Repellent Effects of Different Celery Varieties in Bemisia tabaci (Hemiptera: Aleyrodidae) Biotype Q.

PubMed

Tu, Hongtao; Qin, Yuchuan

2017-06-01

Y-tube olfactometer and net cages experiments were used to investigate the repellent effects of different celery varieties in biotype Q of sweetpotato whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), on cucumber, Cucumis sativus L. (Cucurbitaceae). Y-tube olfactometer tests showed that whiteflies have strong repellent behavior to different celery varieties. Intercropping different celery varieties with cucumbers had significant repellent effects and oviposition deterrent effects in whiteflies. Results obtained demonstrated that the Western Europe celery varieties, Juventus and Ventura, and the Chinese celery variety, Jinnan, had good repellent efficacy against the whitefly. D-Limonene, β-myrcene, and (E)-β-ocimene might be the main active components in celery that affected the selection behavior of B. tabaci. In Western Europe celery varieties, D-limonene was the main volatile component for the repellent effects in B. tabaci; however, the two Chinese celery varieties that showed repellent effects had relatively higher volatilization quantities of β-myrcene than of D-limonene. © 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.

Occurrence of Entomopathogenic Fungi from Agricultural and Natural Ecosystems in Saltillo, México, and their Virulence Towards Thrips and Whiteflies

PubMed Central

Sánchez-Peña, Sergio R.; Lara, Jorge San-Juan; Medina, Raúl F.

2011-01-01

Entomopathogenic fungi were collected from soil in four adjacent habitats (oak forest, agricultural soil, pine reforestation and chaparral habitat) in Saltillo, México using the insect bait method with Tenebrio molitor (L.) (Coleoptera: Tenebrionidae) larvae as bait. Overall, of the larvae exposed to soil, 171 (20%) hosted Beauveria bassiana (Balsamo) Vuillemin (Hypocreales: Cordycipitaceae), 25 (3%) hosted Metarhizium anisopliae (Metschnikoff) Sorokin (Hypocreales: Clavicipitaceae) and 1 (0.1%) hosted lsaria (=Paecilomyces) sp. (Hypocreales: Cordycipitaceae). B. bassiana was significantly more frequent on larvae exposed to oak forest soil. M. anisopliae was significantly more frequent on larvae exposed to agricultural soil. From the infected bait insects, 93 isolates of B. bassiana and 24 isolates of M. anisopliae were obtained. Strains were tested for their infectivity against Cuban laurel thrips, Gynaikothrips uzeli Zimmerman (Thysanoptera: Phlaeothripidae) and the greenhouse whitefly, Trialeurodes vaporariorum (Westwood) (Hemiptera: Aleyrodidae). B. bassiana isolates caused the highest mortality on thrips (some causing 88% mortality after 6 days); both fungal species caused similarly high mortality levels against whiteflies (75%) after 6 days. Large amounts of germplasm of entomopathogenic fungi, fundamentally B. bassiana and M. anisopliae, exist in the habitats sampled; pathogenicity varied among strains, and some strains possessed significant virulence. Soils in these habitats are reservoirs of diverse strains with potential for use in biocontrol. PMID:21521145

Spatiotemporal Dynamics of Whitefly Bemisia tabaci (Hemiptera: Aleyrodidae) in Commercial Watermelon Crops.

PubMed

Lima, Carlos H O; Sarmento, Renato A; Galdino, Tarcísio V S; Pereira, Poliana S; Silva, Joedna; Souza, Danival J; Dos Santos, Gil R; Costa, Thiago L; Picanço, Marcelo C

2018-04-16

Spatiotemporal dynamics studies of crop pests enable the determination of the colonization pattern and dispersion of these insects in the landscape. Geostatistics is an efficient tool for these studies: to determine the spatial distribution pattern of the pest in the crops and to make maps that represent this situation. Analysis of these maps across the development of plants can be used as a tool in precision agriculture programs. Watermelon, Citrullus lanatus (Thunb.) Matsum. and Nakai (Cucurbitales: Cucurbitaceae), is the second most consumed fruit in the world, and the whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is one of the most important pests of this crop. Thus, the objective of this work was to determine the spatiotemporal distribution of B. tabaci in commercial watermelon crops using geostatistics. For 2 yr, we monitored adult whitefly densities in eight watermelon crops in a tropical climate region. The location of the samples and other crops in the landscape was georeferenced. Experimental data were submitted to geostatistical analysis. The colonization of B. tabaci had two patterns. In the first, the colonization started at the outermost parts of the crop. In the second, the insects occupied the whole area of the crop since the beginning of cultivation. The maximum distance between sites of watermelon crops in which spatial dependence of B. tabaci densities was observed was 19.69 m. The adult B. tabaci densities in the eight watermelon fields were positively correlated with rainfall and relative humidity, whereas wind speed negatively affected whiteflies population.

Plastic cup traps equipped with light-emitting diodes for monitoring adult Bemisia tabaci (Homoptera: Aleyrodidae).

PubMed

Chu, Chang-Chi; Jackson, Charles G; Alexander, Patrick J; Karut, Kamil; Henneberry, Thomas J

2003-06-01

Equipping the standard plastic cup trap, also known as the CC trap, with lime-green light-emitting diodes (LED-plastic cup trap) increased its efficacy for catching Bemisia tabaci by 100%. Few Eretmocerus eremicus Rose and Zolnerowich and Encarsia formosa Gahan were caught in LED-plastic cup traps. The LED-plastic cup traps are less expensive than yellow sticky card traps for monitoring adult whiteflies in greenhouse crop production systems and are more compatible with whitefly parasitoids releases for Bemisia nymph control.

Whitefly Bemisia tabaci (Homoptera: Aleyrodidae) infestation on cassava genotypes grown at different ecozones in Nigeria.

PubMed

Ariyo, O A; Dixon, A G O; Atiri, G I

2005-04-01

Large-scale screening of cassava, Manihot esculenta Crantz, genotypes for resistance to infestation by whitefly Bemisia tabaci Gennadius, the vector of cassava mosaic geminiviruses, is limited. A range of new cassava elite clones were therefore assessed for the whitefly infestation in the 1999/2000 and 2000/2001 cropping seasons in experimental fields of International Institute of Tropical Agriculture, Ibadan, Nigeria. On each scoring day, between 0600 and 0800 hours when the whiteflies were relatively immobile, adult whitefly populations on the five topmost expanded leaves of cassava cultivars were counted. All through the 6-mo scoring period, there was a highly significant difference in whitefly infestation among the new cassava elite clones. Vector population buildup was observed in Ibadan (forest-savanna transition zone) and Onne (humid forest), 2 mo after planting (MAP). Mean infestation across cassava genotypes was significantly highest (16.6 whiteflies per plant) in Ibadan and lowest in Zaria (0.2). Generally, whitefly infestation was very low in all locations at 5 and 6 MAP. During this period, cassava genotypes 96/1439 and 91/02324 significantly supported higher infestations than other genotypes. Plants of 96/1089A and TMS 30572 supported the lowest whitefly infestation across cassava genotypes in all locations. The preferential whitefly visitation, the differences between locations in relation to whitefly population, cassava mosaic disease, and the fresh root yield of cassava genotypes are discussed.

Characterization of a Newly Discovered Symbiont of the Whitefly Bemisia tabaci (Hemiptera: Aleyrodidae)

PubMed Central

Bing, Xiao-Li; Yang, Jiao; Zchori-Fein, Einat; Wang, Xiao-Wei

2013-01-01

Bemisia tabaci (Hemiptera: Aleyrodidae) is a species complex containing >28 cryptic species, some of which are important crop pests worldwide. Like many other sap-sucking insects, whiteflies harbor an obligatory symbiont, “Candidatus Portiera aleyrodidarum,” and a number of secondary symbionts. So far, six genera of secondary symbionts have been identified in B. tabaci. In this study, we report and describe the finding of an additional bacterium in the indigenous B. tabaci cryptic species China 1 (formerly known as B. tabaci biotype ZHJ3). Phylogenetic analysis based on the 16S rRNA and gltA genes showed that the bacterium belongs to the Alphaproteobacteria subdivision of the Proteobacteria and has a close relationship with human pathogens of the genus Orientia. Consequently, we temporarily named it Orientia-like organism (OLO). OLO was found in six of eight wild populations of B. tabaci China 1, with the infection rate ranging from 46.2% to 76.8%. Fluorescence in situ hybridization (FISH) of B. tabaci China 1 in nymphs and adults revealed that OLOs are confined to the bacteriome and co-occur with “Ca. Portiera aleyrodidarum.” The vertical transmission of OLO was demonstrated by detection of OLO at the anterior pole end of the oocytes through FISH. Quantitative PCR analysis of population dynamics suggested a complex interaction between “Ca. Portiera aleyrodidarum” and OLO. Based on these results, we propose “Candidatus Hemipteriphilus asiaticus” for the classification of this symbiont from B. tabaci. PMID:23144129

Enumerative and binomial sampling plans for citrus mealybug (Homoptera: pseudococcidae) in citrus groves.

PubMed

Martínez-Ferrer, María Teresa; Ripollés, José Luís; Garcia-Marí, Ferran

2006-06-01

The spatial distribution of the citrus mealybug, Planococcus citri (Risso) (Homoptera: Pseudococcidae), was studied in citrus groves in northeastern Spain. Constant precision sampling plans were designed for all developmental stages of citrus mealybug under the fruit calyx, for late stages on fruit, and for females on trunks and main branches; more than 66, 286, and 101 data sets, respectively, were collected from nine commercial fields during 1992-1998. Dispersion parameters were determined using Taylor's power law, giving aggregated spatial patterns for citrus mealybug populations in three locations of the tree sampled. A significant relationship between the number of insects per organ and the percentage of occupied organs was established using either Wilson and Room's binomial model or Kono and Sugino's empirical formula. Constant precision (E = 0.25) sampling plans (i.e., enumerative plans) for estimating mean densities were developed using Green's equation and the two binomial models. For making management decisions, enumerative counts may be less labor-intensive than binomial sampling. Therefore, we recommend enumerative sampling plans for the use in an integrated pest management program in citrus. Required sample sizes for the range of population densities near current management thresholds, in the three plant locations calyx, fruit, and trunk were 50, 110-330, and 30, respectively. Binomial sampling, especially the empirical model, required a higher sample size to achieve equivalent levels of precision.

Complementary effect of Phloxine B on the insecticidal efficacy of Isaria fumosorosea SFP-198 wettable powder against greenhouse whitefly, Trialeurodes vaporariorum West.

PubMed

Kim, Jae Su; Je, Yeon Ho; Choi, Jae Young

2010-12-01

Insecticidal activities of five photoactive dyes against greenhouse whitefly (GWF), Trialeurodes vaporariorum West., in tomatoes were investigated to improve the control efficacy of an entomopathogenic fungal product, Isaria fumosorosea SFP-198 wettable powder (WP). Azorubine, Eosin B, Erythrosine, Brilliant Green and Phloxine B were used in this work, accompanying pyriproxyfen emulsifiable concentrate (EC) as a commercial standard for comparison. Phloxine B had the highest control efficacy in glasshouse conditions. The most suitable dose of Phloxine B was determined as 0.005 g L(-1) , given the dosage-dependent control efficacy and phytotoxicity of the dye, and its influence on the germination of SFP-198 conidia. In field conditions, SFP-198 WP + Phloxine B (2 + 0.005 g L(-1) ; tank mix) showed 89.1 and 95.3% control efficacy 7 and 14 days post-application, which was significantly higher than the efficacy of SFP-198 WP alone (43.5 and 64.0%), Phloxine B (47.5 and 30.7%) or pyriproxyfen EC (67.7 and 80.2%). Phloxine B cooperates with SFP-198 WP complementarily, possibly in the order of killing action (early: Phloxine B; late: SFP-198 WP). The dye can be incorporated into SFP-198 WP to improve its efficacy and applied to other Hypocrelean entomopathogenic fungal products. Copyright © 2010 Society of Chemical Industry.

Cryptic Species Identification and Composition of Bemisia tabaci (Hemiptera: Aleyrodidae) Complex in Henan Province, China

PubMed Central

Hu, Jian; Wang, Lun-Ji; Dong, Jun-Feng; Song, Yue-Qin; Sun, Hui-Zhong

2017-01-01

Abstract Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is a cryptic species complex, causing significant crop losses in China during the last decade. Although knowledge of cryptic species composition and dynamics within B. tabaci complex is critical for developing sustainable pest management strategies, limited information is available on this pest in the Henan province of China. A systematic survey of the cryptic species composition and distribution of B. tabaci complex in different locations of Henan province was conducted in 2012. The results of RAPD-PCR and the gene for the mitochondrial cytochrome oxidase subunit-1 (mtCOI) based phylogenetic relationships established using Bayesian method indicated there were four known cryptic species MEAM1, MED, Asia II 3, Asia II 9 and a new cryptic species named China 6 in Henan province. In the survey, the invasive cryptic species MED and MEAM1 were found to be predominant with wide spread distribution across the surveyed regions. On the contrary, the indigenous B. tabaci cryptic species including Asia II 3, Asia II 9 and China 6 remained with low prevalence in some surveyed regions. Cryptic species MEAM1 and MED have not completely displaced the native B. tabaci in Henan province. This current study for the first time unifies our knowledge of the diversity and distribution of B. tabaci across Henan province of China. PMID:28973577

Characterization of Phenacoccus solenopsis (Tinsley) (Homoptera: Pseudococcidae) Resistance to Emamectin Benzoate: Cross-Resistance Patterns and Fitness Cost Analysis.

PubMed

Afzal, M B S; Shad, S A

2016-06-01

Cotton mealybug Phenacoccus solenopsis (Tinsley) (Homoptera: Pseudococcidae) is a sucking pest of worldwide importance causing huge losses by feeding upon cotton in various parts of the world. Because of the importance of this pest, this research was carried out to select emamectin resistance in P. solenopsis in the laboratory to study cross-resistance, stability, realized heritability, and fitness cost of emamectin resistance. After selection from third generation (G3) to G6, P. solenopsis developed very high emamectin resistance (159.24-fold) when compared to a susceptible unselected population (Unsel pop). Population selected to emamectin benzoate conferred moderate (45.81-fold), low (14.06-fold), and no cross-resistance with abamectin, cypermethrin, and profenofos, respectively compared to the Unsel pop. A significant decline in emamectin resistance was observed in the resistant population when not exposed to emamectin from G7 to G13. The estimated realized heritability (h (2)) for emamectin resistance was 0.84. A high fitness cost was associated with emamectin resistance in P. solenopsis. Results of this study may be helpful in devising insecticide resistance management strategies for P. solenopsis.

A geographic distribution database of the Neotropical cassava whitefly complex (Hemiptera, Aleyrodidae) and their associated parasitoids and hyperparasitoids (Hymenoptera)

PubMed Central

Vásquez-Ordóñez, Aymer Andrés; Hazzi, Nicolas A.; Escobar-Prieto, David; Paz-Jojoa, Dario; Parsa, Soroush

2015-01-01

Abstract Whiteflies (Hemiptera, Aleyrodidae) are represented by more than 1,500 herbivorous species around the world. Some of them are notorious pests of cassava (Manihot esculenta), a primary food crop in the tropics. Particularly destructive is a complex of Neotropical cassava whiteflies whose distribution remains restricted to their native range. Despite their importance, neither their distribution, nor that of their associated parasitoids, is well documented. This paper therefore reports observational and specimen-based occurrence records of Neotropical cassava whiteflies and their associated parasitoids and hyperparasitoids. The dataset consists of 1,311 distribution records documented by the International Center for Tropical Agriculture (CIAT) between 1975 and 2012. The specimens are held at CIAT’s Arthropod Reference Collection (CIATARC, Cali, Colombia). Eleven species of whiteflies, 14 species of parasitoids and one species of hyperparasitoids are reported. Approximately 66% of the whitefly records belong to Aleurotrachelus socialis and 16% to Bemisia tuberculata. The parasitoids with most records are Encarsia hispida, Amitus macgowni and Encarsia bellottii for Aleurotrachelus socialis; and Encarsia sophia for Bemisia tuberculata. The complete dataset is available in Darwin Core Archive format via the Global Biodiversity Information Facility (GBIF). PMID:26798295

Cryptic Species Identification and Composition of Bemisia tabaci (Hemiptera: Aleyrodidae) Complex in Henan Province, China.

PubMed

Jiu, Min; Hu, Jian; Wang, Lun-Ji; Dong, Jun-Feng; Song, Yue-Qin; Sun, Hui-Zhong

2017-05-01

Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is a cryptic species complex, causing significant crop losses in China during the last decade. Although knowledge of cryptic species composition and dynamics within B. tabaci complex is critical for developing sustainable pest management strategies, limited information is available on this pest in the Henan province of China. A systematic survey of the cryptic species composition and distribution of B. tabaci complex in different locations of Henan province was conducted in 2012. The results of RAPD-PCR and the gene for the mitochondrial cytochrome oxidase subunit-1 (mtCOI) based phylogenetic relationships established using Bayesian method indicated there were four known cryptic species MEAM1, MED, Asia II 3, Asia II 9 and a new cryptic species named China 6 in Henan province. In the survey, the invasive cryptic species MED and MEAM1 were found to be predominant with wide spread distribution across the surveyed regions. On the contrary, the indigenous B. tabaci cryptic species including Asia II 3, Asia II 9 and China 6 remained with low prevalence in some surveyed regions. Cryptic species MEAM1 and MED have not completely displaced the native B. tabaci in Henan province. This current study for the first time unifies our knowledge of the diversity and distribution of B. tabaci across Henan province of China. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America.

Spatial distribution of nymphs of Scaphoideus titanus (Homoptera: Cicadellidae) in grapes, and evaluation of sequential sampling plans.

PubMed

Lessio, Federico; Alma, Alberto

2006-04-01

The spatial distribution of the nymphs of Scaphoideus titanus Ball (Homoptera Cicadellidae), the vector of grapevine flavescence dorée (Candidatus Phytoplasma vitis, 16Sr-V), was studied by applying Taylor's power law. Studies were conducted from 2002 to 2005, in organic and conventional vineyards of Piedmont, northern Italy. Minimum sample size and fixed precision level stop lines were calculated to develop appropriate sampling plans. Model validation was performed, using independent field data, by means of Resampling Validation of Sample Plans (RVSP) resampling software. The nymphal distribution, analyzed via Taylor's power law, was aggregated, with b = 1.49. A sample of 32 plants was adequate at low pest densities with a precision level of D0 = 0.30; but for a more accurate estimate (D0 = 0.10), the required sample size needs to be 292 plants. Green's fixed precision level stop lines seem to be more suitable for field sampling: RVSP simulations of this sampling plan showed precision levels very close to the desired levels. However, at a prefixed precision level of 0.10, sampling would become too time-consuming, whereas a precision level of 0.25 is easily achievable. How these results could influence the correct application of the compulsory control of S. titanus and Flavescence dorée in Italy is discussed.

Cross-kingdom effects of plant-plant signaling via volatile organic compounds emitted by tomato (Solanum lycopersicum) plants infested by the greenhouse whitefly (Trialeurodes vaporariorum).

PubMed

Ángeles López, Yesenia Ithaí; Martínez-Gallardo, Norma Angélica; Ramírez-Romero, Ricardo; López, Mercedes G; Sánchez-Hernández, Carla; Délano-Frier, John Paul

2012-11-01

Volatile organic compounds (VOCs) emitted from plants in response to insect infestation can function as signals for the attraction of predatory/parasitic insects and/or repulsion of herbivores. VOCs also may play a role in intra- and inter-plant communication. In this work, the kinetics and composition of VOC emissions produced by tomato (Solanum lycopersicum) plants infested with the greenhouse whitefly Trialeurodes vaporariorum was determined within a 14 days period. The VOC emission profiles varied concomitantly with the duration of whitefly infestation. A total of 36 different VOCs were detected during the experiment, 26 of which could be identified: 23 terpenoids, plus decanal, decane, and methyl salicylate (MeSA). Many VOCs were emitted exclusively by infested plants, including MeSA and 10 terpenoids. In general, individual VOC emissions increased as the infestation progressed, particularly at 7 days post-infestation (dpi). Additional tunnel experiments showed that a 3 days exposure to VOC emissions from whitefly-infested plants significantly reduced infection by a biotrophic bacterial pathogen. Infection of VOC-exposed plants induced the expression of a likely tomato homolog of a methyl salicylate esterase gene, which preceded the expression of pathogenesis-related protein genes. This expression pattern correlated with reduced susceptibility in VOC-exposed plants. The observed cross-kingdom effect of plant-plant signaling via VOCs probably represents a generalized defensive response that contributes to increased plant fitness, considering that resistance responses to whiteflies and biotrophic bacterial pathogens in tomato share many common elements.

Postembryonic development of the auditory system of the cicada Okanagana rimosa (Say) (Homoptera: Auchenorrhyncha: Cicadidae).

PubMed

Strauss, Johannes; Lakes-Harlan, Reinhard

2009-01-01

Cicadas (Homoptera: Auchenorrhyncha: Cicadidae) use acoustic signalling for mate attraction and perceive auditory signals by a tympanal organ in the second abdominal segment. The main structural features of the ear are the tympanum, the sensory organ consisting of numerous scolopidial cells, and the cuticular link between sensory neurones and tympanum (tympanal ridge and apodeme). Here, a first investigation of the postembryonic development of the auditory system is presented. In insects, sensory neurones usually differentiate during embryogenesis, and sound-perceiving structures form during postembryogenesis. Cicadas have an elongated and subterranian postembryogenesis which can take several years until the final moult. The neuroanatomy and functional morphology of the auditory system of the cicada Okanagana rimosa (Say) are documented for the adult and the three last larval stages. The sensory organ and the projection of sensory afferents to the CNS are present in the earliest stages investigated. The cuticular structures of the tympanum, the tympanal frame holding the tympanum, and the tympanal ridge differentiate in the later stages of postembryogenesis. Thus, despite the different life styles of larvae and adults, the neuronal components of the cicada auditory system develop already during embryogenesis or early postembryogenesis, and sound-perceiving structures like tympana are elaborated later in postembryogenesis. The life cycle allows comparison of cicada development to other hemimetabolous insects with respect to the influence of specially adapted life cycle stages on auditory maturation. The neuronal development of the auditory system conforms to the timing in other hemimetabolous insects.

Reproduction of the whitefly Bemisia tabaci (Hemiptera: Aleyrodidae) B biotype in maize fields (Zea mays L.) in Brazil.

PubMed

Quintela, Eliane D; Abreu, Aluana G; Lima, Julyana F Dos S; Mascarin, Gabriel M; Santos, Jardel B Dos; Brown, Judith K

2016-11-01

Bemisia tabaci (Genn.) (Hemiptera: Aleyrodidae) was observed to have completed its reproductive cycle from the egg to the adult on maize (Zea mays L.). Field and screenhouse studies were carried out to investigate the durability of this putative and unprecedented adaptation to a grass host. Analysis of the mitochondrial COI gene sequence identified the maize-associated B. tabaci as the exotic B biotype (major clade North Africa-Mediterranean-Middle East). Results showed that whiteflies migrated from soybean crops and successfully established in maize plants. Females exhibited a preference for oviposition primarily on the first and second leaves of maize, but were also able to colonise developing leaves. A high, natural infestation on maize (193.3 individuals, all developmental stages) was observed within a 7.1 cm 2 designated 'observation area'. Whiteflies collected from naturally infested maize leaves and allowed to oviposit on maize seedlings grown in a screenhouse developed from egg to adulthood in 28.6 ± 0.2 days. This is the first report of the B biotype completing its development on maize plants. This surprising anomaly indicates that the B biotype is capable of adapting to monocotyledonous host plants, and importantly, broadens the host range to include at least one species in the Poaceae. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Non-invasive delivery of dsGST is lethal to the sweet potato whitefly, Bemisia tabaci (G.) (Hemiptera: Aleyrodidae).

PubMed

Asokan, R; Rebijith, K B; Roopa, H K; Kumar, N K Krishna

2015-02-01

The sweet potato whitefly, Bemisia tabaci (G.) biotype B (Hemiptera: Aleyrodidae), is one of the most economically important pest, by being a dreaded vector of Geminiviruses, and also causes direct damage to the crops by sucking phloem sap. Glutathione S-transferase (GST) is a large family of multifunctional enzymes that play pivotal roles in the detoxification of secondary allelochemical produced by the host plants and in insecticide resistance, thus regulates insect growth and development. The objective of this study is to show the potential of RNA interference (RNAi) in the management of B. tabaci. RNAi is a sequence-specific gene silencing mechanism induced by double-stranded RNA (dsRNA) which holds tremendous potential in pest management. In this regard, we sequenced the GST from B. tabaci and synthesized approximately 500-bp dsRNA from the above and delivered through diet to B. tabaci. Real-time quantitative PCR (RT-qPCR) showed that continuous application of dsGST at 1.0, 0.5, and 0.25 μg/μl reduced mRNA expression levels for BtGST by 77.43, 64.86, and 52.95 % which resulted in mortality by 77, 59, and 40 %, respectively, after 72 h of application. Disruption of BtGST expression will enable the development of novel strategies in pest management and functional analysis of vital genes in B. tabaci.

Diversity and Distribution of Cryptic Species of the Bemisia tabaci (Hemiptera: Aleyrodidae) complex in Pakistan.

PubMed

Masood, Mariyam; Amin, Imran; Hassan, Ishtiaq; Mansoor, Shahid; Brown, Judith K; Briddon, Rob W

2017-12-05

Bemisia tabaci (Gennadius; Hempitera: Aleyrodidae) is considered to be a cryptic (sibling) species complex, the members of which exhibit morphological invariability while being genetically and behaviorally distinct. Members of the complex are agricultural pests that cause direct damage by feeding on plants, and indirectly by transmitting viruses that cause diseases leading to reduced crop yield and quality. In Pakistan, cotton leaf curl disease, caused by multiple begomovirus species, is the most economically important viral disease of cotton. In the study outlined here, the diversity and geographic distribution of B. tabaci cryptic species was investigated by analyzing a taxonomically informative fragment of the mitochondrial cytochrome c oxidase 1 gene (mtCOI-3'). The mtCOI-3' sequence was determined for 285 adult whiteflies and found to represent six cryptic species, the most numerous being Asia II-1 and Middle East Asia Minor 1 (MEAM-1), the later also referred to as the B-biotype, which was previously thought to be confined to Sindh province but herein, was also found to be present in the Punjab province. The endemic Asia I was restricted to Sindh province, while an individual in the Asia II-8 was identified in Pakistan for the first time. Also for the first time, samples were collected from northwestern Pakistan and Asia II-1 was identified. Results indicate that in Pakistan the overall diversity of B. tabaci cryptic species is high and, based on comparisons with findings from previous studies, the distribution is dynamic. © The Author(s) 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Members of Bemisia tabaci (Hemiptera: Aleyrodidae) Cryptic Species and the Status of Two Invasive Alien Species in the Yunnan Province (China)

PubMed Central

Hu, Jian; Jiang, Zhi-Lin; Nardi, Francesco; Liu, Yuan-Yuan; Luo, Xiao-Rong; Li, Hong-Xiang; Zhang, Zhong-Kai

2014-01-01

Abstract Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is a cryptic species complex that includes some of the most significant pests of agriculture and horticulture worldwide. To understand the diversity and distribution of B. tabaci cryptic species in Yunnan, a famous biodiversity hotspot in China, a large-scale sampling was conducted from year 2010 to 2013 in 10 prefectures. Mitochondrial cytochrome oxidase I gene sequences were used to identify different cryptic species. Phylogenetic analyses were performed using Bayesian methods to assess the position of a new B. tabaci cryptic species in the context of the B. tabaci diversity in Asia. The survey indicates at least eight B. tabaci cryptic species are present in Yunnan, two invasive (MEAM1 and MED) and six indigenous (China 2, China3, China 4, Asia I, Asia II 1, and Asia II 6), MEAM1, MED, and Asia I being the three predominant cryptic species in Yunnan. Compared with MEAM1, MED has a wider distribution. Based on molecular data, a new cryptic species, here named China 4, was identified that appears to be related to China 1, China 2, and China 3. Future efforts should focus on the interactions between predominant B. tabaci cryptic species and begomoviruses and on the development of effective control strategies. PMID:25502045

New putative cryptic species detection and genetic network analysis of Bemisia tabaci (Hempitera: Aleyrodidae) in China based on mitochondrial COI sequences.

PubMed

Hu, Jian; Zhang, Xiaoyun; Jiang, Zhilin; Zhang, Feifei; Liu, Yuanyuan; Li, Zhan; Zhang, Zhongkai

2018-04-01

The whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is a cryptic species complex and widely distributed throughout tropical and subtropical regions. To understand the B. tabaci cryptic species diversity in China more comprehensively, in the year 2014 and 2016, a large-scale sampling was conducted from the famous biodiversity hotspot of China, Yunnan province. Mitochondrial cytochrome oxidase I gene sequences were used to identify new putative cryptic species. Phylogenetic analyses were performed using Bayesian methods to evaluate the position of new cryptic species in the context of the B. tabaci diversity in Asia. Two new cryptic species, China 5 and Asia V were identified. In total, 19 B. tabaci cryptic species are present in China, two invasive (MED and MEAM1) and 17 indigenous. A new sibling species of B. tabaci was first defined and reported. Based on the mtCOI sequences and haplotype network analyses, the genetic diversity of MED was far higher than MEAM1. We confirmed the exotic MED was originated from the western Mediterranean regions and first invaded into Yunnan, China. The genetic structures of other four indigenous species (Asia I, Asia II 1, Asia II 6, and China 1) with relatively wide distribution ranges in China were also discussed.

Transgenic Cotton-Fed Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) Affects the Parasitoid Encarsia desantisi Viggiani (Hymenoptera: Aphelinidae) Development.

PubMed

Pessoa, R; Rossi, G D; Busoli, A C

2016-02-01

Cotton cultivars expressing Cry proteins are widely used to control lepidopteran pests. The effects of transgenic plants containing insecticidal Cry proteins on non-target species must be comprehended for a better and rational use of this technology for pest management. We investigated the influence of the Bt cotton cultivars NuOPAL and FM 975 on biological parameters of Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), a non-target pest of Bt cotton cultivars and on its parasitoid Encarsia desantisi Viggiani (Hymenoptera: Aphelinidae). The experiments were conducted in a climatized room, and the non-transgenic near isolines were used for rearing whiteflies as control hosts. The effects of the Bt cotton cultivars on the period of embryonic and larval development and the percentage of adult emergence of B. tabaci were assessed. The period required for embryonic, larval, and pupal development and the percentage of emergence and longevity of E. desantisi females were determined using Bt cotton-fed and non-Bt cotton-fed B. tabaci as hosts. Both Bt cotton cultivars resulted in a decrease of approximately 20% of adult emergence of B. tabaci. Differently, an increase of approximately 10% of adult emergence of E. desantisi was observed for parasitoids that used hosts fed with both Bt cotton cultivars. However, female parasitoid longevity decreased when their hosts were fed on Bt cotton cultivars. Our data suggest that the use of Bt cotton cultivars in association with the biological control agent E. desantisi could be functional for the management of B. tabaci in Bt cotton crops.

Development of a lateral flow test to detect metabolic resistance in Bemisia tabaci mediated by CYP6CM1, a cytochrome P450 with broad spectrum catalytic efficiency.

PubMed

Nauen, Ralf; Wölfel, Katharina; Lueke, Bettina; Myridakis, Antonis; Tsakireli, Dimitra; Roditakis, Emmanouil; Tsagkarakou, Anastasia; Stephanou, Euripides; Vontas, John

2015-06-01

Cotton whitefly, Bemisia tabaci (Genn.) (Homoptera: Aleyrodidae) is a major sucking pest in many agricultural and horticultural cropping systems globally. The frequent use of insecticides of different mode of action classes resulted in populations resisting treatments used to keep numbers under economic damage thresholds. Recently it was shown that resistance to neonicotinoids such as imidacloprid is linked to the over-expression of CYP6CM1, a cytochrome P450 monooxygenase detoxifying imidacloprid and other neonicotinoid insecticides when recombinantly expressed in insect cells. However over-expression of CYP6CM1 is also known to confer cross-resistance to pymetrozine, an insecticide not belonging to the chemical class of neonicotinoids. In addition we were able to demonstrate by LC-MS/MS analysis the metabolisation of pyriproxyfen by recombinantly expressed CYP6CM1. Based on our results CYP6CM1 is one of the most versatile detoxification enzymes yet identified in a pest of agricultural importance, as it detoxifies a diverse range of chemical classes used to control whiteflies. Therefore we developed a field-diagnostic antibody-based lateral flow assay which detects CYP6CM1 protein at levels providing resistance to neonicotinoids and other insecticides. The ELISA based test kit can be used as a diagnostic tool to support resistance management strategies based on the alternation of different modes of action of insecticides. Copyright © 2014 Elsevier Inc. 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.

Population Fluctuation and Altitudinal Distribution of Tetraleurodes perseae (Nakahara) (Hemiptera: Aleyrodidae) in Avocado (Lauraceae) in Morelos, Mexico.

