermore, the impact of (i) cation species, (ii) sand type, and (iii) ammonium polyphosphate fertilizer on the transport potential of a nanoformulation combining nCAP4 capsules and the pyrethroid bifenthrin (nCAP4-BIF) was examined and compared to a commercial bifenthrin formulation (Capture ® LFR). Although nCAP4-BIF and Capture ® LFR formulations were highly mobile in quartz sand saturated with 10 mM NaNO 3 (≥95% elution), they were virtually immobile in the presence of 10% ammonium polyphosphate fertilizer. The presence of Ca 2+ and Mg 2+ did not hinder nCAP4-BIF elution in quartz sand saturated with 10 mM standard CIPAC D synthetic porewater; however, limited Capture ® LFR transport (<10% elution) was observed under the same conditions. Capture ® LFR also exhibited limited mobility in the presence or absence of fertilizer in loamy sand saturated with divalent salt solutions, whereas nCAP4-BIF exhibited increased elution with time and enhanced transport upon the addition of fertilizer. Overall, nCAP4 is a promising delivery vehicle in pyrethroid nanoformulations such as nCAP4-BIF. Copyright © 2016 Elsevier Ltd. All rights reserved.

Runoff of pyrethroid insecticides from concrete surfaces following simulated and natural rainfalls.

PubMed

Jiang, Weiying; Haver, Darren; Rust, Michael; Gan, Jay

2012-03-01

Intensive residential use of insecticides has resulted in their ubiquitous presence as contaminants in urban surface streams. For pest eradication, urban hard surfaces such as concrete are often directly treated with pesticides, and wind/water can also carry pesticides onto hard surfaces from surrounding areas. This study expanded on previous bench-scale studies by considering pesticide runoff caused by irrigation under dry weather conditions and rain during the wet season, and evaluated the effects of pesticide residence time on concrete, single versus recurring precipitations, precipitation intensity, and concrete surface conditions, on pesticide transferability to runoff water. Runoff from concrete 1 d after pesticide treatment contained high levels of bifenthrin (82 μg/L) and permethrin (5143 μg/L for cis and 5518 μg/L for trans), indicating the importance of preventing water contact on concrete after pesticide treatments. Although the runoff transferability quickly decreased as the pesticide residence time on concrete increased, detectable residues were still found in runoff water after 3 months (89 d) exposure to hot and dry summer conditions. ANOVA analysis showed that precipitation intensities and concrete surface conditions (i.e., acid wash, silicone seal, stamping, and addition of microsilica) did not significantly affect the pesticide transferability to runoff. For concrete slabs subjected to natural rainfalls during the winter wet season, pesticide levels in the runoff decreased as the time interval between pesticide application and the rain event increased. However, bifenthrin and permethrin were still detected at 0.15-0.17 and 0.75-1.15 μg/L in the rain runoff after 7 months (221 d) from the initial treatment. In addition, pesticide concentrations showed no decrease between the two rainfall events, suggesting that concrete surfaces contaminated by pesticides may act as a reservoir for pesticide residues, leading to sustained urban runoff contamination. Copyright © 2011 Elsevier Ltd. All rights reserved.

IPM-compatibility of foliar insecticides for citrus: Indices derived from toxicity to beneficial insects from four orders

PubMed Central

Michaud, J.P.; Grant, A.K.

2003-01-01

A series of compounds representing four major pesticide groups were tested for toxicity to beneficial insects representing four different insect orders: Coleoptera (Coccinellidae), Hemiptera (Anthocoridae), Hymenoptera (Aphelinidae), and Neuroptera (Chrysopidae). These materials included organophosphates (methidathion, esfenvalerate and phosmet), carbamates (carbofuran, methomyl and carbaryl), pyrethroids (bifenthrin, fenpropathrin, zeta-cypermethrin, cyfluthrin and permethrin) and the oxadiazine indoxacarb. Toxicity to coccinellid and lacewing species was assessed by treating 1st instar larvae with the recommended field rate of commercial products, and two 10 fold dilutions of these materials, in topical spray applications. Adult Aphytis melinus Debach and 2nd instar Orius insidiosus (Say) were exposed to leaf residues of the same concentrations for 24 h. ANOVA performed on composite survival indices derived from these data resolved significant differences among materials with respect to their overall toxicity to beneficial insects. Cyfluthrin, fenpropathrin and zeta-cypermethrin all increased the developmental time of the lacewing and one or more coccinellid species for larvae that survived topical applications. Bifenthrin increased developmental time for two coccinellid species and decreased it in a third. Indoxacarb (Avaunt® WG, DuPont Corp.) ranked highest overall for safety to beneficial insects, largely because of its low dermal toxicity to all species tested. Zeta-cypermethrin (Super Fury®, FMC Corporation) received the second best safety rating, largely because of its low toxicity as a leaf residue to A. melinus and O. insidiosus. Phosmet (Imidan® 70W, Gowan Co.) and methidathion (Supracide® 25W, Gowan Co.) ranked high for safety to coccinellid species, but compounds currently recommended for use in citrus such as fenpropathrin (Danitol® 2.4EC, Sumimoto Chem. Co.) and carbaryl (Sevin® XLR EC, Rhone Poulenc Ag. Co.) ranked very low for IPM-compatibility based on their relatively high toxicity to all species tested. Abbreviation: FR field rate PMID:15841234

Scientific evidence of three different insecticide-resistant profiles in Triatoma infestans (Hemiptera: Reduviidae) populations from Argentina and Bolivia.

PubMed

Germano, M D; Santo-Orihuela, P; Roca-Acevedo, G; Toloza, A C; Vassena, C; Picollo, M I; Mougabure-Cueto, G

2012-11-01

Triatoma infestans (Klug, 1834) (Hemiptera, Reduviidae) is the main vector of Chagas disease in the southern cone South America. Chemical control to the vectors appears to be the best option to reduce the incidence of the disease. However, since 2002, high resistance to insecticides that correlated with field control failures was detected in T. infestans from Argentina and Bolivia. In this paper, we analyzed three T. infestans populations whose pyrethroid-resistance had been recently detected, and we defined at least three resistant profiles according to the toxicological and biochemical characteristics of the studied resistant populations. The resistance profiles were identified as Ti-R1, Ti-R2, and Ti-R3, corresponding to the Argentinean Acambuco, and the Bolivians Entre Ríos and Mataral. Ti-R1 exhibited nymphs and eggs with medium resistance level to deltamethrin (RR = 32.5 and 28.6; respectively). Pyrethroid-esterases played a relevant role in deltamethrin resistance. Ti-R2 exhibited nymphs with high resistance to deltamethrin (RR = 173.8) and low resistance to fipronil (RR = 12.4). Pyrethroid-esterases were involved in resistance. Moreover, eggs showed medium resistance level to deltamethrin (RR = 39.1). Ti-R3 had nymphs with low resistance to deltamethrin (RR = 17.4), and medium resistance to fipronil (RR = 66.8). Pyrethroid-esterases showed increased activity, and eggs possessed low resistance to deltamethrin (RR = 8.4). The characterization of the resistance to pyrethroid in these T. infestans populations from Argentina and Bolivia do not permit the generalization of three forms of resistance profile. So far as we appear to know, the forms of mechanisms and their frequencies reported here are selected independently, so additional sites might well show additional combinations of resistance mechanisms and their frequencies.

Identifying the causes of sediment-associated toxicity in urban waterways in South China: incorporating bioavailabillity-based measurements into whole-sediment toxicity identification evaluation.

PubMed

Yi, Xiaoyi; Li, Huizhen; Ma, Ping; You, Jing

2015-08-01

Sediments in urban waterways of Guangzhou, China, were contaminated by a variety of chemicals and showed prevalent toxicity to benthic organisms. A combination of whole-sediment toxicity identification evaluation (TIE) and bioavailability-based extraction was used to identify the causes of sediment toxicity. Of the 6 sediment samples collected, 4 caused 100% mortality to Chironomus dilutus in 10-d bioassays, and the potential toxicants were assessed using TIE in these sediments after dilution. The results of phase I characterization showed that organic contaminants were the principal contributors to the mortality of the midges in 2 sediments and that metals and organics jointly caused the mortality in the other 2 sediments. Ammonia played no role in the mortality for any samples. Conventional toxic unit analysis in phase II testing identified Cr, Cu, Ni, Pb, and Zn as the toxic metals, with cypermethrin, lambda-cyhalothrin, deltamethrin, and fipronils being the toxic organics. To improve the accuracy of identifying the toxicants, 4-step sequential extraction and Tenax extraction were conducted to analyze the bioavailability of the metals and organics, respectively. Bioavailable toxic unit analysis narrowed the list of toxic contributors, and the putative toxicants included 3 metals (Zn, Ni, and Pb) and 3 pesticides (cypermethrin, lambda-cyhalothrin, and fipronils). Metals contributed to the mortality in all sediments, but sediment dilution reduced the toxicity and confounded the characterization of toxicity contribution from metals in 2 sediments in phase I. Incorporating bioavailability-based measurements into whole-sediment TIE improved the accuracy of identifying the causative toxicants in urban waterways where multiple stressors occurred and contributed to sediment toxicity jointly. © 2015 SETAC.

Occurrence of commonly used pesticides in personal air samples and their associated health risk among paddy farmers.

PubMed

Hamsan, Hazwanee; Ho, Yu Bin; Zaidon, Siti Zulfa; Hashim, Zailina; Saari, Nazamid; Karami, Ali

2017-12-15

Tanjung Karang, Selangor, is widely known for its paddy cultivation activity and hosts the third largest paddy field in Malaysia. Pesticides contamination in agriculture fields has become an unavoidable problem, as pesticides are used to increase paddy productivity and reduce plant disease. Human exposure to agrichemicals is common and could results in both acute and chronic health effects, such as acute and chronic neurotoxicity. This study aims to determine the concentrations of commonly used pesticides (azoxystrobin, buprofezin, chlorantraniliprole, difenoconazole, fipronil, imidacloprid, isoprothiolane, pretilachlor, propiconazole, pymetrozine, tebuconazole, tricyclazole, and trifloxystrobin) in personal air samples and their associated health risks among paddy farmers. Eighty-three farmers from Tangjung Karang, Selangor were involved in this study. A solid sorbent tube was attached to the farmer's breathing zone with a clip, and an air pump was fastened to the belt to collect personal air samples. Pesticides collected in the XAD-2 resin were extracted with acetone, centrifuged, concentrated via nitrogen blowdown and reconstituted with 1mL of 3:1 ultrapure water/HPLC-grade methanol solution. The extract was analyzed using ultra-high-performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS). The target compounds were detected with a maximum concentration reaching up to 462.5ngm -3 (fipronil). The hazard quotient (HQ) was less than 1 and the hazard index (HI) value was 3.86×10 -3 , indicating that the risk of pesticides related diseases was not significant. The lifetime cancer risk (LCR) for pymetrozine was at an acceptable level (LCR<10 -6 ) with 4.10×10 -8 . The results reported in this study can be beneficial in terms of risk management within the agricultural community. Copyright © 2017 Elsevier B.V. All rights reserved.

Sustainable Diagnostic Tools for Site Characterization and Remediation

NASA Astrophysics Data System (ADS)

Driver, E. M.; Roll, I. B.; Supowit, S. D.; Halden, R. U.

2016-12-01

Three submersible diagnostic tools were developed to enable more precise and cost-effective means of sampling environmental waters and assessing remedial strategies. The In Situ Sampler (IS2) and In Situ Sampler for Biphasic Water Monitoring (IS2B), designed for sampling groundwater or simultaneous pore- and surface water, use affordable off-the-shelf solid phase extraction technology, applicable to a broad range of organic and inorganic contaminants. Flow-through design reduces hazardous waste generation, transportation costs, and carbon footprint by 90-98% compared to traditional methods. The IS2 is ideal for dynamic groundwater systems where discrete sampling may fail to capture temporal variations, leading to inaccurate assessment of exposure and risk. A 28-day sampling event in a Cr(VI)-impacted aquifer captured previously undetected tidally-induced fluctuations, while improving the reporting limit 8-fold. The IS2B elucidates contaminant partitioning and bioavailability, and was validated in a wetland-shallow aquifer system with the pesticide fipronil. Concentrations of total fipronil-related compounds were statistically indistinguishable from those determined by conventional techniques (p > 0.2), ranging from 9.9 ± 4.6 to 18.1 ± 4.6 ng/L in surface water and 9.1 ± 3.0 to 12.6 ± 2.1 ng/L in porewater. For groundwater remedial testing, the In Situ Microcosm Array (ISMA) was developed to integrate laboratory column treatability studies with pilot-scale field-testing, thus minimizing costs associated with sequential lab and field analyses. In situ operation maintains (geo)chemical and microbial groundwater parameters often destroyed by extraction and laboratory storage. Onboard effluent capture permits the deployment well to return to monitoring status immediately after instrument removal. All tools employ reusable internal components and may be operated by solar power. Case study results highlight the capabilities and application range of the each technology.

The effect of temperature on the toxicity of insecticides against Musca domestica L.: implications for the effective management of diarrhea.

PubMed

Khan, Hafiz Azhar Ali; Akram, Waseem

2014-01-01

Diarrhea is an important cause of childhood mortality in developing countries like Pakistan because of unhygienic conditions, lack of awareness, and unwise use of preventive measures. Mechanical transmission of diarrheal pathogens by house flies, Musca domestica, is believed as the most effective route of diarrhea transmission. Although the use of insecticides as a preventive measure is common worldwide for the management of house flies, success of the measure could be compromised by the prevailing environmental temperature since it significantly affects toxicity of insecticides and thus their efficacy. Peaks of the house fly density and diarrheal cases are usually coincided and season specific, yet little is known about the season specific use of insecticides. To determine the temperature-toxicity relationship in house flies, the effect of post-bioassays temperature (range, 20-34°C) on the toxicity of seven insecticides from organophosphate (chlorpyrifos, profenofos), pyrethroid (cypermethrin, deltamethrin) and new chemical (emamectin benzoate, fipronil, spinosad) classes was evaluated by using a feeding bioassay method. From 20-34°C, the toxicities of chlorpyrifos, profenofos, emamectin and fipronil increased 2.10, 2.93, 2.40 and 3.82 fold (i.e. positive temperature coefficient), respectively. Whereas, the toxicities of cypermethrin, deltamethrin and spinosad decreased 2.21, 2.42 and 3.16 fold (i.e. negative temperature coefficient), respectively. These findings suggest that for the reduction in diarrheal cases, house flies should be controlled with insecticides according to the prevailing environmental temperature. Insecticides with a positive temperature coefficient may serve as potential candidates in controlling house flies and diarrhea epidemics in hot season and vice versa.

Development of polyurethane-based passive samplers for ambient monitoring of urban-use insecticides in water.

PubMed

Liao, Chunyang; Richards, Jaben; Taylor, Allison R; Gan, Jay

2017-12-01

Widespread use of insecticides for the control of urban pests such as ants, termites, and spiders has resulted in contamination and toxicity in urban aquatic ecosystems in different regions of the world. Passive samplers are a convenient and integrative tool for in situ monitoring of trace contaminants in surface water. However, the performance of a passive sampler depends closely on its affinity for the target analytes, making passive samplers highly specific to the types of contaminants being monitored. The goal of this study was to develop a passive sampler compatible with a wide range of insecticides, including the strongly hydrophobic pyrethroids and the weakly hydrophobic fipronil and organophosphates. Of six candidate polymeric thin films, polyurethane film (PU) was identified to be the best at enriching the test compounds. The inclusion of stable isotope labeled analogs as performance reference compounds (PRCs) further allowed the use of PU film for pyrethroids under non-equilibrium conditions. The PU sampler was tested in a large aquarium with circulatory water flow, and also deployed at multiple sites in surface streams in southern California. The concentrations of pesticides derived from the PU sampler ranged from 0.5 to 18.5 ng/L, which were generally lower than the total chemical concentration measured by grab samples, suggesting that suspended particles and dissolved organic matter in water rendered them less available. The influence of suspended particles and dissolved organic matter on bioavailability was more pronounced for pyrethroids than for fipronils. The results show that the developed PU film sampler, when coupled with PRCs, may be used for rapid and sensitive in-situ monitoring of a wide range of insecticides in surface water. Copyright © 2017 Elsevier Ltd. All rights reserved.

Preventive efficacy of a topical combination of fipronil--(S)-methoprene--eprinomectin--praziquantel against ear mite (Otodectes cynotis) infestation of cats through a natural infestation model.

PubMed

Beugnet, Frédéric; Bouhsira, Emilie; Halos, Lénaïg; Franc, Michel

2014-01-01

A study based on naturally infested cats was designed to evaluate the effectiveness of a single treatment with a topical formulation containing fipronil, (S)-methoprene, eprinomectin and praziquantel, for the prevention of Otodectes cynotis infestation in cats. Six treated cats and six untreated cats were housed with three chronically Otodectes cynotis-infested cats, respectively. The cats of each group were kept together in a 20-m(2) room for 1 month. Both clinical examination and ear mite counts were conducted on Day 28. All donor cats were confirmed to be chronically infested with Otodectes cynotis on Day -1 and Day 28. From untreated control cats, 129 live mites were recovered on Day 28 and all cats were found to be infested. In the treated group, three cats were found to be infested, with a total of five live mites recovered, the difference between the two groups being significant (p = 0.003). One treatment corresponded to 96% preventive efficacy at Day 28 based on ear mite counts. With regard to cerumen, the clinical score increased significantly for untreated cats between Day -1 and Day 28 (p = 0.00026) and not for treated cats (p = 0.30). The difference in cerumen abundance was significant between untreated and treated cats on Day 28 (p = 0.0035). Concerning the pruritic reflex in at least one ear, all cats were negative at inclusion. All six untreated cats became positive and showed a reflex on Day 28, whereas no treated cat showed ear pruritus (p = 0.00026). © F. Beugnet et al., published by EDP Sciences, 2014.

Efficacy of Broadline® spot-on against Aelurostrongylus abstrusus and Troglostrongylus brevior lungworms in naturally infected cats from Italy.

PubMed

Giannelli, Alessio; Brianti, Emanuele; Varcasia, Antonio; Colella, Vito; Tamponi, Claudia; Di Paola, Giancarlo; Knaus, Martin; Halos, Lénaïg; Beugnet, Frederic; Otranto, Domenico

2015-04-30

The increasing reports of Aelurostrongylus abstrusus infection and the new information on Troglostrongylus brevior have spurred the interest of the scientific community towards the research of pharmaceutical compounds effective against both pathogens. A novel topical combination of fipronil, (S)-methoprene, eprinomectin and praziquantel (Broadline®, Merial) has been released for the treatment of a variety of feline parasitic infections. The present study reports the efficacy of this spot-on in treating cats naturally infected by feline lungworms. Client owned cats (n=191) were enrolled from three geographical areas of Italy and faecal samples were examined by floatation and Baermann techniques. Twenty-three individuals were positive for L1 of A. abstrusus (n=18) or T. brevior (n=3) or for both species (n=2) and they were topically treated with Broadline®. Seventeen of them were also concomitantly infected by other parasites. Four weeks after treatment, faecal samples were collected and examined to assess the efficacy of a single administration of the product. Based on lungworm larvae counts, the efficacy of the treatment was 90.5% or 100% for A. abstrusus or T. brevior, respectively. Cats released significantly lower amounts of lungworm larvae after treatment compared to pre-treatment (p<0.0001). All but three cats were negative for other nematodes after treatment and all cats recovered from respiratory signs. Results of this study indicate that a single administration of the topical combination fipronil, (S)-methoprene, eprinomectin and praziquantel is effective and safe for the treatment of A. abstrusus and/or T. brevior infections in cats living under field conditions. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

Efficacy and safety of a novel oral isoxazoline, sarolaner (Simparica™) in the treatment of naturally occurring flea and tick infestations in dogs presented as veterinary patients in Europe.

PubMed

Becskei, Csilla; De Bock, Filip; Illambas, Joanna; Mahabir, Sean P; Farkas, Robert; Six, Robert H

2016-05-30

Two randomised, blinded, multi-centered field studies were conducted in Europe to demonstrate the efficacy and safety of three monthly oral doses of sarolaner (Simparica™, Zoetis) administered at a minimum dosage of 2.0mg/kg (range 2-4mg/kg) against natural flea or tick infestation of dogs presented as veterinary patients. In the flea study, the improvement in clinical signs associated with flea allergy dermatitis (FAD) was also investigated. The palatability of the sarolaner chewable tablet formulation was evaluated in both studies. Spinosad (Comfortis(®) Chewable Tablets, Elanco) and fipronil (Frontline(®) Spot on, Merial) were used as positive controls in the flea and tick study, respectively. Treatments were administered on Days 0, 30 and 60. Efficacy was calculated based on the mean percent reduction of live parasite counts on post-treatment days 14, 30, 60 and 90 versus the pre-treatment count on Day 0. Non-inferiority of sarolaner to the control products was assessed at each time-point using a margin of 15% at the one-sided 0.025 significance level. Dogs were enrolled in a 2:1 ratio (sarolaner:comparator); 285 flea- and 181 tick-infested dogs were assessed for efficacy and safety, and 137 and 48 dogs were assessed for safety only, in the flea and tick study, respectively. There were no treatment-related adverse events. Efficacy against fleas was 98.8%, 99.4%, >99.9% and >99.9% in the sarolaner-treated group and 98.9%, 93.7%, 96.8% and 95.1% in the spinosad-treated group on Days 14, 30, 60 and 90, respectively. Sarolaner was non-inferior to spinosad at all time-points and was superior on Day 30. For the 42 dogs identified as having FAD at enrolment, the clinical signs of FAD improved in all dogs and the incidence was markedly reduced by the end of the study. Efficacy against ticks was 97.4%, 97.6%, 99.8% and 100% in the sarolaner-treated group and 94.1%, 88.5%, 89.9% and 98.1% in the fipronil-treated group on Days 14, 30, 60 and 90, respectively. Sarolaner was non-inferior to fipronil at all time-points, and was superior on Days 30 and 60. Sarolaner tablets were voluntarily and fully consumed within one minute in 93% of the 1280 occasions offered. Sarolaner administered orally at monthly intervals at a minimum dosage of 2 mg/kg was safe and highly effective against natural infestations of fleas and ticks on dogs. In addition, clinical signs FAD improved in dogs treated with sarolaner, and the flavored, chewable tablets were highly palatable. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Assessing the occurrence and distribution of pyrethroids in water and suspended sediments

USGS Publications Warehouse

Hladik, M.L.; Kuivila, K.M.

2009-01-01

The distribution of pyrethroid insecticides in the environment was assessed by separately measuring concentrations in the dissolved and suspended sediment phases of surface water samples. Filtered water was extracted by HLB solid-phase extraction cartridges, while the sediment on the filter was sonicated and cleaned up using carbon and aluminum cartridges. Detection limits for the 13 pyrethroids analyzed by gas chromatography-tandem mass spectrometry were 0.5 to 1 ng L-1 for water and 2 to 6 ng g for the suspended sediments. Seven pyrethroids were detected in six water samples collected from either urban or agricultural creeks, with bifenthrin detected the most frequently and at the highest concentrations. In spiked water samples and field samples, the majority of the pyrethroids were associated with the suspended sediments.

First ecotoxicological assessment assay in a hydroelectric reservoir: the Lake Taabo (Côte d'Ivoire).

PubMed

Roche, Hélène; Tidou, Abiba

2009-03-01

Organochlorine pesticides (OCPs) contamination was assessed in marketable species, two fishes (tilapia and catfish) and a prawn from the Lake Taabo (Côte d'Ivoire). Lindane and endosulfan were the main contaminants, suggesting their current use. DDT, endrin, heptachlor plus traces of chlordane, aldrin and fipronil were also detected. In fishes and in prawns, enzymatic biomarkers exhibited significant correlations with OCPs levels, showing the feasibility of a biomonitoring. The transfer of OCPs along the aquatic food web and their immunosuppressive effects in human are discussed. This preliminary study highlights that the pesticide contamination was concomitant with the increase in infectious diseases in the bordering population of this African lake.

Synergistic action of octopamine receptor agonists on the activity of selected novel insecticides for control of dengue vector Aedes aegypti (Diptera: Culicidae) mosquito.

PubMed

Ahmed, Mohamed Ahmed Ibrahim; Vogel, Christoph Franz Adam

2015-05-01

Studying insecticide resistance in mosquitoes has attracted the attention of many scientists to elucidate the pathways of resistance development and to design novel strategies in order to prevent or minimize the spread and evolution of resistance. Here, we tested the synergistic action of piperonyl butoxide (PBO) and two octopamine receptor (OR) agonists, amitraz (AMZ) and chlordimeform (CDM) on selected novel insecticides to increase their lethal action on the fourth instar larvae of Aedes aegypti L. However, chlorfenapyr was the most toxic insecticide (LC50 = 193, 102, and 48 ng/ml, after 24, 48, and 72 h exposure, respectively) tested. Further, PBO synergized all insecticides and the most toxic combinatorial insecticide was nitenpyram even after 48 and 72 h exposure. In addition, OR agonists significantly synergized most of the selected insecticides especially after 48 and 72 h exposure. The results imply that the synergistic effects of amitraz are a promising approach in increasing the potency of certain insecticides in controlling the dengue vector Ae. aegypti mosquito. Copyright © 2015 Elsevier Inc. All rights reserved.

Pesticide and trace metal occurrence and aquatic benchmark exceedances in surface waters and sediments of urban wetlands and retention ponds in Melbourne, Australia.

PubMed

Allinson, Graeme; Zhang, Pei; Bui, AnhDuyen; Allinson, Mayumi; Rose, Gavin; Marshall, Stephen; Pettigrove, Vincent

2015-07-01

Samples of water and sediments were collected from 24 urban wetlands in Melbourne, Australia, in April 2010, and tested for more than 90 pesticides using a range of gas chromatographic (GC) and liquid chromatographic (LC) techniques, sample 'hormonal' activity using yeast-based recombinant receptor-reporter gene bioassays, and trace metals using spectroscopic techniques. At the time of sampling, there was almost no estrogenic activity in the water column. Twenty-three different pesticide residues were observed in one or more water samples from the 24 wetlands; chemicals observed at more than 40% of sites were simazine (100%), atrazine (79%), and metalaxyl and terbutryn (46%). Using the toxicity unit (TU) concept, less than 15% of the detected pesticides were considered to pose an individual, short-term risk to fish or zooplankton in the ponds and wetlands. However, one pesticide (fenvalerate) may have posed a possible short-term risk to fish (log10TUf > -3), and three pesticides (azoxystrobin, fenamiphos and fenvalerate) may have posed a risk to zooplankton (logTUzp between -2 and -3); all the photosystem II (PSII) inhibiting herbicides may have posed a risk to primary producers in the ponds and wetlands (log10TUap and/or log10TUalg > -3). The wetland sediments were contaminated with 16 different pesticides; no chemicals were observed at more than one third of sites, but based on frequency of detection and concentrations, bifenthrin (33%, maximum 59 μg/kg) is the priority insecticide of concern for the sediments studied. Five sites returned a TU greater than the possible effect threshold (i.e. log10TU > 1) as a result of bifenthrin contamination of their sediments. Most sediments did not exceed Australian sediment quality guideline levels for trace metals. However, more than half of the sites had threshold effect concentration quotients (TECQ) values >1 for Cu (58%), Pb (50%), Ni (67%) and Zn (63%), and 75% of sites had mean probable effect concentration quotients (PECQ) >0.2, suggesting that the collected sediments may have been having some impact on sediment-dwelling organisms.

In vitro dermal absorption of pyrethroid pesticides in human and rat skin

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hughes, Michael F., E-mail: hughes.michaelf@epa.go; Edwards, Brenda C.

2010-07-15

Dermal exposure to pyrethroid pesticides can occur during manufacture and application. This study examined the in vitro dermal absorption of pyrethroids using rat and human skin. Dermatomed skin from adult male Long Evans rats or human cadavers was mounted in flow-through diffusion cells, and radiolabeled bifenthrin, deltamethrin or cis-permethrin was applied in acetone to the skin. Fractions of receptor fluid were collected every 4 h. At 24 h, the skins were washed with soap and water to remove unabsorbed chemical. The skin was then solubilized. Two additional experiments were performed after washing the skin; the first was tape-stripping the skinmore » and the second was the collection of receptor fluid for an additional 24 h. Receptor fluid, skin washes, tape strips and skin were analyzed for radioactivity. For rat skin, the wash removed 53-71% of the dose and 26-43% remained in the skin. The cumulative percentage of the dose at 24 h in the receptor fluid ranged from 1 to 5%. For human skin, the wash removed 71-83% of the dose and 14-25% remained in the skin. The cumulative percentage of the dose at 24 h in the receptor fluid was 1-2%. Tape-stripping removed 50-56% and 79-95% of the dose in rat and human skin, respectively, after the wash. From 24-48 h, 1-3% and about 1% of the dose diffused into the receptor fluid of rat and human skin, respectively. The pyrethroids bifenthrin, deltamethrin and cis-permethrin penetrated rat and human skin following dermal application in vitro. However, a skin wash removed 50% or more of the dose from rat and human skin. Rat skin was more permeable to the pyrethroids than human skin. Of the dose in skin, 50% or more was removed by tape-stripping, suggesting that permeation of pyrethroids into viable tissue could be impeded. The percentage of the dose absorbed into the receptor fluid was considerably less than the dose in rat and human skin. Therefore, consideration of the skin type used and fractions analyzed are important when using in vitro dermal absorption data for risk assessment.« less

Structure-activity relationships for the action of 11 pyrethroid insecticides on rat Na{sub v}1.8 sodium channels expressed in Xenopus oocytes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Choi, J.-S.; Soderlund, David M.

2006-03-15

Pyrethroid insecticides bind to voltage-sensitive sodium channels and modify their gating kinetics, thereby disrupting nerve function. This paper describes the action of 11 structurally diverse commercial pyrethroid insecticides on the rat Na{sub v}1.8 sodium channel isoform, the principal carrier of the tetrodotoxin-resistant, pyrethroid-sensitive sodium current of sensory neurons, expressed in Xenopus laevis oocytes. All 11 compounds produced characteristic sodium tail currents following a depolarizing pulse that ranged from rapidly-decaying monoexponential currents (allethrin, cismethrin and permethrin) to persistent biexponential currents (cyfluthrin, cyhalothrin, cypermethrin and deltamethrin). Tail currents for the remaining compounds (bifenthrin, fenpropathrin, fenvalerate and tefluthrin) were monoexponential and decayed withmore » kinetics intermediate between these extremes. Reconstruction of currents carried solely by the pyrethroid-modified subpopulation of channels revealed two types of pyrethroid-modified currents. The first type, found with cismethrin, allethrin, permethrin and tefluthrin, activated relatively rapidly and inactivated partially during a 40-ms depolarization. The second type, found with cypermethrin, cyfluthrin, cyhalothrin, deltamethrin, fenpropathrin and fenvalerate, activated more slowly and did not detectably inactivate during a 40-ms depolarization. Only bifenthrin did not produce modified currents that fit clearly into either of these categories. In all cases, the rate of activation of modified channels was strongly correlated with the rate of tail current decay following repolarization. Modification of Na{sub v}1.8 sodium channels by cyfluthrin, cyhalothrin, cypermethrin and deltamethrin was enhanced 2.3- to 3.4-fold by repetitive stimulation; this effect appeared to result from the accumulation of persistently open channels rather than preferential binding to open channel states. Fenpropathrin was the most effective compound against Na{sub v}1.8 sodium channels from the perspective of either resting or use-dependent modification. When use dependence is taken into account, cypermethrin, deltamethrin and tefluthrin approached the effectiveness of fenpropathrin. The selective expression of Na{sub v}1.8 sodium channels in nociceptive neurons suggests that these channels may be important targets for pyrethroids in the production of paresthesia following dermal expo0010su.« less

Inflammatory and oxidative mechanisms potentiate bifenthrin-induced neurological alterations and anxiety-like behavior in adult rats.