PubMed

García-Palacios, Daniel; Bautista-Martínez, Néstor; Lagunes-Tejeda, Ángel; Carrillo-Sánchez, José Luis; Nieto-Ángel, Daniel; García-Gutiérrez, Cipriano

2016-01-01

Although whiteflies Tetraleurodes perseae (Nakahara) (Hemiptera: Aleyrodidae) are considered a secondary pest of avocado crops, their presence and the damages that they cause can decrease crop vigor and affect production. The objective of the present work was to determine the population fluctuation and altitudinal distribution of the T. perseae Nakahara whitefly in avocado trees, as well as to determine the number of possible generations in one year. The study was done in three orchards in Morelos state, located at different altitudes, from February 2014 to April 2015. Samplings were done every 21 days from 10 randomly chosen trees in each orchard. The samples were taken randomly from the middle stratus (1.6 m in height) of each tree; in buds or young leaves for the number of adults and leaves only for nymphs. Additionally, two yellow traps (7 × 14 cm) with glue were placed in each tree for adult samplings. Data were collected regarding vegetative budding, rainfall, relative humidity, and temperature. T. perseae was present in all three sampled orchards, with a greater presence in the lowest orchard, during the whole study period. In the orchard with the lowest altitudinal gradient (1,736 masl), 11 whitefly generations developed; 10 generations developed in the medium gradient orchard (1,934 masl); and 8 generations developed in the highest orchard (2,230 masl). The adults showed a positive relationship with regard to vegetative buds, while the nymphs had a negative relationship with regard to relative humidity. The rest of the parameters showed diverse effects on the species depending on the altitude of the orchard. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America.

Population Fluctuation and Altitudinal Distribution of Tetraleurodes perseae (Nakahara) (Hemiptera: Aleyrodidae) in Avocado (Lauraceae) in Morelos, Mexico

PubMed Central

García-Palacios, Daniel; Bautista-Martínez, Néstor; Lagunes-Tejeda, Ángel; Carrillo-Sánchez, José Luis; Nieto-Ángel, Daniel; García-Gutiérrez, Cipriano

2016-01-01

Although whiteflies Tetraleurodes perseae (Nakahara) (Hemiptera: Aleyrodidae) are considered a secondary pest of avocado crops, their presence and the damages that they cause can decrease crop vigor and affect production. The objective of the present work was to determine the population fluctuation and altitudinal distribution of the T. perseae Nakahara whitefly in avocado trees, as well as to determine the number of possible generations in one year. The study was done in three orchards in Morelos state, located at different altitudes, from February 2014 to April 2015. Samplings were done every 21 days from 10 randomly chosen trees in each orchard. The samples were taken randomly from the middle stratus (1.6 m in height) of each tree; in buds or young leaves for the number of adults and leaves only for nymphs. Additionally, two yellow traps (7 × 14 cm) with glue were placed in each tree for adult samplings. Data were collected regarding vegetative budding, rainfall, relative humidity, and temperature. T. perseae was present in all three sampled orchards, with a greater presence in the lowest orchard, during the whole study period. In the orchard with the lowest altitudinal gradient (1,736 masl), 11 whitefly generations developed; 10 generations developed in the medium gradient orchard (1,934 masl); and 8 generations developed in the highest orchard (2,230 masl). The adults showed a positive relationship with regard to vegetative buds, while the nymphs had a negative relationship with regard to relative humidity. The rest of the parameters showed diverse effects on the species depending on the altitude of the orchard. PMID:27658809

Members of Bemisia tabaci (Hemiptera: Aleyrodidae) cryptic species and the status of two invasive alien species in the Yunnan Province (China).

PubMed

Hu, Jian; Jiang, Zhi-Lin; Nardi, Francesco; Liu, Yuan-Yuan; Luo, Xiao-Rong; Li, Hong-Xiang; Zhang, Zhong-Kai

2014-01-01

Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is a cryptic species complex that includes some of the most significant pests of agriculture and horticulture worldwide. To understand the diversity and distribution of B. tabaci cryptic species in Yunnan, a famous biodiversity hotspot in China, a large-scale sampling was conducted from year 2010 to 2013 in 10 prefectures. Mitochondrial cytochrome oxidase I gene sequences were used to identify different cryptic species. Phylogenetic analyses were performed using Bayesian methods to assess the position of a new B. tabaci cryptic species in the context of the B. tabaci diversity in Asia. The survey indicates at least eight B. tabaci cryptic species are present in Yunnan, two invasive (MEAM1 and MED) and six indigenous (China 2, China3, China 4, Asia I, Asia II 1, and Asia II 6), MEAM1, MED, and Asia I being the three predominant cryptic species in Yunnan. Compared with MEAM1, MED has a wider distribution. Based on molecular data, a new cryptic species, here named China 4, was identified that appears to be related to China 1, China 2, and China 3. Future efforts should focus on the interactions between predominant B. tabaci cryptic species and begomoviruses and on the development of effective control strategies. © The Author 2014. Published by Oxford University Press on behalf of the Entomological Society of America.

Cassava whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) in East African farming landscapes: a review of the factors determining abundance.

PubMed

Macfadyen, S; Paull, C; Boykin, L M; De Barro, P; Maruthi, M N; Otim, M; Kalyebi, A; Vassão, D G; Sseruwagi, P; Tay, W T; Delatte, H; Seguni, Z; Colvin, J; Omongo, C A

2018-02-13

Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is a pest species complex that causes widespread damage to cassava, a staple food crop for millions of households in East Africa. Species in the complex cause direct feeding damage to cassava and are the vectors of multiple plant viruses. Whilst significant work has gone into developing virus-resistant cassava cultivars, there has been little research effort aimed at understanding the ecology of these insect vectors. Here we assess critically the knowledge base relating to factors that may lead to high population densities of sub-Saharan African (SSA) B. tabaci species in cassava production landscapes of East Africa. We focus first on empirical studies that have examined biotic or abiotic factors that may lead to high populations. We then identify knowledge gaps that need to be filled to deliver sustainable management solutions. We found that whilst many hypotheses have been put forward to explain the increases in abundance witnessed since the early 1990s, there are little published data and these tend to have been collected in a piecemeal manner. The most critical knowledge gaps identified were: (i) understanding how cassava cultivars and alternative host plants impact population dynamics and natural enemies; (ii) the impact of natural enemies in terms of reducing the frequency of outbreaks and (iii) the use and management of insecticides to delay the development of resistance. In addition, there are several fundamental methodologies that need to be developed and deployed in East Africa to address some of the more challenging knowledge gaps.

Analysis of Species, Subgroups, and Endosymbionts of Bemisia tabaci (Hemiptera: Aleyrodidae) From Southwestern Cotton Fields in Turkey.

PubMed

Karut, Kamil; Mete Karaca, M; Döker, Ismail; Kazak, Cengiz

2017-08-01

Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is one of the most important insect pests worldwide including Turkey. Although there are substantial data regarding species composition of Turkish B. tabaci populations, the situation is still not clear and further investigations are needed. Therefore, in this study, species and subgroups of B. tabaci collected from cotton fields in southwestern part of Turkey (Antalya, Aydın, Denizli, and Muğla) were determined using microsatellite analysis, AluI-based mtCOI polymerase chain reaction-random length polymorphism, and sequencing. Secondary endosymbionts were also determined using diagnostic species-specific PCR. Middle East Asia Minor 1 (MEAM1), Mediterranean (MED) Q1, and MED Q2 were the species and subgroups found in this study. The MED species (85.3%) were found to be more dominant than MEAM1. Species status of B. tabaci varied depending on the location. Although all samples collected from Aydın were found to be Q1, three species and subgroups were found in Muğla. Secondary endosymbionts varied according to species and subgroups. Arsenophonus was found only from Q2, while Hamiltonella was detected in MEAM1 and Q1. In addition, high Rickettsia and low Wolbachia infections were detected in MEAM1 and Q1 populations, respectively. In conclusion, for the first time, we report the presence and symbiotic communities of Q1 from Turkey. We also found that the symbiont complement of the Q1 is more congruent with Q1 from Greece than other regions of the world, which may have some interesting implications for movement of this invasive subgroup. © 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.

Spirotetramat Resistance Selected in the Phenacoccus solenopsis (Homoptera: Pseudococcidae): Cross-Resistance Patterns, Stability, and Fitness Costs Analysis.

PubMed

Ejaz, Masood; Ali Shad, Sarfraz

2017-06-01

The Phenacoccus solenopsis Tinsley (Homoptera: Pseudococcidae) is a major agricultural and horticultural pest of crops throughout the world. To develop a better resistance management strategy for P. solenopsis, we conducted a study on life history parameters of different populations of this pest, one selected with spirotetramat (Spiro-SEL), an unselected (UNSEL) population, and their reciprocal crosses. We also studied the cross-resistance and the stability of spirotetramat resistance. The Spiro-SEL of P. solenopsis exhibited a 328.69-fold resistance compared to the susceptible population (Lab-PK). The Spiro-SEL population also displayed a moderate level of cross-resistance to profenofos and bifenthrin and a high level of cross-resistance to abamectin. Resistance to spirotetramat in Spiro-SEL was unstable in the absence of selection. The study of life history parameters showed that there was a significant reduction in fitness parameters of Spiro-SEL population with a relative fitness value of 0.14. There was a significant decrease in survival rate, pupal weight, fecundity, egg hatching percentage, male and female generation time, intrinsic rate of population increase of males and females, biotic potential, and mean relative growth rate. It is concluded that selection with spirotetramat had marked effect on resistance development in P. solenopsis and upon removal of selection pressure spirotetramat resistance declined significantly, indicating unstable resistance. Development of resistance led to high fitness costs for the spirotetramat-selected population. Our study may provide the basic information on spirotetramat resistance and its mechanism to help develop the resistance management strategies. © 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.

Sensitivity of Bemisia Tabaci (Hemiptera: Aleyrodidae) to Several New Insecticides in China: Effects of Insecticide Type and Whitefly Species, Strain, and Stage

PubMed Central

Xie, Wen; Liu, Yang; Wang, Shaoli; Wu, Qingjun; Pan, Huipeng; Yang, Xin; Guo, Litao; Zhang, Youjun

2014-01-01

Abstract Whitefly biotypes B and Q are the two most damaging members of the Bemisia tabaci (Hemiptera: Aleyrodidae) species complex. Control of B. tabaci (and especially of Q) has been impaired by resistance to commonly used insecticides. To find new insecticides for B. tabaci management in China, we investigated the sensitivity of eggs, larvae, and adults of laboratory strains of B and Q (named Lab-B and Lab-Q) and field strains of Q to several insecticides. For eggs, larvae, and adults of B. tabaci and for six insecticides (cyantraniliprole, chlorantraniliprole, pyriproxyfen, buprofezin, acetamiprid, and thiamethoxam), LC 50 values were higher for Lab-Q than for Lab-B; avermectin LC 50 values, however, were low for adults of both Lab-Q and Lab-B. Based on the laboratory results, insecticides were selected to test against eggs, larvae, and adults of four field strains of B. tabaci Q. Although the field strains differed in their sensitivity to the insecticides, the eggs and larvae of all strains were highly sensitive to cyantraniliprole, and the adults of all strains were highly sensitive to avermectin. The eggs, larvae, and adults of B. tabaci Q were generally more resistant than those of B. tabaci B to the tested insecticides. B. tabaci Q eggs and larvae were sensitive to cyantraniliprole and pyriproxyfen, whereas B. tabaci Q adults were sensitive to avermectin. Field trials should be conducted with cyantraniliprole, pyriproxyfen, and avermectin for control of B. tabaci Q and B in China. PMID:25434040

Variation to cause host injury between Russian wheat aphid (Homoptera: Aphididae) clones virulent to Dn4 wheat.

PubMed

Shufran, K A; Mornhinweg, D W; Baker, C A; Porter, D R

2007-10-01

Biotypes are infraspecific classifications based on biological rather than morphological characteristics. Cereal aphids are managed primarily by host plant resistance, and they often develop biotypes that injure or kill previously resistant plants. Although molecular genetic variation within aphid biotypes has been well documented, little is known about phenotypic variation, especially virulence or the biotype's ability to cause injury to cultivars with specific resistance genes. Five clones (single maternal lineages) of Russian wheat aphid, Diuraphis noxia (Kurdjumov) (Homoptera: Aphididae), determined to be injurious to wheat, Triticum aestivum L., with the Dn4 gene, were evaluated on resistant and susceptible wheat and barley, Hordeum vulgare L., for their ability to cause chlorosis, reduction in plant height, and reduction in shoot dry weight. Variation to cause injury on resistant 'Halt' wheat, susceptible 'Jagger' wheat, and resistant 'STARS-9301B' barley was found among the Dn4 virulent clones. One clone caused up to 30.0 and 59.5% more reduction in plant height and shoot dry weight, respectively, on resistant Halt than other clones. It also caused up to 29.9 and 55.5% more reduction in plant height and shoot dry weight, respectively, on susceptible Jagger wheat. Although STARS-9301B barley exhibited an equal resistant response to feeding by all five clones based on chlorosis, two clones caused approximately 20% more reduction in plant height and shoot dry weight than three other clones. The most injurious clones on wheat were not the most injurious clones on barley. This is the first report of variation to cause varying degrees of plant damage within an aphid biotype virulent to a single host resistance gene. A single aphid clone may not accurately represent the true virulent nature of a biotype population in the field.

Leaf Morphological Characters Can Be a Factor for Intra-Varietal Preference of Whitefly Bemisia tabaci (Hemiptera: Aleyrodidae) among Eggplant Varieties.

PubMed

Hasanuzzaman, Abu Tayeb Mohammad; Islam, Md Nazrul; Zhang, Yi; Zhang, Chen-Yang; Liu, Tong-Xian

2016-01-01

The sweetpotato whitefly, Bemisia tabaci (Hemiptera: Aleyrodidae) MEAM1, is considered a serious pest of horticultural and many other crops. While eggplant (Solanum melongena) is one of the most favored host plants, the whiteflies exhibit preferences among different varieties. We hypothesized that certain morphological leaf characteristics of different varieties, like leaf trichome density, trichome length, leaf lamina thickness and leaf color, may affect whitefly landing, feeding and oviposition. In this study, we investigated the variation in leaf morphological characters among selected eggplant varieties and evaluated the effect of these leaf characteristics in rendering eggplant varieties either susceptible or resistant to B. tabaci. We evaluated eight eggplant varieties in choice feeding tests, and we found that the varieties JinSheng Zilongchangqie (JSZ) and H149 were the highly preferred varieties with the highest numbers of whitefly adults and eggs. Significantly lower numbers of whitefly adult eggs were found on the resistant variety Tuo Lu Bamu (TLB). The varieties JinGuangbo Luqie (JGL), JinGuangbo Ziquanqie (JGZ), DaYang Ziguanqie (DYZ), QinXing Ziguanqie (QXZ), and QinXing Niuxinqie (QXN) were moderately favored by B. tabaci. Leaf trichome density, trichome length and leaf lamina thickness were positively correlated with numbers of whitefly adults and eggs. B. tabaci was less attracted to the leaves that reflect long and middle wavelength light (higher R and G values) than to the bright green leaves (medium G value), but the short wavelength light (higher B value) had no significant effect on whitefly preference. The degree of hue had a positive effect, and saturation and brightness had a negative effect on whitefly attraction.

Thermotolerance and Heat-Shock Protein Gene Expression Patterns in Bemisia tabaci (Hemiptera: Aleyrodidae) Mediterranean in Relation to Developmental Stage.

PubMed

Jiang, Rui; Qi, Lan-Da; Du, Yu-Zhou; Li, Yuan-Xi

2017-10-01

Temperature plays an important role in the growth, development, and geographic distribution of insects. There is convincing evidence that heat-shock proteins (HSPs) play important roles in helping organisms adapt to thermal stress. To better understand the physiological and ecological influence of thermal stress on the different development stages of Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) Mediterranean species (MED), nymphs and adults were shocked with temperatures of 35, 38, and 41℃ for 1 and 2 h, respectively, and the survival rate, fecundity, and developmental duration were investigated in the laboratory. The expression levels of the hsp40, hsp70, and hsp90 genes were assessed using real-time PCR. The results indicate that the survival rates of the nymphs and adults decreased with increased temperature. A 2-h heat shock at 41℃ induced a significant reduction in fecundity in adults and an increase in developmental duration in young nymphs. Hsp90 showed higher temperature responses to thermal stress than hsp40 or hsp70. The expression levels of the hsps in the adults were significantly down-regulated by a 2-h heat shock at 41℃ compared with that by a 1-h treatment. A significant decrease in the expression levels of the hsps also occurred in the adults when the temperature increased from 38 to 41℃ for the 2-h treatment, whereas no significant decrease occurred in the nymphs. Compared with previous studies, we provide some evidence indicating that MED has the potential to adapt to a wider temperature range than the Middle East-Asia Minor 1 species. © 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.

Inter-regional differences in baseline toxicity of Bemisia argentifolii (Homoptera: Aleyrodidae) to the two insect growth regulators, buprofezin and pyriproxyfen.

PubMed

Toscano, N C; Prabhaker, N; Castle, S J; Henneberry, T J

2001-12-01

A survey of 53 Bemisia argentifolii Bellows & Perring populations from different agricultural regions in California and Arizona was conducted from 1997 to 1999 to establish baseline toxicological responses to buprofezin and pyriproxyfen. Although both compounds proved to be highly toxic even in minute quantities to specific stages, geographical and temporal differences in responses were detected using a leaf spray bioassay technique. Monitoring for three years revealed that six to seven populations had higher LC50 values but not greater survival when exposed to these two insecticides. A significant difference in relative susceptibility to buprofezin was first observed in late season 1997 in San Joaquin Valley populations with LC50s ranging from 16 to 22 microg (AI)/liter(-1) compared with IC50s of 1 to 3 mg (AI)/liter(-1) in Imperial, Palo Verde Valley and Yuma populations. Whiteflies collected in subsequent years from these and other locations showed an increase in susceptibility to buprofezin. Regional differences in susceptibilities to pyriproxyfen were minimal within the same years. Three years of sampling revealed consistently higher LC50s to pyriproxyfen in populations from Palo Verde Valley, CA, compared with whiteflies from Imperial, San Joaquin Valley or Yuma. As was the case with buprofezin, a decline in LC50s to pyriproxyfen was observed in whiteflies from all locations sampled in 1999. However, no correlation was observed between buprofezin and pyriproxyfen toxicity in any of the strains. The variable toxicities observed to both compounds over a period of 3 yr may be due principally to inherent differences among geographical populations or due to past chemical use which may confer positive or negative cross-resistance to buprofezin or pyriproxyfen.

Action threshold for applying insect growth regulators to tomato for management of irregular ripening caused by Bemisia argentifolii (Homoptera: Aleyrodidae).

PubMed

Schuster, D J

2002-04-01

The whitefly Bemisia argentifolii Bellows & Perring is a major pest of tomatoes, causing an irregular ripening disorder characterized externally by incomplete or inhibited reddening of fruit, especially in longitudinal sections, and internally by an increase in the amount of white tissue. Experiments were undertaken during the spring and fall of 1997 and 1998 and the spring of 1999 to develop an action threshold for applying the insect growth regulators (IGRs) buprofezin and pyriproxyfen to manage B. argentifolii and irregular ripening. The IGRs were applied when predetermined thresholds were reached and were compared with a high rate of the systemic insecticide imidacloprid, which was applied at transplanting and provided season-long whitefly control. Only plots treated when the numbers of sessile nymphs (second through fourth instars) reached five per 10 leaflets consistently had both external and internal irregular ripening severity ratings similar to the imidacloprid standard. Results were similar for buprofezin and pyriproxyfen even though the modes of action differ. The five nymphs per 10 leaflets threshold lends itself to field scouting because nymphal counts completed in the field using the unaided eye supplemented with a 10x hand lens were linearly and significantly related to counts completed in the laboratory with a dissecting microscope.

Sensitivity of Bemisia tabaci (Hemiptera: Aleyrodidae) to several new insecticides in China: effects of insecticide type and whitefly species, strain, and stage.

PubMed

Xie, Wen; Liu, Yang; Wang, Shaoli; Wu, Qingjun; Pan, Huipeng; Yang, Xin; Guo, Litao; Zhang, Youjun

2014-01-01

Whitefly biotypes B and Q are the two most damaging members of the Bemisia tabaci (Hemiptera: Aleyrodidae) species complex. Control of B. tabaci (and especially of Q) has been impaired by resistance to commonly used insecticides. To find new insecticides for B. tabaci management in China, we investigated the sensitivity of eggs, larvae, and adults of laboratory strains of B and Q (named Lab-B and Lab-Q) and field strains of Q to several insecticides. For eggs, larvae, and adults of B. tabaci and for six insecticides (cyantraniliprole, chlorantraniliprole, pyriproxyfen, buprofezin, acetamiprid, and thiamethoxam), LC50 values were higher for Lab-Q than for Lab-B; avermectin LC50 values, however, were low for adults of both Lab-Q and Lab-B. Based on the laboratory results, insecticides were selected to test against eggs, larvae, and adults of four field strains of B. tabaci Q. Although the field strains differed in their sensitivity to the insecticides, the eggs and larvae of all strains were highly sensitive to cyantraniliprole, and the adults of all strains were highly sensitive to avermectin. The eggs, larvae, and adults of B. tabaci Q were generally more resistant than those of B. tabaci B to the tested insecticides. B. tabaci Q eggs and larvae were sensitive to cyantraniliprole and pyriproxyfen, whereas B. tabaci Q adults were sensitive to avermectin. Field trials should be conducted with cyantraniliprole, pyriproxyfen, and avermectin for control of B. tabaci Q and B in China. © The Author 2014. Published by Oxford University Press on behalf of the Entomological Society of America.

Assessing Compatibility of Isaria fumosorosea and Buprofezin for Mitigation of Aleurodicus rugioperculatus (Hemiptera: Aleyrodidae): An Invasive Pest in the Florida Landscape.

PubMed

Kumar, Vivek; Francis, Antonio; Avery, Pasco B; McKenzie, Cindy L; Osborne, Lance S

2018-05-28

Rugose spiraling whitefly (RSW), Aleurodicus rugioperculatus Martin (Hemiptera: Aleyrodidae) is a new invasive whitefly pest in the Florida landscape, known to feed on a wide range of plants including palms, woody ornamentals, shrubs, and fruits. With the objective to find an alternative to neonicotinoid insecticides, and develop an ecofriendly management program for RSW, in the current study we evaluated the efficacy of a biopesticide containing the entomopathogenic fungi, Isaria fumosorosea Wize (Hypocreales: Clavicipitaceae), and an insect growth regulator buprofezin applied alone and in combination under laboratory and field conditions. Before assessing the two products, their compatibility was studied at six different concentrations of buprofezin. No significant inhibitive effect of buprofezin was observed on I. fumosorosea spore germination, and the average linear growth of the colony measured 14 d postinoculation. Under laboratory conditions, I. fumosorosea treatments (alone or mixed with buprofezin) provided higher RSW mortality than buprofezin alone. However, in both outdoor cage studies, the efficacy of buprofezin treatments (alone or mixed with I. fumosorosea) was higher than I. fumosorosea alone. A significant reduction in RSW population was reported for more than 5 wk in buprofezin alone and more than 7 wk in the combination treatments. In fall of 2014 and summer of 2015, the mean whitefly mortality observed during the 10-wk assessment period was 52.4 and 42.1% for I. fumosorosea, 79.6 and 79.0% for buprofezin, and 87.6 and 84.3% in mixed treatments, respectively. Results suggest that buprofezin can offer an effective alternate in the battle against invasive whiteflies such as RSW in Florida ecosystems, either as a stand-alone strategy or in an integrated approach.

Distribution of Bemisia tabaci (Hemiptera: Aleyrodidae) biotypes in North America after the Q invasion.

PubMed

McKenzie, Cindy L; Bethke, James A; Byrne, Frank J; Chamberlin, Joseph R; Dennehy, Timothy J; Dickey, Aaron M; Gilrein, Dan; Hall, Paula M; Ludwig, Scott; Oetting, Ronald D; Osborne, Lance S; Schmale, Lin; Shatters, Robert G

2012-06-01

After the 2004 discovery of the Bemisia tabaci (Gennadius) (Hemiptera Aleyrodidae) Q biotype in the United States, there was a vital need to determine the geographical and host distribution as well as its interaction with the resident B biotype because of its innate ability to rapidly develop high-level insecticide resistance that persists in the absence of exposure. As part of a coordinated country-wide effort, an extensive survey of B. tabaci biotypes was conducted in North America, with the cooperation of growers, industry, local, state, and federal agencies, to monitor the introduction and distribution of the Q biotype. The biotype status of submitted B. tabaci samples was determined either by polymerase chain reaction amplification and sequencing of a mitochondrial cytochrome oxidase I small subunit gene fragment and characterization of two biotype discriminating nuclear microsatellite markers or esterase zymogram analysis. Two hundred and eighty collections were sampled from the United States, Bermuda, Canada, and Mexico during January 2005 through December 2011. Host plants were split between ornamental plant and culinary herb (67%) and vegetable and field crop (33%) commodities. The New World biotype was detected on field-grown tomatoes (Solanum lycopersicum L.) in Mexico (two) and in commercial greenhouses in Texas (three) and represented 100% of these five collections. To our knowledge, the latter identification represents the first report of the New World biotype in the United States since its rapid displacement in the late 1980s after the introduction of biotype B. Seventy-one percent of all collections contained at least one biotype B individual, and 53% of all collections contained only biotype B whiteflies. Biotype Q was detected in 23 states in the United States, Canada (British Columbia and Ontario territories), Bermuda, and Mexico. Forty-five percent of all collections were found to contain biotype Q in samples from ornamentals, herbs and a single

[Phagodeterrent activity of the plants Tithonia diversifolia and Montanoa hibiscifolia (Asteraceae) on adults of the pest insect Bemisia tabaci (Homoptera: Aleyrodidae)].

PubMed

Bagnarello, Gina; Hilje, Luko; Bagnarello, Vanessa; Cartín, Victor; Calvo, Marco

2009-12-01

Bemisia tabaci (Gennadius) is a polyphagous, cosmopolitan and worldwide relevant pest, mainly acting as a virus vector on many crops. A sound preventive approach to deal with it would be the application of repellent or deterrent substances hopefully present in tropical plants, which in turn may contribute to take advantage of the remarkable rich Mesoamerican biodiversity. Therefore, extracts of two wild plants belonging to family Asteraceae, titonia (Tithonia diversifolia) and "tora" (Montanoa hibiscifolia), were tested for phagodeterrence to B. tabaci adults. The crude leaf extract of each one, as well as four fractions thereof (hexane, dichlorometane, ethyl acetate, and methanol) were tested under greenhouse conditions; in addition, the extracts were submitted to a phytochemical screening to determine possible metabolites causing phagodeterrence. Both restricted-choice and unrestricted-choice experiments were conducted. In the former ones, each fraction was tested at four doses (0.1, 0.5, 1.0 and 1.5% v/v), which were compared with four control treatments: distilled water, endosulfan, an agricultural oil (Aceite Agricola 81 SC), and the emulsifier Citowett. Tomato plants were sprayed and placed inside sleeve cages, where 50 B. tabaci adults were released. The criterion to appraise phagodeterrence was the number of landed adults on plants at 48h. For the unrestricted-choice experiments, only the two highest doses (1.0 and 1.5%) of the crude extracts of each species were tested, and compared to distilled water and the agricultural oil. The titonia and "tora" crude extracts caused phagodeterrence, and for both plant species the methanol fraction stood out. Results suggest that metabolites causing phagodeterrence are several sesquiterpenic lactones, polyphenolic compounds (flavonoids and tannins) and saponins.

Susceptibility of MED-Q1 and MED-Q3 Biotypes of Bemisia tabaci (Hemiptera: Aleyrodidae) Populations to Essential and Seed Oils.

PubMed

Samuel Fogné, Drabo; Olivier, Gnankine; Bassolé, Imael H N; Nébié, Roger Charles; Laurence, Mouton

2017-06-01

Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is a major pest of many agricultural and ornamental crops in tropical and subtropical regions causing damages that result in important economic losses. Insecticides are commonly used in greenhouses or fields to control B. tabaci populations leading to rapid evolution of resistance that render treatments inefficient. Therefore, and for environmental and human health concerns, other approaches must be developed for this pest management. In the present study, we compare, using the leaf dip method, the toxicity of three essential oils (Cymbopogon citratus, Ocimum americanum, and Hyptis spicigera) and three seed oils (Lannea microcarpa, Lannea acida, and Carapa procera) with three chemical insecticides (acetamiprid, deltamethrin, and chlorpyrifos-ethyl) on adults. Two B. tabaci biotypes (MED-Q1 and MED-Q3) belonging to the Mediterranean species and collected in Burkina Faso were used. Essential oils were analyzed by gas chromatography-mass spectrometry and gas chromatography-flame ionization detector. We showed that these two biotypes have different levels of resistance to the three insecticides, MED-Q3 being more sensitive than MED-Q1. Moreover, they differ in the frequency of resistance alleles to insecticides, especially for organophosphates, as these alleles are almost fixed in MED-Q1. On the other hand, the two biotypes prove to be more susceptible to the plant extracts than to insecticides except for chlorpyrifos-ethyl, with essential oils that showed the highest insecticidal activities. Monoterpenes content were the most abundant and showed the highest insecticidal activities. Our results indicated that essential oils, but also seed oils, have the potential to constitute an alternative strategy of pest management. © 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.

Effect of insecticides on mealybug destroyer (Coleoptera: Coccinellidae) and parasitoid Leptomastix dactylopii (Hymenoptera: Encyrtidae), natural enemies of citrus mealybug (Homoptera: Pseudococcidae).

PubMed

Cloyd, Raymond A; Dickinson, Amy

2006-10-01

In this study, we measured, under laboratory conditions, the direct and indirect effects of insecticides on mealybug destroyer, Cryptolaemus montrouzieri Mulsant (Coleoptera: Coccinellidae), and parasitoid Leptomastix dactylopii Howard (Hymenoptera: Encyrtidae), natural enemies of citrus mealybug, Planococcus citri (Risso) (Homoptera: Pseudococcidae). The adult stages of both natural enemies were exposed to sprays of the insecticides buprofezin, pyriproxyfen, flonicamid, acetamiprid, dinotefuran, and clothianidin at label-recommended rates to assess direct mortality after 24, 48, and 72 h, respectively. The effects of the insecticides on L. dactylopii parasitization rate and percentage of parasitoid emergence also were monitored using the label and 4x the recommended label rate. Dinotefuran was extremely detrimental to the adult parasitoid at the label rate with 100% mortality after 24 h. Buprofezin, pyriproxyfen, and flonicamid were not harmful to L. dactylopii when applied at the label rate. At 4x the recommended label rate, dinotefuran, acetamiprid, and clothianidin were all harmful to the parasitoid with 100% mortality 72 h after application. Both buprofezin and flonicamid were not toxic to L. dactylopii with 100% adult survival after 72 h. Pyriproxyfen and flonicamid, at both the label and 4x the recommended label rate, did not negatively affect L. dactylopii parasitization rate or percentage of parasitoid emergence. Acetamiprid, dinotefuran, and clothianidin were toxic to C. montrouzieri adults with 100% mortality after 48 h, whereas buprofezin, pyriproxyfen, and flonicamid demonstrated minimal (10-20% mortality after 48 h) harmful effects to the predator. Based on the results from our study, the indirect effects of the insect growth regulator (IGR) buprofezin were not decisive; however, the IGR pyriproxyfen and the insecticide flonicamid were not directly or indirectly harmful to the predator C. montrouzieri and parastioid L. dactylopii, indicating that

Colonization by Phloem-Feeding Herbivore Overrides Effects of Plant Virus on Amino Acid Composition in Phloem of Chili Plants.

PubMed

Ángeles-López, Yesenia Ithaí; Rivera-Bustamante, Rafael F; Heil, Martin

2016-10-01

The 'adaptive host manipulation' hypothesis predicts that parasites can enhance their transmission rates via manipulation of their host's phenotype. For example, many plant pathogens alter the nutritional quality of their host for herbivores that serve as their vectors. However, herbivores, including non-vectors, might cause additional alterations in the plant phenotype. Here, we studied changes in the amino acid (AA) content in the phloem of chilli (Capsicum annuum) plants infected with Pepper golden mosaic virus (PepGMV) upon subsequent colonization with a non-vector, the phloem-feeding whitefly (Trialeurodes vaporariorum). Virus infection alone caused an almost 30-fold increase in overall phloem AAs, but colonization by T. vaporariorum completely reversed this effect. At the level of individual AAs, contents of proline, tyrosine, and valine increased, and histidine and alanine decreased in PepGMV -infected as compared to control plants, whereas colonization by T. vaporariorum caused decreased contents of proline, tyrosine, and valine, and increased contents of histidine and alanine. Overall, the colonization by the whitefly had much stronger effects on phloem AA composition than virus infection. We conclude that the phloem composition of a virus-infected host plant can rapidly change upon arrival of an herbivore and that these changes need to be monitored to predict the nutritional quality of the plant in the long run.

Phenology and density of balsam twig aphid, Mindarus abietinus Koch (Homoptera: Aphididae) in relation to bud break, shoot damage, and value of fir Christmas trees.

PubMed

Fondren, K M; McCullough, D G

2003-12-01

The balsam twig aphid, Mindarus abietinus Koch (Homoptera: Aphididae), is a major insect pest of balsam and Fraser fir grown for Christmas trees. Our objectives in this study were to 1) monitor the phenology of A. abietinus in fir plantations; 2) assess relationships among M. abietinus density, tree phenology, and damage to tree foliage; and 3) develop an esthetic injury level for M. abietinus on Christmas trees. We monitored phenology of M. abietinus and fir trees on three commercial Christmas tree plantations in central and northern Lower Michigan for 3 yr (1999-2001). Phenology of M. abietinus fundatrices and sexuparae was strongly correlated with accumulated degree-days (DD) base 10 degrees C. Fundatrices matured by approximately 83 DD(10 degrees C) and sexuparae were first observed at approximately 83-111 DD(10 degrees C). Trees that broke bud approximately 1 wk later than other trees in the same field escaped M. abietinus damage and shoot expansion rate in spring was generally positively correlated with M. abietinus damage. Retail customers surveyed at a choose-and-cut Christmas plantation in 2 yr did not consistently differentiate between similarly sized trees with no, light, and moderate M. abietinus damage, but heavy damage (>50% damaged shoots) did affect customer perception. Similarly, when wholesale grades were assigned, the high quality Grade 1 trees had up to 40% shoot damage, whereas Grade 2 trees had 32-62% shoot damage. Two trees ranked as unsaleable had sparse canopies and distorted needles on 42% to almost 100% of the shoots.

Identification of glutathione S-transferases in Bemisia tabaci (Hemiptera: Aleyrodidae) and evidence that GSTd7 helps explain the difference in insecticide susceptibility between B. tabaci Middle East-Minor Asia 1 and Mediterranean.

PubMed

He, C; Xie, W; Yang, X; Wang, S-L; Wu, Q-J; Zhang, Y-J

2018-02-01

The Bemisia tabaci (Gennadius) (Hemiptera:Aleyrodidae) species complex includes invasive and destructive pests of field crops, and the sibling species MEAM1 and MED are its two most damaging members. Previous research indicated that the replacement of Middle East-Minor Asia 1 (MEAM1) by Mediterranean (MED) as the dominant B. tabaci species in China can be mainly attributed to MED's greater tolerance to insecticides. Glutathione S-transferases (GSTs) play important roles in the detoxification of hydrophobic toxic compounds. To increase our understanding of differences in insecticide resistance between B. tabaci MEAM1 and MED, we searched the genomic and transcriptomic databases and identified 23 putative GSTs in both B. tabaci MEAM1 and MED. Through measuring mRNA levels of 18 of the GSTs after B. tabaci MEAM1 and MED adults were exposed to the insecticide imidacloprid, we found that the expression levels were increased more in B. tabaci MED than in MEAM1 (in particular, the expression level of GST-d7 was increased by 4.39-fold relative to the control). Knockdown of GST-d7 in B. tabaci MED but not in B. tabaci MEAM1 resulted in a substantial increase in the mortality of imidacloprid-treated adults. These results indicate that differences in GST-d7 may help explain why insecticide tolerance is greater in B. tabaci MED than in B. tabaci MEAM1. © 2017 The Royal Entomological Society.

A Molecular Phylogeny of Hemiptera Inferred from Mitochondrial Genome Sequences

PubMed Central

Song, Nan; Liang, Ai-Ping; Bu, Cui-Ping

2012-01-01

Classically, Hemiptera is comprised of two suborders: Homoptera and Heteroptera. Homoptera includes Cicadomorpha, Fulgoromorpha and Sternorrhyncha. However, according to previous molecular phylogenetic studies based on 18S rDNA, Fulgoromorpha has a closer relationship to Heteroptera than to other hemipterans, leaving Homoptera as paraphyletic. Therefore, the position of Fulgoromorpha is important for studying phylogenetic structure of Hemiptera. We inferred the evolutionary affiliations of twenty-five superfamilies of Hemiptera using mitochondrial protein-coding genes and rRNAs. We sequenced three mitogenomes, from Pyrops candelaria, Lycorma delicatula and Ricania marginalis, representing two additional families in Fulgoromorpha. Pyrops and Lycorma are representatives of an additional major family Fulgoridae in Fulgoromorpha, whereas Ricania is a second representative of the highly derived clade Ricaniidae. The organization and size of these mitogenomes are similar to those of the sequenced fulgoroid species. Our consensus phylogeny of Hemiptera largely supported the relationships (((Fulgoromorpha,Sternorrhyncha),Cicadomorpha),Heteroptera), and thus supported the classic phylogeny of Hemiptera. Selection of optimal evolutionary models (exclusion and inclusion of two rRNA genes or of third codon positions of protein-coding genes) demonstrated that rapidly evolving and saturated sites should be removed from the analyses. PMID:23144967

Compatibility of the insect pathogenic fungus Beauveria bassiana with neem against sweetpotato whitefly, Bemisia tabaci, on eggplant

USDA-ARS?s Scientific Manuscript database

A study on the compatibility of the entomopathogenic fungus Beauveria bassiana (Balsamo) Vuillemin (Ascomycota: Hypocreales) with neem was conducted against sweetpotato whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), on eggplant. Initially, three concentrations of B. bassiana (106, 1...

Epidemiology and genetic diversity of criniviruses associated with tomato yellows disease in Greece.

PubMed

Orfanidou, C G; Dimitriou, C; Papayiannis, L C; Maliogka, V I; Katis, N I

2014-06-24

Tomato chlorosis virus (ToCV) and Tomato infectious chlorosis virus (TICV) are two whitefly transmitted viruses which are classified in the genus Crinivirus of the family Closteroviridae. Both induce similar yellowing symptoms in tomato and are responsible for severe economic losses. ToCV is transmitted by Bemisia tabaci Gennadious, Trialeurodes vaporariorum Westwood and Trialeurodes abutilonea Haldeman, whereas TICV is transmitted only by T. vaporariorum. An extensive study was conducted during 2009-2012 in order to identify the virus species involved in tomato yellowing disease in Greece. Samples from tomato, other crops and weeds belonging to 44 species from 26 families were collected and analyzed using molecular methods. In addition, adult whiteflies were collected and analyzed using morphological characters and DNA markers. Results showed that TICV prevailed in tomato crops (62.5%), while ToCV incidence was lower (20.5%) and confined in southern Greece. ToCV was also detected in lettuce plants showing mild yellowing symptoms for the first time in Greece. Approximately 13% of the tested weeds were found to be infected, with TICV being the predominant virus with an incidence of 10.8%, whereas ToCV was detected only in 2.2% of the analyzed samples. These results indicate that the host range of TICV and ToCV in Greece is far more extensive than previously believed. T. vaporariorum was the most widespread whitefly species in Greece (80%), followed by B. tabaci (biotypes B and Q) (20%). Sequence analysis of the CP and CPm genes from Greek tomato and weed isolates of ToCV and TICV showed that even though both viruses have very wide host ranges their populations show very low molecular divergence. Copyright © 2013 Elsevier B.V. All rights reserved.

Shrub-inhabiting insects of the 200 Area Plateau, southcentral Washington.

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

Rogers, L.E.

1979-10-01

This study characterizes the insects (including spiders) associated with major shrubs of the 200 Area Plateau on the Hanford Site in southcentral Washington. Big sagebrush (Artemisia tridentata), rabbitbrush (Chrysothamnus sp.) and hopsage (Grayia spinosa) were the three shrubs included in the study. Hemiptera (true bugs) and homoptera (bugs) were the two groups most abundant on sagebrush. Homoptera and Araneida (spiders) were the common inhabitants of rabbitbrush, and Orthoptera (grasshoppers), Coleoptera (beetles), and Araneida the taxa most frequently collected from hopsage. A discussion of the effects of insects on western native shrubs is included. None of the insect populations appeared tomore » threaten the stability of shrub stands, which is important because of the erodability of 200 Area soils.« less

Insecticide resistance in Bemisia tabaci Gennadius (Homoptera: Aleyrodidae) and Anopheles gambiae Giles (Diptera: Culicidae) could compromise the sustainability of malaria vector control strategies in West Africa.

PubMed

Gnankiné, Olivier; Bassolé, Imael H N; Chandre, Fabrice; Glitho, Isabelle; Akogbeto, Martin; Dabiré, Roch K; Martin, Thibaud

2013-10-01

Insecticides from the organophosphate (OP) and pyrethroid (PY) chemical families, have respectively, been in use for 50 and 30 years in West Africa, mainly against agricultural pests, but also against vectors of human disease. The selection pressure, with practically the same molecules year after year (mainly on cotton), has caused insecticide resistance in pest populations such as Bemisia tabaci, vector of harmful phytoviruses on vegetables. The evolution toward insecticide resistance in malaria vectors such as Anopheles gambiae sensus lato (s.l.) is probably related to the current use of these insecticides in agriculture. Thus, successful pest and vector control in West Africa requires an investigation of insect susceptibility, in relation to the identification of species and sub species, such as molecular forms or biotypes. Identification of knock down resistance (kdr) and acetylcholinesterase gene (Ace1) mutations modifying insecticide targets in individual insects and measure of enzymes activity typically involved in insecticide metabolism (oxidase, esterase and glutathion-S-transferase) are indispensable in understanding the mechanisms of resistance. Insecticide resistance is a good example in which genotype-phenotype links have been made successfully. Insecticides used in agriculture continue to select new resistant populations of B. tabaci that could be from different biotype vectors of plant viruses. As well, the evolution of insecticide resistance in An. gambiae threatens the management of malaria vectors in West Africa. It raises the question of priority in the use of insecticides in health and/or agriculture, and more generally, the question of sustainability of crop protection and vector control strategies in the region. Here, we review the susceptibility tests, biochemical and molecular assays data for B. tabaci, a major pest in cotton and vegetable crops, and An. gambiae, main vector of malaria. The data reviewed was collected in Benin and Burkina Faso between 2008 and 2010 under the Corus 6015 research program. This review aims to show: (i) the insecticide resistance in B. tabaci as well as in An. gambiae; and (ii) due to this, the impact of selection of resistant populations on malaria vector control strategies. Some measures that could be beneficial for crop protection and vector control strategies in West Africa are proposed. Copyright © 2013 Elsevier B.V. All rights reserved.

INVESTIGATING GIANT RED MUSTARD AS A DETERRENT OF SILVERLEAF WHITEFLY OVIPOSITION IN VEGETABLE CROPS

USDA-ARS?s Scientific Manuscript database

One of the major insect pests of vegetable crops is the silverleaf whitefly, Bemisia argentifolii Bellows and Perring (Hemiptera: Aleyrodidae), due to direct feeding damage and its ability to transmit plant diseases. The use of companion crops with repellent or masking volatiles has been suggested ...

Genome sequencing and analysis of the whitefly (Bemisia tabaci) MEAM1, one of the most important vectors for plant viruses

USDA-ARS?s Scientific Manuscript database

Among whiteflies, the Bemisia tabaci (Hemiptera: Aleyrodidae) species complex is particularly important because of its ability to transmit hundreds of plant viruses, resulting in the loss of billions of U.S. dollars on agronomically important crops such as tomato, cucurbits, cassava, and cotton worl...

EVALUATING SILVERLEAF WHITEFLY OVIPOSITION ON GIANT RED MUSTARD AND OTHER VEGETABLE CROPS

USDA-ARS?s Scientific Manuscript database

One of the major insect pests of vegetable crops is the silverleaf whitefly, Bemisia argentifolii (Hemiptera: Aleyrodidae), due to direct feeding damage and its ability to transmit plant diseases. The use of companion crops with repellant or masking volatiles has been suggested as a potential crop p...

Evaluating the impact of invasive species in forest landscapes: the southern pine beetle and the hemlock woolly adelgid

Treesearch

John D. Waldron; Robert N. Coulson; David M. Cairns; Charles W. Lafon; Maria D. Tchakerian; Weimin Xi; Kier Klepzig; Andrew Birt

2010-01-01

The southern pine beetle, Dendroctonus frontalis (Zimmerman) (Coleoptera: Curculionidae: Scolytinae) (SPB), is an indigenous invasive species that infests and causes mortality to pines (Pinus spp.) throughout the Southern United States. The hemlock woolly adelgid, Adelges tsugae (Annand) (Homoptera:...

Papaya is not a host for Tomato Yellow Leaf Curl Virus

USDA-ARS?s Scientific Manuscript database

The economic value of tomato production is threatened by tomato yellow leaf-curl virus TYLCV and its vector, the silverleaf whitefly Bemisia tabaci biotype B (Gennadius) (Hemiptera: Aleyrodidae). Use of papaya Carica papaya L. as a banker plant for a whitefly parasitoid shows promise as a whitefly m...

Density-dependent impacts of the arundo scale (Rhizaspidiotus donacis) on the productivity and physiology of giant reed

USDA-ARS?s Scientific Manuscript database

The armored arundo scale, Rhizaspidiotus donacis (Homoptera: Diaspididae) has been permitted for a biological control agent to control invasive populations of giant reed (Arundo donax L.). A non-native, highly invasive woody grass, giant reed infests waterways and riparian areas of the southwestern...

Fungal Endophytes of Wild Barley and their Effects on Diuraphis noxia Population Development

Treesearch

S.L. Clement; A. Dan Wilson; D.G. Lester; C.M. Davitt

1997-01-01

Laboratory experiments were conducted to compare the expression of Diuraphis noxia (Mordvilko) (Homoptera: Aphididae) resistance in four plant introduction (PI) lines of wild barley (Hordeum) infected with different species or strains of endophytic fungi (tribe Balansieae, family Clavicipitaceae, Neotyphodium gen. nov. [formerly...

Spruce aphid in high elevation habitats in the Southwest U.S.

Treesearch

Ann M. Lynch

2003-01-01

Spruce aphid, Elatobium abietinum (Walker) (Homoptera: Aphididae), is a new invasive pest in the interior Southwestern United States. This insect is causing extensive and severe damage on dormant Engelmann spruce, Picea engelmannii Parry, and Colorado blue spruce, P. pungens Engelm., in high elevation forests in...

Is Pseudoscymnus tsugae the solution to the hemlock woolly adelgid problem?: An early perspective

Treesearch

Mark S. McClure; Carole A. S-J. Cheah; Timothy C. Tigner

2000-01-01

Hemlock woolly adelgid, Adelges tsugae Annand (Homoptera: Adelgidae) is native to Japan where it is an innocuous inhabitant of Tsuga diversifolia Masters and T. sieboldii Carriere. Native populations of this insect are regulated by host resistance and natural enemies. However, introduced populations in eastern...

Characterizing pathways of invasion using Sternorryhncha on imported plant material in cargo

Treesearch

Timothy T. Work

2011-01-01

Non-indigenous Homoptera, mainly scales, aphids, and mealy bugs, intercepted on plants destined for cultivation represent an elevated risk for the establishment of invasive insects in North America. These insects [grouped as the suborder Sternorrhyncha] are often parthenogenic and are imported on viable host plants.

Resistance to lettuce aphid (Nasonovia ribisnigri) biotype 0 in wild lettuce accessions PI 491093 and PI 274378

USDA-ARS?s Scientific Manuscript database

Lettuce aphid, Nasonovia ribisnigri Mosley (Homoptera : Aphididae), is a major insect pest of lettuce, Lactuca sativa L, in many commercial lettuce productions areas around the world. Resistance to lettuce aphid was first reported in Lactuca virosa L. accession IVT 280 and characterized as complete,...

Landscape context does not constrain biological control of Phenacoccus manihoti in intensified cassava systems of southern Vietnam

USDA-ARS?s Scientific Manuscript database

Following its continent-wide spread in Africa during the 1970s and early 1980s, the cassava mealybug, Phenacoccus manihoti (Homoptera: Pseudococcidae) was inadvertently introduced to Southeast (SE) Asia in late 2008. In both regions P. manihoti can inflict severe damage on cassava, impact food secur...

Previsual detection of two conifer-infesting adelgid species in North American forest

Treesearch

Stephen Cook; Karen Humes; Ryan Hruska; Christopher Williams; Grant Fraley

2010-01-01

The balsam woolly adelgid, Adelges piceae, and hemlock woolly adelgid, A. tsugae (Homoptera: Adelgidae), are invasive pests of coniferous forests in both the Eastern and Western United States. Balsam woolly adelgid is capable of attacking and killing native North American firs, with Fraser fir (Abies fraseri...

Evaluation of aestival diapause in hemlock woolly adelgid

Treesearch

Scott M. Salom; Warren T. Mays; John Neal; Alexei Sharov

2000-01-01

Hemlock woolly adelgid, Adelges tsugae Annand (Homoptera: Adelgidae), has two generations/year that feed and reproduce on hemlock, Tsugae spp. The spring generation, present from March to June, is called progrediens. The next generation, present from June until the following March, is called sistens (McClure 1987, Gray and Salom...

A New Species of Torymus (Hymenoptera: Torymidae) Parasitic on Pachypsylla Celtidis-Vesicula Riley (Chermidae) with Notes on its Biology and Other Parasitoids attacking the same host at Columbus, Ohio

Treesearch

John C. Moser

1956-01-01

The genus Torymus is a group in which the vast majority of species are ectoparasitic on dipterous or hymenopterous gall makers. Three species, however, have been recorded from Homoptera, one on the eggs of Cicadidae and two others as gall parasitoids of the genus Pachypsylla which are gall makers of Celtis sp. (...

Monitoring hemlock vitality using ground-based digital imaging

Treesearch

Neil A. Clark; Sang-Mook Lee

2005-01-01

The vitality of hemlock (Tsuga spp.) trees needs to be assessed in order to evaluate the effectiveness of treatments that combat hemlock woolly adelgid (HWA), Adelges tsugae Annand 1 (Homoptera: Adelgidae). Ground-based photomonitoring can be used to assess canopy dynamics, which serves as a visual indicator of tree vitality. Here we propose a...

Release of Predators of the Balsam Woolly Aphid in North Carolina

Treesearch

Gene D. Amman; Charles F. Speers

1964-01-01

The balsam woolly aphid, Chermes piceae Ratz. (Homoptera: Chermidae), was accidentally introduced into North America from Europe about 1900 (Balch 1952). The aphid is now a serious pest of Fraser fir, Abies fraseri (Pursh)Poir., in the Southern Appalachians. Since its discovery in Northo-1957 (Speers 1958), the aphid has killed thousands of trees annually. Fraser fir...

Diversity and Phylogenetic Analyses of Bacterial Symbionts in Three Whitefly Species from Southeast Europe

PubMed Central

Skaljac, Marisa; Zanic, Katja; Puizina, Jasna; Lepen Pleic, Ivana; Ghanim, Murad

2017-01-01

Bemisia tabaci (Gennadius), Trialeurodes vaporariorum (Westwood), and Siphoninus phillyreae (Haliday) are whitefly species that harm agricultural crops in many regions of the world. These insects live in close association with bacterial symbionts that affect host fitness and adaptation to the environment. In the current study, we surveyed the infection of whitefly populations in Southeast Europe by various bacterial symbionts and performed phylogenetic analyses on the different symbionts detected. Arsenophonus and Hamiltonella were the most prevalent symbionts in all three whitefly species. Rickettsia was found to infect mainly B. tabaci, while Wolbachia mainly infected both B. tabaci and S. phillyreae. Furthermore, Cardinium was rarely found in the investigated whitefly populations, while Fritschea was never found in any of the whitefly species tested. Phylogenetic analyses revealed a diversity of several symbionts (e.g., Hamiltonella, Arsenophonus, Rickettsia), which appeared in several clades. Reproductively isolated B. tabaci and T. vaporariorum shared the same (or highly similar) Hamiltonella and Arsenophonus, while these symbionts were distinctive in S. phillyreae. Interestingly, Arsenophonus from S. phillyreae did not cluster with any of the reported sequences, which could indicate the presence of Arsenophonus, not previously associated with whiteflies. In this study, symbionts (Wolbachia, Rickettsia, and Cardinium) known to infect a wide range of insects each clustered in the same clades independently of the whitefly species. These results indicate horizontal transmission of bacterial symbionts between reproductively isolated whitefly species, a mechanism that can establish new infections that did not previously exist in whiteflies. PMID:29053633

Diversity and Phylogenetic Analyses of Bacterial Symbionts in Three Whitefly Species from Southeast Europe.

PubMed

Skaljac, Marisa; Kanakala, Surapathrudu; Zanic, Katja; Puizina, Jasna; Pleic, Ivana Lepen; Ghanim, Murad

2017-10-20

Bemisia tabaci (Gennadius), Trialeurodes vaporariorum (Westwood), and Siphoninus phillyreae (Haliday) are whitefly species that harm agricultural crops in many regions of the world. These insects live in close association with bacterial symbionts that affect host fitness and adaptation to the environment. In the current study, we surveyed the infection of whitefly populations in Southeast Europe by various bacterial symbionts and performed phylogenetic analyses on the different symbionts detected. Arsenophonus and Hamiltonella were the most prevalent symbionts in all three whitefly species. Rickettsia was found to infect mainly B. tabaci, while Wolbachia mainly infected both B. tabaci and S. phillyreae. Furthermore, Cardinium was rarely found in the investigated whitefly populations, while Fritschea was never found in any of the whitefly species tested. Phylogenetic analyses revealed a diversity of several symbionts (e.g., Hamiltonella, Arsenophonus, Rickettsia), which appeared in several clades. Reproductively isolated B. tabaci and T. vaporariorum shared the same (or highly similar) Hamiltonella and Arsenophonus, while these symbionts were distinctive in S. phillyreae. Interestingly, Arsenophonus from S. phillyreae did not cluster with any of the reported sequences, which could indicate the presence of Arsenophonus, not previously associated with whiteflies. In this study, symbionts (Wolbachia, Rickettsia, and Cardinium) known to infect a wide range of insects each clustered in the same clades independently of the whitefly species. These results indicate horizontal transmission of bacterial symbionts between reproductively isolated whitefly species, a mechanism that can establish new infections that did not previously exist in whiteflies.

Effectiveness of two insect growth regulators against Bemisia tabaci (Gennadius) (Homoptera: Aleyrodidae) and Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) and their impact on population densities of arthropod predators in cotton in Pakistan.

PubMed

Gogi, Muhammad D; Sarfraz, Rana M; Dosdall, Lloyd M; Arif, Muhammad J; Keddie, Andrew B; Ashfaq, Muhammad

2006-10-01

Field efficacies of two insect growth regulators (IGRs) at two recommended application rates, buprofezin at 370 and 555 g AI ha(-1) and lufenuron at 37 and 49 g AI ha(-1), were determined against the sweet potato whitefly, Bemisia tabaci (Gennadius), and the cotton bollworm, Helicoverpa armigera (Hübner), in experimental plots of cotton at the Directorate of Cotton Research, Faisalabad, Pakistan. Adverse effects of the IGRs on populations of associated arthropod predators, namely geocorids, chrysopids, coccinellids, formicids and arachnids, were also assessed. Both IGRs significantly reduced populations of B. tabaci at each application rate 24, 48 and 72 h after treatment, and higher doses were more effective than lower doses. Buprofezin was not effective against H. armigera at any tested dose for any time of treatment in any spray. Lufenuron applied at 37 and 49 g AI ha(-1) effectively suppressed H. armigera populations, resulting in significant reductions in crop damage. At lower doses, both IGRs appeared safe to predator populations, which did not differ significantly in IGR-treated versus untreated control plots. Population densities of formicids and coccinellids were significantly lower at high concentrations of both IGRs in treatment plots, possibly as a result of reduced prey availability. The potential role of buprofezin and lufenuron for control of B. tabaci and H. armigera in a spray programme and the likelihood of direct toxic effects of IGRs on predatory fauna of cotton are discussed.

An Initial Study of the Greenhouse Whitefly Trialeurodes vaporariorum Westwood

ERIC Educational Resources Information Center

Hitchon, A.

1975-01-01

Describes the life cycle and control of the greenhouse whitefly. Explains the culture of the whitefly for school use and presents a list of laboratory exercises that can be done in a double period. (GS)

Agroecosystems shape population genetic structure of the greenhouse whitefly in Northern and Southern Europe

PubMed Central

2014-01-01

Background To predict further invasions of pests it is important to understand what factors contribute to the genetic structure of their populations. Cosmopolitan pest species are ideal for studying how different agroecosystems affect population genetic structure within a species at different climatic extremes. We undertook the first population genetic study of the greenhouse whitefly (Trialeurodes vaporariorum), a cosmopolitan invasive herbivore, and examined the genetic structure of this species in Northern and Southern Europe. In Finland, cold temperatures limit whiteflies to greenhouses and prevent them from overwintering in nature, and in Greece, milder temperatures allow whiteflies to inhabit both fields and greenhouses year round, providing a greater potential for connectivity among populations. Using nine microsatellite markers, we genotyped 1274 T. vaporariorum females collected from 18 greenhouses in Finland and eight greenhouses as well as eight fields in Greece. Results Populations from Finland were less diverse than those from Greece, suggesting that Greek populations are larger and subjected to fewer bottlenecks. Moreover, there was significant population genetic structure in both countries that was explained by different factors. Habitat (field vs. greenhouse) together with longitude explained genetic structure in Greece, whereas in Finland, genetic structure was explained by host plant species. Furthermore, there was no temporal genetic structure among populations in Finland, suggesting that year-round populations are able to persist in greenhouses. Conclusions Taken together our results show that greenhouse agroecosystems can limit gene flow among populations in both climate zones. Fragmented populations in greenhouses could allow for efficient pest management. However, pest persistence in both climate zones, coupled with increasing opportunities for naturalization in temperate latitudes due to climate change, highlight challenges for the

Substrate vibrations during acoustic signalling in the cicada Okanagana rimosa

PubMed Central

Stölting, Heiko; Moore, Thomas E.; Lakes-Harlan, Reinhard

2002-01-01

Males of the North American cicada Okanagana rimosa (Homoptera: Cicadidae, Tibicininae) emit loud airborne acoustic signals for intraspecific communication. Specialised vibratory signals could not be detected; however, the airborne signal induced substrate vibrations. Both auditory and vibratory spectra peak in the range from 7–10 kHz. Thus, the vibrations show similar frequency components to the sound spectrum within biologically relevant distances. These vibratory signals could be important as signals involved in mate localization and perhaps even as the context for the evolution of the ear in a group of parasitoid flies. PMID:15455036

Update on the Status of Bemisia tabaci in the UK and the Use of Entomopathogenic Fungi within Eradication Programmes

PubMed Central

Cuthbertson, Andrew G. S.

2013-01-01

The sweetpotato whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) continues to be a serious threat to crops worldwide. The UK holds Protected Zone status against this pest and, as a result, B. tabaci entering on plant material is subjected to a policy of eradication. Both B and Q Bemisia biotypes are now regularly intercepted entering the UK. With increasing reports of neonicotinoid resistance in both these biotypes, it is becoming more problematic to control/eradicate. Therefore, alternative means of control are necessary. Entomopathogenic fungi (Lecanicilllium muscarium and Beauveria bassiana) offer much potential as control agents of B. tabaci within eradication programmes in the UK. PMID:26464385

Assessing the effects of cultivating genetically modified glyphosate-tolerant varieties of soybeans (Glycine max (L.) Merr.) on populations of field arthropods.

PubMed

Imura, Osamu; Shi, Kun; Iimura, Keiji; Takamizo, Tadashi

2010-01-01

We assessed the effects of cultivating two genetically modified (GM) glyphosate-tolerant soybean varieties (Glycine max (L.) Merr.) derived from Event 40-3-2 and a Japanese conventional variety on arthropods under field conditions, with weed control using glyphosate and conventional weed control for two years. Plant height and dry weight of the conventional variety were significantly larger than those of the GM varieties, but the GM varieties bore more pods than the conventional variety. We found arthropods of nine taxonomic orders (Araneae, Acari, Thysanoptera, Homoptera, Heteroptera, Coleoptera, Diptera, Lepidoptera, and Hymenoptera) on the plants. The arthropod incidence (number per plant unit weight pooled for each taxonomic order) on the soybean stems and leaves generally did not differ significantly between the GM and conventional varieties. However, the incidence of Thysanoptera and total incidence (all orders combined) were greater on the GM variety in the second year. The weed control regimes had no significant influence on the arthropod incidence on the soybean stems and leaves. The number of flower-inhabiting Thysanoptera (the dominant arthropod in the flowers) was not significantly different between the GM and conventional varieties. Asphondylia yushimai (Diptera, Cecidomyiidae) was more numerous on the pods of the GM variety in both years. Neither the soybean variety nor the weed control regime significantly affected the density of soil macro-organisms. However, the glyphosate weed control affected arthropods between the rows of plants by decreasing the abundances of Homoptera, Heteroptera, Coleoptera and Lepidoptera, and diversity of arthropods. © ISBR, EDP Sciences, 2011.

Comparative cytogenetics of Auchenorrhyncha (Hemiptera, Homoptera): a review

PubMed Central

Kuznetsova, Valentina; Aguin-Pombo, Dora

2015-01-01

Abstract A comprehensive review of cytogenetic features is provided for the large hemipteran suborder Auchenorrhyncha, which currently contains approximately 42,000 valid species. This review is based on the analysis of 819 species, 483 genera, and 31 families representing all presently recognized Auchenorrhyncha superfamilies, e.i. Cicadoidea (cicadas), Cercopoidea (spittle bugs), Membracoidea (leafhoppers and treehoppers), Myerslopioidea (ground-dwelling leafhoppers), and Fulgoroidea (planthoppers). History and present status of chromosome studies are described, as well as the structure of chromosomes, chromosome counts, trends and mechanisms of evolution of karyotypes and sex determining systems, their variation at different taxonomic levels and most characteristic (modal) states, occurrence of parthenogenesis, polyploidy, B-chromosomes and chromosome rearrangements, and methods used for cytogenetic analysis of Auchenorrhyncha. PMID:26807037

Nomenclatural changes in Cicadellidae: Typhlocybinae and Delphacidae (Homoptera).

USDA-ARS?s Scientific Manuscript database

New replacement names are proposed for seven species of the subfamily Typhlocybinae; one new synonym is recognized in the family Delphacidae. The following changes are proposed: Empoasca (Empoasca) angustata nom.nov. for Empoasca angusta Linnavuori & DeLong (not Dworakowska); Empoasca (Empoasca) ch...

First report on the whitefly, Aleurodicus pseudugesii on the coconut palm, Cocos nucifera in Brazil.

PubMed

de Omena, Rose Paula Mendonça; Guzzo, Elio Cesar; Ferreira, Joana Maria Santos; de Mendonça, Fernando Antônio Cavalcante; de Lima, Aurino Florencio; Racca-Filho, Francisco; Santana, Antônio Euzébio Goulart

2012-01-01

The coconut palm, Cocos nucifera L. (Arecales: Arecaceae), is currently grown extensively throughout the intertropical zones of the world, including Brazil, where it constitutes an important source of income for growers. Although whiteflies are not normally considered coconut pests, these insects can damage crops directly by sucking the sap, which weakens the plant; indirect damage may be caused by sooty mold formation over the excreted honeydew and by the transmission of pathogens. Whiteflies have infested coconut plants in the northeastern, northern, and southeastern regions of Brazil. Infested materials were collected and the causative insect was identified as Aleurodicus pseudugesii Martin (Hemiptera: Aleyrodidae). This is the first report of A. pseudugesii in Brazil as a pest of the coconut palm.

Comparison of exclusion and imidacloprid for reduction of oviposition damage to young trees by periodical cicadas (Hemiptera: Cicadidae).

PubMed

Ahern, Robert G; Frank, Steven D; Raupp, Michael J

2005-12-01

Insecticides are traditionally used to control periodical cicadas (Homoptera: Cicadidae) and to reduce associated injury caused by oviposition. However, research has shown that conventional insecticides have low or variable season-long efficacy in reducing injury caused by cicadas. New systemic neonicotinoid insecticides provide excellent levels of control against a variety of sucking insects. We compared the efficacy of a neonicotinoid insecticide, imidacloprid, and a nonchemical control measure, netting, to reduce cicada injury. Netted trees sustained very little injury, whereas unprotected trees were heavily damaged. Fewer eggnests, scars, and flags were observed on trees treated with imidacloprid compared with unprotected trees; however, the hatching of cicada eggs was unaffected by imidacloprid.

First Report on the Whitefly, Aleurodicus pseudugesii on the Coconut Palm, Cocos nucifera in Brazil

PubMed Central

de Omena, Rose Paula Mendonça; Guzzo, Elio Cesar; Ferreira, Joana Maria Santos; de Mendonça, Fernando Antônio Cavalcante; de Lima, Aurino Florencio; Racca-Filho, Francisco; Santana, Antônio Euzébio Goulart

2012-01-01

The coconut palm, Cocos nucifera L. (Arecales: Arecaceae), is currently grown extensively throughout the intertropical zones of the world, including Brazil, where it constitutes an important source of income for growers. Although whiteflies are not normally considered coconut pests, these insects can damage crops directly by sucking the sap, which weakens the plant; indirect damage may be caused by sooty mold formation over the excreted honeydew and by the transmission of pathogens. Whiteflies have infested coconut plants in the northeastern, northern, and southeastern regions of Brazil. Infested materials were collected and the causative insect was identified as Aleurodicus pseudugesii Martin (Hemiptera: Aleyrodidae). This is the first report of A. pseudugesii in Brazil as a pest of the coconut palm. PMID:22958126

Insect symbiosis: derivation of yeast-like endosymbionts within an entomopathogenic filamentous lineage.