PubMed

Gargouri, Brahim; Bhatia, Harsharan S; Bouchard, Michèle; Fiebich, Bernd L; Fetoui, Hamadi

2018-05-21

Bifenthrin (BF) is a synthetic pyrethroid pesticide widely used in several countries to manage insect pests on diverse agricultural crops. Growing evidence indicates that BF exposure is associated with an increased risk of developing neurodegenerative disorders. However, the mechanisms by which BF induces neurological and anxiety alterations in the frontal cortex and striatum are not well known. The present in vivo study was carried out to determine whether reactive oxygen species (ROS)-mediated oxidative stress (OS) and neuroinflammation are involved in such alterations. Thirty-six Wistar rats were thus randomly divided into three groups and were orally administered with BF (0.6 and 2.1 mg/kg body weight, respectively) or the vehicle (corn oil), on a daily basis for 60 days. Results revealed that BF exposure in rats enhanced anxiety-like behavior after 60 days of treatment, as assessed with the elevated plus-maze test by decreases in the percentage of time spent in open arms and frequency of entries into these arms. BF-treated rats also exhibited increased oxidation of lipids and carbonylated proteins in the frontal cortex and striatum, and decreased glutathione levels and antioxidant enzyme activities including superoxide dismutase, catalase and glutathione peroxidase. Treatment with BF also increased protein synthesis and mRNA expression of the inflammatory mediators cyclooxygenase-2 (COX-2), microsomal prostaglandin synthase-1 (mPGES-1) and nuclear factor-kappaBp65 (NF-kBp65), as well as the production of tumor necrosis factor-α (TNF-α) and ROS. Moreover, BF exposure significantly decreased protein synthesis and mRNA expression of nuclear factor erythroid-2 (Nrf2) and acetylcholinesterase (AChE), as well as gene expression of muscarinic-cholinergic receptors (mAchR) and choline acetyltransferase (ChAT) in the frontal cortex and striatum. These data suggest that BF induced neurological alterations in the frontal cortex and striatum of rats, and that this may be associated with neuroinflammation and oxidative stress via the activation of Nrf2/NF-kBp65 pathways, which might promote anxiety-like behavior. Copyright © 2018 Elsevier B.V. All rights reserved.

Meroterpenoid Chrodrimanins Are Selective and Potent Blockers of Insect GABA-Gated Chloride Channels

PubMed Central

Ihara, Makoto; Ling, Yun; Yang, Xinling; Kai, Kenji; Hayashi, Hideo; Matsuda, Kazuhiko

2015-01-01

Meroterpenoid chrodrimanins, produced from Talaromyces sp. YO-2, are known to paralyze silkworm (Bombyx mori) larvae, but their target is unknown. We have investigated the actions of chrodrimanin B on ligand-gated ion channels of silkworm larval neurons using patch-clamp electrophysiology. Chrodrimanin B had no effect on membrane currents when tested alone at 1 μM. However, it completely blocked the γ-aminobutyric acid (GABA)-induced current and showed less pronounced actions on acetylcholine- and L-glutamate-induced currents, when delivered at 1 μM for 1 min prior to co-application with transmitter GABA. Thus, chrodrimanins were also tested on a wild-type isoform of the B. mori GABA receptor (GABAR) RDL using two-electrode voltage-clamp electrophysiology. Chrodrimanin B attenuated the peak current amplitude of the GABA response of RDL with an IC50 of 1.66 nM. The order of the GABAR-blocking potency of chrodrimanins B > D > A was in accordance with their reported insecticidal potency. Chrodrimanin B had no open channel blocking action when tested at 3 nM on the GABA response of RDL. Co-application with 3 nM chrodrimanin B shifted the GABA concentration response curve to a higher concentration and further increase of chrodrimanin B concentration to10 nM; it reduced maximum current amplitude of the GABA response, pointing to a high-affinity competitive action and a lower affinity non-competitive action. The A282S;T286V double mutation of RDL, which impairs the actions of fipronil, hardly affected the blocking action of chrodrimanin B, indicating a binding site of chrodrimanin B distinct from that of fipronil. Chrodrimanin B showed approximately 1,000-fold lower blocking action on human α1β2γ2 GABAR compared to RDL and thus is a selective blocker of insect GABARs. PMID:25902139

Pyrethroid resistance and cross-resistance in the German cockroach, Blattella germanica (L).

PubMed

Wei, Y; Appel, A G; Moar, W J; Liu, N

2001-11-01

A German cockroach (Blatella germanica (L)) strain, Apyr-R, was collected from Opelika, Alabama after control failures with pyrethroid insecticides. Levels of resistance to permethrin and deltamethrin in Apyr-R (97- and 480-fold, respectively, compared with a susceptible strain, ACY) were partially or mostly suppressed by piperonyl butoxide (PBO) and S,S,S,-tributylphosphorotrithioate (DEF), suggesting that P450 monooxygenases and hydrolases are involved in resistance to these two pyrethroids in Apyr-R. However, incomplete suppression of pyrethroid resistance with PBO and DEF implies that one or more additional mechanisms are involved in resistance. Injection, compared with topical application, resulted in 43- and 48-fold increases in toxicity of permethrin in ACY and Apyr-R, respectively. Similarly, injection increased the toxicity of deltamethrin 27-fold in ACY and 28-fold in Apyr-R. These data indicate that cuticular penetration is one of the obstacles for the effectiveness of pyrethroids against German cockroaches. However, injection did not change the levels of resistance to either permethrin or deltamethrin, suggesting that a decrease in the rate of cuticular penetration may not play an important role in pyrethroid resistance in Apyr-R. Apyr-R showed cross-resistance to imidacloprid, with a resistance ratio of 10. PBO treatment resulted in no significant change in the toxicity of imidacloprid, implying that P450 monooxygenase-mediated detoxication is not the mechanism responsible for cross-resistance. Apyr-R showed no cross-resistance to spinosad, although spinosad had relatively low toxicity to German cockroaches compared with other insecticides tested in this study. This result further confirmed that the mode of action of spinosad to insects is unique. Fipronil, a relatively new insecticide, was highly toxic to German cockroaches, and the multi-resistance mechanisms in Apyr-R did not confer significant cross-resistance to this compound. Thus, we propose that fipronil could be a valuable tool in integrated resistance management of German cockroaches.

Removal of six pesticide residues in cowpea with alkaline electrolysed water.

PubMed

Han, Yongtao; Song, Le; An, Quanshun; Pan, Canping

2017-06-01

Reduction of six pesticide residues (isoprocarb, chlorpyrifos, bifenthrin, beta-cypermethrin, difenoconazole and azoxystrobin) in cowpea by alkaline electrolysed water (AlEW) solutions with different pH was investigated. The commonly used washing treatments in household processing were used for comparison. The residue magnitudes were determined by gas chromatography coupled with tandem mass spectrometry (GC-MS/MS). Results showed that the removal effect of AlEW solution on the six pesticides was superior to tap water, 5% sodium chloride, 5% sodium carbonate and 5% acetic acid solution. AlEW with pH 12.2 had more potential to eliminate the six pesticides in cowpeas. Moreover, the reduction of pesticide residues gradually increased with the increase of washing time. This study demonstrated that AlEW solution with pH of 12.2 could be used to reduce pesticide residues on fresh cowpea samples. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Determination of Pyrethroids through Liquid-Liquid Extraction and GC-ECD

NASA Astrophysics Data System (ADS)

Ding, B.

2010-12-01

Storm water samples from various locations in San Diego Creek and Newport Bay watershed, southern California, were taken to study the occurrence and fate of pyrethroids. This study focused on four commonly used pyrethroids: bifenthrin, cypermethrin, permethrin, and fenpropathrin. Since the ban of DDT, usage of pyrethroids became an effective second choice. However, pyrethroids are extremely toxic to fish and aquatic organisms. They can pass through secondary wastewater treatment system, causing the final effluent to be in lethal doses to aquatic invertebrates and some insects such as mayflies. Hence, it is necessary to monitor the amount of pyrethroid concentration in storm water. As a part of this study, I attended the RISE internship program at Stanford University in this summer. In the seven weeks, I learned liquid-liquid extraction, water-bath evaporation, nitrogen evaporation, and gas chromatography-electron capture detector techniques to extract and detect the pyrethroid residues in the water sample.

Determination of Pesticide Residues in Cannabis Smoke

PubMed Central

Sullivan, Nicholas; Elzinga, Sytze; Raber, Jeffrey C.

2013-01-01

The present study was conducted in order to quantify to what extent cannabis consumers may be exposed to pesticide and other chemical residues through inhaled mainstream cannabis smoke. Three different smoking devices were evaluated in order to provide a generalized data set representative of pesticide exposures possible for medical cannabis users. Three different pesticides, bifenthrin, diazinon, and permethrin, along with the plant growth regulator paclobutrazol, which are readily available to cultivators in commercial products, were investigated in the experiment. Smoke generated from the smoking devices was condensed in tandem chilled gas traps and analyzed with gas chromatography-mass spectrometry (GC-MS). Recoveries of residues were as high as 69.5% depending on the device used and the component investigated, suggesting that the potential of pesticide and chemical residue exposures to cannabis users is substantial and may pose a significant toxicological threat in the absence of adequate regulatory frameworks. PMID:23737769

Pesticides residues and metals in plant products from agricultural area of Belgrade, Serbia.

PubMed

Ethorđević, Tijana; Ethurović, Rada

2012-03-01

The objective of study was to assess the levels of selected metals and pesticides in plant products from agricultural area of Belgrade, Serbia in order to indicate their possible sources and risks of contamination and to evaluate their sanitary probity and safety. The concentrations of cadmium, copper, iron, manganese, nickel, lead and zinc were below limits established by national and international regulations (maximum found concentrations were 0.028, 1.91, 11.16, 1.77, 0.605, 0.073 and 1.76 mg kg(-1) respectively). Only residue of one of examined pesticides was found in amount below MRL (bifenthrin 2.46 μg kg(-1)) in only one of analysed samples, while others were below detection limits. Obtained results indicate that crops from examined agricultural areas are unpolluted by contaminants used for plant protection and nutrition, indicating good agricultural practice regarding pesticides and fertilizer usage as well as moderate industrial production within examined areas.

Toxicity and residual effects of insecticides on Ascia monuste and predator Solenopsis saevissima.

PubMed

Araújo, Tamíris A de; Picanço, Marcelo C; Ferreira, Dalton de O; Campos, Júlia Nd; Arcanjo, Lucas de P; Silva, Gerson A

2017-11-01

Investigating the impact of pesticides on non-target organisms is essential for sustainable integrated pest management programs. We therefore assessed the toxicity of ten insecticides to the brassica caterpillar Ascia monuste and its ant predator Solenopsis saevissima and examined the effect that the insecticide synergists had on toxicity to the predator. We also assessed the residual period of control and impact of the insecticides during the brassica growing cycle. All insecticides except flubendiamide exhibited mortality above the threshold required by Brazilian legislation (80%). Chlorantraniliprole, cyantraniliprole, indoxacarb and spinosad exhibited lower toxicity to the ant predator than they did to the brassica caterpillar. The results obtained for synergized insecticides suggest that selectivity to the predator was due the involvement of cytochrome P450-dependent monooxygenases. Chlorfenapyr and cyantraniliprole exhibited the highest residual periods of control to the brassica caterpillar, whereas malathion had the greatest impact on the predator. Most of the insecticides efficiently controlled the brassica caterpillar, but not all exhibited selectivity to the predator. Therefore, due to the distinctive responses of organisms with respect to residual periods of control and the impact of the insecticides, spraying frequency must be strongly considered in integrated pest management programs. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Water-quality, sediment-quality, stream-habitat, and biological data for Mustang Bayou near Houston, Texas, 2004-05

USGS Publications Warehouse

Sneck-Fahrer, Debra A.; East, Jeffery W.

2007-01-01

The U.S. Geological Survey, in cooperation with the Houston-Galveston Area Council and the Texas Commission on Environmental Quality, collected water-quality, stream-habitat, and biological data from six sites (downstream order M6-M1) primarily in Brazoria County southeast of Houston, Texas, during September 2004-August 2005 and collected bed sediment data from one site in September 2005. Water-quality data collection consisted of continuously monitored (for periods of 24 hours to several days, six times) water temperature, pH, specific conductance, and dissolved oxygen and periodically collected samples of several properties and constituents. Monitored dissolved oxygen measurements were below minimum and 24-hour criteria at all sites except M2. Nitrogen compounds, phosphorus, biochemical oxygen demand, chlorophyll-a, E. coli, chloride, sulfate, solids, suspended sediment concentration, and pesticides were assessed at all sites. Concentrations of nitrogen compounds and phosphorus did not exceed Texas State screening levels. Biochemical oxygen demand was less than 4.0 milligrams per liter at all sites except M6, where the maximum concentration was 8.1 milligrams per liter. Concentrations of chlorophyll-a were less than the State screening level at all sites except M6, where four of eight samples equaled or exceeded the screening level. Twenty of 48 samples from Mustang Bayou had E. coli densities that exceeded the State single-sample water-quality standard. Median chloride concentrations from each site were between 42.2 and 123 milligrams per liter. Fifteen pesticide compounds (six herbicides and nine insecticides) were detected in 24 water samples. The most frequently detected pesticide was atrazine, which was found in every sample. Other frequently detected pesticides were 2-chloro-4-isopropylamino-6-amino-s-triazine (CIAT), prometon, tebuthiuron, fipronil, and the pesticide degradates, fipronil sulfide and fipronil sulfone. Sediment samples were collected from the stream bottom at M1 and analyzed for concentrations of trace elements (metals), polycyclic aromatic hydrocarbons, organochlorine pesticides, and polychlorinated biphenyls. No organochlorine pesticides or polychlorinated biphenyls were detected. No concentrations of metals exceeded State screening levels. Measurable concentrations of 11 polycyclic aromatic hydrocarbon (PAH) compounds were detected, and three other PAH compounds were detected but not quantified by the laboratory. Stream habitat and aquatic biota (benthic macroinvertebrates and fish) were surveyed at each site three times during the study to evaluate aquatic life use. Characteristics of habitat measured during each survey were scored using a habitat quality index. Average aquatic-life-use scores were 'limited' for M3-M6 and 'intermediate' for M1 and M2. A total of 2,557 macroinvertebrate individuals were identified from Mustang Bayou. Benthic macroinvertebrate assemblages were scored using indexes specified by the Texas Commission on Environmental Quality. Average aquatic-life-use scores were 'limited' at M1, 'intermediate' at M3-M6, and 'high' at M2. Forty-six species of fish representing 20 families were collected from Mustang Bayou. A total of 4,115 fish were collected. Sunfish (Centrarchidae) was the most abundant family, accounting for about 28 percent. Aquatic-life-use scores at sites in Mustang Bayou were determined using the regional index of biotic integrity for ecoregion 34 and were 'high' for all sites.