PubMed

Suh, S O; Noda, H; Blackwell, M

2001-06-01

Yeast-like endosymbionts (YLSs) of insects often are restricted to specific hosts and are essential to the host's survival. For example, in planthoppers (Homoptera: Delphacidae), endosymbionts function in sterol utilization and nitrogen recycling for the hosts. Our study, designed to investigate evolutionary changes in the YLS lineage involved in the planthopper association, strongly suggests an origin of the YLSs from within the filamentous ascomycetes (Euascomycetes), not the true yeasts (Saccharomycetes), as their morphology might indicate. During divergence of the planthopper YLSs, dramatic changes would have occurred in the insect-fungus interaction and the fungal morphology that have previously been undescribed in filamentous ascomycetes. Phylogenetic trees were based on individual and combined data sets of 2.6 kb of the nuclear small- and large-subunit ribosomal RNA genes for YLSs from three rice planthoppers (Laodelphax striatellus, Nilaparvata lugens, and Sogatella furcifera) compared with 56 other fungi. Parsimony analysis placed the planthopper YLSs within Cordyceps (Euascomycetes: Hypocreales: Clavicipitaceae), a genus of filamentous insects and a few fungal pathogenic ascomycetes. Another YLS species restricted to the aphid Hamiltonaphis styraci (Homoptera: Aphididae) was a sister taxon to the planthopper YLSS: Filamentous insect pathogens (Metarhizium and Beauveria) specific to the same species of insect hosts as the YLSs also formed lineages within the Clavicipitaceae, but these were distinct from the clade comprising YLS species. Trees constrained to include the YLSs in families of the Hypocreales other than the Clavicipitaceae were rejected by the Kishino-Hasegawa test. In addition, the results of this study support a hypothesis of two independent origins of insect-associated YLSs from among filamentous ascomycetes: the planthopper YLSs in the Clavicipitaceae and the YLSs associated with anobiid beetles (Symbiotaphrina species). Several lineages of

Demography of soybean aphid (Homoptera: Aphididae) at summer temperatures.

PubMed

McCornack, B P; Ragsdale, D W; Venette, R C

2004-06-01

Soybean aphid, Aphis glycines Matsumura, is now widely established in soybean, Glycine max L., production areas of the northern United States and southern Canada and is becoming an important economic pest. Temperature effect on soybean aphid fecundity and survivorship is not well understood. We determined the optimal temperature for soybean aphid growth and reproduction on soybean under controlled conditions. We constructed life tables for soybean aphid at 20, 25, 30, and 35 degrees C with a photoperiod of 16:8 (L:D) h. Population growth rates were greatest at 25 degrees C. As temperature increased, net fecundity, gross fecundity, generation time, and life expectancy decreased. The prereproductive period did not differ between 20 and 30 degrees C; however, at 30 degrees C aphids required more degree-days (base 8.6 degrees C) to develop. Nymphs exposed to 35 degrees C did not complete development, and all individuals died within 11 d. Reproductive periods were significantly different at all temperatures, with aphids reproducing longer and producing more progeny at 20 and 25 degrees C than at 30 or 35 degrees C. Using a modification of the nonlinear Logan model, we estimated upper and optimal developmental thresholds to be 34.9 and 27.8 degrees C, respectively. At 25 degrees C, aphid populations doubled in 1.5 d; at 20 and 30 degrees C, populations doubled in 1.9 d.

Microbial control of the invasive spiraling whitefly on cassava with entomopathogenic fungi.

PubMed

Boopathi, Thangavel; Karuppuchamy, Palaniappan; Singh, Soibam B; Kalyanasundaram, Manickavasagam; Mohankumar, S; Ravi, Madhaiyan

2015-01-01

The entomopathogenic fungi Beauveria bassiana, Metarhizium anisopliae, Lecanicillium lecanii and Isaria fumosorosea were tested for their efficacy in managing the exotic spiraling whitefly Aleurodicus dispersus (Hemiptera, Aleyrodidae) on cassava (Manihot esculenta) during 2 seasons (2011-2012 and 2012-2013). The fungi I. fumosorosea and L. lecanii exhibited promising levels of control (> 70% mortality of the A. dispersus population). The percent mortality increased over time in both seasons. Application of I. fumosorosea was highly pathogenic to A. dispersus in both seasons compared to the other entomopathogenic fungi. Analysis of the percent mortality in both seasons revealed differences in efficacy between 3 and 15 days after treatment. The season also influenced the effects of the fungi on the A. dispersus population. Thus, entomopathogenic fungi have the potential to manage A. dispersus infestation of cassava.

Microbial control of the invasive spiraling whitefly on cassava with entomopathogenic fungi

PubMed Central

Boopathi, Thangavel; Karuppuchamy, Palaniappan; Singh, Soibam B.; Kalyanasundaram, Manickavasagam; Mohankumar, S.; Ravi, Madhaiyan

2015-01-01

Abstract The entomopathogenic fungi Beauveria bassiana, Metarhizium anisopliae, Lecanicillium lecanii and Isaria fumosorosea were tested for their efficacy in managing the exotic spiraling whitefly Aleurodicus dispersus (Hemiptera, Aleyrodidae) on cassava (Manihot esculenta) during 2 seasons (2011-2012 and 2012-2013). The fungi I. fumosorosea and L. lecanii exhibited promising levels of control (> 70% mortality of the A. dispersus population). The percent mortality increased over time in both seasons. Application of I. fumosorosea was highly pathogenic to A. dispersus in both seasons compared to the other entomopathogenic fungi. Analysis of the percent mortality in both seasons revealed differences in efficacy between 3 and 15 days after treatment. The season also influenced the effects of the fungi on the A. dispersus population. Thus, entomopathogenic fungi have the potential to manage A. dispersus infestation of cassava. PMID:26691465

Food habits of introduced rodents in high-elevation shrubland of Haleakala National Park, Maui, Hawai'i

USGS Publications Warehouse

Cole, F. Russell; Loope, Lloyd L.; Medeiros, Arthur C.; Howe, Cameron E.; Anderson, Laurel J.

2000-01-01

Mus musculus and Rattus rattus are ubiquitous consumers in the high-elevation shrubland of Haleakala National Park. Food habits of these two rodent species were determined from stomach samples obtained by snaptrapping along transects located at four different elevations during November 1984 and February, May, and August 1985. Mus musculus fed primarily on fruits, grass seeds, and arthropods. Rattus rattus ate various fruits, dicot leaves, and arthropods. Arthropods, many of which are endemic, were taken frequently by Mus musculus throughout the year at the highest elevation where plant food resources were scarce. Araneida, Lepidoptera (primarily larvae), Coleoptera, and Homoptera were the main arthropod taxa taken. These rodents, particularly Mus musculus, exert strong predation pressure on populations of arthropod species, including locally endemic species on upper Haleakala Volcano.

Protecting Unrooted Cuttings From Bemisia tabaci (Hemiptera Aleyrodidae) During Propagation

PubMed Central

Krauter, Peter C.; Arthurs, Steven

2017-01-01

Abstract In North America, the sweetpotato whitefly, Bemisia tabaci Genn., is an important pest of greenhouse poinsettia. Growers have limited options to control this pest during propagation of cuttings, which are rooted under mist for several weeks. Early establishment of this pest increases the difficulty of managing the whitefly and retaining high aesthetic standard during the remaining crop production phase. We evaluated two neonicotinoids with translaminar activity, thiamethoxam (Flagship 25WG), and acetamiprid (TriStar 70 WSP), for control of B. tabaci pre-infested on unrooted cuttings propagated under mist. In an experimental greenhouse, both materials significantly reduced whitefly populations, providing an average reduction of 87.8% and 61.5% total recovered whitefly stages respectively, compared with controls. In another test, dipping cuttings in thiamethoxam (immersion treatment) did not improve control significantly, when compared with foliar sprays applied at label rate. In a commercial greenhouse operation, immersion treatments of thiamethoxam on pre-infested poinsettia cuttings maintained whiteflies at ≤ 0.02/plant, compared with up to 0.33/plant in untreated cuttings. Our data suggest that treating unrooted cuttings before or at the start of propagation can be part of an overall strategy for growers to manage whiteflies in poinsettia production. PMID:28973486

Metapopulation structure of the specialized herbivore Macrosiphoniella tanacetaria (Homoptera, Aphididae).

PubMed

Massonnet, Blandine; Simon, Jean-Christophe; Weisser, Wolfgang W

2002-12-01

We investigated population dynamics, genetic diversity and spatial structure in the aphid species Macrosiphoniella tanacetaria, a specialist herbivore feeding on tansy, Tanacetum vulgare. Tansy plants (genets) consist of many shoots (ramets), and genets are grouped in sites. Thus, aphids feeding on tansy can cluster at the level of ramets, genets and sites. We studied aphid population dynamics in 1997 and 2001 and found that within sites: (i). at any time, aphids used only a fraction of the available ramets and genets; (ii). at the level of ramets, most aphid colonies survived only one week; (iii). at the level of genets, mean survival time was less than 4 weeks; and (iv). colonization and extinction events occurred throughout the season. We sampled aphids in seven sites in the Alsace region, France (4-45 km apart) and two sites in Germany in 1999 to study genetic structure within and between populations. Genetic analyses using nine microsatellite loci showed that: (i). genotypic variability was high, (ii). none of the populations was in Hardy-Weinberg equilibrium, (iii). heterozygote deficits and linkage disequilibria were frequent, and (iv). all populations were genetically differentiated, even at a small geographical scale. Renewed sampling of the Alsace sites in 2001 showed that three populations had become extinct and significant genetic changes had occurred in the remaining four populations. The frequencies of extinction and colonization events at several spatial scales suggest a hierarchical metapopulation structure for M. tanacetaria. Frequent population turnover and drift are likely causes for the genetic differentiation of M. tanacetaria populations.

A guide to the winged aphids (Homoptera) of Costa Rica.

PubMed

Voegtlin, David; Villalobos, William; Sánchez, Marco Vinicio; Saborio-R, Guido; Rivera, Carmen

2003-05-01

This guide is a compilation of limited morphological and biological information on the winged morphs of 60 species of aphids that have been collected in Costa Rica. It should not be viewed as a definitive taxonomic treatise on the aphids of Costa Rica, rather it is a tool that can be used to assist in research on the biology, host plant relationships, taxonomy, and virus transmission capabilities of aphids. Each species is covered in an identical manner. Morphological and biological information is provided in both Spanish and English as well as photographs of slide mounted specimens. Keys are provided to help the user in identifying the species. Most of the specimens examined were taken in traps associated with epidemiological studies. Limited field collecting has generated host records and these have been added to a list of the aphids of Central America that was compiled by Pamela Anderson and appended in the guide with her permission. The authors hope that this book will be useful to entomologists in Costa Rica and Central America.

Particle film affects black pecan aphid (Homoptera: Aphididae) on pecan.

PubMed

Cottrell, Ted E; Wood, Bruce W; Reilly, Charles C

2002-08-01

Three species of aphids attack pecan foliage, Carya illinoensis (Wang.) K. Koch, and cause economic damage. We tested a kaolin-based particle film against one of these aphid species, black pecan aphid, Melanocallis caryaefoliae (Davis). Effect of particle film on host selection, adult mortality, and production of nymphs by M. caryaefoliae was tested on seedling pecans in the laboratory. Fewer M. caryaefoliae adults selected treated foliage compared with untreated foliage. A higher percentage of adults that did select treated foliage were recovered from upper leaf surfaces compared with the percentage of adults recovered from upper leaf surfaces of untreated leaves. Observations with a microscope revealed an accumulation of particle film on aphid body parts, especially on tarsi, and strongly suggests that aphid mobility was restricted. Adult mortality was higher on treated foliage and led to an overall decrease in production of nymphs on those seedlings. In addition, we measured spectral properties of treated seedling pecan foliage. Light reflectance by treated foliage was increased and absorptance decreased compared with control foliage whereas transmittance of light through control and particle film-treated leaves was similar. We did not detect any phytotoxic effect on pecan due to application of particle film.

Endosymbiotic Microbiota of the Bamboo Pseudococcid Antonina crawii (Insecta, Homoptera)

PubMed Central

Fukatsu, Takema; Nikoh, Naruo

2000-01-01

We characterized the intracellular symbiotic microbiota of the bamboo pseudococcid Antonina crawii by performing a molecular phylogenetic analysis in combination with in situ hybridization. Almost the entire length of the bacterial 16S rRNA gene was amplified and cloned from A. crawii whole DNA. Restriction fragment length polymorphism analysis revealed that the clones obtained included three distinct types of sequences. Nucleotide sequences of the three types were determined and subjected to a molecular phylogenetic analysis. The first sequence was a member of the γ subdivision of the division Proteobacteria (γ-Proteobacteria) to which no sequences in the database were closely related, although the sequences of endosymbionts of other homopterans, such as psyllids and aphids, were distantly related. The second sequence was a β-Proteobacteria sequence and formed a monophyletic group with the sequences of endosymbionts from other pseudococcids. The third sequence exhibited a high level of similarity to sequences of Spiroplasma spp. from ladybird beetles and a tick. Localization of the endosymbionts was determined by using tissue sections of A. crawii and in situ hybridization with specific oligonucleotide probes. The γ- and β-Proteobacteria symbionts were packed in the cytoplasm of the same mycetocytes (or bacteriocytes) and formed a large mycetome (or bacteriome) in the abdomen. The spiroplasma symbionts were also present intracellularly in various tissues at a low density. We observed that the anterior poles of developing eggs in the ovaries were infected by the γ- and β-Proteobacteria symbionts in a systematic way, which ensured vertical transmission. Five representative pseudococcids were examined by performing diagnostic PCR experiments with specific primers; the β-Proteobacteria symbiont was detected in all five pseudococcids, the γ-Proteobacteria symbiont was found in three, and the spiroplasma symbiont was detected only in A. crawii. PMID:10653730

Spiroplasma Symbiont of the Pea Aphid, Acyrthosiphon pisum (Insecta: Homoptera)

PubMed Central

Fukatsu, Takema; Tsuchida, Tsutomu; Nikoh, Naruo; Koga, Ryuichi

2001-01-01

From a laboratory strain of the pea aphid, Acyrthosiphon pisum, we discovered a previously unknown facultative endosymbiotic bacterium. Molecular phylogenetic analysis based on 16S ribosomal DNA revealed that the bacterium is a member of the genus Spiroplasma. The Spiroplasma organism showed stable vertical transmission through successive generations of the host. Injection of hemolymph from infected insects into uninfected insects established a stable infection in the recipients. The Spiroplasma symbiont exhibited negative effects on growth, reproduction, and longevity of the host, particularly in older adults. Of 58 clonal strains of A. pisum established from natural populations in central Japan, 4 strains possessed the Spiroplasma organism. PMID:11229923

Food habits of Nyctinomops macrotis at a maternity roost in New Mexico, as indicated by analysis of guano

USGS Publications Warehouse

Sparks, D.W.; Valdez, E.W.

2003-01-01

We examined 56 fecal pellets from under a maternity colony of big free-tailed bats (Nyctinomops macrotis) in the Jemez Mountains of northern New Mexico. The most important food items, listed in order of decreasing percent volume, were Cicadellidae, leafhoppers (26.7% volume, 58.9% frequency); Ichneumonidae, Ichneumon wasps (19.3% volume, 35.7% frequency); and Lepidoptera, moths (17.2% volume, 82.1% frequency). Overall, the most important orders as prey consumed, listed by decreasing percent volume, were Homoptera (27.6% volume, 62.5% frequency), Hymenoptera (19.5% volume, 37.5% frequency), Lepidoptera (17.2% volume, 82.1% frequency), Hemiptera (11.7% volume, 37.5% frequency), and Diptera (10.6% volume, 50.0% frequency). Our study documents an unusually varied diet, as previous studies indicated that these bats fed almost exclusively on moths.

Volatiles from whitefly-infested plants elicit a host-locating response in the parasitoid, Encarsia formosa.

PubMed

Birkett, M A; Chamberlain, K; Guerrieri, E; Pickett, J A; Wadhams, L J; Yasuda, T

2003-07-01

The blend of volatile compounds emitted by bean plants (Phaseolus vulgaris) infested with greenhouse whitefly (Trialeurodes vaporariorum) has been studied comparatively with undamaged plants and whiteflies themselves. Collection of the volatiles and analysis by gas chromatography revealed more than 20 compounds produced by plants infested with whitefly. Of these, 4 compounds, (Z)-3-hexen-1-ol, 4,8-dimethyl-1,3,7-nonatriene, 3-octanone, and one unidentified compound were emitted at higher levels than from the undamaged control plants. Synthetic (Z)-3-hexen-1-ol, 4,8-dimethyl-1,3,7-nonatriene, or 3-octanone all elicited a significant increase in oriented flight and landing on the source by the parasitoid, Encarsia formosa, in wind tunnel bioassays. Two-component mixtures of the compounds and the three-component mixture all elicited a similar or, in most cases, a better response by the parasitoid, the most effective being a mixture of (Z)-3-hexen-1-ol and 3-octanone. These results demonstrate that E. formosa uses volatiles from the plant-host complex as olfactory cues for host location.

Aqueous Extracts of Some Medicinal Plants are as Toxic as Lmidacloprid to the Sweet Potato Whitefly, Bemisia tabaci

PubMed Central

Ateyyat, Mazen A.; Al-Mazra'awi, Mohammad; Abu-Rjai, Talal; Shatnawi, Mohamad A.

2009-01-01

Aqueous extracts of nine plants, known to have medicinal activity, were tested for their toxicity against the sweet potato whitefly, Bemisia tabaci Genn. (Homoptera: Aleurodidae) compared to the toxicity of the insecticide, Imidacloprid. Extracts of Lepidiuim sativum L. (Brassicales: Brassicaceae) killed 71 % of early stage nymphs, which was not significantly different from mortality caused by Imidacloprid. Treatment of pupae with three plant extracts, L. sativum, Achillea biebersteinii L. (Asterales: Asteraceae), or Retama raetam (Forssk.) Webb and Berthel (Fabales: Fabaceae) prevented adult development, and treatment with R. raetam extract killed adults, at levels that were not significantly different from Imidacloprid. None of the other plants showed significant toxicity. However extracts of four plants, Pimpinella anisum L. (Apiales: Apiaceae), Galium longifolium (Sibth. and SM.) (Gentianales: Rubiaceae), R. raetam and Ballota undulata Bentham (Lamiales: Lamiaceae) had a repellent effect. PMID:19613450

Ant tending influences soldier production in a social aphid.

PubMed

Shingleton, A W; Foster, W A

2000-09-22

The aphid Pseudoregma sundanica (Van der Goot) (Homoptera: Aphididae) has two defence strategies. It is obligatorily tended by various species of ant and also produces sterile soldiers. We investigated how they allocate their investment in these two strategies. We measured the size, number of soldiers, number and species of tending ant, and number and species of predators in P. sundanica populations. We found that the level of ant tending correlated negatively with soldier investment in P. sundanica. The species of tending ant also influenced soldier investment. We excluded ants from aphid populations and recorded changes in population size and structure over four weeks. Ant exclusion led to population decline and extinction. At the same time, surviving populations showed a significant increase in soldier investment. The data demonstrate that social aphids can adjust their investment in soldiers in direct response to environmental change.

[Anthropoentomophagic biodiversity of the Zongolica region, Veracruz, Mexico].

PubMed

Ramos-Elorduy, Julieta; Landero-Torres, Ivonne; Murguía-González, Joaquín; Pino, José M M

2008-03-01

Anthropoentomophagic biodiversity of the Zongolica region, Veracruz, Mexico. During two and a half years (2003-2005) we recorded the insect species used as food at Zongolica, Veracruz State, Mexico. Interviews were made among people (200) of this municipality to know which insects they consumed. The total of registered species was 57 (Orthoptera, Hemiptera, Homoptera, Megaloptera, Coleoptera, Lepidoptera and Hymenoptera). The Orthoptera was the most frequently ingested. Twenty-four of these species were new records for edible insects of Mexico. They are eaten in immature stages or as adults, generally only roasted. Consumption is seasonal. Some species are commercialized in the "tianguis" (little town markets) and/or in the larger Zongolica market. There is a "protoculture" of three species, one cockroach (Periplaneta australasiae Fabricius) and two moths (Latebraria amphipyroides Guenée and Arsenura armida armida Cramer). In Zongolica, anthropoentomophagy is an ancestral habit.

Temperature stress effects in Bemisia tabaci (Hemiptera: Aleyrodidae) type B whiteflies

USDA-ARS?s Scientific Manuscript database

Oxidative stress occurs in response to changes in the redox equilibiurm, which may be caused by increases in reactive oxygen species (ROS), a decrease in antioxidant protection or failure of cells to repair oxidative damage. ROS are either free radicals, reactive molecules containing oxygen atoms or...

Observations of the larval stages of Diceroprocta apache Davis (Homoptera: Tibicinidae)

USGS Publications Warehouse

Ellingson, A.R.; Andersen, D.C.; Kondratieff, B.C.

2002-01-01

Diceroprocta apache Davis is a locally abundant cicada in the riparian woodlands of the southwestern United States. While its ecological importance has often been hypothesized, very little is known of its specific life history. This paper presents preliminary information on life history of D. apache from larvae collected in the field at seasonal intervals as well as a smaller number of reared specimens. Morphological development of the fore-femoral comb closely parallels growth through distinct size classes. The data indicate the presence of five larval instars in D. apache. Development times from greenhouse-reared specimens suggest a 3-4 year life span and overlapping broods were present in the field. Sex ratios among pre-emergent larvae suggest the asynchronous emergence of sexes.

Hemlock woolly adelgid (Homoptera: Adelgidae): stylet bundle insertion and feeding sites

Treesearch

Rebecca F. Young; Kathleen S. Shields; Graeme P. Berlyn

1995-01-01

Stylet bundle insertion site, path traveled, and feeding site were examined for the hemlock woolly adelgid, Adelges tsugae Annand, on needles from current and previous years of eastern hemlock, Tsuga canadensis Carriere. The stylet bundle is composed of 4 individual stylets--2 outer mandibular stylets and 2 inner maxillary stylets...

Timbal muscle physiology in the endothermic cicada Tibicen winnemanna (Homoptera: Cicadidae).

PubMed

Sanborn, A F

2001-08-01

The operative muscle temperature and contraction kinetics are described for the endothermic cicada Tibicen winnemanna (Davis). Measurements of timbal muscle temperature in the field demonstrate that timbal muscle temperature is elevated above ambient temperature during activity. Timbal muscle temperature increases as the acoustic output progresses from a 'warm-up' buzz (27.9-29.7 degrees C) to full song production (36.3-39.5 degrees C). Mean muscle-ambient temperature difference increases from 5.8 degrees C in buzzing animals to 13.1 degrees C in animals producing a full calling song. Twitch rise time and onset to 50% relaxation time decrease while tension production increases with increasing temperature to 40 degrees C. Mean force production at 20 degrees C was determined to be 0.22+/-0.06 N/cm(2). The characteristics of T. winnemanna muscle are similar to those reported in other cicada species. Analysis of the songs produced by animals with one timbal destroyed and the sounds produced by mechanical manipulation suggest that the timbals alternately contract and relax in the sequence IN(1)-IN(2)-OUT(1)-OUT(2). Measurements of the inferred period of muscle contraction from song recordings and the contraction kinetics of isolated timbal muscles measured in the laboratory show that the temperature of the timbal muscle must be elevated in order for the cicada to be able to produce the calling song.

General trends of chromosomal evolution in Aphidococca (Insecta, Homoptera, Aphidinea + Coccinea)

PubMed Central

Gavrilov-Zimin, Ilya A.; Stekolshchikov, Andrey V.; Gautam, D.C.

2015-01-01

Abstract Parallel trends of chromosomal evolution in Aphidococca are discussed, based on the catalogue of chromosomal numbers and genetic systems of scale insects by Gavrilov (2007) and the new catalogue for aphids provided in the present paper. To date chromosome numbers have been reported for 482 species of scale insects and for 1039 species of aphids, thus respectively comprising about 6% and 24% of the total number of species. Such characters as low modal numbers of chromosomes, heterochromatinization of part of chromosomes, production of only two sperm instead of four from each primary spermatocyte, physiological sex determination, "larval" meiosis, wide distribution of parthenogenesis and chromosomal races are considered as a result of homologous parallel changes of the initial genotype of Aphidococca ancestors. From a cytogenetic point of view, these characters separate Aphidococca from all other groups of Paraneoptera insects and in this sense can be considered as additional taxonomic characters. In contrast to available paleontological data the authors doubt that Coccinea with their very diverse (and partly primitive) genetic systems may have originated later then Aphidinea with their very specialised and unified genetic system. PMID:26312130

Embryonic development of pleuropodia of the cicada, Magicicada cassini

PubMed Central

Strauß, Johannes; Lakes-Harlan, Reinhard

2006-01-01

In many insects the first abdominal segment possesses embryonic appendages called pleuropodia. Here we show the embryogenesis of pleuropodial cells of the periodical cicada, Magicicada cassini (Fisher 1851) (Insecta, Homoptera, Cicadidae). An antibody, anti-horseradish perioxidase (HRP), that is usually neuron-specific strongly marked the pleuropodial anlagen and revealed their ectodermal origin shortly after limb bud formation. Thereafter the cells sank into the epidermis and their apical parts enlarged. A globular part protruded from the body wall. Filamentous structures were marked at the stem region and into the apical dilation. In later embryonic stages the pleuropodia degenerated. Despite the binding of anti-HRP the cells had no morphological neuronal characters and cannot be regarded as neurons. The binding indicates that glycosylated cell surface molecules contribute to the adhesion between the presumably glandular pleuropodial cells. In comparison, anti-HRP does not mark the pleuropodia of Orthoptera. PMID:19537987

Cross-resistance relationships between neonicotinoids and pymetrozine in Bemisia tabaci (Hemiptera: Aleyrodidae).

PubMed

Gorman, Kevin; Slater, Russell; Blande, James D; Clarke, Alison; Wren, Jodie; McCaffery, Alan; Denholm, Ian

2010-11-01

Although cross-resistance between compounds in the same insecticide group is a frequently observed phenomenon, cross-resistance between groups that differ in structural and functional characteristics can be extremely unpredictable. In the case of controlling the whitefly, Bemisia tabaci Gennadius, neonicotinoids and the pyridine azomethine antifeedant pymetrozine represent independent lines of discovery that should be suited for alternation to avoid prolonged selection for the same resistance mechanism. Reports of an association between responses to neonicotinoids and pymetrozine were investigated by resistance profiling of seven B. tabaci strains and complementary reciprocal selection experiments. All strains demonstrated a consistent correlation between responses to three neonicotinoid compounds: thiamethoxam, imidacloprid and acetamiprid. Responses to neonicotinoids for six field strains clearly correlated with responses to pymetrozine. Reciprocal selection experiments confirmed an unexpected case of intergroup cross-resistance. A seventh strain exhibited a so far unique phenotype of strong resistance to pymetrozine but full susceptibility to neonicotinoids. Selection experiments confirmed that in this strain the mechanism of pymetrozine resistance is specific and has no implications for neonicotinoids. Cross-resistance between neonicotinoids and pymetrozine in B. tabaci probably reflects the overexpression of a cytochrome-P450-dependent monooxygenase capable of metabolising both types of compound in spite of their apparent structural dissimilarity. Given the predominance of this mechanism in B. tabaci, both can contribute to resistance management but should be placed within the same treatment 'window'. Copyright © 2010 Society of Chemical Industry.

Egg parasitoids of Sophonia rufofascia (Homoptera: Cicadellidae) in Hawaii Volcanoes National Park

USGS Publications Warehouse

Johnson, M.T.; Yang, P.; Huber, J.T.; Jones, V.P.

2001-01-01

Parasitism of the leafhopper Sophonia rufofascia (Kuoh and Kuoh), a recent immigrant that has become a widespread pest in Hawaii, was examined in a 1-year survey in Hawaii Volcanoes National Park. Samples of young leaves of four plant species infested with eggs of S. rufofascia were collected at five sites ranging from 880 to 1190 m in elevation. Leafhopper eggs were parasitized principally by three species of Mymaridae (Hymenoptera): Polynema sp., Schizophragma sp. probably bicolor (Dozier), and Chaetomymar sp. Although parasitism by each species fluctuated at levels usually below 10%, all three were detected consistently across most host plants, sites, and sample periods. Total parasitism differed at a marginally significant level among host plants and sites, but not among sample periods. Total parasitism averaged 14.3% (maximum: 26.3%) on Dodonaea viscosa Jacquin, 10.6% (maximum: 17.5%) on Myrica faya Aiton, 8.7% (maximum: 29.5%) on Metrosideros polymorpha Gaudich-Beaupre, and 1.6% (maximum: 4.3%) on Vaccinium reticulatum Smith. Parasitism was generally higher at sites lower in elevation. Further monitoring is recommended to determine whether parasitism will increase to levels that can effectively suppress S. rufofascia populations. The efficacy of natural enemies already present in Hawaii is important because concern over nontarget impacts on endemic leafhoppers makes introduction of new biological control agents difficult. ?? 2001 Academic Press.

Fixed precision sampling plans for white apple leafhopper (Homoptera: Cicadellidae) on apple.

PubMed

Beers, Elizabeth H; Jones, Vincent P

2004-10-01

Constant precision sampling plans for the white apple leafhopper, Typhlocyba pomaria McAtee, were developed so that it could be used as an indicator species for system stability as new integrated pest management programs without broad-spectrum pesticides are developed. Taylor's power law was used to model the relationship between the mean and the variance, and Green's constant precision sequential sample equation was used to develop sampling plans. Bootstrap simulations of the sampling plans showed greater precision (D = 0.25) than the desired precision (Do = 0.3), particularly at low mean population densities. We found that by adjusting the Do value in Green's equation to 0.4, we were able to reduce the average sample number by 25% and provided an average D = 0.31. The sampling plan described allows T. pomaria to be used as reasonable indicator species of agroecosystem stability in Washington apple orchards.

Insect-vacs for sampling Asian citrus psyllid (Homoptera: psyllidae) on citrus trees

USDA-ARS?s Scientific Manuscript database

Three vacuum devices were compared for sampling psyllid populations. One was an AC rechargeable, handheld, cordless model and a second was a handheld, DC model powered through a cord connected to a 12V vehicle battery. Each of these devices had a mesh cylinder (substituted for a dust bag) in which...

The Secondary Endosymbiotic Bacterium of the Pea Aphid Acyrthosiphon pisum (Insecta: Homoptera)

PubMed Central

Fukatsu, Takema; Nikoh, Naruo; Kawai, Rena; Koga, Ryuichi

2000-01-01

The secondary intracellular symbiotic bacterium (S-symbiont) of the pea aphid Acyrthosiphon pisum was investigated to determine its prevalence among strains, its phylogenetic position, its localization in the host insect, its ultrastructure, and the cytology of the endosymbiotic system. A total of 14 aphid strains were examined, and the S-symbiont was detected in 4 Japanese strains by diagnostic PCR. Two types of eubacterial 16S ribosomal DNA sequences were identified in disymbiotic strains; one of these types was obtained from the primary symbiont Buchnera sp., and the other was obtained from the S-symbiont. In situ hybridization and electron microscopy revealed that the S-symbiont was localized not only in the sheath cells but also in a novel type of cells, the secondary mycetocytes (S-mycetocytes), which have not been found previously in A. pisum. The size and shape of the S-symbiont cells were different when we compared the symbionts in the sheath cells and the symbionts in the S-mycetocytes, indicating that the S-symbiont is pleomorphic under different endosymbiotic conditions. Light microscopy, electron microscopy, and diagnostic PCR revealed unequivocally that the hemocoel is also a normal location for the S-symbiont. Occasional disordered localization of S-symbionts was also observed in adult aphids, suggesting that there has been imperfect host-symbiont coadaptation over the short history of coevolution of these organisms. PMID:10877764

Comparison of the ionizing radiation effects on cochineal, annatto and turmeric natural dyes

NASA Astrophysics Data System (ADS)

Cosentino, Helio M.; Takinami, Patricia Y. I.; del Mastro, Nelida L.

2016-07-01

As studies on radiation stability of food dyes are scarce, commercially important natural food grade dyes were evaluated in terms of their sensitivity against gamma ionizing radiation. Cochineal, annatto and turmeric dyes with suitable concentrations were subjected to increasing doses up to 32 kGy and analyzed by spectrophotometry and capillary electrophoresis. The results showed different pattern of absorbance versus absorbed dose for the three systems. Carmine, the glucosidal coloring matter from the scale insect Coccus cacti L., Homoptera (cochineal) remained almost unaffected by radiation up to doses of about 32 kGy (absorbance at 494 nm). Meanwhile, at that dose, a plant-derived product annatto or urucum (Bixa orellana L.) tincture presented a nearly 58% reduction in color intensity. Tincture of curcumin (diferuloylmethane) the active ingredient in the eastern spice turmeric (Curcuma longa) showed to be highly sensitive to radiation when diluted. These data shall be taken in account whenever food products containing these food colors were going to undergo radiation processing.