A method to induce stable atopic dermatitis-like symptoms in NC/Nga mice housed with skin-lesioned mice.

PubMed

Takano, N; Arai, I; Kurachi, M

2006-03-01

Itching is a characteristic symptom in various forms of dermatosis, especially atopic dermatitis; consequently it is a major diagnostic criterion. All features are similar to events seen in patients, hence NC/Nga mice are considered to be a suitable model of human atopic dermatitis. However, there were data spreads in commencing time and the degree of skin lesions in NC/Nga mice. In the present study, we attempted to improve experimental conditions to induce stable skin lesions and to establish a more appropriate method. Methods NC/Nga mice were kept together with skin-lesioned mice during the experiment period (mixed-NC mice). The dermatitis scores of face, ears and rostral back were assessed. Scratching behaviour was measured using an apparatus, MicroAct (Neuroscience, Tokyo, Japan). Transepidermal water loss (TEWL) and serum total IgE levels were also measured. To observe the presence of mites, the skin of the rostral backs of the mixed-NC mice was stripped using cellulose tape. We also investigated the effects of fipronil (Wako, Osaka, Japan), an acaricidal compound, on skin lesions and scratching behaviour of these mixed-NC mice. In mixed-NC mice, skin lesions appeared from 2 weeks, worsened gradually and reached peak levels of a dermatitis score in 8 weeks. Scratching behaviour increased significantly from day 3. TEWL also increased from day 3, but total IgE increased from day 7. Mites were observed on the rostral backs of mixed-NC mice from day 3, and all mice had these mites on day 28. Giving pretreatment with fipronil (Wako), the skin lesions and scratching behaviour of mixed-NC mice was significantly suppressed. The findings of the present study suggest that the method of being kept together with skin-lesioned mice can induce stable skin lesions and scratching behaviour at an early stage, without skin lesions. This method could help investigate a more stable evaluation of the effects on symptoms of atopic dermatitis, and mechanisms of the itching. It was considered that parasitism of mites, not allergic reactions, was the pathogenesis of skin lesions and scratching behaviour in mixed-NC mice.

Insecticidal, repellent and fungicidal properties of novel trifluoromethylphenyl amides.

PubMed

Tsikolia, Maia; Bernier, Ulrich R; Coy, Monique R; Chalaire, Katelyn C; Becnel, James J; Agramonte, Natasha M; Tabanca, Nurhayat; Wedge, David E; Clark, Gary G; Linthicum, Kenneth J; Swale, Daniel R; Bloomquist, Jeffrey R

2013-09-01

Twenty trifluoromethylphenyl amides were synthesized and evaluated as fungicides and as mosquito toxicants and repellents. Against Aedes aegypti larvae, N-(2,6-dichloro-4-(trifluoromethyl)phenyl)-3,5-dinitrobenzamide (1e) was the most toxic compound (24 h LC50 1940 nM), while against adults N-(2,6-dichloro-4-(trifluoromethyl)phenyl)-2,2,2-trifluoroacetamide (1c) was most active (24 h LD50 19.182 nM, 0.5 μL/insect). However, the 24 h LC50 and LD50 values of fipronil against Ae. aegypti larvae and adults were significantly lower: 13.55 nM and 0.787 × 10(-4) nM, respectively. Compound 1c was also active against Drosophila melanogaster adults with 24 h LC50 values of 5.6 and 4.9 μg/cm(2) for the Oregon-R and 1675 strains, respectively. Fipronil had LC50 values of 0.004 and 0.017 μg/cm(2) against the two strains of D. melanogaster, respectively. In repellency bioassays against female Ae. aegypti, 2,2,2-trifluoro-N-(2-(trifluoromethyl)phenyl)acetamide (4c) had the highest repellent potency with a minimum effective dosage (MED) of 0.039 μmol/cm(2) compared to DEET (MED of 0.091 μmol/cm(2)). Compound N-(2-(trifluoromethyl)phenyl)hexanamide (4a) had an MED of 0.091 μmol/cm(2) which was comparable to DEET. Compound 4c was the most potent fungicide against Phomopsis obscurans. Several trends were discerned between the structural configuration of these molecules and the effect of structural changes on toxicity and repellency. Para- or meta- trifluoromethylphenyl amides with an aromatic ring attached to the carbonyl carbon showed higher toxicity against Ae. aegypti larvae, than ortho- trifluoromethylphenyl amides. Ortho- trifluoromethylphenyl amides with trifluoromethyl or alkyl group attached to the carbonyl carbon produced higher repellent activity against female Ae. aegypti and Anopheles albimanus than meta- or para- trifluoromethylphenyl amides. The presence of 2,6-dichloro- substitution on the phenyl ring of the amide had an influence on larvicidal and repellent activity of para- trifluoromethylphenyl amides. Copyright © 2013 The Authors. Published by Elsevier Inc. All rights reserved.

Light Induced Degradation of Eight Commonly Used Pesticides Adsorbed on Atmospheric Particles: Kinetics and Product Study

NASA Astrophysics Data System (ADS)

Socorro, J.; Durand, A.; Gligorovski, S.; Wortham, H.; Quivet, E.

2014-12-01

Pesticides are widely used all over the world whether in agricultural production or in non-agricultural settings. They may pose a potential human health effects and environmental risks due to their physico-chemical properties and their extensive use which is growing every year. Pesticides are found in the atmosphere removed from the target area by volatilization or wind erosion, and carried over long distances. These compounds are partitioned between the gaseous and particulate atmospheric phases. The increasingly used pesticides are semi-volatile compounds which are usually adsorbed on the surface of the atmospheric particles. These pesticides may undergo chemical and photo-chemical transformation. New compounds may then be formed that could be more hazardous than the primary pesticides. The atmospheric fate and lifetime of adsorbed pesticides on particles are controlled by the these (photo)chemical processes. However, there is a lack of kinetic data regarding the pesticides in the particle phase. This current work focuses on the photolytic degradation of commonly used pesticides in particulate phase. It aims at estimating the photolytic rates and thus the lifetimes of pesticides adsorbed on silica particles as a proxy of atmospheric particles. The following eight commonly used pesticides, cyprodinil, deltamethrin, difenoconazole, fipronil, oxadiazon, pendimethalin, permethrin, tetraconazole, were chosen because of their physico-chemical properties. The photolysis rates of tetraconazole and permethrin were extremely slow ≤ 1.2 · 10-6 s-1. The photolysis rates for the other pesticides were determined in the range of: (5.9 ± 0.3) · 10-6 < k < (1.7 ± 0.1) · 10-4 s-1 from slowest to the fastest: pendimethalin < cyprodinil < deltamethrin < difenoconazole < oxadiazon < fipronil. Finally, the identification of the surface products upon light irradiation was performed, using GC-(QqQ)-MS/MS and LC-(Q-IMS-ToF)-MS/MS. The potentially formed gas-phase products during these photolysis processes were followed continuously and on-line by PTR-ToF-MS. We hope that the obtained results from this study will help in the development of future environmental strategies to better understand and control phyto-sanitary product application and human exposure.

Vitamin C attenuates biochemical and genotoxic damage in common carp (Cyprinus carpio) upon joint exposure to combined toxic doses of fipronil and buprofezin insecticides.

PubMed

Ghazanfar, Madiha; Shahid, Sana; Qureshi, Irfan Zia

2018-03-01

In the present study, potential protective role of Vitamin C (l-ascorbic acid) was investigated in aquaria acclimated common carp (Cyprinus carpio) following exposure for 96 h to combined toxic doses of fipronil (FP) and buprofezin (BPFN) insecticides in combination (FP: 200 μg/L; 4.57 × 10 -7  mol/L and BPFN: 50 mg/L; 1.64 × 10 -4  mol/L). At end of 96 h exposure, fish were supplemented with low (25 mg/L) and high (50 mg/L) doses of Vitamin C, added once daily to aquaria water for continuous three weeks. Appropriate control groups were run in parallel. Fish behavior was monitored throughout for signs of toxicity. At completion of experiments, liver, kidney, brain and gills were excised for toxicity assessment and possible remediation by the Vitamin C through biochemical determination of reactive oxygen species (ROS), thiobarbituric acid reactive substances or TBARS, reduced glutathione (GSH) and total protein content, levels of catalase (CAT), superoxide dismutase (SOD) and peroxidase (POD), and the Comet assay. Hepatosomatic index (HSI), condition factor (CF), survival rate (SR), and combination index (CI) were also determined. Data were compared statistically at p < 0.05. Results showed significant behavioral and biochemical alterations, and DNA damage in the fish group exposed to FP and BPFN in combination. In fish groups supplemented with Vitamin C following FP and BPFN treatment, significant alleviation in tissue damage and toxic effects was represented by substantial decreases in ROS and TBARS production (p < 0.001), along with a concomitant significant increase in the survival rate, GSH and total protein content, HSI, CF, and activities of SOD, CAT and POD enzymes (p < 0.001). Mean tail length of comet and percent tail DNA decreased significantly (p < 0.001), which indicated amelioration of DNA damage. The study concludes that Vitamin C is an effective remedial treatment against FP and BPFN-induced damage in exposed fish. Copyright © 2018 Elsevier B.V. All rights reserved.

Cross-resistance and biochemical mechanisms of resistance to indoxacarb in the diamondback moth, Plutella xylostella.

PubMed

Zhang, Shuzhen; Zhang, Xiaolei; Shen, Jun; Li, Dongyang; Wan, Hu; You, Hong; Li, Jianhong

2017-08-01

Indoxacarb belongs to a class of insecticides known as oxadiazines and is the first commercialized pyrazoline-type voltage-dependent sodium channel blocker. A moderate level of resistance to indoxacarb has evolved in field populations of Plutella xylostella from Central China. In the present study, cross-resistance, resistance stability and metabolic mechanisms of indoxacarb resistance were investigated in this moth species. A P. xylostella strain with a high level of resistance to indoxacarb was obtained through continuous selection in the laboratory. The strain showed cross-resistance to metaflumizone, beta-cypermethrin and chlorfenapyr, but no resistance to cyantraniliprole, chlorantraniliprole, abamectin, chlorfluazuron, spinosad and diafenthiuron compared with the susceptible strain. Synergism tests revealed that piperonyl butoxide (PBO) (synergistic ratio, SR=7.8) and diethyl maleate (DEF) (SR=3.5) had considerable synergistic effects on indoxacarb toxicity in the resistant strain (F 58 ). Enzyme activity data showed there was an approximate 5.8-fold different in glutathione S-transferase (GST) and a 6.8-fold different in cytochrome P450 monooxygenase between the resistant strain (F 58 ) and susceptible strain, suggesting that the increased activity of these two enzymes is likely the main detoxification mechanism responsible for the species' resistance to indoxacarb. These results will be helpful for insecticide resistance management strategies to delay the development of indoxacarb resistance in fields. Copyright © 2017. Published by Elsevier Inc.

Residual mosquito barrier treatments on U.S. military camouflage netting in a southern California desert environment.

PubMed

Britch, Seth C; Linthicum, Kenneth J; Wynn, Wayne W; Walker, Todd W; Farooq, Muhammad; Smith, Vincent L; Robinson, Cathy A; Lothrop, Branka B; Snelling, Melissa; Gutierrez, Arturo; Lothrop, Hugh D

2010-08-01

Treating perimeters of vegetation with residual insecticides for protection from mosquito vectors has potential for U.S. military force health protection. However, for current U.S. military operations in hot-arid environments with little or no vegetation, residual applications on portable artificial materials may be a viable alternative. We evaluated bifenthrin residual treatments of U.S. military camouflage netting under hot-arid field conditions in a desert area in southern California exposed to abundant wild Culex tarsalis mosquitoes. We assessed the ability of the treatment to reduce the numbers of mosquitoes penetrating perimeters of netting and reaching CO2-baited mosquito traps. Treated camouflage netting barriers reduced mosquitoes by > or = 50% for 7-14 days and by 20-35% for 21-28 days compared to untreated barriers. Although reductions may be translated into reductions in risk of exposure to mosquito-borne diseases, we emphasize that barrier treatments should be a component in a suite of insect control measures to be effective.

Evaluation of an analytical methodology using QuEChERS and GC-SQ/MS for the investigation of the level of pesticide residues in Brazilian melons.

PubMed

da Silva Sousa, Jonas; de Castro, Rubens Carius; de Albuquerque Andrade, Gilliane; Lima, Cleidiane Gomes; Lima, Lucélia Kátia; Milhome, Maria Aparecida Liberato; do Nascimento, Ronaldo Ferreira

2013-12-01

A multiresidue method based on the sample preparation by modified QuEChERS and detection by gas chromatography coupled to single quadruple mass spectrometers (GC-SQ/MS) was used for the analysis of 35 multiclass pesticides in melons (Cucumis melo inodorus) produced in Ceara-Brazil. The rates of recovery for pesticides studied were satisfactory (except for the etridiazole), ranging from 85% to 117% with a relative standard deviation (RSD) of less than 15%, at concentrations between 0.05 and 0.20 mg kg(-1). The limit of quantification (LOQ) for most compounds was below the MRLs established in Brazil. The combined relative uncertainty (Uc) and expanded uncertainty (Ue) was determined using repeatability, recovery and calibration curves data for each pesticide. Analysis of commercial melons samples revealed the presence of pesticides bifenthrin and imazalil at levels below the MRLs established by ANVISA, EU and USEPA. Copyright © 2013 Elsevier Ltd. All rights reserved.

Preventive efficacy of Frontline® Combo and Certifect® against Dipylidium caninum infestation of cats and dogs using a natural flea (Ctenocephalides felis) infestation model

PubMed Central

Beugnet, Frederic; Delport, Peet; Luus, Hermann; Crafford, Dione; Fourie, Josephus

2013-01-01

Two studies were performed to evaluate the effectiveness of two monthly topical anti-flea products for the prevention of Dipylidium caninum infestations in cats and dogs. A single treatment with Frontline® Combo spot-on for cats (fipronil-(S)-methoprene) and two successive monthly treatments of Certifect® for dogs (fipronil-amitraz-(S)-methoprene) were assessed for the prevention of D. caninum infestations following weekly challenges of treated cats or dogs with metacestode naturally-infected fleas. The rate of infestations using the model in cats versus dogs explains the choice of a 1-month trial in cats and a 2-month trial in dogs. The experimental flea-infection model resulted in a range of 22–53% of the fleas being infected by Dipylidium cysticercoids. The arithmetic mean flea counts recorded for the untreated cats ranged from 51.2 to 68. The geometric mean flea counts recorded for the Frontline Combo treated cats differed significantly (p < 0.05) from those of the untreated control cats on all assessment days. The arithmetic mean flea counts recorded for the untreated dogs ranged from 166.6 to 238.6. The geometric mean flea counts recorded for the Certifect treated dogs differed significantly (p < 0.001) from those of the untreated group on all assessment days. Frontline Combo treatment on cats provided ≥99.8% persistent anti-flea efficacy throughout the 30-day treatment period. In the dog study, the two Certifect treatments provided ≥97% persistent efficacy throughout the 60-day study. Based on the collection of expelled D. caninum proglottids by cats, 100% (6/6) of the control cats and 0% (0/6) of Frontline Combo treated cats were infested with D. caninum. Frontline Combo spot-on for cats was therefore 100% effective in preventing infection with D. caninum. In dogs, 7 out of the 8 control group dogs (87.5%) produced proglottids following infestation of infected fleas, whereas 0 out of 8 dogs (0%) in the treated group were infected. The infection rates of the two groups were significantly different. The percent effectiveness for the Certifect treatment group for the prevention of D. caninum infection was 100% during this 2-month trial. No treatment-related adverse events were observed in either cats or dogs during these studies. PMID:23419268

Environmental setting, water quality, and ecological indicators of surface-water quality in the Mermentau River Basin, southwestern Louisiana, 1998-2001

USGS Publications Warehouse

Skrobialowski, Stanley C.; Mize, Scott V.; Demcheck, Dennis K.