Kirtland's warbler diet as determined through fecal analysis

USGS Publications Warehouse

Deloria-Sheffield, Christie M.; Millenbah, Kelly F.; Bocetti, Carol I.; Sykes, P.W.; Kepler, C.B.

2001-01-01

The endangered Kirtland's Warbler (Dendroica kirtlandii) nests primarily in large (>32 ha) stands of young (5- to 25-yr-old) jack pine (Pinus banksiana) which grow on Grayling sand soil. These specific habitat requirements restrict the Kirtland's Warbler breeding range to only 13-16 counties in the northern lower peninsula of Michigan. Although the nature of the species' affinity for this habitat is poorly understood, one theory suggests that higher prey abundance in young jack pine may play a role. To explore further the hypothesis that Kirtland's Warblers choose nesting habitat due to prey abundance, a more thorough knowledge of the warblers' diet is needed. To better understand the diet, we identified arthropod and plant fragments found in 202 Kirtland's Warbler fecal samples, collected from June to September, 1995-1997. The major food items recorded were spittlebugs and aphids (Homoptera; found in 61% of all samples), ants and wasps (Hymenoptera; 45%), blueberry (Vaccinium augustifolium; 42%), beetles (Coleoptera; 25%), and moth larvae (Lepidoptera; 22%).

New record for Woldstedtius flavolineatus (Ichneumonidae: Diplazontinae), a hymenopteran parasitoid of syrphid flies in Hawaii

USGS Publications Warehouse

Cappadonna, Justin; Euaparadorn, Melody; Peck, Robert W.; Banko, Paul C.

2009-01-01

The parasitoid wasp Woldstedtius flavolineatus (Gravenhorst) (Ichneumonidae) attacks the larvae of syrphid flies (Syrphidae). Woldstedtius flavolineatus was collected in Hawaii for the first time during an extensive malaise trap-based survey of parasitoids in Hawaiian forests. Since its initial collection on Hawaii Island in January 2006, it has been collected at five additional sites on Hawaii Island and at one site each on Maui and Oahu. Malaise trap results from Hakalau Forest National Wildlife Refuge showed a strong seasonal pattern of abundance, with peak population levels reached during July–September. Rearing of its host, Allograpta obliqua (Say), collected from koa (Acacia koa Gray) at Hakalau over two days, revealed a parasitism rate of approximately 95%. Broader impacts of this alien wasp are unknown, but a reduction in host syrphid abundance could result in an increase in numbers of psyllids and aphids (Homoptera) that are preyed upon by syrphid larvae. Furthermore, a reduction in adult syrphids could impact the reproductive success of some of the plants they pollinate.

COMPOSITION, STRUCTURE, ET MODE DE FORMATION DES CONCRÉTIONS MINÉRALES DANS L'INTESTIN MOYEN DES HOMOPTERES CERCOPIDES

PubMed Central

Gouranton, Jean

1968-01-01

The granules which occur in the cells of a part of the midgut wall in Cercopid larvae and adults (Homoptera) have been studied by biochemical and cytochemical methods and by electron microscopy. The granules have a diameter up to about 2µ and contain calcium, magnesium, iron, carbonates, and phosphates. Protein and acid mucopolysaccharide have also been detected. A chromatographic study shows that uric acid and guanine are not present. The young concretions occur primarily in ergastoplasmic cisternae. They are first wholly electron-opaque, but their center becomes more and more clear. In very old spheres, only a thin shell of electron-opaque material remains. The spheres which have reached about 1µ in diameter are all associated with myelin figures. The granule-containing cells, which nearly occlude the lumen of the midgut in larvae, are eliminated in the very young adults, but the storage excretion still continue in adults. PMID:4231917

Characterizing population and genetic structure of Aleurodicus rugioperculatus Martin (Hemiptera: Aleyrodidae) in Florida

USDA-ARS?s Scientific Manuscript database

The genus Aleurodicus comprises over 30 species of whiteflies natively found in abundancethroughout Central America and the Caribbean. Whiteflies are tiny, polyphagous, sap-ingesting insects affecting fruit crops, ornamental plantings as well as various shrubs and trees. A widerange of hosts with an...

DNA barcode development for three recent exotic whitefly (Hemiptera: Aleyrodidae) invaders in Florida

USDA-ARS?s Scientific Manuscript database

Several new whitefly species have become established in Florida in the past decade. Three, in particular, have caused noticible damage to residential plants in the landscape such as ficus hedges, palms, and bird of paradise. These are fig whitefly (FW), rugose spiraling whitefly (RSW), and Bondar’s ...

Six New Record Species of Whiteflies (Hemiptera: Aleyrodidae) Infesting Morus alba in China

PubMed Central

Wang, Ji-Rui; Song, Zao-Qin; Du, Yu-Zhou

2014-01-01

Abstract To determine the species of whiteflies occurring on mulberry, Morus alba L. (Rosales: Moraceae) in China, we collected samples in more than 87 sites in 16 provinces of China from 2008 to 2011. In total, 10 species, representing seven genera of the subfamily Aleyrodinae, were identified. Of these, six species are newly recorded on mulberry in China, namely, Aleuroclava ficicola Takahashi, Aleuroclava gordoniae (Takahashi), Aleurotrachelus camelliae (Kuwana), Bemisia afer (Priesner & Hosny), Bemisia tabaci Gennadius, and Pealius machili Takahashi. Information on the taxonomy, distribution, and host plants of the whitefly species found on mulberry in China, along with a brief description and illustrations of each species are provided. PMID:25368095

Distribution of Bemisia tabaci (Hemiptera: Aleyrodidae) biotypes in Florida - Investigating the "Q" invasion

USDA-ARS?s Scientific Manuscript database

After the 2004 discovery of the Bemisia tabaci Q biotype in the U.S., there was an urgent need to determine its distribution. As part of a coordinated country-wide effort, an extensive survey of B. tabaci biotypes was conducted in Florida, with the cooperation of growers and state agencies, to moni...

Quantifying conservation biological control for management of Bemisia tabaci (Hemiptera: Aleyrodidae) in cotton

USDA-ARS?s Scientific Manuscript database

Conservation biological control can be an effective tactic for minimizing insect-induced damage to agricultural production. The most effective manner of applying CBC is through an Integrated Pest Management (IPM) strategy, combining many tactics including cultural controls, pest sampling, the use of...

Characterization of Antixenosis in Soybean Genotypes to Bemisia tabaci (Hemiptera: Aleyrodidae) Biotype B.

PubMed

Baldin, E L L; Cruz, P L; Morando, R; Silva, I F; Bentivenha, J P F; Tozin, L R S; Rodrigues, T M

2017-08-01

Bemisia tabaci biotype B (Gennadius) is one of the most important soybean pest worldwide. Herein, 15 soybean genotypes were evaluated, to characterize the occurrence of antixenosis to B. tabaci biotype B. Initially, a multiple-choice test with all genotypes was carried out, evaluating the settling and oviposition preference at 3 d after infestation, and the colonization by nymphs after 48 d of infestation. Subsequently, a no-choice test, using 14 genotypes, was conducted with infested plants individually, and the number of eggs was counted after 72 h. Then, 10 genotypes were selected (indicative of resistance and susceptibility), which were evaluated for whitefly settling 24, 48, and 72 h after infestation and for oviposition 72 h after infestation. The trichomes of the leaflets were characterized for density, size, and inclination to establish possible correlations with the settling and oviposition in the genotypes. In the first multiple-choice test, involving 15 genotypes, 'IAC-17,' 'IAC-19,' and UX-2569-159 expressed antixenosis against B. tabaci. 'Jackson,' 'P98Y11,' and PI-229358 exhibited the same behavior in the no-choice test. In the multiple-choice test, 'Jackson,' 'P98Y11,' and 'TMG1176 RR' were the least attractive and least used for oviposition. The antixenosis shown by 'Jackson,' 'P98Y11,' and PI-229358 may be related to the characteristics of the trichomes (lower density and inclined). Based on the experiments carried out, 'IAC-17,' 'IAC-19,' 'Jackson,' 'P98Y11,' PI-229358, TMG1176 RR, and UX-2569-159 are considered promising for resistance to B. tabaci biotype B and may be exploited in soybean breeding programs for resistance to insects. © 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.

Potential sources of whitefly (Hemiptera: Aleyrodidae) resistance in desert watermelon (Citrullus colocynthis) germplasm

USDA-ARS?s Scientific Manuscript database

Selection for host plant resistance and incorporation of natural resistance into cultivars is a fundamental strategy to control insects and diseases in an environmentally-sensitive manner, and may help reduce reliance on synthetic pesticides. The sweetpotato whitefly, Bemisia tabaci (Gennadius), is...

Omnivore-herbivore interactions: thrips and whiteflies compete via the shared host plant.

PubMed

Pappas, Maria L; Tavlaki, Georgia; Triantafyllou, Anneta; Broufas, George

2018-03-05

Phytophagy is a common feature among pure herbivorous insects and omnivores that utilise both plant and prey as food resources; nevertheless, experimental evidence for factors affecting their interactions is restricted to intraguild predation and predator-mediated competition. We herein focused on plant-mediated effects that could result from plant defence activation or quality alteration and compared the performance of an omnivore, the western flower thrips Frankliniella occidentalis, and a pure herbivore, the greenhouse whitefly Trialeurodes vaporariorum, on cucumber plants previously infested with either species. Furthermore, we recorded their behavioural responses when given a choice among infested and clean plants. Whiteflies laid less eggs on plants previously exposed to thrips but more on whitefly-infested plants. Thrips survival was negatively affected on whitefly-infested than on thrips-infested or clean plants. Notably, whiteflies developed significantly faster on plants infested with conspecifics. In accordance, whiteflies avoided thrips-infested plants and preferred whitefly-infested over clean plants. Thrips showed no preference for either infested or clean plants. Our study is a first report on the role of plant-mediated effects in shaping omnivore-herbivore interactions. Considering the factors driving such interactions we will likely better understand the ecology of the more complex relationships among plants and pest organisms.

Influences of pea morphology and interacting factors on pea aphid (Homoptera: Aphididae) reproduction.

PubMed

Buchman, N; Cuddington, K

2009-08-01

It has been claimed that plant architecture can alter aphid reproductive rates, but the mechanism driving this effect has not been identified. We studied interactions between plant architecture, aphid density, environmental conditions, and nutrient availability on the reproduction of pea aphids [Acyrthosiphon pisum (Harris)] using four near-isogenic peas (Pisum sativum L.) that differ in morphology. Manipulations of aphid density (1, 5, and 10 adults per plant) allowed us to examine any effects of plant morphology on crowding and consequently reproduction. Pea morphology per se did not alter pea aphid crowding, as measured by mean nearest neighbor distance, and there was no effect on reproduction. In addition, reproduction increased with increasing adult density, indicating positive density dependence. In a separate experiment, peas were fertilized to determine whether differences between nutrient availability of the four different morphologies might drive any observed differences in aphid reproduction. Although plant nitrogen content was altered by fertilization treatments, this did not have an impact on aphid reproduction. Greenhouse experiments, however, suggested that pea morphology can interact with environmental conditions to reduce aphid reproduction under some conditions. We conclude that plant morphology only influences aphid reproduction when environmental conditions are less than optimal.

Energetics of emergence in the cicadas, Cyclochila australasiae and Abricta curvicosta (Homoptera: Cicadidae).

PubMed

Harvey, Prudence M; Thompson, Michael B

2006-09-01

The final moult in cicadas marks a major transition in lifestyle and is a behaviour that makes the cicada vulnerable to predation. Consequently, emergence times are short and, we predict, therefore the rate of energy consumption would be high. Hence, we measured the energetic cost of emergence in Cyclochila australasiae (green grocer) and Abricta curvicosta (floury baker) cicadas during the final moult from nymph to adult cicada. Maximum energy expended whilst emerging was compared between the sexes and species. Even though C. australasiae take longer to emerge than A. curvicosta, the mass-specific cost of emergence is not different between the two species (C. australasiae: 11.34+/-2.55 J g(-1); A. curvicosta: 12.91+/-1.90 J g(-1)). The mass-specific metabolic rates of fully emerged adults of both species are approximately twice those of the nymphs and the maximum metabolic rate during emergence is about 1.5 times higher than the resting metabolic rate of emerged adults. Emergence times, as indicated by rates of oxygen consumption, are longer than expected and probably reflect limitations in the oxygen capacity of the cicadas during moulting.

Biology of Scymnus ningshanensis (Coleoptera: Coccinellidae): A predator of Adelges tsugae (Homoptera: Adelgidae)

Treesearch

Michael Montgomery; Hongbin Wang; Defu Yao; Wenhau Lu; Nathan Havill; Guangwu Li

2002-01-01

Information is presented on the occurrence, development, and feeding of Scymnus (Neopullus) ningshanensis Yu et Yao. Information on its biology was collected in the field and laboratory in China and in quarantine in the United States. This lady beetle was found in China only on hemlock infested with ...

Are cicadas (Diceroprocta apache) both a "keystone" and a "critical-link" species in lower Colorado River riparian communities?

USGS Publications Warehouse

Andersen, Douglas C.

1994-01-01

Apache cicada (Homoptera: Cicadidae: Diceroprocta apache Davis) densities were estimated to be 10 individuals/m2 within a closed-canopy stand of Fremont cottonwood (Populus fremontii) and Goodding willow (Salix gooddingii) in a revegetated site adjacent to the Colorado River near Parker, Arizona. Coupled with data drawn from the literature, I estimate that up to 1.3 cm (13 1/m2) of water may be added to the upper soil layers annually through the feeding activities of cicada nymphs. This is equivalent to 12% of the annual precipitation received in the study area. Apache cicadas may have significant effects on ecosystem functioning via effects on water transport and thus act as a critical-link species in this southwest desert riverine ecosystem. Cicadas emerged later within the cottonwood-willow stand than in relatively open saltcedar-mesquite stands; this difference in temporal dynamics would affect their availability to several insectivorous bird species and may help explain the birds' recent declines. Resource managers in this region should be sensitive to the multiple and strong effects that Apache cicadas may have on ecosystem structure and functioning.

Soral crypsis: protective mimicry of a coccid on an Indian fern.

PubMed

Patra, Biplab; Bera, Subir; Hickey, R James

2008-06-01

Herbivory with crypsis is not well documented in ferns. The present record of cryptic coloration of coccid Saissetia filicum Boisduval (Homoptera: Coccidae) to the sori of a fern species Asplenium nidus L. (Aspleniaceae) is unique. Predatory beetles (Jauravia sp., Coleoptera: Coccinellidae) that feed on the coccids, are suggested to be selective pressure for the development of the present homopteran soral crypsis. A higher rate of effective predation is noticed in the vegetative leaves than the fertile leaves. Aggressive ants were found harvesting honeydew secretions from the coccids and defending the trophobionts as well as the host fern from their natural enemies. In addition, a possible three-way mutualistic relationship among the coccids, its host fern and the tending ant is suggested. Differential numbers of coccids on vegetative and fertile leaves is correlated with their phenol content and degree of predation by beetles. Such coloration mimicry by the coccids may enable them to obtain the necessary blend of sorus of the host fern needed to evade beetle detection and attack.

Isolation and in vitro cultivation of the aphid pathogenic fungus Entomophthora planchoniana.

PubMed

Freimoser, F M; Jensen, A B; Tuor, U; Aebi, M; Eilenberg, J

2001-12-01

Entomophthora planchoniana is an important fungal pathogen of aphids. Although Entomophthora chromaphidis has been considered a synonym for E. planchoniana, the two species are now separated, and E. planchoniana is reported not to grow in vitro. In this paper, we describe for the first time the isolation and cultivation of this species. Entomophthora planchoniana was isolated from a population of Ovatus crataegarius (Homoptera, Aphididae), which was infected by E. planchoniana only. The isolates did not sporulate, but the sequence of the small subunit rDNA and the restriction fragment length polymorphism patterns of the first part of the large subunit rDNA and the ITS II region confirm that the isolates were E. planchoniana. The isolated fungus grew in a medium consisting of Grace's insect cell culture medium supplemented with lactalbumin hydrolysate, yeastolate, and 10% fetal bovine serum or in GLEN medium with 10% fetal bovine serum. Vegetative cells of E. planchoniana were long and club-shaped and did not stain with Calcofluor, thus suggesting that they were protoplasts.

Development and use of EST-SSR markers for assessing genetic diversity in the brown planthopper (Nilaparvata lugens Stål).

PubMed

Jing, S; Liu, B; Peng, L; Peng, X; Zhu, L; Fu, Q; He, G

2012-02-01

To assess genetic diversity in populations of the brown planthopper (Nilaparvata lugens Stål) (Homoptera: Delphacidae), we have developed and applied microsatellite, or simple sequence repeat (SSR), markers from expressed sequence tags (ESTs). We found that the brown planthopper clusters of ESTs were rich in SSRs with unique frequencies and distributions of SSR motifs. Three hundred and fifty-one EST-SSR markers were developed and yielded clear bands from samples of four brown planthopper populations. High cross-species transferability of these markers was detected in the closely related planthopper N. muiri. The newly developed EST-SSR markers provided sufficient resolution to distinguish within and among biotypes. Analyses based on SSR data revealed host resistance-based genetic differentiation among different brown planthopper populations; the genetic diversity of populations feeding on susceptible rice varieties was lower than that of populations feeding on resistant rice varieties. This is the first large-scale development of brown planthopper SSR markers, which will be useful for future molecular genetics and genomics studies of this serious agricultural pest.

Diet of Wilson's warblers and distribution of arthropod prey in the understory of Douglas-fir forests

USGS Publications Warehouse

Hagar, Joan C.; Dugger, Kate; Starkey, Edward E.

2007-01-01

Availability of food resources is an important factor in avian habitat selection. Food resources for terrestrial birds often are closely related to vegetation structure and composition. Identification of plant species important in supporting food resources may facilitate vegetation management to achieve objectives for providing bird habitat. We used fecal analysis to describe the diet of adult Wilson's Warblers (Wilsonia pusilla) that foraged in the understory of Douglas-fir (Pseudotsuga menziesii) forests in western Oregon during the breeding season. We sampled arthropods at the same sites where diet data were collected, and compared abundance and biomass of prey among seven common shrub species. Wilson's Warblers ate more caterpillars (Lepidoptera larvae), flies (Diptera), beetles (Coleoptera), and Homoptera than expected based on availability. Deciduous shrubs supported higher abundances of arthropod taxa and size classes used as prey by Wilson's Warblers than did evergreen shrubs. The development and maintenance of deciduous understory vegetation in conifer forests of the Pacific Northwest may be fundamental for conservation of food webs that support breeding Wilson's Warblers and other shrub-associated, insectivorous songbirds.

Arthropod prey of Wilson's Warblers in the understory of Douglas-fir forests

USGS Publications Warehouse

Hagar, J.C.; Dugger, K.M.; Starkey, E.E.

2007-01-01

Availability of food resources is an important factor in avian habitat selection. Food resources for terrestrial birds often are closely related to vegetation structure and composition. Identification of plant species important in supporting food resources may facilitate vegetation management to achieve objectives for providing bird habitat. We used fecal analysis to describe the diet of adult Wilson's Warblers (Wilsonia pusilla) that foraged in the understory of Douglas-fir (Pseudotsuga menziesii) forests in western Oregon during the breeding season. We sampled arthropods at the same sites where diet data were collected, and compared abundance and biomass of prey among seven common shrub species. Wilson's Warblers ate more caterpillars (Lepidoptera larvae), flies (Diptera), beetles (Coleoptera), and Homoptera than expected based on availability. Deciduous shrubs supported higher abundances of arthropod taxa and size classes used as prey by Wilson's Warblers than did evergreen shrubs. The development and maintenance of deciduous understory vegetation in conifer forests of the Pacific Northwest may be fundamental for conservation of food webs that support breeding Wilson's Warblers and other shrub-associated, insectivorous songbirds.

Recessive Resistance Derived from Tomato cv. Tyking-Limits Drastically the Spread of Tomato Yellow Leaf Curl Virus

PubMed Central

Pereira-Carvalho, Rita C.; Díaz-Pendón, Juan A.; Fonseca, Maria Esther N.; Boiteux, Leonardo S.; Fernández-Muñoz, Rafael; Moriones, Enrique; Resende, Renato O.

2015-01-01

The tomato yellow leaf curl disease (TYLCD) causes severe damage to tomato (Solanum lycopersicum L.) crops throughout tropical and subtropical regions of the world. TYLCD is associated with a complex of single-stranded circular DNA plant viruses of the genus Begomovirus (family Geminiviridae) transmitted by the whitefy Bemisia tabaci Gennadius (Hemiptera: Aleyrodidae). The tomato inbred line TX 468-RG is a source of monogenic recessive resistance to begomoviruses derived from the hybrid cv. Tyking F1. A detailed analysis of this germplasm source against tomato yellow leaf curl virus-Israel (TYLCV-IL), a widespread TYLCD-associated virus, showed a significant restriction to systemic virus accumulation even under continuous virus supply. The resistance was effective in limiting the onset of TYLCV-IL in tomato, as significantly lower primary spread of the virus occurred in resistant plants. Also, even if a limited number of resistant plants could result infected, they were less efficient virus sources for secondary spread owing to the impaired TYLCV-IL accumulation. Therefore, the incorporation of this resistance into breeding programs might help TYLCD management by drastically limiting TYLCV-IL spread. PMID:26008699

Improved Sweetpotato Whitefly and Potato Psyllid Control in Tomato by Combining the Mirid Dicyphus hesperus (Heteroptera: Miridae) With Specialist Parasitic Wasps.

PubMed

Calvo, F J; Torres-Ruiz, A; Velázquez-González, J; Rodríguez-Leyva, E; Lomeli-Flores, J R

2018-04-02

Bemisia tabaci Gennadius (Hemiptera: Aleyrodidae) and Bactericera cockerelli Sulcer (Hemiptera: Psyllidae) are important pests in tomato, and the mirid Dicyphus hesperus Knight (Heteroptera: Miridae) has been shown as an effective predator of both pests. Although the predator was able to suppress populations of both pests, the remaining levels could still exceed tolerable levels. Thus, we here hypothesized whether the combination of D. hesperus with the specialist parasitoids Eretmocerus eremicus Rose y Zolnerowich (Hymenoptera: Aphelinidae) (whitefly) and Tamarixia triozae (Burks) (Hymenoptera: Eulophidae) (psyllid) would result in better pest control on a greenhouse scale. For that, we conducted a trial in which we compared the results against B. tabaci and B. cockerelli in greenhouses treated with D. hesperus alone or the predator in combination with the specialist parasitoids. The results showed that the predator was able to establish and suppress B. tabaci and B. cockerelli in tomato, but the addition of the specialist parasitoids resulted in better and more cost-effective pest control. Implementation of this method would therefore increase the robustness and reliability of biocontrol-based integrated pest management programmes for tomato crops, over methods based exclusively on D. hesperus release.

Aphid-induced Defences in Chilli Affect Preferences of the Whitefly, Bemisia tabaci (Hemiptera: Aleyrodidae).

PubMed

Saad, Khalid A; Mohamad Roff, M N; Hallett, Rebecca H; Idris, A B

2015-09-03

The sweetpotato whitefly (WF), Bemisia tabaci, is a major pest that damages a wide range of vegetable crops in Malaysia. WF infestation is influenced by a variety of factors, including previous infestation of the host plant by other insect pests. This study investigated the effects of previous infestation of host chilli plants by the green peach aphid (Myzus persicae) on the olfactory behavioural response of B. tabaci, using free-choice bioassay with a Y-tube olfactometer. We analysed volatile organic compounds (VOCs) emitted by non-infested and M. persicae-infested chilli plants using solid-phase microextraction and gas chromatography-mass spectrometry. Our results showed that female WFs preferred non-infested to pre-infested plants. Collection and analysis of volatile compounds emitted by infested plants confirmed that there were significant increases in the production of monoterpenes (cymene; 1,8-cineole), sesquiterpenes (β-cadinene, α-copaene), and methyl salicylate (MeSA) compared to non-infested plants. Our results suggest that host plant infestation by aphids may induce production of secondary metabolites that deter B. tabaci from settling on its host plants. These results provide important information for understanding WF host selection and dispersal among crops, and also for manipulating WF behaviour to improve IPM in chilli.

Extensive survey of Bemisia tabaci (Hemiptera: Aleyrodidae) biotypes in Florida investigating the Q invasion

USDA-ARS?s Scientific Manuscript database

After the discovery of the Bemisia tabaci Q biotype in the U.S., there was an urgent need to determine its spread. As part of a coordinated whole country survey, an extensive survey of Bemisia tabaci biotypes was conducted in Florida through cooperation with growers and state agencies. This was done...

Temperature stress, anti-oxidative enzyme activity and virus acquisition in Bemisia tabaci (Hemiptera: Aleyrodidae)

USDA-ARS?s Scientific Manuscript database

In most eukaryotic systems, antioxidants provide protection when cells are exposed to stressful environmental conditions. Antioxidants, such as superoxide dismutase (SOD), glutathione peroxidase (GPX) and catalase, function in a stepwise series with SOD initially preventing oxidative damage by conve...

Larval development of Diaphorencyrtus aligarhensis (Hymenoptera: Encyrtidae) an endoparasitoid of Diaphorina citri (Homoptera: Psyllidae).

USDA-ARS?s Scientific Manuscript database

The encyrtid koinobiont endoparasitoid Diaphorencyrtus aligarhensis (Shafee, Alam and Agarwal) is an imported biological control agent being released in Florida against the Asian citrus psyllid, Diaphorina citri Kuwayama. The eggs and early larvae were found free-floating within the hemocoel. Larvae...

Comparison of insect vacuums for sampling Asian citrus psyllid (Homoptera: Psyllidae) on citrus trees

USDA-ARS?s Scientific Manuscript database

Three vacuum devices were compared for sampling psyllid populations. One was an AC rechargeable, handheld, cordless model and a second was a handheld, DC model powered through a cord connected to a 12V vehicle battery. Each of these devices had a mesh cylinder (substituted for a dust bag) in which...

Food habits of the southwestern willow flycatcher during the nesting season

USGS Publications Warehouse

Drost, Charles A.; Paxton, Eben H.; Sogge, Mark K.; Whitfield, Mary J.

2003-01-01

The food habits and prey base of the endangered Southwestern Willow Flycatcher (Empidonax traillii extimus) are not well known. We analyzed prey remains in 59 fecal samples from an intensively-studied population of this flycatcher at the Kern River Preserve in southern California. These samples were collected during the nesting season in 1996 and 1997 from adults caught in mist nets, and from nestlings temporarily removed from the nest for banding. A total of 379 prey individuals were identified in the samples. Dominant prey taxa, both in total numbers and in percent occurrence, were true bugs (Hemiptera), flies (Diptera), and beetles (Coleoptera). Leafhoppers (Homoptera: Cicadellidae), spiders (Araneae), bees and wasps (Hymenoptera), and dragonflies and damselflies (Odonata) were also common items. Diet composition was significantly different between years, due to a large difference in the numbers of spiders between 1996 and 1997. There was also a significant difference between the diet of young and adults, with the diet of young birds having significantly higher numbers of odonates and beetles. There was a trend toward diet differences between males and females, but this was not significant at the P = 0.05 level.

Two cytochrome P450 genes are involved in imidacloprid resistance in field populations of the whitefly, Bemisia tabaci, in China.

PubMed

Yang, Xin; Xie, Wen; Wang, Shao-li; Wu, Qing-jun; Pan, Hui-peng; Li, Ru-mei; Yang, Ni-na; Liu, Bai-ming; Xu, Bao-yun; Zhou, Xiaomao; Zhang, You-jun

2013-11-01

The sweet potato whitefly, Bemisia tabaci (Gennadius) (Hemiptera:Aleyrodidae), is an invasive and damaging pest of field crops worldwide. The neonicotinoid insecticide imidacloprid has been widely used to control this pest. We assessed the species composition (B vs. Q), imidacloprid resistance, and association between imidacloprid resistance and the expression of five P450 genes for 14-17 B. tabaci populations in 12 provinces in China. Fifteen of 17 populations contained only B. tabaci Q, and two populations contained both B and Q. Seven of 17 populations exhibited moderate to high resistance to imidacloprid, and eight populations exhibited low resistance to imidacloprid, compared with the most susceptible field WHHB population. In a study of 14 of the populations, resistance level was correlated with the expression of the P450 genes CYP6CM1 and CYP4C64 but not with the expression of CYP6CX1, CYP6CX4, or CYP6DZ7. This study indicates that B. tabaci Q has a wider distribution in China than previously reported. Resistance to imidacloprid in field populations of B. tabaci is associated with the increased expression of two cytochrome P450 genes (CYP6CM1 and CYP4C64). Crown Copyright © 2013. Published by Elsevier Inc. All rights reserved.

Application of RNA-seq for mitogenome reconstruction, and reconsideration of long-branch artifacts in Hemiptera phylogeny.

PubMed

Song, Nan; An, Shiheng; Yin, Xinming; Cai, Wanzhi; Li, Hu

2016-09-16

Hemiptera make up the largest nonholometabolan insect assemblage. Despite previous efforts to elucidate phylogeny within this group, relationships among the major sub-lineages remain uncertain. In particular, mitochondrial genome (mitogenome) data are still sparse for many important hemipteran insect groups. Recent mitogenomic analyses of Hemiptera have usually included no more than 50 species, with conflicting hypotheses presented. Here, we determined the nearly complete nucleotide sequence of the mitogenome for the aphid species of Rhopalosiphum padi using RNA-seq plus gap filling. The 15,205 bp mitogenome included all mitochondrial genes except for trnF. The mitogenome organization and size for R. padi are similar to previously reported aphid species. In addition, the phylogenetic relationships for Hemiptera were examined using a mitogenomic dataset which included sequences from 103 ingroup species and 19 outgroup species. Our results showed that the seven species representing the Aleyrodidae exhibit extremely long branches, and always cluster with long-branched outgroups. This lead to the failure of recovering a monophyletic Hemiptera in most analyses. The data treatment of Degen-coding for protein-coding genes and the site-heterogeneous CAT model show improved suppression of the long-branch effect. Under these conditions, the Sternorrhyncha was often recovered as the most basal clade in Hemiptera.

Application of RNA-seq for mitogenome reconstruction, and reconsideration of long-branch artifacts in Hemiptera phylogeny

PubMed Central

Song, Nan; An, Shiheng; Yin, Xinming; Cai, Wanzhi; Li, Hu

2016-01-01

Hemiptera make up the largest nonholometabolan insect assemblage. Despite previous efforts to elucidate phylogeny within this group, relationships among the major sub-lineages remain uncertain. In particular, mitochondrial genome (mitogenome) data are still sparse for many important hemipteran insect groups. Recent mitogenomic analyses of Hemiptera have usually included no more than 50 species, with conflicting hypotheses presented. Here, we determined the nearly complete nucleotide sequence of the mitogenome for the aphid species of Rhopalosiphum padi using RNA-seq plus gap filling. The 15,205 bp mitogenome included all mitochondrial genes except for trnF. The mitogenome organization and size for R. padi are similar to previously reported aphid species. In addition, the phylogenetic relationships for Hemiptera were examined using a mitogenomic dataset which included sequences from 103 ingroup species and 19 outgroup species. Our results showed that the seven species representing the Aleyrodidae exhibit extremely long branches, and always cluster with long-branched outgroups. This lead to the failure of recovering a monophyletic Hemiptera in most analyses. The data treatment of Degen-coding for protein-coding genes and the site-heterogeneous CAT model show improved suppression of the long-branch effect. Under these conditions, the Sternorrhyncha was often recovered as the most basal clade in Hemiptera. PMID:27633117

Effects of cucumber mosaic virus-infected chilli plants on non-vector Bemisia tabaci (Hemiptera: Aleyrodidae).

PubMed

Saad, Khalid A; Mohamad Roff, M N; Hallett, Rebecca H; ABd-Ghani, Idris B

2017-06-08

Plant virus infections are known to alter host plant attractiveness and suitability for insect herbivores. This study was conducted to determine how cucumber mosaic virus (CMV)-infected chilli plants affect the fitness and settling preferences of nonvector whitefly, Bemisia tabaci adults under dual-choice conditions with volatile organic compounds analyzed using solid phase microextraction coupled with gas chromatography-mass spectrometry (GC-MS). Results showed that the presence of CMV in chilli plants substantially affects the settling preferences of the B. tabaci, which preferred to settle on noninfected plants. Duration of the egg stage and the longevity and fecundity of adult B. tabaci on CMV-infected chilli plants were not markedly different from those on noninfected chilli plants. In contrast, the developmental time from egg to adult was significantly reduced in CMV-infected chilli plants compared to the noninfected plants. The results also showed that CMV-infected chilli plants released significantly more linalool and phenylacetaldehyde than noninfected plants. Overall, it was suggested that the behavioral response of B. tabaci might be modified by CMV-infected plants, which alter the release of specific headspace volatiles. Based on these results, the modification of plant volatile profiles may help in enhancing the effectiveness of biological control and the protection of crop plants against B. tabaci. © 2017 Institute of Zoology, Chinese Academy of Sciences.

Complete mitochondrial DNA genome of Bemisia tabaci cryptic pest species complex Asia I (Hemiptera: Aleyrodidae).

PubMed

Tay, W T; Elfekih, S; Court, L; Gordon, K H; De Barro, P J

2016-01-01

The complete length of the Asia I member of the Bemisia tabaci species complex mitochondrial DNA genome (mitogenome) is 15,210 bp (GenBank accession no. KJ778614) with an A-T biased nucleotide composition (A: 32.7%; T: 42.4%; G: 14.0%; C: 10.8%). The mitogenome consists of 13 protein-coding genes (PCGs), 22 transfer RNAs (tRNAs), 2 ribosomal RNA (rRNAs) and a 467 bp putative control region which also includes the A+T rich repeat region. All PCGs have an ATA (n = 8) or ATG (n = 5) start codon. Gene synteny of Asia I is overall similar to B. afer and two other members of the B. tabaci species complex Mediterranean and New World 1, and contains the tRNA-Ser2 located between the Cytb and ND1 genes found in Mediterranean and New World 1, but which is absent in B. afer. The orientation of the tRNA-Arg in Asia I is on the "plus" strand and differed from Mediterranean which is found on the "minus" strand. The Asia I mitogenome size is currently ranked the second smallest after B. afer (14,968 bp) followed by New World 1 (15,322 bp) and Mediterranean (15,632 bp).

[Occurrence of Aleurocanthus woglumi Ashby (Hemiptera: Aleyrodidae) in the state of Maranhão, Brazil].

PubMed

de Lemos, Raimunda N S; da Silva, Gilson S; Araújo, José R G; Das Chagas, Evandro F; Moreira, Aldenise A; Soares, Ana T M

2006-01-01

Aleurocanthus woglumi Ashby in citrus and mango crops in the state of Maranhão, Brazil, is recorded. Samples of 2003 and 2004 from several counties were identified and deposited in the Insect Collection of the Laboratório de Entomologia of the Núcleo de Biotecnologia Agronômica, Universidade Estadual do Maranhão.

Monitoring changes in Bemisia tabaci (Hemiptera: Aleyrodidae) susceptibility to neonicotinoid insecticides in Arizona and California.

PubMed

Castle, S J; Prabhaker, N

2013-06-01

Bemisia tabaci (Gennadius) biotype B is a highly prolific and polyphagous whitefly that established in much of North America during the 1980s. Neonicotinoid insecticides have been fundamental in regaining control over outbreak populations of B. tabaci, but resistance threatens their sustainability. Susceptibility of B. tabaci in the southwestern United States to four neonicotinoid insecticides varied considerably across populations within each year over a 3 yr period. Using a variability ratio of highest LC50 to lowest LC50 in field-collected whitefly adults from Arizona and California, the ranges of LC50(s) across all tests within compounds were highest to imidacloprid and lowest to thiamethoxam. Patterns of susceptibility were similar among all four neonicotinoid insecticides, but the greater variability in responses to imidacloprid and significantly higher LC50(s) attained indicated higher resistance levels to imidacloprid in all field populations. Further evidence of differential toxicities of neonicotinoids was observed in multiple tests of dinotefuran against imidacloprid-resistant lab strains that yielded significant differences in the LC50(s) of dinotefuran and imidacloprid in simultaneous bioassays. To test the possibility that resistance expression in field-collected insects was sometimes masked by stressful conditions, field strains cultured in a greenhouse without insecticide exposure produced significantly higher LC50(s) to all neonicotinoids compared with LC50(s) attained directly from the field. In harsh climates such as the American southwest, resistance expression in field-collected test insects may be strongly influenced by environmental stresses such as high temperatures, overcrowding, and declining host plant quality.

Microsatellite marker analysis of peach-potato aphids (Myzus persicae, Homoptera: Aphididae) from Scottish suction traps.

PubMed

Malloch, G; Highet, F; Kasprowicz, L; Pickup, J; Neilson, R; Fenton, B

2006-12-01

The peach-potato aphid Myzus persicae (Sulzer) is an important vector of plant viruses. A network of suction traps collects aerial samples of this aphid in order to monitor and help predict its spatial distribution and likely impact on virus transmission in crops. A suction trap catch is thought to be a good representation of the total aphid pool. Sensitive molecular markers have been developed that determine the genetic composition of the M. persicae population. In Scotland, UK, these were applied to field collections revealing a limited number of clones. Molecular markers are less successful when applied to specimens that have been preserved in an ethanol-based trap fluid designed to preserve morphology. An assessment of different DNA extraction and PCR techniques is presented and the most efficient are used to analyse M. persicae specimens caught in the Dundee suction trap in 2001, a year when exceptionally high numbers were caught. The results reveal that the majority of the M. persicae caught belonged to two highly insecticide resistant clones. In addition, it was possible to compare the relative frequencies of genotypes caught in the trap with those collected at insecticide treated and untreated field sites in the vicinity. These results indicate that, in addition to suction trap data, the ability to sample field sites provides valuable early warning data which have implications for pest control and virus management strategies.

Comparative biology of three Scymnus lady beetles (Coleoptera: Coccinellidae): predators of Adelges tsugae (Homoptera: Adelgidae)

Treesearch

Wenhua Lu; Michael E. Montgomery

2000-01-01

Scymnus (Neopullus) sinuanodulus Yu et Yao, S. (N.) camptodromusYu et Liu, and Scymnus (Neopullus) n. sp. (in press) were collected in the People's Republic of China from hemlocks infested with the hemlock woolly adelgid, Adelges tsugae Annand. To date, 3 of the 14 provinces in China where...

Appearance of cicada fauna (Homoptera: Cicadoidea) by altitudes in Johor National Park, Mount Ledang, Johor

NASA Astrophysics Data System (ADS)

Tahir, Aliadi Mohd; Sulaiman, Azman

2015-09-01

A total of 31 cicada species in 15 genera under two families (Cicadidae, 27 species in 11 genera; Tibicinidae, four species in three genera) was recorded for Johor National Park, Mount Ledang, Johor. This was based on 666 individuals were obtained through six sampling occasions in November 2012 until October 2013, each time using light trap set in six sampling locations (L1, L2, L3, L4a, L4b, L4c) that were selected based on altitudes. The most common and abundant species in L1 is Pomponia sp1 and recognized as new species that need to be described as new to science. Orientopsaltria saudarapadda Duffles & Zaidi appeared as the most common and abundant species in L2, represented by 21 individuals which covers 34.43 % of the total cicadas specimen in that area. In the location of L3, Dundubia vaginata (Fabricius) appeared as the most abundant species represented by 37 individuals or 26.81% while Abroma maculicollis Guerin appeared as the most common species. Shannon's Species Diversity Index (H') in L3 was the highest (H'=2.28) followed by L4b (H'=2.21), L2 (H'=1.93) L4a (H'=1.92), L4c (H'=1.84) and L1 (H'=1.58), and the evenness index in L1 was the highest (E= 0.88), followed by L4b (E= 0.79), L3 (E= 0.77), L2 (E= 0.75), L4c (E= 0.74) and L4a (E= 0.79). Margalef Species Richness Index in L3 was the highest (R'=3.65), followed by oleh L4b (R'=3.01), L4a (R'=2.97), L2 (R'=2.92), L4c (R'=2.4), and L1 (R'=2.01). Generally shows that L3 at the altitude 350 m appear as the best sampling site for cicadas species in Mount Ledang Johor with the highest value of species diversity and richness index.

Annual Fire, Mowing and Fertilization Effects on Two Cicada Species (Homoptera: Cicadidae) in Tallgrass Prairie

Treesearch

Mac A. Callaham; Matt R. Whiles; John M. Blair

2002-01-01

In tallgrass prairie, cicadas emerge annually, are abundant and their emergence can be an important flux of energy and nutrients. However, factors influencing the distribution and abundance of these cicadas are virtually unknown. We examined cicada emergence in plots from a long-term (13 y) experimental manipulation involving common tallgrass prairie management...

The Toxicity and Detoxifying Mechanism of Cycloxaprid and Buprofezin in Controlling Sogatella furcifera (Homoptera: Delphacidae)

PubMed Central

Chang, Xiaoli; Yuan, Yongda; Zhang, Tianshu; Wang, Dongsheng; Du, Xingbin; Wu, Xiangwen; Chen, Haixia; Chen, Yaozhong; Jiao, Yuetong; Teng, Haiyuan

2015-01-01

The effects of cycloxaprid (a modified neonicotinoid insecticide) and buprofezin (a thiadiazine insecticide) on mortality of the white-backed planthopper (WBPH), Sogatella furcifera, were determined in laboratory assays. Cycloxaprid killed WBPH nymphs and adults but buprofezin killed only nymphs, and cycloxaprid acted faster than buprofezin. One day after infestation, mortality of third-instar nymphs was >65% with cycloxaprid at 125 mg liter−1 but was <38% with buprofezin at 148 mg liter−1. By the 4th day after infestation, however, control of nymphs by the two insecticides was similar, and cycloxaprid at 125 mg liter−1 caused ≥80% mortality of adults but buprofezin at 148 mg liter−1 (the highest rate tested) caused almost no adult mortality. LC50 values for cycloxaprid were lowest with nymphs, intermediate with adult males, and highest with adult females. Although buprofezin was slower acting than cycloxaprid, its LC50 for nymphs 5 d after infestation was 3.79-fold lower than that of cycloxaprid. Mean carboxylesterase (CarE) specific activity of nymphal WBPH treated with cycloxaprid and buprofezin was higher than that of control, but there was no significant difference between cycloxaprid and control (no insecticide), and it was significantly higher for buprofezin than those of cycloxaprid and control. For glutathione S-transferase and mixed function oxygenase, the specific activity of nymphal WBPH treated with buprofezin was significantly higher than those of cycloxaprid and control, too. PMID:26175461

Behavior Performance of Diuraphis noxia (Homoptera: Aphididae) on Fungal Endophyte-Infected and Uninfected Perennial Ryegrass

Treesearch

S.L. Clement; D.G. Lester; A. Dan Wilson; K.S. Pike

1992-01-01

The behavior and performance of the Russian wheat aphid, Diuraphis noxia (Mordvilko), on fungal endophyte-infected and endophyte-free perennial ryegrass, Lolium perenne L., was investigated in the laboratory and field. Aphids did not select endophyte-free over endophyte-infected leaf sheaths and stem segments in petri dish preference tests....

Isolation and characterization of polymorphic microsatellite loci in the green leafhopper Empoasca vitis Goethe (Homoptera).

PubMed

Papura, D; Giresse, X; Chauvin, B; Caron, H; Delmotte, F; VAN Helden, M

2009-05-01

Eight dinucleotide microsatellite loci were isolated and characterized within the green leafhopper Empoasca vitis (Goethe) using an enrichment cloning procedure. Primers were tested on 171 individuals collected in the southwest of France from the vine plants. The identified loci were polymorphic, with allelic diversity ranging from two to 18 alleles per locus. Observed heterozygosities were from 0.021 to 0.760. These microsatellite markers should prove to be a useful tool for estimating the population genetic structure, host-plant specialization and migration capacity of this insect. © 2009 The Authors. Journal compilation © 2009 Blackwell Publishing Ltd.

The authority and types for the hackberry gall psyllid genus Pachypsylla (Riley) (Hemiptera-Homoptera: Psyllidae)

USDA-ARS?s Scientific Manuscript database

The nomenclatural problems with the hackberry gall psyllid species names are rectified. The genus Pachypsylla Riley, 1883, type species, Psylla venusta Osten-Sacken, includes 14 nominal species. These are: Pachypsylla venusta (Osten-Sacken, 1861); P. celtidismamma Riley, 1875; P. celtidisgemma Ri...

The Toxicity and Detoxifying Mechanism of Cycloxaprid and Buprofezin in Controlling Sogatella furcifera (Homoptera: Delphacidae).

PubMed

Chang, Xiaoli; Yuan, Yongda; Zhang, Tianshu; Wang, Dongsheng; Du, Xingbin; Wu, Xiangwen; Chen, Haixia; Chen, Yaozhong; Jiao, Yuetong; Teng, Haiyuan

2015-01-01

The effects of cycloxaprid (a modified neonicotinoid insecticide) and buprofezin (a thiadiazine insecticide) on mortality of the white-backed planthopper (WBPH), Sogatella furcifera, were determined in laboratory assays. Cycloxaprid killed WBPH nymphs and adults but buprofezin killed only nymphs, and cycloxaprid acted faster than buprofezin. One day after infestation, mortality of third-instar nymphs was >65% with cycloxaprid at 125 mg liter(-1) but was <38% with buprofezin at 148 mg liter(-1). By the 4th day after infestation, however, control of nymphs by the two insecticides was similar, and cycloxaprid at 125 mg liter(-1) caused ≥ 80% mortality of adults but buprofezin at 148 mg liter(-1) (the highest rate tested) caused almost no adult mortality. LC50 values for cycloxaprid were lowest with nymphs, intermediate with adult males, and highest with adult females. Although buprofezin was slower acting than cycloxaprid, its LC50 for nymphs 5 d after infestation was 3.79-fold lower than that of cycloxaprid. Mean carboxylesterase (CarE) specific activity of nymphal WBPH treated with cycloxaprid and buprofezin was higher than that of control, but there was no significant difference between cycloxaprid and control (no insecticide), and it was significantly higher for buprofezin than those of cycloxaprid and control. For glutathione S-transferase and mixed function oxygenase, the specific activity of nymphal WBPH treated with buprofezin was significantly higher than those of cycloxaprid and control, too. © The Author 2015. Published by Oxford University Press on behalf of the Entomological Society of America.

Climate change and Bemisia tabaci (Hemiptera: Aleyrodidae): Impacts of temperature and carbon dioxide on life history

USDA-ARS?s Scientific Manuscript database

Climate change is relevant to life around the globe. A rise in ambient temperature and CO2 may have various impacts on arthropods such as altered life cycles, modified reproductive patterns, and changes in distribution. The sweetpotato whitefly, Bemisia tabaci (Gennadius), is a global agricultural...

Baseline susceptibility of Bemisia tabaci B biotype (Hemiptera:Aleyrodidae) populations from Californis and Arizona to spirotetramat

USDA-ARS?s Scientific Manuscript database

Baseline toxicity levels to foliarly applied spirotetramat were established for 19 field populations of whiteflies, Bemisia tabaci B biotype from Arizona and California in 2008 and 2009. The susceptibility data was determined against the 2nd instar of B. tabaci field collections before the registrat...

Identification of unique volatile compounds associated with repelling whiteflies (Hemiptera: Aleyrodidae) in desert watermelon (Citrullus colocynthis)

USDA-ARS?s Scientific Manuscript database

Commercial watermelon cultivars (Citrullus lanatus var. lanatus) share a narrow genetic base and are susceptible to many insect pests and diseases. The insects include whiteflies which cause serious economic damages to this important cucurbit crop. However, several United States Plant Introduction a...

Ovary structure in a presocial insect, Elasmucha grisea (Heteroptera, Acanthosomatidae).

PubMed

Ogorzałek, Antoni; Trochimczuk, Artur

2009-11-01

First generation egg clusters of Elasmucha grisea are more closely guarded than second generation clusters. The ovaries of this species are structured to enhance this behavior. The population of E. grisea from S-W Poland breeds in the spring (May-June) and late summer (July-August). The second generation clutches contain fewer eggs and are destroyed 3-4 days after oviposition by predators and parasitoids. The ovary structure in the studied species differs from that found in other Heteroptera. The average number of ovarioles per ovary is 24 while in the other investigated species the number of ovarioles per ovary is 6-7. Lateral oviducts are elongated and the ovarioles are arranged in a pennate pattern. Each ovariole contains only one growing ovarian follicle. Differentiation of the ovarioles and ovarian follicles is synchronised thus enabling simultaneous oviposition. A comparative analysis of the ovary structure during the life cycle, particularly the presence of atresive ovarian follicles in the ovarioles of egg- and nymph guarding females, as well as the shape and structure of the apical part of the tropharium all support the hypothesis of cooperation between females in E. grisea. A similar ovary structure has been observed in the Coccoidea (Hemiptera, Homoptera) which indicates presocial behavior.

Responses of prairie arthropod communities to fire and fertilizer: Balancing plant and arthropod conservation

USGS Publications Warehouse

Hartley, M.K.; Rogers, W.E.; Siemann, E.; Grace, J.

2007-01-01

Fire is an important tool for limiting woody plant invasions into prairies, but using fire management to maintain grassland plant communities may inadvertently reduce arthropod diversity. To test this, we established twenty-four 100 m2 plots in a tallgrass prairie in Galveston County, Texas, in spring 2000. Plots were assigned a fire (no burn, one time burn [2000], two time burn [2000, 2001]) and fertilization treatment (none, NPK addition) in a full factorial design. Fertilization treatments allowed us to examine the effects of fire at a different level of productivity. We measured plant cover by species and sampled arthropods with sweep nets during the 2001 growing season. Path analysis indicated that fertilization reduced while annual fires increased arthropod diversity via increases and decreases in woody plant abundance, respectively. There was no direct effect of fire on arthropod diversity or abundance. Diptera and Homoptera exhibited particularly strong positive responses to fires. Lepidoptera had a negative response to nutrient enrichment. Overall, the negative effects of fire on the arthropod community were minor in contrast to the strong positive indirect effects of small-scale burning on arthropod diversity if conservation of particular taxa is not a priority. The same fire regime that minimized woody plant invasion also maximized arthropod diversity.

Evaluating shading bias in malaise and intercept traps

USGS Publications Warehouse

Irvine, Kathryn M.; Woods, Stephen A.

2007-01-01

Foresters are increasingly focusing on landscape level management regimes. At the landscape level, managed acreage may differ substantially in structure and micro-climatic conditions. Trapping is a commonly used method to evaluate changes in insect communities across landscapes. Among those trapping techniques, Malaise and window-pane traps are conveniently deployed to collect large numbers of insects for relative estimates of density. However, the catch within traps may be affected by a wide range of environmental variables including trap location, height, and factors such as exposure to sunlight and temperature. Seven experiments were conducted from 1996 through 2000 to evaluate the effects of shading on trap catch of a variety of Malaise trap designs and one window-pane trap design. Overall, differences in shading effects on trap catch were detected across different traps and taxa and suggested that, in general, more insects are collected in traps that were in direct sunlight. The effect of shading varied from a reduction in trap catch of 10 % to an increase of 7%, the results depended on trap color. Diptera, Coleoptera, and Homoptera were most likely to exhibit this bias. In contrast, trap catch of the Hymenoptera was the most variable and appeared to be sensitive to factors that might interact with sun/shade conditions

With or without pheromone habituation: possible differences between insect orders?

PubMed

Suckling, David Maxwell; Stringer, Lloyd D; Jiménez-Pérez, Alfredo; Walter, Gimme H; Sullivan, Nicola; El-Sayed, Ashraf M

2018-06-01

Habituation to sex pheromones is one of the key mechanisms in mating disruption, an insect control tactic. Male moths often show reduced sexual response after pre-exposure to female sex pheromone. Mating disruption is relatively rare in insect orders other than Lepidoptera. As a positive control we confirmed habituation in a moth (Epiphyas postvittana) using 24 h pre-exposure to sex pheromone to reduce subsequent activation behaviour. We then tested the impact of pre-exposure to sex or trail pheromone on subsequent behavioural response with insects from three other orders. Similar pre-exposure for 24 h to either sex pheromone [Pseudococcus calceolariae (Homoptera) and apple leaf curling midge Dasineura mali (Diptera), or trail pheromone of Argentine ants (Linepithema humile (Hymenoptera)], followed by behavioural assay in clean air provided no evidence of habituation after pre-exposure in these latter cases. The moths alone were affected by pre-exposure to pheromone. For pests without habituation, sustained attraction to a point source may make lure and kill more economical. Improved knowledge of behavioural processes should lead to better success in pest management and mechanisms should be investigated further to inform studies and practical efforts generally enhancing effectiveness of pheromone-based management. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Molecular and Insecticidal Characterization of a Novel Cry-Related Protein from Bacillus Thuringiensis Toxic against Myzus persicae

PubMed Central

Palma, Leopoldo; Muñoz, Delia; Berry, Colin; Murillo, Jesús; Ruiz de Escudero, Iñigo; Caballero, Primitivo

2014-01-01

This study describes the insecticidal activity of a novel Bacillus thuringiensis Cry-related protein with a deduced 799 amino acid sequence (~89 kDa) and ~19% pairwise identity to the 95-kDa-aphidicidal protein (sequence number 204) from patent US 8318900 and ~40% pairwise identity to the cancer cell killing Cry proteins (parasporins Cry41Ab1 and Cry41Aa1), respectively. This novel Cry-related protein contained the five conserved amino acid blocks and the three conserved domains commonly found in 3-domain Cry proteins. The protein exhibited toxic activity against the green peach aphid, Myzus persicae (Sulzer) (Homoptera: Aphididae) with the lowest mean lethal concentration (LC50 = 32.7 μg/mL) reported to date for a given Cry protein and this insect species, whereas it had no lethal toxicity against the Lepidoptera of the family Noctuidae Helicoverpa armigera (Hübner), Mamestra brassicae (L.), Spodoptera exigua (Hübner), S. frugiperda (J.E. Smith) and S. littoralis (Boisduval), at concentrations as high as ~3.5 μg/cm2. This novel Cry-related protein may become a promising environmentally friendly tool for the biological control of M. persicae and possibly also for other sap sucking insect pests. PMID:25384108

Continuous Measurement of Macronutrient Ions in the Transpiration Stream of Intact Plants Using the Meadow Spittlebug Coupled with Ion Chromatography1

PubMed Central

Malone, Michael; Herron, Michelle; Morales, M.-Angeles

2002-01-01

A method is described for continuous, nondestructive analysis of xylem-borne mineral nutrients in intact transpiring plants. The method uses the xylem-feeding insect the meadow spittlebug (Philaenus spumarius L. [Homoptera: Cercopidae]). This insect will feed from a wide range of plant species and organs. Insect excreta can be collected at all times of the day and night, and its mineral ion content can be analyzed rapidly, and without purification, by ion chromatography. The excreta will have a mineral content virtually identical to that of xylem sap. Cages suitable for containing the insects and collecting excreta from any desired location on plants in both laboratory and greenhouse are described. Even in the greenhouse, evaporation had only a minor effect on the sample ion content. Example results are presented which illustrate dynamics, over several days, in the xylem concentrations of sodium (Na+), potassium (K+), NH4+, magnesium (Mg2+), calcium (Ca2+), chloride (Cl−), NO3−, PO43−, and SO42−. These data were collected from young plants growing in pots of compost in the laboratory and from fully mature pepper (Capsicum annuum L. cv Bellboy) plants growing in hydroponics (rockwool) in the greenhouse. This method should facilitate studies of macronutrient uptake and transport in a range of plants and environments. PMID:12428008

Mechanisms of Oryza sativa (Poaceae) resistance to Tagosodes orizicolus (Homoptera: Delphacidae) under greenhouse condition in Venezuela.

PubMed

González, Alex; Labrín, Natalia; Alvarez, Rosa M; Jayaro, Yorman; Gamboa, Carlos; Reyes, Edicta; Barrientos, Venancio

2012-03-01

Tagosodes orizicolus is one of the main plagues of rice in tropical America causing two types of damages, the direct one, feeding and oviposition effect, and an indirect one, by the transmission of the "Rice hoja blanca virus". During 2006-2007 we carried out research under greenhouse conditions at Fundaci6n Danac, Venezuela, in order to determine the mechanisms of antixenosis, antibiosis and tolerance to T. orizicolus, which could be acting in commercial varieties and advanced lines of the rice genetic breeding programs of INIA and Fundaci6n Danac. The method of free feeding was used for the antixenosis evaluation, whereas the method of forced feeding was used for antibiosis evaluation (effect on survival and oviposition). Additionally, we used the indirect method based on biomass depression to estimate the tolerance. Some of the evaluated traits included: grade of damage, number of insects settling on rice plants, percentage of sogata mortality at the mature state, number of eggs in the leaf midrib and an index of tolerance. The results showed that rice genotypes possess different combinations of resistance mechanisms, as well as different grades of reactions. The susceptible control 'Bluebonnet 50' was consistently susceptible across experiments and the resistant control 'Makalioka' had high antixenosis and high antibiosis based on survival and oviposition. The rest of the genotypes presented lower or higher degrees of antixenosis and antibiosis for survival and oviposition. The genotype 'FD0241-M-17-6-1-1-1-1' was identified with possible tolerance to the direct damage of sogata.

Relationships Between Aphids (Insecta: Homoptera: Aphididae) and Slugs (Gastropoda: Stylommatophora: Agriolimacidae) Pests of Legumes (Fabaceae: Lupinus)

PubMed Central

Kozłowski, Jan; Strażyński, Przemysław; Jaskulska, Monika; Kozłowska, Maria

2016-01-01

Lupin plants are frequently damaged by various herbivorous invertebrates. Significant among these are slugs and aphids, which sometimes attack the same plants. Relationships between aphids, slugs and food plant are very interesting. Grazing by these pests on young plants can lead to significant yield losses. There is evidence that the alkaloids present in some lupin plants may reduce grazing by slugs, aphids and other invertebrates. In laboratory study was analyzed the relationships between aphid Aphis craccivora and slug Deroceras reticulatum pests of legumes Lupinus angustifolius. It was found that the presence of aphids significantly reduced slug grazing on the plants. The lupin cultivars with high alkaloid content were found to be less heavily damaged by D. reticulatum, and the development of A. craccivora was found to be inhibited on such plants. PMID:27324580

Relationships Between Aphids (Insecta: Homoptera: Aphididae) and Slugs (Gastropoda: Stylommatophora: Agriolimacidae) Pests of Legumes (Fabaceae: Lupinus).

PubMed

Kozłowski, Jan; Strażyński, Przemysław; Jaskulska, Monika; Kozłowska, Maria

2016-01-01

Lupin plants are frequently damaged by various herbivorous invertebrates. Significant among these are slugs and aphids, which sometimes attack the same plants. Relationships between aphids, slugs and food plant are very interesting. Grazing by these pests on young plants can lead to significant yield losses. There is evidence that the alkaloids present in some lupin plants may reduce grazing by slugs, aphids and other invertebrates. In laboratory study was analyzed the relationships between aphid Aphis craccivora and slug Deroceras reticulatum pests of legumes Lupinus angustifolius. It was found that the presence of aphids significantly reduced slug grazing on the plants. The lupin cultivars with high alkaloid content were found to be less heavily damaged by D. reticulatum, and the development of A. craccivora was found to be inhibited on such plants. © The Author 2016. Published by Oxford University Press on behalf of the Entomological Society of America.

Bioactivity of indigenous medicinal plants against the cotton whitefly, Bemisia tabaci

PubMed Central

Hammad, E. Abou-Fakhr; Zeaiter, A.; Saliba, N.; Talhouk, S.

2014-01-01

Abstract Forty-one methanol extracts of 28 indigenous medicinal plant species were tested for their insecticidal bioactivity against cotton whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), adults and second nymphal instars under controlled conditions. This study is within a bioprospection context, in the form of utilizing local plant species as an alternative in sustainable agriculture development. Eighteen and nine plant extracts caused a significant decrease in number of live adult and nymphal whiteflies, respectively, compared to the control. This is the first report for the potential effect on survival of insects for 22 out of 28 tested medicinal plant species. Whole plant extracts of Ranunculus myosuroudes Boiss. and Kotschy (Ranunculaceae), Achillea damascena L. (Asteraceae), and Anthemis hebronica Boiss. and Kotschy (Asteraceae) and leaf extracts of Verbascum leptostychum DC. (Scrophulariaceae) and Heliotropium rotundifolium Boiss. (Borangiaceae) caused both repellent and toxic effects against the adult and second nymphal instars, respectively. Extracts of leaves and stems of Anthemis scariosa Boiss. (Asteraceae) and Calendula palestina Pers. (Asteraceae) were found to be more bioactive against the adult and nymphal instars, respectively, than extracts of other plant parts, such as flowers. Thus, the bioactive extracts of these medicinal plants have the potential to lower whitefly populations in a comprehensive pest management program in local communities, pending cultivation of these medicinal plant species. PMID:25204756

Electrostatic Insect Sweeper for Eliminating Whiteflies Colonizing Host Plants: A Complementary Pest Control Device in An Electric Field Screen-Guarded Greenhouse.

PubMed

Takikawa, Yoshihiro; Matsuda, Yoshinori; Kakutani, Koji; Nonomura, Teruo; Kusakari, Shin-Ichi; Okada, Kiyotsugu; Kimbara, Junji; Osamura, Kazumi; Toyoda, Hideyoshi

2015-05-12

Our greenhouse tomatoes have suffered from attacks by viruliferous whiteflies Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) over the last 10 years. The fundamental countermeasure was the application of an electric field screen to the greenhouse windows to prevent their entry. However, while the protection was effective, it was incomplete, because of the lack of a guard at the greenhouse entrance area; in fact, the pests entered from the entrance door when workers entered and exited. To address this, we developed a portable electrostatic insect sweeper as a supplementary technique to the screen. In this sweeper, eight insulated conductor wires (ICWs) were arranged at constant intervals along a polyvinylchloride (PVC) pipe and covered with a cylindrical stainless net. The ICWs and metal net were linked to a DC voltage generator (operated by 3-V alkaline batteries) inside the grip and oppositely electrified to generate an electric field between them. Whiteflies on the plants were attracted to the sweeper that was gently slid along the leaves. This apparatus was easy to operate on-site in a greenhouse and enabled capture of the whiteflies detected during the routine care of the tomato plants. Using this apparatus, we caught all whiteflies that invaded the non-guarded entrance door and minimized the appearance and spread of the viral disease in tomato plants in the greenhouse.

Resistance Mechanisms to Chlorpyrifos and F392W Mutation Frequencies in the Acetylcholine Esterase Ace1 Allele of Field Populations of the Tobacco Whitefly, Bemisia tabaci in China

PubMed Central

Zhang, Ning-ning; Liu, Cai-feng; Yang, Fang; Dong, Shuang-lin; Han, Zhao-jun

2012-01-01

The tobacco whitefly B-biotype Bemisia tabaci Gennadius (Hemiptera: Aleyrodidae) is a worldwide pest of many crops. In China, chlorpyrifos has been used to control this insect for many years and is still being used despite the fact that some resistance has been reported. To combat resistance and maintain good control efficiency of chlorpyrifos, it is essential to understand resistance mechanisms. A chlorpyrifos resistant tobacco whitefly strain (NJ-R) and a susceptible strain (NJ-S) were derived from a field-collected population in Nanjing, China, and the resistance mechanisms were investigated. More than 30-fold resistance was achieved after selected by chlorpyrifos for 13 generations in the laboratory. However, the resistance dropped significantly to about 18-fold in only 4 generations without selection pressure. Biochemical assays indicated that increased esterase activity was responsible for this resistance, while acetylcholine esterase, glutathione S-transferase, and microsomal-O-demethylase played little or no role. F392W mutations in acel were prevalent in NJ-S and NJ-R strains and 6 field-collected populations of both B and Q-biotype from locations that cover a wide geographical area of China. These findings provide important information about tobacco whitefly chlorpyrifos resistance mechanisms and guidance to combat resistance and optimize use patterns of chlorpyrifos and other organophosphate and carbamate insecticides. PMID:22954331

Susceptibility of Bemisia tabaci MEAM1 (Hemiptera: Aleyrodidae) to imidacloprid, thiamethoxam, dinotefuran and flupyradifurone in south Florida

USDA-ARS?s Scientific Manuscript database

Populations of Bemisa tabaci Middle East Asia Minor 1 (MEAM 1) were established from nineteen locations in south Florida, primarily from commercial tomato fields, and were tested using a cotton leaf petiole systemic uptake method for susceptibility to the nicotinic acetylcholine agonist insecticides...

Response of Bemisia tabaci Genn. (Hemiptera: Aleyrodidae) biotype B to genotypes of pepper Capsicum annuum (Solanales: Solanaceae).

PubMed

Ballina-Gomez, H; Ruiz-Sanchez, E; Chan-Cupul, W; Latournerie-Moreno, L; Hernández-Alvarado, L; Islas-Flores, I; Zuñiga-Aguilar, J J

2013-04-01

Bemisia tabaci Genn. biotype B is a widely distributed plant pest that represents one of the major constraints for horticultural crop production. The purpose of the present work was to evaluate the oviposition preference, survivorship, and development of B. tabaci biotype B on semi-cultivated genotypes of Capsicum annuum from southeast Mexico. In free-choice experiments to evaluate the oviposition preference, lower number of eggs laid by B. tabaci biotype B was observed in the genotypes Maax and Xcat´ik relative to that in the commercial genotype Parado. Egg hatchability was significantly lower in Pico Paloma, Bolita, Blanco, Chawa, Payaso, and Xcat´ik than in the rest of the genotypes, including the commercial genotype Jalapeño. Likewise, survivorship of nymphs was significantly lower in Pico Paloma, Bolita, and Blanco than in the remaining genotypes. Nymph developmental time and the period of development from egg to adult were the shortest in Amaxito. Therefore, sources of resistance to B. tabaci biotype B by antibiosis (accumulation of plant defense compounds) might be found in the semi-cultivated genotypes Pico Paloma, Bolita, and Blanco.