2004-01-01

The U.S. Geological Survey collected data from 29 wells and 24 surface-water sites in the Mermentau River Basin, 1998-2001, to better understand ground-water and surface-water quality; aquatic invertebrate communities; and habitat conditions, in relation to land use. This study was apart of the National Water-Quality Assessment Program, which was designed to assess water quality as it relates to various land uses. Water-quality data were evaluated with criteria established for the protection of drinking water and aquatic life, and bed-sediment data were compared to aquatic life criteria. Water-quality and ecological data were analyzed statistically in relation to drainage area and agricultural land-use integrity. Concentrations of nutrients and major inorganic ions in ground water and surface water generally were highest in the southeastern part of the study area where soils contain thick loess deposits. Peak concentrations of nutrients in surface water occurred March-may at two sites with high agricultural intensity; the lowest concentrations occurred August-January. The greatest potential for eutrophic conditions in surface water, based on nutrient concentrations, existed March-May, at about the same time or shortly after ricefields were drained. Secondary Maximum Contaminant Levels established by the U.S. Environmental Protection Agency (USEPA) were exceeded for sulfate, chloride, iron, or manganese in samples from 20 wells, and for iron or manganese in samples from all surface-water sites. Fewer pesticides were detected in ground water than in surface water. In 11 of of the 29 wells sampled, at least one pesticide or pesticide degradation product was detected. The most frequently detected pesticides or pesticide degradation products in ground water were the herbicides benzaton and atrazine. Concentrations of 47 pesticides and degradation products were detected in surface water. At least 3 pesticides were detected in all surface-water samples. In 72 percent of the samples at least 5 hydrophilic pesticides were detected, and in more than 70 percent of the samples at least 3 hydrophobic pesticides were detected. Although atrazine concentrations in three samples collected in the spring exceeded 3 micrograms per liter, the USEPA Maximum Contaminant Level of 3 micrograms per liter was not exceeded because it is based on an annual average of quarterly samples. Concentrations larger than 3.0 micrograms per liter were not detected in samples collected during other times of the year. Tebuthiuron was detected at all surface-water sites; the largest concentration (6.33 micrograms per liter) was detected at a site on Bayou des Cannes, and was the only detection that exceeded the criterion (1.6 micrograms per liter) for the protection of aquatic life. Malathion was detected at 16 surface-water sites; the largest concentration (0.113 micrograms per liter) was detected at a site on Bayou Lacassine and was the only detection that exceeded the criterion (0.1 micrograms per liter) for the protection of aquatic life. Concentrations of fipronil exceeded numeric targets for acute total maximum daily loads (2.3 micrograms per liter) at 3 sites and chronic total maximum daily loads (4.6 micrograms per liter) at 14 sites. Maximum pesticide concentrations in surface water usually occurred in the spring at about the same time or shortly after ricefields were drained. Concentrations of DDE in bed sediment at two sites exceeded interim freshwater sediment quality guidelines for the protection of aquatic life. Fipronil sulfide and desulfinylpronil were detected at all 17 sites from which bed-sediment samples were collected, but there are no current (2002) guidelines with which to evaluate the environmental effects of fipronil and degradation products. Two methods were used to group the ecological data-collection sites: (1) Sites were grouped before data collection (according to the study design) using drainage area

[Resistance mechanisms and cross-resistance of phoxim-resistant Frankliniella occidentalis Pergande population].

PubMed

Wang, Sheng-Yin; Zhou, Xian-Hong; Zhang, An-Sheng; Li, Li-Li; Men, Xing-Yuan; Zhang, Si-Cong; Liu, Yong-Jie; Yu, Yi

2012-07-01

To understand the resistance risks of Frankliniella occidentalis Pergande against phoxim, this paper studied the resistance mechanisms of phoxim-resistant F. occidentalis population against phoxim and the cross-resistance of the population against other insecticides. The phoxim-resistant population had medium level cross-resistance to chlorpyrifos, lambda-cyhalothrin, and methomyl, low level cross-resistance to chlorfenapyr, imidacloprid, emamectin-benzoate, and spinosad, but no cross-resistance to acetamiprid and abamectin. The synergists piperonyl butoxide (PBO), s, s, s-tributyl phosphorotrithioate (DEF), and triphenyl phosphate (TPP) had significant synergism (P < 0.05) on the toxicity of phoxim to the resistant (XK), field (BJ), and susceptible (S) populations, while diethyl maleate (DEM) had no significant synergism to XK and S populations but had significant synergism to BJ population. As compared with S population, the XK and BJ populations had significantly increased activities of mixed-functional oxidases P450 (2.79-fold and 1.48-fold), b, (2.88-fold and 1.88-fold), O-demethylase (2.60-fold and 1.68-fold), and carboxylesterase (2.02-fold and 1.61-fold, respectively), and XK population had a significantly increased acetylcholine esterase activity (3.10-fold). Both XK and BJ population had an increased activity of glutathione S-transferases (1.11-fold and 1.20-fold, respectively), but the increment was not significant. The increased detoxification enzymes activities in F. occidentalis could play an important role in the resistance of the plant against phoxim.

Identifying the cause of sediment toxicity in agricultural sediments: the role of pyrethroids and nine seldom-measured hydrophobic pesticides.

PubMed

Weston, Donald P; Ding, Yuping; Zhang, Minghua; Lydy, Michael J

2013-01-01

Few currently used agricultural pesticides are routinely monitored for in the environment. Even if concentrations are known, sediment LC(50) values are often lacking for common sediment toxicity testing species. To help fill this data gap, sediments in California's Central Valley were tested for nine hydrophobic pesticides seldom analyzed: abamectin, diazinon, dicofol, fenpropathrin, indoxacarb, methyl parathion, oxyfluorfen, propargite, and pyraclostrobin. Most were detected, but rarely at concentrations acutely toxic to Hyalella azteca or Chironomus dilutus. Only abamectin, fenpropathrin, and methyl parathion were found at concentrations of potential concern, and only in one or two samples. One-quarter of over 100 samples from agriculture-affected waterways exhibited toxicity, and in three-fourths of the toxic samples, pyrethroids exceeded concentrations expected to cause toxicity. The pyrethroid Bi-fen-thrin in particular, as well as lambda-cyhalothrin, cypermethrin, esfenvalerate, permethrin, and the organophosphate chlorpyrifos, were primarily responsible for the observed toxicity, rather than the more novel analytes, despite the fact that much of the sampling targeted areas of greatest use of the novel pesticides. Copyright © 2012 Elsevier Ltd. All rights reserved.

Development of a multiresidue method for the determination of endocrine disrupters in fish fillet using gas chromatography-triple quadrupole tandem mass spectrometry.

PubMed

Munaretto, Juliana S; Ferronato, Giovana; Ribeiro, Lucila C; Martins, Manoel L; Adaime, Martha B; Zanella, Renato

2013-11-15

Endocrine Disrupter Compounds (EDCs) are responsible for alterations in the endocrine system functions. Aquatic organisms are able to accumulate EDCs residues, being the major source of contamination for top predators and human consumers. This study aimed to develop and validate a method for the determination of 40 EDCs in fish fillet using modified QuEChERS and Gas Chromatography coupled with Mass Spectrometry in tandem (GC-MS/MS). A factorial design was used to optimize the extraction procedure. Method validation presented recoveries from 70.1% to 120.0% with RSD<20% and method limit of detection ranged from 0.3 to 7.5 µg kg(-1), showing good accuracy and precision. This method was successfully applied to the analysis of fish fillet from different species and residues of bisphenol A, chlorpyrifos and bifenthrin were detected. The proposed method proved to be effective for the determination of EDCs in fish fillet at very low concentration levels. © 2013 Elsevier B.V. All rights reserved.

Inter-compartmental transport of organophosphate and pyrethroid pesticides in South China: implications for a regional risk assessment.

PubMed

Li, Huizhen; Wei, Yanli; Lydy, Michael J; You, Jing

2014-07-01

The dynamic flux of an organophosphate and four pyrethroid pesticides was determined in an air-(soil)-water-sediment system based on monitoring data from Guangzhou, China. The total air-water flux, including air-water gaseous exchange and atmospheric deposition, showed deposition from air to water for chlorpyrifos, bifenthrin and cypermethrin, but volatilization for lambda-cyhalothrin and permethrin. The transport of the pesticides from overlying water to sediment suggested that sediment acted as a sink for the pesticides. Additionally, distinct annual atmospheric depositional fluxes between legacy and current-use pesticides suggested the role of consumer usage in their transport throughout the system. Finally, pesticide toxicity was estimated from annual air-water-sediment flux within an urban stream in Guangzhou. A dynamic flux-based risk assessment indicated that inter-compartmental transport of chlorpyrifos decreased its atmospheric exposure, but had little influence on its aquatic toxicity. Instead, water-to-sediment transport of pyrethroids increased their sediment toxicity, which was supported by previously reported toxicity data. Copyright © 2014 Elsevier Ltd. All rights reserved.

[Exposure to persistent and non-persistent pesticides in a non-occupationally exposed population in Tenerife Island (Spain)].

PubMed

Burillo-Putze, Guillermo; Luzardo, Octavio P; García, Carlos Pérez; Zumbado, Manuel; Yanes, Carmen; Trujillo-Martín, María del Mar; Boada Fernández del Campo, Carlos; Boada, Luis D

2014-01-01

Chronic exposure to non-persistent pesticides (NPPs) is of concern because these substances have been associated with chronic diseases. However, few studies have addressed chronic exposure to NPPs in Spanish populations. We determined the presence of 24 pesticide residues by gas chromatography/mass spectrometry in 363 serum samples obtained from non-occupationally exposed adults from Tenerife island in 2007. Most of the samples (99.45%) showed detectable residues (6 ± 2 pesticides per sample). The most frequently detected pesticides were pyrethrins (96.1%), organophosphates (93.9%) and organochlorines (92.3%). The neurotoxicants bifenthrin and malathion were detected in 81% of the samples and hexachlorobenzene DDT and buprofezin in more than 50%. Malation, an "environmental obesogen", was detected in 82%, and "endocrine disrupter" pesticides were present in 97.2% of the samples. Because there is clear, continuous and inadvertent exposure to NPPs that may be inducing adverse effects on human health, NPPs should be included in biomonitoring studies. Copyright © 2013 SESPAS. Published by Elsevier Espana. All rights reserved.

A method for the simultaneous quantification of eight metabolites of synthetic pyrethroids in urine of the general population using gas chromatography-tandem mass spectrometry.

PubMed

Schettgen, Thomas; Dewes, Petra; Kraus, Thomas

2016-08-01

Synthetic pyrethroids are highly effective, widespread insecticides applied worldwide for different purposes. Among the possible sources of exposure for the general population, pyrethroid residues in food and their prominent use for the conservation of wool carpets or in indoor pest control might play a major role. On the basis of previous works, we have developed and validated a highly sensitive and specific GC/MS/MS-method to simultaneously quantify the metabolites of the most common synthetic pyrethroids in urine, namely cis- and trans-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylic acid (DCCA), cis-(2,2-dibromovinyl)-2,2-dimethylcyclopropanecarboxylic acid (DBCA), 4-fluoro-3-phenoxybenzoic acid (F-PBA), 3-phenoxybenzoic acid (3-PBA) as well as the metabolites cis-3-(2-chloro-3,3,3-trifluoroprop-1-enyl)-2,2-dimethyl-cyclopropanecarboxylic acid (ClF3CA, λ-cyhalothrin/bifenthrin), 4-chloro-α-isopropylbenzene acetic acid (CPBA, esfenvalerate), and 2-methyl-3-phenylbenzoic acid (MPB, bifenthrin). After acidic hydrolysis to cleave conjugates in urine, the analytes are subjected to a pH-controlled extraction into n-hexane. After concentration, the analytes are derivatised using MTBSTFA and finally quantified by GC/MS/MS in EI-mode using d6-trans-DCCA and (13)C6-3-PBA as internal standards. The limit of quantification for these metabolites was 0.01 μg/L urine. Precision within and between series was determined to range between 1.6 and 10.7 % using a native quality control sample as well as a urine sample spiked with 0.3 μg/L of the analytes. To investigate possible background excretions, we analysed spot urine samples of 38 persons of the general population in a pilot study. cis- and trans-DCCA as well as 3-PBA could be quantified in every urine sample investigated, while MPB and F-PBA could only be detected in two samples. The median levels for excretion of cis-DCCA, trans-DCCA, 3-PBA, ClF3CA, DBCA, CPBA, F-PBA and MPA were 0.08, 0.17, 0.22, 0.04, 0.04, <0.01, <0.01 and < 0.01 μg/L urine, respectively. The excretion of metabolites revealed excellent correlations between cyclopropane carboxylic acids and 3-PBA. Our method is highly suitable for human biomonitoring of exposures to synthetic pyrethroids in environmental medicine. Remarkable are the high detection rates for the metabolites ClF3CA (90 %) and CPBA (40 %), proving that their parent pyrethroids have entered the market in Germany.

Molecular mechanism and genetic determinants of buprofezin degradation.

PubMed

Chen, Xueting; Ji, Junbin; Zhao, Leizhen; Qiu, Jiguo; Dai, Chen; Wang, Weiwu; He, Jian; Jiang, Jiandong; Hong, Qing; Yan, Xin

2017-07-14

Buprofezin is a widely used insect growth regulator whose residue has been frequently detected in the environment, posing a threat to aquatic organisms and non-target insects. Microorganisms play an important role in the degradation of buprofezin in the natural environment. However, the relevant catabolic pathway has not been fully characterized, and the molecular mechanism of catabolism is still completely unknown. Rhodococcus qingshengii YL-1 can utilize buprofezin as a sole source of carbon and energy for growth. In this study, the upstream catabolic pathway in strain YL-1 was identified using tandem mass spectrometry. Buprofezin is composed of a benzene ring and a heterocyclic ring. The degradation is initiated by the dihydroxylation of the benzene ring and continues via dehydrogenation, aromatic ring cleavage, breaking of an amide bond and the release of the heterocyclic ring 2- tert -butylimino-3-isopropyl-1,3,5-thiadiazinan-4-one (2-BI). A buprofezin degradation-deficient mutant strain YL-0 was isolated. Comparative genomic analysis combined with gene deletion and complementation experiments revealed that the gene cluster bfzBA3A4A1A2C is responsible for the upstream catabolic pathway of buprofezin. bfzA3A4A1A2 encodes a novel Rieske non-heme iron oxygenase (RHO) system that is responsible for the dihydroxylation of buprofezin at the benzene ring; bfzB is involved in dehydrogenation, and bfzC is in charge of benzene ring cleavage. Furthermore, the products of bfzBA3A4A1A2C can also catalyze dihydroxylation, dehydrogenation and aromatic ring cleavage of biphenyl, flavanone, flavone and bifenthrin. In addition, a transcriptional study revealed that bfzBA3A4A1A2C is organized in one transcriptional unit that is constitutively expressed in strain YL-1. Importance There is an increasing concern about the residue and environmental fate of buprofezin. Microbial metabolism is an important mechanism responsible for the buprofezin degradation in natural environment. However, the molecular mechanism and genetic determinants of microbial degradation of buprofezin has not been well identified. This work revealed that gene cluster bfzBA3A4A1A2C is responsible for the upstream catabolic pathway of buprofezin in R. qingshengii YL-1. The products of bfzBA3A4A1A2C could also degrade bifenthrin, a widely used pyrethroid insecticide. These findings enhance our understanding of the microbial degradation mechanism of buprofezin and benefit the application of strain YL-1 and bfzBA3A4A1A2C in the bioremediation of buprofezin contamination. Copyright © 2017 American Society for Microbiology.

Molecular Mechanism and Genetic Determinants of Buprofezin Degradation

PubMed Central

Chen, Xueting; Ji, Junbin; Zhao, Leizhen; Qiu, Jiguo; Dai, Chen; Wang, Weiwu; He, Jian; Jiang, Jiandong; Hong, Qing

2017-01-01

ABSTRACT Buprofezin is a widely used insect growth regulator whose residue has been frequently detected in the environment, posing a threat to aquatic organisms and nontarget insects. Microorganisms play an important role in the degradation of buprofezin in the natural environment. However, the relevant catabolic pathway has not been fully characterized, and the molecular mechanism of catabolism is still completely unknown. Rhodococcus qingshengii YL-1 can utilize buprofezin as a sole source of carbon and energy for growth. In this study, the upstream catabolic pathway in strain YL-1 was identified using tandem mass spectrometry. Buprofezin is composed of a benzene ring and a heterocyclic ring. The degradation is initiated by the dihydroxylation of the benzene ring and continues via dehydrogenation, aromatic ring cleavage, breaking of an amide bond, and the release of the heterocyclic ring 2-tert-butylimino-3-isopropyl-1,3,5-thiadiazinan-4-one (2-BI). A buprofezin degradation-deficient mutant strain YL-0 was isolated. A comparative genomic analysis combined with gene deletion and complementation experiments revealed that the gene cluster bfzBA3A4A1A2C is responsible for the upstream catabolic pathway of buprofezin. The bfzA3A4A1A2 cluster encodes a novel Rieske nonheme iron oxygenase (RHO) system that is responsible for the dihydroxylation of buprofezin at the benzene ring; bfzB is involved in dehydrogenation, and bfzC is in charge of benzene ring cleavage. Furthermore, the products of bfzBA3A4A1A2C can also catalyze dihydroxylation, dehydrogenation, and aromatic ring cleavage of biphenyl, flavanone, flavone, and bifenthrin. In addition, a transcriptional study revealed that bfzBA3A4A1A2C is organized in one transcriptional unit that is constitutively expressed in strain YL-1. IMPORTANCE There is an increasing concern about the residue and environmental fate of buprofezin. Microbial metabolism is an important mechanism responsible for the buprofezin degradation in the natural environment. However, the molecular mechanism and genetic determinants of microbial degradation of buprofezin have not been well identified. This work revealed that gene cluster bfzBA3A4A1A2C is responsible for the upstream catabolic pathway of buprofezin in Rhodococcus qingshengii YL-1. The products of bfzBA3A4A1A2C could also degrade bifenthrin, a widely used pyrethroid insecticide. These findings enhance our understanding of the microbial degradation mechanism of buprofezin and benefit the application of strain YL-1 and bfzBA3A4A1A2C in the bioremediation of buprofezin contamination. PMID:28710269

GluCl a target of indole alkaloid okaramines: a 25 year enigma solved

NASA Astrophysics Data System (ADS)

Furutani, Shogo; Nakatani, Yuri; Miura, Yuka; Ihara, Makoto; Kai, Kenji; Hayashi, Hideo; Matsuda, Kazuhiko

2014-08-01

In 1989, indole alkaloid okaramines isolated from the fermentation products of Penicillium simplicissimum were shown to be insecticidal, yet the mechanism of their toxicity to insects remains unknown. We therefore examined the action of okaramine B on silkworm larval neurons using patch-clamp electrophysiology. Okaramine B induced inward currents which reversed close to the chloride equilibrium potential and were blocked by fipronil. Thus it was tested on the silkworm RDL (resistant-to-dieldrin) γ-aminobutyric-acid-gated chloride channel (GABACl) and a silkworm L-glutamate-gated chloride channel (GluCl) expressed in Xenopus laevis oocytes. Okaramine B activated GluCl, but not RDL. GluCl activation by okaramines correlated with their insecticidal activity, offering a solution to a long-standing enigma concerning their insecticidal actions. Also, unlike ivermectin, okaramine B was inactive at 10 μM on human α1β2γ2 GABACl and α1β glycine-gated chloride channels and provides a new lead for the development of safe insect control chemicals.

Preventive efficacy of Frontline® Combo and Certifect® against Dipylidium caninum infestation of cats and dogs using a natural flea (Ctenocephalides felis) infestation model.

PubMed

Beugnet, Frederic; Delport, Peet; Luus, Hermann; Crafford, Dione; Fourie, Josephus

2013-01-01

Two studies were performed to evaluate the effectiveness of two monthly topical anti-flea products for the prevention of Dipylidium caninum infestations in cats and dogs. A single treatment with Frontline(®) Combo spot-on for cats (fipronil-(S)-methoprene) and two successive monthly treatments of Certifect(®) for dogs (fipronil-amitraz-(S)-methoprene) were assessed for the prevention of D. caninum infestations following weekly challenges of treated cats or dogs with metacestode naturally-infected fleas. The rate of infestations using the model in cats versus dogs explains the choice of a 1-month trial in cats and a 2-month trial in dogs. The experimental flea-infection model resulted in a range of 22-53% of the fleas being infected by Dipylidium cysticercoids. The arithmetic mean flea counts recorded for the untreated cats ranged from 51.2 to 68. The geometric mean flea counts recorded for the Frontline Combo treated cats differed significantly (p < 0.05) from those of the untreated control cats on all assessment days. The arithmetic mean flea counts recorded for the untreated dogs ranged from 166.6 to 238.6. The geometric mean flea counts recorded for the Certifect treated dogs differed significantly (p < 0.001) from those of the untreated group on all assessment days. Frontline Combo treatment on cats provided ≥99.8% persistent anti-flea efficacy throughout the 30-day treatment period. In the dog study, the two Certifect treatments provided ≥97% persistent efficacy throughout the 60-day study. Based on the collection of expelled D. caninum proglottids by cats, 100% (6/6) of the control cats and 0% (0/6) of Frontline Combo treated cats were infested with D. caninum. Frontline Combo spot-on for cats was therefore 100% effective in preventing infection with D. caninum. In dogs, 7 out of the 8 control group dogs (87.5%) produced proglottids following infestation of infected fleas, whereas 0 out of 8 dogs (0%) in the treated group were infected. The infection rates of the two groups were significantly different. The percent effectiveness for the Certifect treatment group for the prevention of D. caninum infection was 100% during this 2-month trial. No treatment-related adverse events were observed in either cats or dogs during these studies. © F. Beugnet et al., Published by EDP Sciences 2013.

Evaluation of on-line concentration coupled to liquid chromatography tandem mass spectrometry for the quantification of neonicotinoids and fipronil in surface water and tap water.

PubMed

Montiel-León, Juan Manuel; Duy, Sung Vo; Munoz, Gabriel; Amyot, Marc; Sauvé, Sébastien

2018-04-01

A study was initiated to investigate a fast and reliable method for the determination of selected systemic insecticides in water matrixes and to evaluate potential sources of bias in their analysis. Acetamiprid, clothianidin, desnitro-imidacloprid, dinotefuran, fipronil, imidacloprid, nitenpyram, thiacloprid, and thiamethoxam were amenable to analysis via on-line sample enrichment hyphenated to ultra-high-performance liquid chromatography tandem mass spectrometry. The selection of on-line solid-phase extraction parameters was dictated by a multicriterion desirability approach. A 2-mL on-line injection volume with a 1500 μL min -1 loading flow rate met the objectives sought in terms of chromatographic requirements, extraction efficiency, sensitivity, and precision. A total analysis time of 8 min per sample was obtained with method limits of detection in the range of 0.1-5 ng L -1 for the scope of targeted analytes. Automation at the sample concentration step yielded intraday and interday precisions in the range of 1-23 and 2-26%, respectively. Factors that could affect the whole method accuracy were further evaluated in matrix-specific experiments. The impact of the initial filtration step on analyte recovery was evaluated in ultra-pure water, tap water, and surface water. Out of the nine membranes tested, glass fiber filters and polyester filters appeared as the most appropriate materials. Sample storage stability was also investigated across the three matrix types; the targeted analytes displayed suitable stability during 28 days at either 4 °C or - 20 °C, with little deviations (± 10%) with respect to the initial T 0 concentration. Method applicability was demonstrated in a range of tap water and surface water samples from the province of Québec, Canada. Results from the present survey indicated a predominance of thiamethoxam (< 0.5-10 and 3-61 ng L -1 in tap water and river water, respectively), clothianidin (< 0.5-6 and 2-88 ng L -1 in tap water and river water, respectively), and imidacloprid (< 0.1-1 and 0.8-38 ng L -1 in tap water and river water, respectively) among the targeted analytes. Graphical abstract ᅟ Development of solid-phase extraction coupled on-line to UHPLC-MS/MS for the rapid screening of systemic insecticides in water.

Knockout of a P-glycoprotein gene increases susceptibility to abamectin and emamectin benzoate in Spodoptera exigua.

PubMed

Zuo, Y-Y; Huang, J-L; Wang, J; Feng, Y; Han, T-T; Wu, Y-D; Yang, Y-H

2018-02-01

P-glycoprotein [P-gp or the ATP-binding cassette transporter B1 (ABCB1)] is an important participant in multidrug resistance of cancer cells, yet the precise function of this arthropod transporter is unknown. The aim of this study was to determine the importance of P-gp for susceptibility to insecticides in the beet armyworm (Spodoptera exigua) using clustered regularly interspaced short palindromic repeats/CRISPR-associated 9 (CRISPR/Cas9) gene-editing technology. We cloned an open reading frame (ORF) encoding the S. exigua P-gp protein (SeP-gp) predicted to display structural characteristics common to P-gp and other insect ABCB1 transporters. A knockout line with a frame shift deletion of four nucleotides in the SeP-gp ORF was established using the CRISPR/Cas9 gene-editing system to test its potential role in determining susceptibility to chemical insecticides or insecticidal proteins from the bacterium Bacillus thuringiensis (Bt). Results from comparative bioassays demonstrate that knockout of SeP-gp significantly increases susceptibility of S. exigua by around threefold to abamectin and emamectin benzoate (EB), but not to spinosad, chlorfenapyr, beta-cypermethrin, carbosulfan indoxacarb, chlorpyrifos, phoxim, diafenthiuron, chlorfluazuron, chlorantraniliprole or two Bt toxins (Cry1Ca and Cry1Fa). Our data support an important role for SeP-gp in susceptibility of S. exigua to abamectin and EB and imply that overexpression of SeP-gp may contribute to abamectin and EB resistance in S. exigua. © 2017 The Royal Entomological Society.

Biological trait analysis and stability of lambda-cyhalothrin resistance in the house fly, Musca domestica L. (Diptera: Muscidae).

PubMed

Abbas, Naeem; Shah, Rizwan Mustafa; Shad, Sarfraz Ali; Iqbal, Naeem; Razaq, Muhammad

2016-05-01

House flies, Musca domestica L., (Diptera: Muscidae), are pests of poultry and have the ability to develop resistance to insecticides. To design a strategy for resistance management, life history traits based on laboratory observations were established for lambda-cyhalothrin-resistant, susceptible and reciprocal crosses of M. domestica strains. Bioassay results showed that the lambda-cyhalothrin-selected strain developed a resistance ratio of 98.34 compared to its susceptible strain. The lambda-cyhalothrin-selected strain had a relative fitness of 0.26 and lower fecundity, hatchability, lower number of next generation larvae, and net reproductive rate compared with its susceptible strain. Mean population growth rates, such as intrinsic rate of population increase, and biotic potential were lower for the lambda-cyhalothrin-selected strain compared to its susceptible strain. Resistance to lambda-cyhalothrin, indoxacarb, and abamectin was unstable while resistance to bifenthrin and methomyl was stable in the lambda-cyhalothrin-selected strain of M. domestica. Development of resistance can cost considerable fitness for the lambda-cyhalothrin-selected strain. The present study provided useful information for making potential management strategies to delay resistance development in M. domestica.

Toxicity of Pesticide Tank Mixtures from Rice Crops Against Telenomus podisi Ashmead (Hymenoptera: Platygastridae).

PubMed

de B Pazini, J; Pasini, R A; Rakes, M; de Armas, F S; Seidel, E J; da S Martins, J F; Grützmacher, A D

2017-08-01

The use of insecticides, herbicides, and fungicides commonly occurs in mixtures in tanks in order to control phytosanitary problems in crops. However, there is no information regarding the effects of these mixtures on non-target organisms associated to the rice agroecosystem. The aim of this study was to know the toxicity of pesticide tank mixtures from rice crops against Telenomus podisi Ashmead (Hymenoptera: Platygastridae). Based on the methods adapted from the International Organisation for Biological and Integrated Control of Noxious Animals and Plants (IOBC), adults of T. podisi were exposed to residues of insecticides, herbicides, and fungicides, individually or in mixture commonly used by growers, in laboratory and on rice plants in a greenhouse. The mixture between fungicides tebuconazole, triclyclazole, and azoxystrobin and the mixture between herbicides cyhalofop-butyl, imazethapyr, imazapyr/imazapic, and penoxsulam are harmless to T. podisi and can be used in irrigated rice crops without harming the natural biological control. The insecticides cypermethin, thiamethoxam, and bifenthrin/carbosulfan increase the toxicity of the mixtures in tank with herbicides and fungicides, being more toxic to T. podisi and less preferred for use in phytosanitary treatments in the rice crop protection.

Occurrence, Distribution, and Accumulation of Pesticides in Exterior Residential Areas.

PubMed

Jiang, Weiying; Conkle, Jeremy L; Luo, Yuzhou; Li, Juying; Xu, Karen; Gan, Jay

2016-12-06

Pesticides are commonly applied around residential homes, but their occurrence on exterior surfaces (e.g., pavement) has not been thoroughly evaluated. We collected 360 dust samples from curbside gutters, sidewalks, and street surfaces at 40 houses in southern California to evaluate pesticide occurrence on urban paved surfaces as well as their spatial and temporal distributions. Pesticides and select degradates were ubiquitously detected in dust, with the median concentration of total target analytes at 85 μg kg -1 . A total of 75% of samples contained at least five pesticides. As a result of recurring pesticide applications, concentrations increased throughout the summer. The pyrethroids bifenthrin and permethrin accounted for 55% of total pesticides detected in the dust. The highest concentrations in dust were found on the sidewalk and in the gutter. Relative to indoor environments, human exposure risk to pesticides on paved surfaces was estimated to be lower, with the highest potential oral and dermal exposure predicted to be 38 ng day -1 for permethrin. The ubiquitous detection of pesticides on residential outdoor surfaces and the fact that the exterior concentrations did not correlate to the indoor areas highlight the necessity to measure pesticides in both indoor and outdoor areas for complete residential pesticide risk assessment.

Lethal and sublethal effects of seven insecticides on three beneficial insects in laboratory assays and field trials.