A new species of Aleuromarginatus Corbett, 1935 with a key and checklist of Chinese species (Hemiptera, Aleyrodidae)

PubMed Central

Wang, Ji-Rui; Xu, Zhi-Hong; Du, Yu-Zhou

2017-01-01

Abstract A new whitefly species, Aleuromarginatus dielsianae Wang & Xu, sp. n. collected from Millettia dielsiana Harms (Rosales: Fabaceae) in Jiangshan (28°40'N, 118°40'E, 512 m) and Xinchang (29°22'N, 120°46'E, 308 m), Zhejiang, China, is described and illustrated. This new species is characterized by the dark brown lateral margin area and a pair of longitudinal furrows extending from the cephalothorax to the vasiform orifice. The submargin has an elongate-oval fold at the base of each marginal tooth and with 3-4 rows of irregular shaped papillae, nine pairs submedian setae and 13 pairs submarginal setae. Thoracic and caudal tracheal folds and pores discernible. An identification key and checklist of species of Aleuromarginatus known from China are provided. PMID:28769724

Effects of a foliar neem formulation on colonization and mortality of whiteflies (Hemiptera: Aleyrodidae) on collard plants

USDA-ARS?s Scientific Manuscript database

A study was conducted to determine the effects of foliar sprays of a selected neem (Azadirachta indica A. Juss) product (GOS Neem 7-Way) on colonization and development by the Middle-East Asia Minor-1 (= B-biotype sweetpotato whitefly) Bemisia tabaci (Gennadius) on collard (Brassica oleracea variety...

Bacterial symbionts, Buchnera, and starvation on wing dimorphism in English grain aphid, Sitobion avenae (F.) (Homoptera: Aphididae)

PubMed Central

Zhang, Fangmei; Li, Xiangrui; Zhang, Yunhui; Coates, Brad; Zhou, Xuguo “Joe”; Cheng, Dengfa

2015-01-01

Wing dimorphism in aphids can be affected by multiple cues, including both biotic (nutrition, crowding, interspecific interactions, the presence of natural enemies, maternal and transgenerational effects, and alarm pheromone) and abiotic factors (temperature, humidity, and photoperiod). The majority of the phloem-feeding aphids carry Buchnera, an obligate symbiotic proteobacteria. Buchnera has a highly reduced genome size, but encode key enzymes in the tryptophan biosynthetic pathway and is crucial for nutritional balance, development and reproduction in aphids. In this study, we investigated the impact of two nutritional-based biotic factors, symbionts and starvation, on the wing dimorphism in the English grain aphid, Sitobion avenae, a devastating insect pest of cereal crops (e.g., wheat) worldwide. Elimination of Buchnera using the antibiotic rifampicin significantly reduced the formation of winged morphs, body mass, and fecundity in S. avenae. Furthermore, the absence of this primary endosymbiont may disrupt the nutrient acquisition in aphids and alter transgenerational phenotypic expression. Similarly, both survival rate and the formation of winged morphs were substantially reduced after neonatal (<24 h old) offspring were starved for a period of time. The combined results shed light on the impact of two nutritional-based biotic factors on the phenotypic plasticity in aphids. A better understanding of the wing dimorphism in aphids will provide the theoretical basis for the prediction and integrated management of these phloem-feeding insect pests. PMID:26042046

Natural enemies of adelgids in North America: Their prospect for biological control of Adelges tsugae (Homoptera: Adelgidae)

Treesearch

Michael E. Montgomery; Suzanne M. Lyon

1995-01-01

On eastern hemlock, we found two resident beetles preying on Adelges tsugae Annand. One is a coccinellid native to Europe, Scymnus suturalis Thunberg, that also feeds on Pineus sp. that attack pines. The other is a native derodontid beetle, Laricobius rubidus LeConte. The seasonal life history...

Buprofezin susceptibility survey, resistance selection and preliminary determination of the resistance mechanism in Nilaparvata lugens (Homoptera: Delphacidae).

PubMed

Wang, Yanhua; Gao, Congfen; Xu, Zhiping; Zhu, Yu Cheng; Zhang, Jiushuang; Li, Wenhong; Dai, Dejiang; Lin, Youwei; Zhou, Weijun; Shen, Jinliang

2008-10-01

Buprofezin has been used for many years to control Nilaparvata lugens (Stål). Assessment of susceptibility change in the insect is essential for maintaining control efficiency and resistance management. Eleven-year surveys showed that most field populations were susceptible before 2004. However, substantially higher levels of resistance (up to 28-fold) were found in most of the rice fields in China after 2004. A field population was collected and periodically selected for buprofezin resistance in the laboratory. After 65 generations (56 were selected), the colony successfully obtained 3599-fold resistance to buprofezin. Synergism tests showed that O,O-diethyl-O-phenyl phosphorothioate (SV1), piperonyl butoxide (PBO) and diethyl maleate (DEM) increased buprofezin toxicity in the resistant strain by only 1.5-1.6 fold, suggesting that esterases, P450-monooxygenases and glutathione S-transferases had no substantial effect on buprofezin resistance development. The results from this study indicate that N. lugens has the potential to develop high resistance to buprofezin. A resistance management program with rotation of buprofezin and other pesticides may efficiently delay or slow down resistance development in the insect. Further investigation is also necessary to understand the resistance mechanisms in N. lugens.

Bacterial symbionts, Buchnera, and starvation on wing dimorphism in English grain aphid, Sitobion avenae (F.) (Homoptera: Aphididae)

USDA-ARS?s Scientific Manuscript database

Wing dimorphism in aphids can be affected by multiple cues including both biotic (nutrition, crowding, interspecific interactions, the presence of natural enemies, maternal and transgenerational effects, and alarm pheromone) and abiotic factors (temperature, humidity, and photoperiod). Virtually al...

The Effects of Dispersal and Predator Density on Prey Survival in an Insect-Red Clover Metacommunity

PubMed Central

Radl, James N; Crist, Thomas O

2018-01-01

Abstract Trophic interactions are often studied within habitat patches, but among-patch dispersal of individuals may influence local patch dynamics. Metacommunity concepts incorporate the effects of dispersal on local and community dynamics. There are few experimental tests of metacommunity theory using insects compared to those conducted in microbial microcosms. Using connected experimental mesocosms, we varied the density of the leafhopper Agallia constricta Van Duzee (Homoptera: Cicadellidae) and a generalist insect predator, the damsel bug (Nabis spp., Heteroptera: Nabidae), to determine the effects of conspecific and predator density and varying the time available to dispersal among mesocosms on predation rates, dispersal rates, and leafhopper survival. Conspecific and damsel bug density did not affect dispersal rates in leafhoppers, but this may be due to leafhoppers’ aversion to leaving the host plants or the connecting tubes between mesocosms hindering leafhopper movement. Leafhopper dispersal was higher in high-dispersal treatments. Survival rates of A. constricta were also lowest in treatments where dispersal was not limited. This is one of the first experimental studies to vary predator density and the time available to dispersal. Our results indicate that dispersal is the key to understanding short-term processes such as prey survival in predator-prey metacommunities. Further work is needed to determine how dispersal rates influence persistence of communities in multigenerational studies. PMID:29301047

Habitat management of organic vineyard in Northern Italy: the role of cover plants management on arthropod functional biodiversity.

PubMed

Burgio, G; Marchesini, E; Reggiani, N; Montepaone, G; Schiatti, P; Sommaggio, D

2016-12-01

The effect of cover plants on arthropod functional biodiversity was investigated in a vineyard in Northern Italy, through a 3-year field experiment. The following six ground cover plants were tested: Sweet Alyssum; Phacelia; Buckwheat; Faba Bean; Vetch and Oat; control. Arthropods were sampled using different techniques, including collection of leaves, vacuum sampling and sweeping net. Ground cover plant management significantly affected arthropod fauna, including beneficial groups providing ecosystem services like biological control against pests. Many beneficial groups were attracted by ground cover treatments in comparison with control, showing an aggregative numerical response in the plots managed with some of the selected plant species. Alyssum, Buckwheat and 'Vetch and Oat' mixture showed attractiveness on some Hymenoptera parasitoid families, which represented 72.3% of the insects collected by sweeping net and 45.7 by vacuum sampling. Phytoseiidae mites showed a significant increase on leaves of the vineyard plots managed with ground covers, in comparison with control, although they did not show any difference among the treatments. In general, the tested ground cover treatments did not increase dangerous Homoptera populations in comparison with control, with the exception of Alyssum. The potential of ground cover plant management in Italian vineyards is discussed: the overall lack of potential negative effects of the plants tested, combined with an aggregative numerical response for many beneficials, seems to show a potential for their use in Northern Italy vineyards.

Hairy nightshade as a potential Potato leafroll virus (Luteoviridae: Polerovirus) inoculum source in Pacific Northwest potato ecosystems.

PubMed

Srinivasan, R; Alvarez, J M

2008-09-01

Hairy nightshade, Solanum sarrachoides, is a solanaceous weed found abundantly in Pacific Northwest potato ecosystems. It serves as a reservoir for one of the important potato viruses, Potato leafroll virus (PLRV) (Luteoviridae: Polerovirus), and its most important vector, the green peach aphid, Myzus persicae (Homoptera: Aphididae). Laboratory research indicated an increased green peach aphid settling and performance on S. sarrachoides than on potato. It also revealed that green peach aphids transmitted PLRV more efficiently from S. sarrachoides to potato than from potato to potato. To test the efficiency of S. sarrachoides as an inoculum source in the field, a two season (2004 and 2005) trial was conducted at Kimberly, Idaho. Two inoculum sources, PLRV-infected potato and PLRV-infected S. sarrachoides, were compared in this trial. Green peach aphid density and temporal and spatial PLRV spread were monitored at weekly intervals. Higher densities of green peach aphids were observed on plots with S. sarrachoides and inoculum sources (PLRV-infected S. sarrachoides and potato) than on plots without S. sarrachoides and inoculum sources. PLRV infection in plots with PLRV-infected S. sarrachoides was similar to or slightly higher than in plots with PLRV-infected potato as an inoculum source. Temporal and spatial PLRV spread was similar in plots with either inoculum source. Thus, S. sarrachoides is as efficient as or a better PLRV inoculum source than potato.

Mealybugs with distinct endosymbiotic systems living on the same host plant.

PubMed

Koga, Ryuichi; Nikoh, Naruo; Matsuura, Yu; Meng, Xian-Ying; Fukatsu, Takema

2013-01-01

Mealybugs (Homoptera: Coccoidea: Pseudococcidae) possess a large bacteriome consisting of a number of bacteriocytes whose cytoplasm is populated by endosymbiotic bacteria. In many mealybugs of the subfamily Pseudococcinae, a peculiar endosymbiotic configuration has been identified: within the bacteriocytes, the primary betaproteobacterial endosymbiont Tremblaya princeps endocellularly harbor secondary gammaproteobacterial endosymbionts in a nested manner. Meanwhile, some mealybugs of the subfamily Phenacoccinae are associated only with a betaproteobacterial endosymbiont, designated as Tremblaya phenacola, which constitutes a distinct sister clade of T. princeps. However, cytological configuration of the endosymbiotic system in the phenacoccine mealybugs has not been established. Here, we investigated the endosymbiotic systems of the azalea mealybugs Crisicoccus azaleae (Pseudococcinae) and Phenacoccus azaleae (Phenacoccinae) living on the same host plants. Crisicoccus azaleae possessed a nested endosymbiotic system with T. princeps within the bacteriocyte cytoplasm and itself endocellularly harboring gammaproteobacterial cells, whereas P. azaleae exhibited a simple endosymbiotic system in which T. phenacola cells are localized within the bacteriocytes without additional gammaproteobacterial associates. Considering that these mealybugs live on the identical plant phloem sap, these different endosymbiotic consortia likely play similar biological roles for their host insects. The findings presented here should be helpful for future functional and comparative genomics toward elucidating evolutionary pathways of mealybugs and their endosymbionts. © 2012 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

Auditory sensitivity of an acoustic parasitoid (Emblemasoma sp., Sarcophagidae, Diptera) and the calling behavior of potential hosts

PubMed Central

Farris, H.E.; Oshinsky, M.; Forrest, T.G.; Hoy, R.R.

2009-01-01

Using field broadcasts of model male calling songs, we tested whether Tibicen pruinosa and T. chloromera (Homoptera: Cicadidae) are candidate hosts for acoustic parasitoid flies. The model calling song of T. pruinosa attracted 90% of the flies (Sarcophagidae: Emblemasoma sp.; all larvapositing females) when broadcast simultaneously with the model T. chloromera song, a phonotactic bias reconfirmed in single song playbacks. In paired broadcasts of model T. pruinosa songs with different relative amplitudes (3 dB or 6 dB), significantly more flies were attracted to the more powerful song, a result consistent with the responses predicted by a model proposed by Forrest and Raspet [1994]. Using intracellular recordings and dye injections, we characterized the sensitivity of auditory units in sound-trapped flies. Intracellular recordings from six auditory units (5 interneurons, 1 afferent) revealed best sensitivity for frequencies near 3-4 kHz, matching the predominant spectral components of the calling songs of both species of cicada. Interestingly, although flies could be attracted to T. pruinosa broadcasts throughout the day, hourly censuses of singing males revealed that calling occurred exclusively at dusk. Furthermore, the duration of the dusk chorus in T. pruinosa was significantly shorter than the midday chorus of the less attractive song of T. chloromera. We propose that the tight temporal aggregation of the dusk chorus time could function to reduce risk from attracted parasitoids. PMID:18560209

Presence of the Aphid, Chaetosiphon fragaefolii, on Strawberry in Argentina

PubMed Central

Cédola, Claudia; Grecob, Nancy

2010-01-01

Seasonal abundance of the strawberry aphid complex under different agronomic practices in the outskirts of La Plata, Argentina was studied on strawberry, Fragaria x ananassa Duchesne (Rosales: Rosaceae). Aphid densities were low in strawberry fields in which insecticides and fungicides were used. In addition to Aphis gossypii, Aphis fabae, Mysus persicae and Macrosiphum euphorbiae, the aphid, Chaetosiphon fragaefolii (Cockerell) (Homoptera: Aphididae), was recorded for the first time in this horticultural area. Life history and some demographic parameters were calculated for C. fragaefolii. The mean duration of nymphal stages was 10.44 days, the oviposition period was 11.8 days, and the mean number of nymph/female/day was 2.4 ± 0.3. Demographic parameters analyzed included the net reproductive rate Ro = 14.55 ± 0.096 nymph/female, generation time T=16.91 ± 0.035 days, and the intrinsic rate of increase rm = 0.158 ± (0.004). No parasites were found associated with C. fragaefolli. The pathogenic fungus, Entomophthora planchoniana Cornu (Zygomycetes: Entomophthorales) was the main mortality factor. Although aphids are not the main pests in strawberry fields, C. fragaefolii can be a serious problem because it can transmit several virus diseases of strawberry. Greater knowledge of life history traits and mortality factors of this species is needed in order to design appropriate control strategies. PMID:20569141

Presence of the aphid, Chaetosiphon fragaefolii, on strawberry in Argentina.

PubMed

Cédola, Claudia; Grecob, Nancy

2010-01-01

Seasonal abundance of the strawberry aphid complex under different agronomic practices in the outskirts of La Plata, Argentina was studied on strawberry, Fragaria x ananassa Duchesne (Rosales: Rosaceae). Aphid densities were low in strawberry fields in which insecticides and fungicides were used. In addition to Aphis gossypii, Aphis fabae, Mysus persicae and Macrosiphum euphorbiae, the aphid, Chaetosiphon fragaefolii (Cockerell) (Homoptera: Aphididae), was recorded for the first time in this horticultural area. Life history and some demographic parameters were calculated for C. fragaefolii. The mean duration of nymphal stages was 10.44 days, the oviposition period was 11.8 days, and the mean number of nymph/female/day was 2.4 +/- 0.3. Demographic parameters analyzed included the net reproductive rate R(o) = 14.55 +/- 0.096 nymph/female, generation time T=16.91 +/- 0.035 days, and the intrinsic rate of increase r(m) = 0.158 +/- (0.004). No parasites were found associated with C. fragaefolli. The pathogenic fungus, Entomophthora planchoniana Cornu (Zygomycetes: Entomophthorales) was the main mortality factor. Although aphids are not the main pests in strawberry fields, C. fragaefolii can be a serious problem because it can transmit several virus diseases of strawberry. Greater knowledge of life history traits and mortality factors of this species is needed in order to design appropriate control strategies.

Beyond Predation: The Zoophytophagous Predator Macrolophus pygmaeus Induces Tomato Resistance against Spider Mites

PubMed Central

Pappas, Maria L.; Steppuhn, Anke; Geuss, Daniel; Topalidou, Nikoleta; Zografou, Aliki; Broufas, George D.

2015-01-01

Many predatory insects that prey on herbivores also feed on the plant, but it is unknown whether plants affect the performance of herbivores by responding to this phytophagy with defence induction. We investigate whether the prior presence of the omnivorous predator Macrolophus pygmaeus (Rambur) on tomato plants affects plant resistance against two different herbivore species. Besides plant-mediated effects of M. pygmaeus on herbivore performance, we examined whether a plant defence trait that is known to be inducible by herbivory, proteinase inhibitors (PI), may also be activated in response to the interactions of this predator with the tomato plant. We show that exposing tomato plants to the omnivorous predator M. pygmaeus reduced performance of a subsequently infesting herbivore, the two-spotted spider mite Tetranychus urticae Koch, but not of the greenhouse whitefly Trialeurodes vaporariorum (Westwood). The spider-mite infested tomato plants experience a lower herbivore load, i.e., number of eggs deposited and individuals present, when previously exposed to the zoophytophagous predator. This effect is not restricted to the exposed leaf and persists on exposed plants for at least two weeks after the removal of the predators. The decreased performance of spider mites as a result of prior exposure of the plant to M. pygmaeus is accompanied by a locally and systemically increased accumulation of transcripts and activity of proteinase inhibitors that are known to be involved in plant defence. Our results demonstrate that zoophytophagous predators can induce plant defence responses and reduce herbivore performance. Hence, the suppression of populations of certain herbivores via consumption may be strengthened by the induction of plant defences by zoophytophagous predators. PMID:25974207

Shallot Aphids, Myzus ascalonicus, in Strawberry: Biocontrol Potential of Three Predators and Three Parasitoids

PubMed Central

Enkegaard, Annie; Sigsgaard, Lene; Kristensen, Kristian

2013-01-01

The parasitization capacity of 3 parasitoids and the predation capacity of 3 predators towards the shallot aphid, Myzus ascalonicus Doncaster (Homoptera: Aphididae), on strawberry, Fragaria x ananassa Duchesne (Rosales: Rosaceae) cv. Honeoye, were examined in laboratory experiments. In Petri dish assays, both Aphidius colemani Viereck (Hymenoptera: Aphidiidae) and A. ervi Haliday readily stung shallot aphids, with no significant difference in stinging frequency between the two species. A. ervi induced a significantly higher mortality (79.0 ± 7.2%) in terms of stung aphids compared with A. colemani (55.3 ± 4.1%); however, only a minor fraction (2.7 ± 1.8% and 7.1 ± 3.1%, respectively) of the killed aphids resulted in formation of mummies, presumably due to a physiological response to parasitism. The low percentage of mummification precludes the use of either Aphidius species in anything but inundative biocontrol. In similar set-ups, Aphelinus abdominalis (Dalman) (Hymenoptera: Aphelinidae) killed almost half (49.6 ± 5.3%) of the exposed aphids through host feeding. In addition, 23.2 ± 7.3% of non-host-fed aphids developed into mummified aphids, and 38.1 ± 13.2% of non-host-fed aphids died from other parasitoid-induced causes. However, the host feeding rate was reduced to only 1.2 ± 0.8%, and no significant parasitization mortality was observed on strawberry plants, suggesting that host plants interfered with A. abdominalis activity. This parasitoid does not, therefore, seem to be suited to either inoculative or inundative biocontrol of shallot aphids in strawberry. The three predators studied were the green lacewing, Chrysoperla carnea Steph. (Neuroptera: Chrysopidae), the two-spotted lady beetle, Adalia bipunctata L. (Coleoptera: Coccinellidae), and the gall midge Aphidoletes aphidimyza (Rondani) (Diptera: Cecidomyiidae). Third instars of all 3 predators readily preyed upon the shallot aphid in Petri dish set-ups with significant differences in daily

Multilocus approach to clarify species status and the divergence history of the Bemisia tabaci (Hemiptera: Aleyrodidae) species complex.

PubMed

Hsieh, Chia-Hung; Ko, Chiun-Cheng; Chung, Cheng-Han; Wang, Hurng-Yi

2014-07-01

The sweet potato whitefly, Bemisia tabaci, is a highly differentiated species complex. Despite consisting of several morphologically indistinguishable entities and frequent invasions on all continents with important associated economic losses, the phylogenetic relationships, species status, and evolutionary history of this species complex is still debated. We sequenced and analyzed one mitochondrial and three single-copy nuclear genes from 9 of the 12 genetic groups of B. tabaci and 5 closely related species. Bayesian species delimitation was applied to investigate the speciation events of B. tabaci. The species statuses of the different genetic groups were strongly supported under different prior settings and phylogenetic scenarios. Divergence histories were estimated by a multispecies coalescence approach implemented in (*)BEAST. Based on mitochondrial locus, B. tabaci was originated 6.47 million years ago (MYA). Nevertheless, the time was 1.25MYA based on nuclear loci. According to the method of approximate Bayesian computation, this difference is probably due to different degrees of migration among loci; i.e., although the mitochondrial locus had differentiated, gene flow at nuclear loci was still possible, a scenario similar to parapatric mode of speciation. This is the first study in whiteflies using multilocus data and incorporating Bayesian coalescence approaches, both of which provide a more biologically realistic framework for delimiting species status and delineating the divergence history of B. tabaci. Our study illustrates that gene flow during species divergence should not be overlooked and has a great impact on divergence time estimation. Copyright © 2014 Elsevier Inc. All rights reserved.

Effects of selected defoliants in combination with insecticides on sweetpotato whitefly (Hemiptera: Aleyrodidae) and its parasitoids in cotton

USDA-ARS?s Scientific Manuscript database

Effects of two defoliants, Def (S, S, Stributylphosphorotrithioate) and Dropp (thidiazuron) alone and in combination with two commonly used insecticides, a pyrethroid, Karate (lambda-cyhalothrin) and an organophosphate, Guthion (azinphosmethyl) on sweetpotato whitefly, Bemisia tabaci Gennadius Bioty...

Host-Mediated Effects of Semipersistently Transmitted Squash Vein Yellowing Virus on Sweetpotato Whitefly (Hemiptera: Aleyrodidae) Behavior and Fitness.

PubMed

Shrestha, Deepak; McAuslane, Heather J; Adkins, Scott T; Smith, Hugh A; Dufault, Nicholas; Colee, James; Webb, Susan E

2017-08-01

Plant viruses may indirectly affect insect vector behavior and fitness via a shared host plant. Here, we evaluated the host-mediated effects of Squash vein yellowing virus (SqVYV) on the behavior and fitness of its whitefly vector, Bemisia tabaci (Gennadius) Middle East-Asia Minor 1, formerly biotype B. Alighting, settling, and oviposition behavioral assays were conducted on infected and mock-inoculated squash (Cucurbita pepo L.) and watermelon [Citrullus lanatus (Thunb) Matsum and Nakai] plants. Developmental time of immature stages, adult longevity, and fecundity were measured on infected and mock-inoculated squash plants. For adult longevity and fecundity, whiteflies were reared on infected and mock-inoculated squash plants to determine the effects of nymphal rearing host on the adult stage. More whiteflies alighted and remained settled on infected squash than on mock-inoculated squash 0.25, 1, 8, and 24 h after release. No such initial preference was observed on watermelon plants, but by 8 h after release, more whiteflies were found on mock-inoculated watermelon plants than on infected plants. Whiteflies laid approximately six times more eggs on mock-inoculated watermelon than on infected watermelon; however, no differences were observed on squash. Development from egg to adult emergence was 3 d shorter on infected than mock-inoculated squash plants. Females lived 25% longer and had higher fecundity on infected squash plants than on mock-inoculated plants, regardless of infection status of the rearing host. The host-mediated effects of SqVYV infection on whitefly behavior differ on two cucurbit host plants, suggesting the potential for more rapid spread of the virus within watermelon fields. © 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.

Effects of Three Insect Growth Regulators on Encarsia formosa (Hymenoptera: Aphelinidae), an Endoparasitoid of Bemisia tabaci (Hemiptera: Aleyrodidae).

PubMed

Wang, Q L; Liu, T-X

2016-12-01

Insect growth regulators (IGRs) disrupt the normal activity of the endocrine or hormone system of insects, affecting the development, reproduction, or metamorphosis of the target insects, and normally causing less detrimental effects to beneficial insects. The effects of three IGRs (pyriproxyfen, fenoxycarb, and buprofezin) on Encarsia formosa Gahan, an endoparasitoid of whiteflies, were determined using B. tabaci as a host. We assessed the effects of the IGRs on parasitoid's larval development, pupation, emergence, and contact effects of the dry residues on plant leaf and glass vial surface on adult mortality and parasitism. When the three IGRs were applied at larval stage, no or few larvae pupated in the pyriproxyfen treatments and the highest concentration of fenoxycarb, and a majority of larvae pupated in the buprofezin treatments; of those pupated, 62.3-88.1% became adults. When the IGRs were applied at the pupal stage, 2.3-17.5% developed to adults in the pyriproxyfen treatments, 59.7-89.0% in the fenoxycarb treatments, and 58.4-83.6% in the buprofezin treatments. The leaf residues of the IGRs had no appreciable effects on adults, whereas the residues on glass vial caused significantly lower adult survival than on plant leaves. The residues of pyriproxyfen and fenoxycarb slightly reduced parasitism as compared with buprofezin and controls. However, the rates of parasitoids that became adults were significantly lower, especially in the pyriproxyfen treatments. According to the standards of International Organization of Biological Control (IOBC), pyriproxyfen was harmful, while fenoxycarb and buprofezin were slightly or moderately harmful to larvae and harmless to E. formosa pupae. © 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.

Host-mediated effects of semipersistently transmitted Squash vein yellowing virus on sweetpotato whitefly (Hemiptera: Aleyrodidae) behavior and fitness

USDA-ARS?s Scientific Manuscript database

Alighting, settling and oviposition behavioral assays were conducted on Squash vein yellowing virus- (SqVYV-) infected and mock-inoculated squash and watermelon plants. Developmental time of immature stages, adult longevity, and fecundity were measured on SqVYV-infected and mock-inoculated squash p...

Inundative Field Releases and Evaluation of Three Predators for Bemisia tabasi (Hemiptera: Aleyrodidae) Management in Three Vegetable Crops

USDA-ARS?s Scientific Manuscript database

The sweetpotato whitefly, Bemisia tabaci (Gennadius), is a global pest on numerous crops, including vegetables. Weekly inundative releases of a coccinellid predator (Coccinella undecimpunctata L.), a mirid predator [Macrophillus caliginosus (Wagner)] and a neuropteran predator [Chrysoperla carnea S...

Lady beetles (Coleoptera: Coccinellidae) from Chinese hemlocks infested with the hemlock woolly adelgid, Adelges tsugae Annand (Homoptera: Adelgidae)

Treesearch

Gouyue Yu; Michael E. Montgomery; Defu Yao

2000-01-01

Fifty-four species of lady beetles were collected from three Chinese hemlock species, Tsuga dumosa (D. Don) Eichler, T. forrestii Downie and T. chinensis (Franchet) Pritzel, in Yunnan, Sichuan and Shaanxi provinces of China as part of a search for natural enemies of the hemlock woolly adelgid, Adelges tsugae Annand. Twenty new species are described: Clitostethus...

Distribution and abundance of mymarid parasitoids (Hymenoptera: Mymaridae) of Sophonia rufofascia Kuoh and Kuoh (Homoptera: Cicadellidae)in Hawaii

USGS Publications Warehouse

Yang, P.; Foote, D.; Alyokhin, A.V.; Lenz, L.; Messing, R.H.

2002-01-01

The abundance of mymarid parasitoids attacking the two-spotted leafhopper (Sophonia rufofascia [Kuoh and Kuoh]), a polyphagous pest recently adventive to Hawaii, was monitored using yellow sticky cards deployed in several areas on the islands of Kauai and Hawaii. The yellow cards captured Chaetomymar sp. nr bagicha Narayanan, Subba Rao, & Kaur and Schizophragma bicolor (Dozier), both adventive species, and Polynema sp. Haliday, which is endemic to Hawaii (Hymenoptera: Mymaridae). The former two species were most abundant at all sites. On Kauai, there was a negative correlation between the captures of C. sp. nr bagicha and those of Polynema sp. Throughout the season, the increase in parasitoid numbers generally followed the increase in leafhopper numbers. C. sp. nr. bagicha and S. bicolor showed distinct habitat preferences. Removal of Myrica faya Aiton, an invasive weed that is a highly preferred two-spotted leafhopper host, decreased the overall numbers of captured parasitoids, but led to a twofold increase in the ratio of trapped parasitoids/hosts in weed-free areas. ?? 2002 Elsevier Science (USA).

Resistance of Endophyte-Infected Plants of Tall Fescue and Perennial Ryegrass to the Russian Wheat Aphid (Homoptera: Aphididae)

Treesearch

S.L. Clement; K.S. Pike; W.J. Kaiser; A. Dan Wilson

1991-01-01

Fewer aphids of the Russian wheat aphid, (Mordvilko), were found on tall fescue and perennial ryegrass plants harboring systemic fungal endophytes than on endophyte-free plants in laboratory tests. These results indicate that enhanced resistance in some perennial grasses to D. noxia is associated with the presence of endophytic fungi.

Comparative profiling of microRNAs in the winged and wingless English grain aphid, Sitobion avenae (F.) (Homoptera: Aphididae)

USDA-ARS?s Scientific Manuscript database

English green aphid, Sitobion avenae (F.), show a classic polyphenic wing dimorphism among isogenic adults that is an intriguing model for the study of morphological plasticity in response to the environment. Short non-coding microRNA (miRNA) molecules regulate gene expression by post-transcriptiona...

Inheritance Mode and Realized Heritability of Resistance to Imidacloprid in the Brown Planthopper, Nilaparvata lugens (Stal) (Homoptera: Delphacidae)

USDA-ARS?s Scientific Manuscript database

BACKGROUND: The brown planthopper, Nilaparvata lugens (Stål) is a serious pest which causes enormous losses to the rice crop in Asia. The genetic basis of imidacloprid resistance was investigated in N. lugens. RESULTS: The resistant strain, selected for imidacloprid resistance from a laboratory pop...

The Effects of Dispersal and Predator Density on Prey Survival in an Insect-Red Clover Metacommunity.

PubMed

Stasek, David J; Radl, James N; Crist, Thomas O

2018-01-01

Trophic interactions are often studied within habitat patches, but among-patch dispersal of individuals may influence local patch dynamics. Metacommunity concepts incorporate the effects of dispersal on local and community dynamics. There are few experimental tests of metacommunity theory using insects compared to those conducted in microbial microcosms. Using connected experimental mesocosms, we varied the density of the leafhopper Agallia constricta Van Duzee (Homoptera: Cicadellidae) and a generalist insect predator, the damsel bug (Nabis spp., Heteroptera: Nabidae), to determine the effects of conspecific and predator density and varying the time available to dispersal among mesocosms on predation rates, dispersal rates, and leafhopper survival. Conspecific and damsel bug density did not affect dispersal rates in leafhoppers, but this may be due to leafhoppers' aversion to leaving the host plants or the connecting tubes between mesocosms hindering leafhopper movement. Leafhopper dispersal was higher in high-dispersal treatments. Survival rates of A. constricta were also lowest in treatments where dispersal was not limited. This is one of the first experimental studies to vary predator density and the time available to dispersal. Our results indicate that dispersal is the key to understanding short-term processes such as prey survival in predator-prey metacommunities. Further work is needed to determine how dispersal rates influence persistence of communities in multigenerational studies. © The Author(s) 2017. Published by Oxford University Press on behalf of Entomological Society of America.

Toxicity and physiological effects of neem pesticides applied to rice on the Nilaparvata lugens Stål, the brown planthopper.

PubMed

Senthil-Nathan, Sengottayan; Choi, Man-Young; Paik, Chae-Hoon; Seo, Hong-Yul; Kalaivani, Kandaswamy

2009-09-01

The effects of two different neem products (Parker Oil and Neema) on mortality, food consumption and survival of the brown planthopper, Nilaparvata lugens Stål (BPH) (Homoptera: Delphacidae) were investigated. The LC(50) (3.45 ml/L for nymph and 4.42 ml/L for adult in Parker Oil treatment; 4.18 ml/L for nymph and 5.63 ml/L for adult in Neema treatment) and LC(90) (8.72 ml/L for nymph and 11.1 ml/L for adult in Parker Oil treatment; 9.84 ml/L for nymph and 13.07 ml/L for adult in Neema treatment) were identified by probit analysis. The LC(90) (equal to recommended dose) was applied in the rice field. The effective concentration of both Parker Oil and Neema took more than 48 h to kill 80% of the N. lugens. Fourth instar nymph and adult female N. lugens were caged on rice plants and exposed to a series (both LC(50) and LC(90)) of neem concentrations. Nymph and adult female N. lugens that were chronically exposed to neem pesticides showed immediate mortality after application in laboratory experiment. The quantity of food ingested and assimilated by N. lugens on neem-treated rice plants was significantly less than on control rice plants. The results clearly indicate the neem-based pesticide (Parker Oil and Neema), containing low lethal concentration, can be used effectively to inhibit the growth and survival of N. lugens.