PubMed

Fernandes, Maria E S; Alves, Flávia M; Pereira, Renata C; Aquino, Leonardo A; Fernandes, Flávio L; Zanuncio, José C

2016-08-01

Lethal and sublethal effects of insecticides on target and non-target arthropods are a concern of pest management programs. Cycloneda sanguinea, Orius insidiosus and Chauliognathus flavipes are important biological control agents for aphids, whitefly, lepidopterus eggs, thrips and mites. All three test species were subjected to a toxicity study using the insecticides acephate, bifenthrin, chlorantraniliprole, chlorpyrifos, deltamethrin, imidacloprid, and thiamethoxam. Experiments were done in the lab and field. In the laboratory we evaluated the mortality and sublethal effects of the concentration that killed 20% of the population (LC20) on feeding, repellence and reproduction of the species tested. The lethal effects of these insecticides at the recommended doses was evaluated in the field. Concentration-response bioassays indicated chlorantraniliprole had the lowest toxicity, while chlorpyrifos and acephate were the most toxic. Test species exposed to filter paper surfaces treated with pyrethroids, neonicotinoids and organophosphates were repelled. On the other hand, test species were not repelled from surfaces treated with chlorantraniliprole. Chlorantraniliprole therefore seemed to be the least dangerous insecticide for these three beneficial arthropod test species. Copyright © 2016 Elsevier Ltd. All rights reserved.

The use of silica-coated magnetic graphene microspheres as the adsorbent for the extraction of pyrethroid pesticides from orange and lettuce samples followed by GC-MS analysis.

PubMed

Hou, Mengying; Zang, Xiaohuan; Wang, Chun; Wang, Zhi

2013-10-01

Graphene-grafted ferroferric oxide microspheres were used as the adsorbent to extract some pyrethroid pesticides (bifenthrin, λ-cyhalothrin, cyfluthrin, cypermethrin, fenvalerate, and deltamethrin) from orange and lettuce samples prior to their determination by GC-MS. The main variables that could affect the extraction, including the amount of the adsorbent, pH of the sample solution, extraction time, concentration of salt, and desorption conditions, were investigated and optimized. Under the optimized conditions, a linear response was obtained in the concentration range of 0.3-100.0 ng/g for the analytes with the coefficients of determination ranging from 0.9877 to 0.9925. The LODs for the pyrethroids ranged from 0.01 to 0.02 ng/g. The method provided a good repeatability with RSDs < 10.6%. The recoveries for the six pyrethroid pesticides were in the range from 90.0 to 103.7%. The method was applied to the determination of the pesticides in orange and lettuce samples with a satisfactory result. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Determination of six pesticides in the medicinal herb Cordia salicifolia by matrix solid-phase dispersion and gas chromatography/mass spectrometry.

PubMed

de Carvalho, Pedro Henrique Viana; Prata, Vanessa de Menezes; Alves, Péricles Barreto; Navickiene, Sandro

2009-01-01

A simple and effective extraction method based on matrix solid-phase dispersion was developed for acephate, chlorpropham, pyrimicarb, bifenthrin, tetradifon, and phosalone in leaves of the medicinal plant Cordia salicifolia, whose extracts are commercialized in Brazil as diuretic, appetite suppressant, and weight loss products. The determination method was GC/MS with selected-ion monitoring. Different parameters of the method were evaluated, such as type of solid phase (C18, alumina, silica gel, and Florisil) and the amount of solid phase and eluent (dichloromethane, ethyl acetate, chloroform, and cyclohexane). The best results were obtained using 0.5 g herb sample, 0.5 g neutral alumina as the dispersant sorbent, 0.5 g C18 as the cleanup sorbent, and cyclohexane-dichloromethane (3 + 1, v/v) as the eluting solvent. The method was validated using herb samples fortified with pesticides at different concentration levels (0.3, 0.5, and 1.0 mg/kg). Average recoveries (seven replicates) ranged from 67.7 to 129.9%, with relative standard deviations between 6.3 and 26%. Detection and quantitation limits for the herb ranged from 0.10 to 0.15 and 0.15 to 0.25 mg/kg, respectively.

Application of pseudo-template molecularly imprinted polymers by atom transfer radical polymerization to the solid-phase extraction of pyrethroids.

PubMed

Zhang, Ming; He, Juan; Shen, Yanzheng; He, Weiye; Li, Yuanyuan; Zhao, Dongxin; Zhang, Shusheng

2018-02-01

A polymer-based adsorption medium with molecular recognition ability for homologs of pyrethroids was prepared by atom transfer radical polymer iration using a fragment imprinting technique. Phenyl ether-biphenyl eutectic was utilized as a pseudo-template molecule, and the adsorption medium prepared was evaluated by solid-phase extraction and gas chromatography. Selectivity of the medium for pyrethroids was evaluated using it as solid phase extraction packing by Gas Chromatography. The results demonstrated that the absorption amount of bifenthrin, fenpropathrin, permethrin, cypermethrin, fenvalerate, Dursban and pentachloronitrobenzene for molecularly imprinted polymers were 2.32, 2.12, 2.18, 2.20, 2.30, 1.30 and 1.40mgg -1 , respectively, while the non-imprinted polymers were 1.20, 1.13, 1.25, 1.05, 1.20, 1.23 and 1.32mgg -1 , respectively. The rebinding test based on the molecularly imprinted solid phase extraction column technique showed the recoveries of honey sample spiked with seven insecticides within 88.5-106.2%, with relative standard deviations of 2.38-5.63%. Finally, the method was successfully applied to the analysis of pyrethroids in a honey sample. Copyright © 2017 Elsevier B.V. All rights reserved.

Evaluation of a modified QuEChERS extraction of multiple classes of pesticides from a rice paddy soil by LC-APCI-MS/MS.

PubMed

Caldas, Sergiane S; Bolzan, Cátia M; Cerqueira, Maristela B; Tomasini, Débora; Furlong, Eliana B; Fagundes, Carlos; Primel, Ednei G

2011-11-23

A new method for the determination of clomazone, fipronil, tebuconazole, propiconazole, and azoxystrobin in samples of rice paddy soil is presented. The extraction of the pesticides from soil samples was performed by using a modified quick, easy, cheap, effective, rugged, and safe (QuEChERS) method. Some extraction conditions such as salt addition, sample acidification, use of buffer, and cleanup step were evaluated. The optimized method dealt with a single extraction of the compounds under study with acidified acetonitrile, followed by the addition of MgSO(4) and NaCl prior to the final determination by liquid chromatography-atmospheric chemical pressure ionization-tandem mass spectrometry. Validation studies were carried out in soil samples. Recoveries of the spiked samples ranged between 70.3 and 120% with relative standard deviation lower than 18.2%. The limits of quantification were between 10 and 50 μg kg(-1). The method was applied to the analysis of real samples of soils where rice is cultivated.

Dissolved pesticides, dissolved organic carbon, and water-quality characteristics in selected Idaho streams, April--December 2010

USGS Publications Warehouse

Reilly, Timothy J.; Smalling, Kelly L.; Wilson, Emma R.; Battaglin, William A.

2012-01-01

Water-quality samples were collected from April through December 2010 from four streams in Idaho and analyzed for a suite of pesticides, including fungicides, by the U.S. Geological Survey. Water samples were collected from two agricultural and two nonagricultural (control) streams approximately biweekly from the beginning of the growing season (April) through the end of the calendar year (December). Samples were analyzed for 90 pesticides using gas chromatography/mass spectrometry. Twenty-three pesticides, including 8 fungicides, 10 herbicides, 3 insecticides, and 2 pesticide degradates, were detected in 45 water samples. The most frequently detected compounds in the two agricultural streams and their detection frequencies were metolachlor, 96 percent; azoxystrobin, 79 percent; boscalid, 79 percent; atrazine, 46 percent; pendimethalin, 33 percent; and trifluralin, 33 percent. Dissolved-pesticide concentrations ranged from below instrumental limits of detection (0.5-1.0 nanograms per liter) to 771 nanograms per liter (hexazinone). The total number of pesticides detected in any given water sample ranged from 0 to 11. Only three pesticides (atrazine, fipronil, and simazine) were detected in samples from the control streams during the sampling period.

Cross-resistance and Inheritance of Resistance to Emamectin Benzoate in Spodoptera exigua (Lepidoptera: Noctuidae).

PubMed

Che, Wunan; Huang, Jianlei; Guan, Fang; Wu, Yidong; Yang, Yihua

2015-08-01

Beet armyworm, Spodoptera exigua (Hübner), is a worldwide pest of many crops. Chemical insecticides are heavily used for its control in China, and serious resistance has been evolved in the field to a variety of insecticides including emamectin benzoate. Through repeated backcrossing to a susceptible strain (WH-S) and selection with emamectin benzoate, the trait conferring resistance to emamectin benzoate in a field-collected population of S. exigua (moderately resistant to emamectin benzoate and strongly resistant to pyrethroids and indoxacarb) was introgressed into WH-S to generate a near-isogenic resistant strain (WH-EB). Compared with WH-S, the WH-EB strain developed a 1,110-fold resistance to emamectin benzoate and a high level of cross-resistance to abamectin (202-fold), with low levels of cross-resistance to cypermethrin (10-fold) and chlorfluazuron (7-fold), but no cross-resistance to representatives of another six different classes of insecticides (chlorantraniliprole, chlorfenapyr, indoxacarb, spinosad, tebufenozide, and chlorpyrifos). Resistance to emamectin benzoate in WH-EB was autosomal, incompletely dominant, and polygenic. Limited cross-resistance in WH-EB indicates that emamectin benzoate can be rotated with other classes of insecticides to which it does not show cross-resistance to delay the evolution of resistance in S. exigua. The incompletely dominant nature of resistance in S. exigua may explain the rapid evolution of resistance to emamectin benzoate in the field, and careful deployment of this chemical within a resistance management program should be considered. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Revealing Pesticide Residues Under High Pesticide Stress in Taiwan's Agricultural Environment Probed by Fresh Honey Bee (Hymenoptera: Apidae) Pollen.

PubMed

Nai, Yu-Shin; Chen, Tsui-Yao; Chen, Yi-Cheng; Chen, Chun-Ting; Chen, Bor-Yann; Chen, Yue-Wen

2017-10-01

Significant pesticide residues are among the most serious problems for sustainable agriculture. In the beekeeping environment, pesticides not only impact a honey bee's survival, but they also contaminate bee products. Taiwan's agricultural environment has suffered from pesticide stress that was higher than that found in Europe and America. This study deciphered problems of pesticide residues in fresh honey bee pollen samples collected from 14 monitoring apiaries in Taiwan, which reflected significant contaminations within the honey bee population. In total, 155 pollen samples were screened for 232 pesticides, and 56 pesticides were detected. Among the residues, fluvalinate and chlorpyrifos showed the highest concentrations, followed by carbendazim, carbaryl, chlorfenapyr, imidacloprid, ethion, and flufenoxuron. The average frequency of pesticide residues detected in pollen samples was ca. 74.8%. The amounts and types of pesticides were higher in winter and in southwestern Taiwan. Moreover, five of these pollen samples were contaminated with 11-15 pesticides, with average levels between 1,560 and 6,390 μg/kg. Compared with the literature, this study emphasized that pollen gathered by honey bee was highly contaminated with more pesticides in Taiwan than in the America, France, and Spain. The ubiquity of pesticides in the pollen samples was likely due to the field applications of common pesticides. Recently, the Taiwanese government began to improve the pesticide policy. According to the resurvey data in 2016, there were reductions in several pesticide contamination parameters in pollen samples from west to southwest Taiwan. A long-term investigation of pollen pesticide residues should be conducted to inspect pesticides usage in Taiwan's agriculture. © The Author 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Activity of Selected Formulated Biorational and Synthetic Insecticides Against Larvae of Helicoverpa armigera (Lepidoptera: Noctuidae).

PubMed

Vivan, L M; Torres, J B; Fernandes, P L S

2017-02-01

This work studied 17 insecticides belonging to nucleopolyhedrovirus (NPV), Bacillus thuringiensis (Bt kurstaki and Bt aizawai), benzoylureas (insect growth regulators [IGRs]), carbamates, organophosphates, spinosyns, and diamides against larvae of Helicoverpa armigera (Hübner), invasive species in the South American continent. Larvae of different instars were fed for 7 d with untreated or insecticide-treated diets. Mortality was recorded daily for 7 d, and surviving larvae were individually weighed on the seventh day. The NPV and Bt insecticides caused 100% mortality of first-instar larvae and first-instar and second-instar larvae, respectively. However, both NPV and Bt-based products caused low mortality of third-instar larvae and did not kill older larvae. The IGR lufenuron was highly effective against all three ages of larvae tested, whereas teflubenzuron and triflumuron produced maximum 60% mortality of second-instar larvae and lower than 50% to older larvae. Thiodicarb, chlorantraniliprole, indoxacarb, chlorpyrifos, and chlorfenapyr, irrespective of tested age, caused 100% mortality of larvae, with the last two insecticides reaching 100% mortality within 2 d of feeding on the treated diet. Flubendiamide caused lower mortality but significantly affected the weight of surviving larvae, whereas neither spinosad nor methomyl produced significant mortality or affected the weight of larvae. Based on the results, the age of H. armigera larvae plays an important role in the recommendation of NPV and Bt insecticides. Furthermore, there are potential options between biological and synthetic insecticides tested against H. armigera, and recording larval size during monitoring, in addition to the infestation level, should be considered when recommending biological-based insecticides to control this pest. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Direct and Indirect Effects of Pesticides on the Insidious Flower Bug (Hemiptera: Anthocoridae) Under Laboratory Conditions.

PubMed

Herrick, Nathan J; Cloyd, Raymond A

2017-06-01

Greenhouse producers are interested in integrating natural enemies along with pesticides to suppress western flower thrips, Frankliniella occidentalis (Pergande), populations. The insidious flower bug, Orius insidiosus (Say), is a commercially available natural enemy of western flower thrips. We conducted a series of laboratory experiments to determine the direct and indirect effects of 28 pesticides (insecticides, miticides, and fungicides), 4 pesticide mixtures, and 4 surfactants (36 total treatments plus a water control) on the adult O. insidiosus survival and predation on western flower thrips adults under laboratory conditions. The number of live and dead O. insidiosus adults was recorded after 24, 48, 72, and 96 h. The results of the study indicate that the fungicides (aluminum tris, azoxystrobin, fenhexamid, and kresoxim-methyl), insect growth regulators (azadirachtin, buprofezin, kinoprene, and pyriproxyfen), botanicals (Capsicum oleoresin extract, garlic oil, soybean oil; and rosemary, rosemary oil, peppermint oil, and cottonseed oil), and entomopathogenic fungi (Beauveria bassiana and Metarhizium anisopliae) were minimally directly harmful to adult O. insidiosus, with 80% to 100% adult survival. However, abamectin, spinosad, pyridalyl, chlorfenapyr, tau-fluvalinate, imidacloprid, dinotefuran, acetamiprid, and thiamethoxam directly affected O. insidiosus survival after 96 h (0-60% adult survival). The pesticide mixtures of abamectin + spinosad and chlorfenapyr + dinotefuran reduced adult survival (20% and 0%, respectively, after 48 h). Furthermore, the surfactants were not directly harmful to O. insidiosus adults. All western flower thrips adults were killed by the surviving adult O. insidiosus after 48 h, indicating no indirect effects of the pesticides on predation. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Resistance to Diamide Insecticides in Plutella xylostella (Lepidoptera: Plutellidae): Comparison Between Lab-Selected Strains and Field-Collected Populations.

PubMed

Qin, Chao; Wang, Cheng-Hua; Wang, Ying-Ying; Sun, Shi-Qing; Wang, Huan-Huan; Xue, Chao-Bin

2018-04-02

Diamondback moth, Plutella xylostella (L.; Lepidoptera: Plutellidae), is an important pest of crucifers worldwide. The extensive use of diamide insecticides has led to P. xylostella resistance and this presents a serious threat to vegetable production. We selected chlorantraniliprole (Rf) and flubendiamide (Rh) resistance strains of P. xylostella with resistance ratios of 684.54-fold and 677.25-fold, respectively. The Rf and Rh strains underwent 46 and 36 generations of lab-selection for resistance, respectively. Low cross resistance of Rh to cyantraniliprole was found. Cross resistance to chlorfenapyr, tebufenozid, and indoxacarb was not found in Rf and Rh strains. The P. xylostella ryanodine receptor gene (PxRyR) transcripts level in the Rf and Rh strains was up-regulated. Except for Rf34 and Rh36, PxRyR expression in all generations of Rf and Rh selection gradually increased with increasing resistance. Two resistant populations were field-collected from Guangzhou Baiyun (Rb) and Zengcheng (Rz) and propagated for several generations without exposure to any pesticide had higher PxRyR expression than the susceptible strain (S). In the S strain, PxRyR expression was not related to the resistance ratio. Gene sequencing found that the RyR 4946 gene site was glycine (G) in the S, Rf, and Rh strains, and was glutamate (E) with 70% and 80% frequency in the Rb and Rz populations, respectively. The 4946 gene site was substituted by valine (V) with the frequency of 30% and 20% in Rb and Rz populations, respectively. These results increase the understanding of the mechanisms of diamide insecticide resistance in P. xylostella.

Sowing simulation tests of a pneumatic drill equipped with systems aimed at reducing the emission of abrasion dust from maize dressed seed.

PubMed

Biocca, Marcello; Conte, Elisa; Pulcini, Patrizio; Marinelli, Enzo; Pochi, Daniele

2011-01-01

The utilization of dressed seed for spring sowing is a widespread practice to control some pests with reduced doses of chemical products. However some insecticides employed in maize seed dressing, namely belonging to the neonicotinoid family and fipronil, have been claimed to play a role in the decline of honeybees (Apis mellifera L.). Pneumatic drills used in maize sowing are charged with contributing to the dispersion of the abrasion dust produced by dressed seeds, favoring the contamination of the honeybee habitat. Different devices similar to air deflectors have been introduced on pneumatic drills in order to reduce dust drift. During previous field tests carried out by the authors during recent years reduction of dust concentration both in the air and at soil surface has been shown as a consequence of their application. As field tests are affected by the variability of environmental parameters (namely wind speed and direction) the results are not always reliable, comparable and of a general validity. This paper refers to a sowing simulation test system in which pneumatic drills can be tested at a fixed point under controlled conditions of the main environmental parameters. In the test area, protected by external influences, artificial wind conditions are created by means of a fan. The drill, suitably placed in the test area, operates the seed distribution "sur place" by means of an electric engine connected to the drill's driving wheel. A 22.5 m long sampling area, leeward with respect to the drill position, has been identified. Along the sampling area a series of Petri dishes has been placed, with the aim of capturing the depositing dust and providing the concentration of the active ingredients (a.i.) at ground level. At the same time, three air samplers with PTFE diskette filters have been used for the detection of the a.i. The test system has been used for the test of a pneumatic drill, equipped with and without air deflectors, using maize seed dressed with four a. i. (imidacloprid, clothianidin, thiametoxam, fipronil). The results showed regularly decreasing of the concentrations as distance increased, both in the air and at ground level. Moreover, the difference determined by the adoption of the drift reducing device (air deflectors) resulted clear and it can be quantified at around 50 % of the a.i. amounts observed without deflectors. Finally, the paper proposes a data processing method that, from the values observed at fixed point, provides the theoretical a.i. concentration behavior that would occur in field, under the same conditions of wind speed and direction and working speed. The obtained results are coherent with previous field test.

Field Study of the Comparative Efficacy of Three Pyrethroid/Neonicotinoid Mixture Products for the Control of the Common Bed Bug, Cimex lectularius.

PubMed

Wang, Changlu; Singh, Narinderpal; Cooper, Richard

2015-03-18

Three insecticide mixtures that contain two classes of insecticides (pyrethroid and neonicotinoid) were recently developed to control bed bugs. We evaluated three integrated bed bug management strategies in apartments, each using the same non-chemical control methods and one of the three insecticide mixture products: Tandem (lambda-cyhalothrin + thiamethoxam), Temprid SC (beta-cyfluthrin + imidacloprid), and Transport Mikron (bifenthrin + acetamiprid). No insecticides were applied in the Control apartments. In all apartments, we installed vinyl mattress encasements (if not already present) and applied steam to beds and other infested upholstered furniture. Insecticide sprays were applied in the three treatments. Each treatment and the Control included 8-10 occupied apartments. Re-treatment was conducted during biweekly inspections if necessary. After eight weeks, the mean (± SEM) bed bug count reduction in the Tandem, Temprid SC, Transport Mikron, and Control was 89 ± 9, 87 ± 6, 98 ± 1, and 23 ± 54%, respectively. Only Tandem and Transport Mikron treatments resulted in significantly higher population reduction than the Control at eight weeks. There were no significant differences in mean percent reduction among the three treatments (Tandem, Temprid SC, Transport Mikron) at eight weeks. Tandem spray caused significantly faster bed bug reduction than Temprid SC spray and Transport Mikron spray.

Mechanisms of Pyrethroid Insecticide-Induced Stimulation of Calcium Influx in Neocortical Neurons

PubMed Central

Cao, Zhengyu; Shafer, Timothy J.

2011-01-01

Pyrethroid insecticides bind to voltage-gated sodium channels (VGSCs) and modify their gating kinetics, thereby disrupting neuronal function. Pyrethroids have also been reported to alter the function of other channel types, including activation of voltage-gated calcium channels. Therefore, the present study compared the ability of 11 structurally diverse pyrethroids to evoke Ca2+ influx in primary cultures of mouse neocortical neurons. Nine pyrethroids (tefluthrin, deltamethrin, λ-cyhalothrin, β-cyfluthrin, esfenvalerate, S-bioallethrin, fenpropathrin, cypermethrin, and bifenthrin) produced concentration-dependent elevations in intracellular calcium concentration ([Ca2+]i) in neocortical neurons. Permethrin and resmethrin were without effect on [Ca2+]i. These pyrethroids displayed a range of efficacies on Ca2+ influx; however, the EC50 values for active pyrethroids all were within one order of magnitude. Tetrodotoxin blocked increases in [Ca2+]i caused by all nine active pyrethroids, indicating that the effects depended on VGSC activation. The pathways for deltamethrin- and tefluthrin-induced Ca2+ influx include N-methyl-d-aspartic acid receptors, L-type Ca2+ channels, and reverse mode of operation of the Na+/Ca2+ exchanger inasmuch as antagonists of these sites blocked deltamethrin-induced Ca2+ influx. These data demonstrate that pyrethroids stimulate Ca2+ entry into neurons subsequent to their actions on VGSCs. PMID:20881019

Evaluation of spray application methods for navel orangeworm control in almonds.

PubMed

Markle, James C; Niederholzer, Franz Ja; Zalom, Frank G

2016-12-01

Gear Up/Throttle Down (GUTD) and Inward Only strategies represent potential alternatives to conventional airblast applications to reduce spray drift. This study evaluates Inward Only and a modified version of GUTD in almonds, the largest US tree crop, at the recommended hull split treatment timing for control of navel orangeworm (NOW), the key almond insect pest. Conventional treatment produced the most drift (15.6% of total bifenthrin load), while the GUTD and Inward Only treatments produced only 7.6 and 9.7% respectively. For all methods, 92-94% of the drift was found in the first 15.2 m downwind of the orchard. NOW control was lower for the Inward Only treatment compared with the GUTD and conventional treatments. NOW control was consistently lower at 4.88 m height relative to 2.44 m in all treatments, reflecting the reduced deposition higher in the tree canopy recorded in deposition samples. While Inward Only treatments reduced spray drift relative to the conventional application method, poorer control of NOW, the key insect pest of almonds, in the Inward Only treatment would likely limit its voluntary use by growers. However, GUTD holds promise for use at the hull split treatment timing to address spray drift. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Field Study of the Comparative Efficacy of Three Pyrethroid/Neonicotinoid Mixture Products for the Control of the Common Bed Bug, Cimex lectularius

PubMed Central

Wang, Changlu; Singh, Narinderpal; Cooper, Richard

2015-01-01

Three insecticide mixtures that contain two classes of insecticides (pyrethroid and neonicotinoid) were recently developed to control bed bugs. We evaluated three integrated bed bug management strategies in apartments, each using the same non-chemical control methods and one of the three insecticide mixture products: Tandem (lambda-cyhalothrin + thiamethoxam), Temprid SC (beta-cyfluthrin + imidacloprid), and Transport Mikron (bifenthrin + acetamiprid). No insecticides were applied in the Control apartments. In all apartments, we installed vinyl mattress encasements (if not already present) and applied steam to beds and other infested upholstered furniture. Insecticide sprays were applied in the three treatments. Each treatment and the Control included 8–10 occupied apartments. Re-treatment was conducted during biweekly inspections if necessary. After eight weeks, the mean (± SEM) bed bug count reduction in the Tandem, Temprid SC, Transport Mikron, and Control was 89 ± 9, 87 ± 6, 98 ± 1, and 23 ± 54%, respectively. Only Tandem and Transport Mikron treatments resulted in significantly higher population reduction than the Control at eight weeks. There were no significant differences in mean percent reduction among the three treatments (Tandem, Temprid SC, Transport Mikron) at eight weeks. Tandem spray caused significantly faster bed bug reduction than Temprid SC spray and Transport Mikron spray. PMID:26463075

Dynamics of uptake and elimination of pyrethroid insecticides in zebrafish (Danio rerio) eleutheroembryos.

PubMed

Tu, Wenqing; Lu, Bin; Niu, Lili; Xu, Chao; Lin, Chunmian; Liu, Weiping

2014-09-01

Synthetic pyrethroids (SPs) are among the most heavily used insecticides for residential and agricultural applications. Their residues have frequently been detected in aquatic ecosystems. Despite their high aquatic toxicity, their toxicokinetics are still unclear. In this study, the kinetics of uptake and depuration of three SPs, permethrin (PM), bifenthrin (BF) and λ-cyhalothrin (λ-CH), were determined for the first time using zebrafish eleutheroembryo assays. The diastereoisomer selectivity of PM in eleutheroembryos was further examined. The results indicated that three SPs were quickly taken up by eleutheroembryos. The bioaccumulation factors of the SPs ranged from 125.4 to 708.4. The depuration of SPs in zebrafish eleutheroembryos followed the first-order process. The elimination rate constants (k2) of SPs in eleutheroembryos ranged from 0.018 h(-1) to 0.0533 h(-1). The half-lives (t1/2) were in the range 13.0-38.5h. The diastereoisomer fraction (DF) values for PM in the eleutheroembryos estimated at different uptake and depuration times were all significantly greater than the original value (DF=0.43), indicating selective enrichment and elimination of cis-PM relative to trans-PM. These results reveal a high capacity for SP bioconcentration by zebrafish eleutheroembryos, suggesting that SPs possess a highly cumulative risk to fish. Copyright © 2014 Elsevier Inc. All rights reserved.

Extraction and analysis methods for the determination of pyrethroid insecticides in surface water, sediments and biological tissues at environmentally relevant concentrations.

PubMed

Mekebri, A; Crane, D B; Blondina, G J; Oros, D R; Rocca, J L

2008-05-01

The aim of this study was to develop and validate chemical methods for measuring pyrethroid insecticides at environmentally relevant concentrations in different matrices. The analytes included six synthetic pyrethroids with the highest agricultural and commercial structural uses in California: bifenthrin, cyfluthrin, cypermethrin, esfenvalerate/fenvalerate, lambda-cyhalothrin, permethrin, and their corresponding stereoisomers, which includes enantiomers, diastereomers and racemic mixtures. Fortified water samples were extracted for analysis of synthetic pyrethroids using liquid-liquid extraction, while fortified sediment and fish tissue samples were extracted using pressurized fluid extraction followed by gel permeation chromatography (GPC) to remove matrix interferences. A florisil column was used for additional cleanup and fractionation of sediment and tissue extracts. Extracts were analyzed using dual column high resolution gas chromatography with electron capture detection (GC/ECD) and confirmation was obtained with gas chromatography mass spectrometry using a quadrupole ion trap detector in MS-MS mode. Method detection limits (MDLs) have been established for water (1-3 ng/L), sediment (0.5-4 ng/g dry weight) and tissue (1-3 ng/g fresh weight). Mean percent recoveries of fortified blanks and samples ranged from 75 to 115% with relative standard deviation (RSD) values less than 20% for all target compounds.

Sublethal Effects of Insecticide Exposure on Megacopta cribraria (Fabricius) Nymphs: Key Biological Traits and Acetylcholinesterase Activity.

PubMed

Miao, Jin; Reisig, Dominic D; Li, Guoping; Wu, Yuqing

2016-01-01

Megacopta cribraria F. (Hemiptera: Plataspidae), the kudzu bug, is an invasive insect pest of U.S. soybean. At present, insecticide application is the primary and most effective control option for M. cribraria In this study, the potential effects of sublethal and low-lethal concentrations (LC10 and LC40) of three common insecticides on key biological traits and acetylcholinesterase (AChE) activity of the treated nymphal stage of insect were assessed. The results show that the sublethal concentration of imidacloprid significantly reduced adult emergence rate of M. cribraria A low-lethal concentration of imidacloprid significantly increased nymphal development time, but significantly decreased adult emergence rate and adult longevity. Both sublethal and low-lethal concentrations of acephate caused an increase in nymphal development time and a reduction in adult emergence rate and adult longevity. Fecundity of females was significantly reduced only by exposure to low-lethal concentrations of acephate. Sublethal and low-lethal concentrations of bifenthrin increased nymphal development time, but significantly decreased adult emergence rate. In addition, we found that the AChE activity of M. cribraria was significantly increased only by LC40 imidacloprid, but strongly inhibited by acephate. © The Author 2016. Published by Oxford University Press on behalf of the Entomological Society of America.

Knockdown, residual, and antifeedant activity of pyrethroids and home landscape bioinsecticides against Japanese beetles (Coleoptera: Scarabaeidae) on Linden foliage.

PubMed

Baumler, Rebecca E; Potter, Daniel A

2007-04-01

Residual toxicity and leaf protection capability of five pyrethroids, professional and home garden azadirachtin formulations, and six other bioinsecticides for the home landscape were evaluated against the Japanese beetle, Popillia japonica Newman (Coleoptera: Scarabaeidae), on linden, Tilia cordata L. Capacity of intoxicated beetles to recover and subsequently feed and disperse also was evaluated to provide insight on activity characteristics of the different compounds. Intact shoots were sprayed and left in the field for varying intervals before being challenged with beetles in no-choice and choice tests. All pyrethroids except permethrin gave greater leaf protection, knockdown, and kill than did carbaryl, the standard, after 14 d of weathering. Deltamethrin, cyfluthrin, bifenthrin, and lamda-cyhalothrin gave a high level of protection for at least 19 d, and azadirachtin (Azatin XL) deterred feeding in choice tests for as long as 14 d. Home garden formulations containing pyrethrins in canola oil (Pyola) or azadiractin (Neem-Away) gave good short-term (< 3-d) protection. Formulations of capsaicin, rotenone + pyrethrins, kaolin particle film, D-limonene, or garlic extract were ineffective, the latter two formulations being highly phytotoxic to linden. Results of this study should help support updating of guidelines for insecticidal control of Japanese beetles.