Fungi Associated with the Hemlock Woolly Adelgid, Adelges tsugae, and Assessment of Entomopathogenic Isolates for Management

PubMed Central

Reid, W.R.; Parker, B.L.; Gouli, S.Y.; Skinner, M.; Gouli, V.V.; Teillon, H.B.

2010-01-01

Fungi associated with the hemlock wooly adelgid, Adelges tsugae Annand (Hemiptera: Adelgidae), were collected throughout the eastern USA and southern China. Twenty fungal genera were identified, as were 79 entomopathogenic isolates, including: Lecanicillium lecanii (Zimmermann) (Hypocreales: Insertae sedis), Isaria farinosa (Holm: Fries.) (Cordycipitaceae), Beauveria bassiana (Balasamo) (Hyphomycetes), and Fusarium spp (Nectriaceae). The remaining fungal genera associated with insect cadavers were similar for both the USA and China collections, although the abundance of Acremonium (Hypocreaceae) was greater in China. The entomopathogenic isolates were assayed for efficacy against Myzus persicae (Sulzer) (Homoptera: Aphididae) and yielded mortality ranging from 3 to 92%. Ten isolates demonstrating the highest efficacy were further assessed for efficacy against field-collected A. tsugae under laboratory conditions. Overall, two B. bassiana, one L. lecanii, and a strain of Metarhizium anisopliae (Metchnikoff) (Hypocreales: Clavicipitaceae), demonstrated significantly higher efficacy against A. tsugae than the others. Isolates were further evaluated for conidial production, germination rate and colony growth at four temperatures representative of field conditions. All isolates were determined to be mesophiles with optimal temperature between 25–30° C. In general, conidial production increased with temperature, though two I. farinosa produced significantly more conidia at cooler temperatures. When efficacy values were compared with conidial production and temperature tolerances, Agricultural Research Service Collection of Entomopathogenic Fungi (ARSEF) 1080, 5170, and 5798 had characteristics comparable to the industrial B. bassiana strain GHA. PMID:20672977

Mitochondrial gene sequences alone or combined with ITS region sequences provide firm molecular criteria for the classification of Lecanicillium species.

PubMed

Kouvelis, Vassili N; Sialakouma, Aphrodite; Typas, Milton A

2008-07-01

The recent revision of Verticillium sect. Prostrata led to the introduction of the genus Lecanicillium, which comprises the majority of the entomopathogenic strains. Sixty-five strains previously classified as Verticillium lecanii or Verticillium sp. from different geographical regions and hosts were examined and their phylogenetic relationships were determined using sequences from three mitochondrial (mt) genes [the small rRNA subunit (rns), the NADH dehydrogenase subunits 1 (nad1) and 3 (nad3)] and the ITS region. In general, single gene phylogenetic trees differentiated and placed the strains examined in well-supported (by BS analysis) groups of L. lecanii, L. longisporum, L. muscarium, and L. nodulosum, although in some cases a few uncertainties still remained. nad1 was the most informative single gene in phylogenetic analyses and was also found to contain group I introns with putative open reading frames (ORFs) encoding for GIY-YIG endonucleases. The combined use of mt gene sequences resolved taxonomic uncertainties arisen from ITS analysis and, alone or in combination with ITS sequences, helped in placing uncharacterised Verticillium lecanii and Verticillium sp. firmly into Lecanicillium species. Combined gene data from all the mt genes and all the mt genes and the ITS region together, were very similar. Furthermore, a relaxed correlation with host specificity -- at least for Homoptera -- was indicated for the rns and the combined mt gene sequences. Thus, the usefulness of mt gene sequences as a convenient molecular tool in phylogenetic studies of entomopathogenic fungi was demonstrated.

New Views on Strand Asymmetry in Insect Mitochondrial Genomes

PubMed Central

Wei, Shu-Jun; Shi, Min; Chen, Xue-Xin; Sharkey, Michael J.; van Achterberg, Cornelis; Ye, Gong-Yin; He, Jun-Hua

2010-01-01

Strand asymmetry in nucleotide composition is a remarkable feature of animal mitochondrial genomes. Understanding the mutation processes that shape strand asymmetry is essential for comprehensive knowledge of genome evolution, demographical population history and accurate phylogenetic inference. Previous studies found that the relative contributions of different substitution types to strand asymmetry are associated with replication alone or both replication and transcription. However, the relative contributions of replication and transcription to strand asymmetry remain unclear. Here we conducted a broad survey of strand asymmetry across 120 insect mitochondrial genomes, with special reference to the correlation between the signs of skew values and replication orientation/gene direction. The results show that the sign of GC skew on entire mitochondrial genomes is reversed in all species of three distantly related families of insects, Philopteridae (Phthiraptera), Aleyrodidae (Hemiptera) and Braconidae (Hymenoptera); the replication-related elements in the A+T-rich regions of these species are inverted, confirming that reversal of strand asymmetry (GC skew) was caused by inversion of replication origin; and finally, the sign of GC skew value is associated with replication orientation but not with gene direction, while that of AT skew value varies with gene direction, replication and codon positions used in analyses. These findings show that deaminations during replication and other mutations contribute more than selection on amino acid sequences to strand compositions of G and C, and that the replication process has a stronger affect on A and T content than does transcription. Our results may contribute to genome-wide studies of replication and transcription mechanisms. PMID:20856815

Modeling trophic dependencies and exchanges among insects' bacterial symbionts in a host-simulated environment.

PubMed

Opatovsky, Itai; Santos-Garcia, Diego; Ruan, Zhepu; Lahav, Tamar; Ofaim, Shany; Mouton, Laurence; Barbe, Valérie; Jiang, Jiandong; Zchori-Fein, Einat; Freilich, Shiri

2018-05-25

Individual organisms are linked to their communities and ecosystems via metabolic activities. Metabolic exchanges and co-dependencies have long been suggested to have a pivotal role in determining community structure. In phloem-feeding insects such metabolic interactions with bacteria enable complementation of their deprived nutrition. The phloem-feeding whitefly Bemisia tabaci (Hemiptera: Aleyrodidae) harbors an obligatory symbiotic bacterium, as well as varying combinations of facultative symbionts. This well-defined bacterial community in B. tabaci serves here as a case study for a comprehensive and systematic survey of metabolic interactions within the bacterial community and their associations with documented occurrences of bacterial combinations. We first reconstructed the metabolic networks of five common B. tabaci symbionts genera (Portiera, Rickettsia, Hamiltonella, Cardinium and Wolbachia), and then used network analysis approaches to predict: (1) species-specific metabolic capacities in a simulated bacteriocyte-like environment; (2) metabolic capacities of the corresponding species' combinations, and (3) dependencies of each species on different media components. The predictions for metabolic capacities of the symbionts in the host environment were in general agreement with previously reported genome analyses, each focused on the single-species level. The analysis suggests several previously un-reported routes for complementary interactions and estimated the dependency of each symbiont in specific host metabolites. No clear association was detected between metabolic co-dependencies and co-occurrence patterns. The analysis generated predictions for testable hypotheses of metabolic exchanges and co-dependencies in bacterial communities and by crossing them with co-occurrence profiles, contextualized interaction patterns into a wider ecological perspective.

Plant insects and mites uptake double-stranded RNA upon its exogenous application on tomato leaves.

PubMed

Gogoi, Anupam; Sarmah, Nomi; Kaldis, Athanasios; Perdikis, Dionysios; Voloudakis, Andreas

2017-12-01

Exogenously applied double-stranded RNA (dsRNA) molecules onto tomato leaves, moved rapidly from local to systemic leaves and were uptaken by agricultural pests namely aphids, whiteflies and mites. Four small interfering RNAs, deriving from the applied dsRNA, were molecularly detected in plants, aphids and mites but not in whiteflies. Double-stranded RNA (dsRNA) acts as the elicitor molecule of the RNA silencing (RNA interference, RNAi), the endogenous and evolutionary conserved surveillance system present in all eukaryotes. DsRNAs and their subsequent degradation products, namely the small interfering RNAs (siRNAs), act in a sequence-specific manner to control gene expression. Exogenous application of dsRNAs onto plants elicits resistance against plant viruses. In the present work, exogenously applied dsRNA molecules, derived from Zucchini yellow mosaic virus (ZYMV) HC-Pro region, onto tomato plants were detected in aphids (Myzus persicae), whiteflies (Trialeurodes vaporariorum) and mites (Tetranychus urticae) that were fed on treated as well as systemic tomato leaves. Furthermore, four siRNAs, deriving from the dsRNA applied, were detected in tomato and the agricultural pests fed on treated tomato plants. More specifically, dsRNA was detected in agricultural pests at 3 and 10 dpt (days post treatment) in dsRNA-treated leaves and at 14 dpt in systemic leaves. In addition, using stem-loop RT-PCR, siRNAs were detected in agricultural pests at 3 and 10 dpt in aphids and mites. Surprisingly, in whiteflies carrying the applied dsRNA, siRNAs were not molecularly detected. Our results showed that, upon exogenous application of dsRNAs molecules, these moved rapidly within tomato and were uptaken by agricultural pests fed on treated tomato. As a result, this non-transgenic method has the potential to control important crop pests via RNA silencing of vital genes of the respective pests.

Transmission of Squash vein yellowing virus to and From Cucurbit Weeds and Effects on Sweetpotato Whitefly (Hemiptera: Aleyrodidae) Behavior.

PubMed

Shrestha, D; McAuslane, H J; Adkins, S T; Smith, H A; Dufault, N; Webb, S E

2016-08-01

Since 2003, growers of Florida watermelon [Citrullus lanatus (Thunb.) Matsum. and Nakai] have periodically suffered large losses from a disease caused by Squash vein yellowing virus (SqVYV), which is transmitted by the whitefly Middle East-Asia Minor 1 (MEAM1), formerly Bemisia tabaci (Gennadius) biotype B. Common cucurbit weeds like balsam apple (Momordica charantia L.) and smellmelon [Cucumis melo var. dudaim (L.) Naud.] are natural hosts of SqVYV, and creeping cucumber (Melothria pendula L.) is an experimental host. Study objectives were to compare these weeds and 'Mickylee' watermelon as sources of inoculum for SqVYV via MEAM1 transmission, to determine weed susceptibility to SqVYV, and to evaluate whitefly settling and oviposition behaviors on infected vs. mock-inoculated (inoculated with buffer only) creeping cucumber leaves. We found that the lowest percentage of watermelon recipient plants was infected when balsam apple was used as a source of inoculum. Watermelon was more susceptible to infection than balsam apple or smellmelon. However, all weed species were equally susceptible to SqVYV when inoculated by whitefly. For the first 5 h after release, whiteflies had no preference to settle on infected vs. mock-inoculated creeping cucumber leaves. After 24 h, whiteflies preferred to settle on mock-inoculated leaves, and more eggs were laid on mock-inoculated creeping cucumber leaves than on SqVYV-infected leaves. The transmission experiments (source of inoculum and susceptibility) show these weed species as potential inoculum sources of the virus. The changing settling preference of whiteflies from infected to mock-inoculated plants could lead to rapid spread of virus in the agroecosystem. Published by Oxford University Press on behalf of Entomological Society of America 2016. This work is written by US Government employees and is in the public domain in the United States.

Phenology, natural enemies, and efficacy of horticultural oil for control of Chionaspis heterophyllae (Homoptera: Diaspididae) on Christmas tree plantations.

PubMed

Fondren, Kirsten M; McCullough, Deborah G

2005-10-01

Pine needle scale, Chionaspis pinifoliae (Fitch), and Chionaspis heterophyllae Cooley are important pests of Scots pine, Pinus sylvestris L., and other conifers in much of North America. On Christmas tree plantations, these insects are typically controlled by spraying broad-spectrum insecticides when the vulnerable immature stages are present. However, effective control of bivoltine populations can be difficult to achieve due to asynchronous hatch and development of the second generation. Our objectives were to 1) determine the phenology of the second generation of C. heterophyllae in Michigan; 2) characterize the natural enemy complex; and 3) assess the effectiveness of horticultural oil for control of C. heterophyllae on P. sylvestris Christmas tree plantations. We monitored scale populations in three counties in lower Michigan for 3 yr. Scale phenology was consistently associated with cumulative degree-days base 10 degrees C (DD(10 degrees C)). Second-generation egg hatch began at approximately 1230-1300 DD(10 degrees C), and continued for approximately 3 wk. The peak of the second instar coincided with 1500-1600 DD(10 degrees C). Common predators included the coccinellids Chilocorus stigma (Say) and Microweisia misella (LeConte). On average, 70% of the C. heterophyllae population in unsprayed fields was killed by predators in 1999. Two endoparasitic wasps, Encarsia bella Gahan and Marietta mexicana Howard (Hymenoptera: Aphelinidae), also were recovered. In 2000 and 2001, we applied a highly refined horticultural spray oil with a backpack mist blower at 1500-1600 DD(10 degrees). Scale mortality on trees treated with oil ranged from 66 to 80% and was similar to control achieved using conventional insecticides in both years.

Susceptibility to neonicotinoids and risk of resistance development in the brown planthopper, Nilaparvata lugens (Stål) (Homoptera: Delphacidae).

PubMed

Wang, Yanhua; Chen, Jin; Zhu, Yu Cheng; Ma, Chongyong; Huang, Yue; Shen, Jinliang

2008-12-01

In recent years, outbreaks of the brown planthopper, Nilaparvata lugens (Stål), have occurred more frequently in China. The objective of this study was to determine the susceptibility of N. lugens to neonicotinoids and other insecticides in major rice production areas in China. Results indicated that substantial variations in the susceptibility to different insecticides existed in N. lugens. Field populations had developed variable resistance levels to neonicotinoids, with a high resistance level to imidacloprid (RR: 135.3-301.3-fold), a medium resistance level to imidaclothiz (RR: 35-41.2-fold), a low resistance level to thiamethoxam (up to 9.9-fold) and no resistance to dinotefuran, nitenpyram and thiacloprid (RR < 3-fold). Further examinations indicated that a field population had developed medium resistance level to fipronil (up to 10.5-fold), and some field populations had evolved a low resistance level to buprofezin. In addition, N. lugens had been able to develop 1424-fold resistance to imidacloprid in the laboratory after the insect was selected with imidacloprid for 26 generations. Long-term use of imidacloprid in a wide range of rice-growing areas might be associated with high levels of resistance in N. lugens. Therefore, insecticide resistance management strategies must be developed to prevent further increase in resistance.

Expression of Russian Wheat Aphid (Homoptera: Aphididae) Resistance in Genotypes of Tall Fescue Harboring Different Isolates of Acremonium Endophyte

Treesearch

S.L. Clement; D.G. Lester; A. Dan Wilson; R.C. Johnson; J.H. Bouton

1996-01-01

Experiments were conducted to compare the expression of Russian wheat aphid, Diurnphis noxia (Mordvilko), resistance in 2 genotypes of tall fescue grass, Festucn arundinacea Schreb., harboring different isolates of the endophytic fungus Acremonium coenophialum Morgan-Jones & cams. Aphids did not select...

Laboratory selection of chlorpyrifos resistance in an Invasive Pest, Phenacoccus solenopsis (Homoptera: Pseudococcidae): Cross-resistance, stability and fitness cost.

PubMed

Ejaz, Masood; Afzal, Muhammad Babar Shahzad; Shabbir, Ghulam; Serrão, José Eduardo; Shad, Sarfraz Ali; Muhammad, Wali

2017-04-01

The cotton mealybug, Phenacoccus solenopsis is an important polyphagous sucking pest of ornamentals, horticultural and fiber crops worldwide. Some P. solenopsis populations have developed insecticide resistance. This study evaluated cross-resistance, stability of insecticide resistance and life history traits affected by chlorpyrifos resistance in P. solenopsis. After nine generations selected with chlorpyrifos, P. solenopsis exhibited a 539.76-fold resistance level compared to an unselected population (UNSEL Pop). Chlorpyrifos selected population (Chlor-SEL Pop) displayed moderate cross-resistance to profenofos, nitenpyram and high cross-resistance to lambda-cyhalothrin. Biological parameters of P. Solenopsis were affected by chlorpyrifos resistance. The Chlor-SEL Pop had a significant reduction in fitness (relative fitness=0.10), along with significant decreases in pupal weight, fecundity, egg hatching %, intrinsic rate of natural population increase, biotic potential, and mean relative growth rate. It is concluded that selection with chlorpyrifos had marked effect on resistance development in P. solenopsis and upon removal of selection pressure chlorpyrifos resistance declined significantly indicating unstable resistance. Development of resistance led to high fitness costs for the chlorpyrifos-selected strain. These findings should be helpful for better and more successful resistance management of P. solenopsis. Copyright © 2016 Elsevier B.V. All rights reserved.

Scale insects and mealy bugs (Homoptera: Coccoidea) attacking deciduous fruit trees in the western north coast of Alexandria, Egypt.

PubMed

Mourad, A K; Moursi Khadiga, S; Mesbah, H A; Abdel-Razak Soad, I

2008-01-01

This investigation covered a survey of scale insects and mealy bugs infesting ten growing species of deciduous fruit trees in three localities in Alexandria govemorate. These localities were Merghem, Burg El-Arab, and El-Nahda about 50 Km. West of Alexandria under both rain-fed and irrigation system conditions. The common inspected fruit trees were fig, white mulberry, pomegranate, apple, pear, apricot, European plum, peach, almond, and persimmon. It was shown that a group of twenty scale insects and meaty bug species pertaining to fifteen genera belonging to six families of the super family: Coccoidea were collected and identified during the elapsing period from January to December, 2004. Among these species, Diaspidiotus perniciosus (Comstock) was recorded for the first time in Egypt. In the present study, many insect and non-insect parasitoids and predators were also found associated with these scale insects and mealy bugs on deciduous fruit trees in the three concerned localities throughout this investigation. These natural enemies were identified and recorded.

Resistance of Collard Green Genotypes to Bemisia tabaci Biotype B: Characterization of Antixenosis.

PubMed

Domingos, G M; Baldin, E L L; Canassa, V F; Silva, I F; Lourenção, A L

2018-08-01

Bemisia tabaci (Genn.) biotype B (Hemiptera: Aleyrodidae) is an important pest of vegetable crops, including collard greens Brassica oleracea var. acephala (Brassicaceae). The use of resistant genotypes is an interesting option to reduce insect populations and can be used as an important tool for integrated pest management (IPM). This study evaluated 32 genotypes of collard greens against the attack of silver leaf whitefly, with the aim to characterize antixenosis. Initially, a multiple-choice trial was conducted using all genotypes, in which the adult attractiveness was assessed on two leaves per genotype at 24 and 48 h after infestation. After 48 h, one leaf of each genotype was randomly selected for the determination of the number of eggs per square centimeter. From the results of the multiple-choice trial, 13 genotypes were selected for a no-choice oviposition test, following the same method of the previous test. Colorimetric analyses were also performed to establish possible correlations between leaf color and insect colonization. Genotypes HS-20, OE, and VA were less attractive, demonstrating antixenosis. Genotypes LG, VE, J, MG, MOP, HS-20, VA, and MT had less oviposition in the multiple-choice test, which indicated expression of antixenosis. In the no-choice test, genotypes VE, P1C, CCB, RI-919, H, and J had less oviposition, which also characterized antixenosis. Therefore, genotypes VE and J showed the highest resistance stability because both had less oviposition in both test modalities. Thus, the resistance to B. tabaci biotype B indicates the genotypes HS-20, OE, VA, VE, and J are promising for use in breeding programs to develop resistance to whitefly.

Further insight into reproductive incompatibility between putative cryptic species of the Bemisia tabaci whitefly complex.

PubMed

Qin, Li; Pan, Li-Long; Liu, Shu-Sheng

2016-04-01

The whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), with its global distribution and extensive genetic diversity, is now known to be a complex of over 35 cryptic species. However, a satisfactory resolution of the systematics of this species complex is yet to be achieved. Here, we designed experiments to examine reproductive compatibility among species with different levels of mitochondrial cytochrome oxidase I (mtCOI) divergence. The data show that putative species with mtCOI divergence of >8% between them consistently exhibited complete reproductive isolation. However, two of the putative species, Asia II 9 and Asia II 3, with mtCOI divergence of 4.47% between them, exhibited near complete reproductive compatibility in one direction of their cross, and partial reproductive compatibility in the other direction. Together with some recent reports on this topic from the literature, our data indicates that, while divergence in the mtCOI sequences provides a valid molecular marker for species delimitation in most clades, more genetic markers and more sophisticated molecular phylogeny will be required to achieve adequate delimitation of all species in this whitefly complex. While many attempts have been made to examine the reproductive compatibility among genetic groups of the B. tabaci complex, our study represents the first effort to conduct crossing experiments with putative species that were chosen with considerations of their genetic divergence. In light of the new data, we discuss the best strategy and protocols to conduct further molecular phylogenetic analysis and crossing trials, in order to reveal the overall pattern of reproductive incompatibility among species of this whitefly complex. © 2015 Institute of Zoology, Chinese Academy of Sciences.

Transcriptomic and Proteomic Responses of Sweetpotato Whitefly, Bemisia tabaci, to Thiamethoxam

PubMed Central

Yang, Nina; Xie, Wen; Yang, Xin; Wang, Shaoli; Wu, Qingjun; Li, Rumei; Pan, Huipeng; Liu, Baiming; Shi, Xiaobin; Fang, Yong; Xu, Baoyun; Zhou, Xuguo; Zhang, Youjun

2013-01-01

Background The sweetpotato whitefly, Bemisia tabaci (Hemiptera: Aleyrodidae), is one of the most widely distributed agricultural pests. Although it has developed resistance to many registered insecticides including the neonicotinoid insecticide thiamethoxam, the mechanisms that regulate the resistance are poorly understood. To understand the molecular basis of thiamethoxam resistance, “omics” analyses were carried out to examine differences between resistant and susceptible B. tabaci at both transcriptional and translational levels. Results A total of 1,338 mRNAs and 52 proteins were differentially expressed between resistant and susceptible B. tabaci. Among them, 11 transcripts had concurrent transcription and translation profiles. KEGG analysis mapped 318 and 35 differentially expressed genes and proteins, respectively, to 160 and 59 pathways (p<0.05). Thiamethoxam treatment activated metabolic pathways (e.g., drug metabolism), in which 118 transcripts were putatively linked to insecticide resistance, including up-regulated glutathione-S-transferase, UDP glucuronosyltransferase, glucosyl/glucuronosyl transferase, and cytochrome P450. Gene Ontology analysis placed these genes and proteins into protein complex, metabolic process, cellular process, signaling, and response to stimulus categories. Quantitative real-time PCR analysis validated “omics” response, and suggested a highly overexpressed P450, CYP6CX1, as a candidate molecular basis for the mechanistic study of thiamethoxam resistance in whiteflies. Finally, enzymatic activity assays showed elevated detoxification activities in the resistant B. tabaci. Conclusions This study demonstrates the applicability of high-throughput omics tools for identifying molecular candidates related to thiamethoxam resistance in an agricultural important insect pest. In addition, transcriptomic and proteomic analyses provide a solid foundation for future functional investigations into the complex molecular mechanisms

Gene Expression Profiling in the Thiamethoxam Resistant and Susceptible B-biotype Sweetpotato Whitefly, Bemisia tabaci

PubMed Central

Xie, Wen; Yang, Xin; Wang, Shao-Ii; Wu, Qing-jun; Yang, Ni-na; Li, Ru-mei; Jiao, Xiaoguo; Pan, Hui-peng; Liu, Bai-ming; Feng, Yun-tao; Xu, Bao-yun; Zhou, Xu-guo; Zhang, You-jun

2012-01-01

Thiamethoxam has been used as a major insecticide to control the B-biotype sweetpotato whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae). Due to its excessive use, a high level of resistance to thiamethoxam has developed worldwide over the past several years. To better understand the molecular mechanisms underlying this resistance in B. tabaci, gene profiles between the thiamethoxam-resistant and thiamethoxam-susceptible strains were investigated using the suppression subtractive hybridization (SSH) library approach. A total of 72 and 52 upand down-regulated genes were obtained from the forward and reverse SSH libraries, respectively. These expressed sequence tags (ESTs) belong to several functional categories based on their gene ontology annotation. Some categories such as cell communication, response to abiotic stimulus, lipid particle, and nuclear envelope were identified only in the forward library of thiamethoxam-resistant strains. In contrast, categories such as behavior, cell proliferation, nutrient reservoir activity, sequence-specific DNA binding transcription factor activity, and signal transducer activity were identified solely in the reverse library. To study the validity of the SSH method, 16 differentially expressed genes from both forward and reverse SSH libraries were selected randomly for further analyses using quantitative realtime PCR (qRT-PCR). The qRT-PCR results were fairly consistent with the SSH results; however, only 50% of the genes showed significantly different expression profiles between the thiamethoxam-resistant and thiamethoxam-susceptible whiteflies. Among these genes, a putative NAD-dependent methanol dehydrogenase was substantially over-expressed in the thiamethoxamresistant adults compared to their susceptible counterparts. The distributed profiles show that it was highly expressed during the egg stage, and was most abundant in the abdomen of adult females. PMID:22957505

New cost-effective bioconversion process of palm kernel cake into bioinsecticides based on Beauveria bassiana and Isaria javanica.

PubMed

do Nascimento Silva, Jaqueline; Mascarin, Gabriel Moura; Dos Santos Gomes, Isabel Cristina; Tinôco, Ricardo Salles; Quintela, Eliane Dias; Dos Reis Castilho, Leda; Freire, Denise Maria Guimarães

2018-03-01

The present study aimed to add value to palm oil by-products as substrates to efficiently produce conidia of Beauveria bassiana and Isaria javanica (Hypocreales: Cordycipitaceae) for biological control of the whitefly Bemisia tabaci (Hemiptera: Aleyrodidae), through a solid-state fermentation process using palm kernel cake and palm fiber as nutrient source and solid matrix, respectively. The optimum culture conditions yielded high concentrations of viable conidia after air-drying, when the fungi were grown on palm kernel cake (B. bassiana 7.65 × 10 9 and I. javanica 2.91 × 10 9  conidia g -1 dry substrate) after 6 days under optimal growth conditions set to 60% substrate moisture and 32 °C. Both fungal strains exhibited high efficacy against third-instar whitefly nymphs, inducing mortality up to 62.9 and 56.6% by B. bassiana and I. javanica, respectively, assessed after 9 days post-application in a screenhouse. Furthermore, we noted that insect mortality was strongly correlated with high atmospheric moisture, while B. bassiana appeared to require shorter accumulative hours under high moisture to kill whitefly nymphs compared to I. javanica. Our results underpin a feasible and cost-effective mass production method for aerial conidia, using palm kernel as the main substrate in order to produce efficacious fungal bioinsecticides against an invasive whitefly species in Brazil. Finally, our fermentation process may offer a sustainable and cost-effective means to produce eco-friendly mycoinsecticides, using an abundant agro-industrial by-product from Brazil that will ultimately assist in the integrated management of agricultural insect pests.

Composition of arthropod species assemblages in Bt-expressing and near isogenic eggplants in experimental fields.

PubMed

Arpaia, Salvatore; Di Leo, Grazia M; Fiore, Maria C; Schmidt, Jörg E U; Scardi, Michele

2007-02-01

The environmental impact of genetically modified (GM) plants in experimental fields has been examined in several ways, in particular with respect to the dynamics of specific nontarget organisms. The approach of sampling for biodiversity in agroecosystems to compare complex patterns could also be useful in studying potential disruptions caused by GM crops. In this study, we set up replicated field plots of Bt-expressing eggplants and near isogenic untransformed eggplants as a control. We monitored the presence and abundance of herbivore and predator arthropods in weekly visual samplings of the plant canopy for three growing seasons (2001-2003). Insect species were pooled in organismal taxonomic units (OTUs); three multivariate methods were used to compare species assemblage as an estimate of insect biodiversity. This multistep statistical approach proved to be efficient in recognizing association patterns, as evidenced by the data for the target species Leptinotarsa decemlineata Say (Coleoptera: Chrysomelidae) clearly showing a significant association with the control plots. All the analyses indicate a comparable species assemblage between transgenic and near isogenic eggplant areas. Our results suggest that some taxa may warrant more specific study. For example, Alticinae beetles (Coleoptera: Chrysomelidae) were alternatively more abundant in either of the two treatments, and their overall abundance was significantly higher on transgenic eggplants. In light of these results and because of their taxonomic proximity to the target species, these herbivores may represent an important nontarget group to be further studied. Moreover, some sap feeders (e.g., Homoptera: Cicadellidae) were more abundant on Bt-expressing plants in some samples in all 3 yr.

DNA Barcoding of Bemisia tabaci Complex (Hemiptera: Aleyrodidae) Reveals Southerly Expansion of the Dominant Whitefly Species on Cotton in Pakistan

PubMed Central

Ashfaq, Muhammad; Hebert, Paul D. N.; Mirza, M. Sajjad; Khan, Arif M.; Mansoor, Shahid; Shah, Ghulam S.; Zafar, Yusuf

2014-01-01

Background Although whiteflies (Bemisia tabaci complex) are an important pest of cotton in Pakistan, its taxonomic diversity is poorly understood. As DNA barcoding is an effective tool for resolving species complexes and analyzing species distributions, we used this approach to analyze genetic diversity in the B. tabaci complex and map the distribution of B. tabaci lineages in cotton growing areas of Pakistan. Methods/Principal Findings Sequence diversity in the DNA barcode region (mtCOI-5′) was examined in 593 whiteflies from Pakistan to determine the number of whitefly species and their distributions in the cotton-growing areas of Punjab and Sindh provinces. These new records were integrated with another 173 barcode sequences for B. tabaci, most from India, to better understand regional whitefly diversity. The Barcode Index Number (BIN) System assigned the 766 sequences to 15 BINs, including nine from Pakistan. Representative specimens of each Pakistan BIN were analyzed for mtCOI-3′ to allow their assignment to one of the putative species in the B. tabaci complex recognized on the basis of sequence variation in this gene region. This analysis revealed the presence of Asia II 1, Middle East-Asia Minor 1, Asia 1, Asia II 5, Asia II 7, and a new lineage “Pakistan”. The first two taxa were found in both Punjab and Sindh, but Asia 1 was only detected in Sindh, while Asia II 5, Asia II 7 and “Pakistan” were only present in Punjab. The haplotype networks showed that most haplotypes of Asia II 1, a species implicated in transmission of the cotton leaf curl virus, occurred in both India and Pakistan. Conclusions DNA barcodes successfully discriminated cryptic species in B. tabaci complex. The dominant haplotypes in the B. tabaci complex were shared by India and Pakistan. Asia II 1 was previously restricted to Punjab, but is now the dominant lineage in southern Sindh; its southward spread may have serious implications for cotton plantations in this region. PMID:25099936

DNA barcoding of Bemisia tabaci complex (Hemiptera: Aleyrodidae) reveals southerly expansion of the dominant whitefly species on cotton in Pakistan.

PubMed

Ashfaq, Muhammad; Hebert, Paul D N; Mirza, M Sajjad; Khan, Arif M; Mansoor, Shahid; Shah, Ghulam S; Zafar, Yusuf

2014-01-01

Although whiteflies (Bemisia tabaci complex) are an important pest of cotton in Pakistan, its taxonomic diversity is poorly understood. As DNA barcoding is an effective tool for resolving species complexes and analyzing species distributions, we used this approach to analyze genetic diversity in the B. tabaci complex and map the distribution of B. tabaci lineages in cotton growing areas of Pakistan. Sequence diversity in the DNA barcode region (mtCOI-5') was examined in 593 whiteflies from Pakistan to determine the number of whitefly species and their distributions in the cotton-growing areas of Punjab and Sindh provinces. These new records were integrated with another 173 barcode sequences for B. tabaci, most from India, to better understand regional whitefly diversity. The Barcode Index Number (BIN) System assigned the 766 sequences to 15 BINs, including nine from Pakistan. Representative specimens of each Pakistan BIN were analyzed for mtCOI-3' to allow their assignment to one of the putative species in the B. tabaci complex recognized on the basis of sequence variation in this gene region. This analysis revealed the presence of Asia II 1, Middle East-Asia Minor 1, Asia 1, Asia II 5, Asia II 7, and a new lineage "Pakistan". The first two taxa were found in both Punjab and Sindh, but Asia 1 was only detected in Sindh, while Asia II 5, Asia II 7 and "Pakistan" were only present in Punjab. The haplotype networks showed that most haplotypes of Asia II 1, a species implicated in transmission of the cotton leaf curl virus, occurred in both India and Pakistan. DNA barcodes successfully discriminated cryptic species in B. tabaci complex. The dominant haplotypes in the B. tabaci complex were shared by India and Pakistan. Asia II 1 was previously restricted to Punjab, but is now the dominant lineage in southern Sindh; its southward spread may have serious implications for cotton plantations in this region.

Status of Resistance of Bemisia tabaci (Hemiptera: Aleyrodidae) to Neonicotinoids in Iran and Detoxification by Cytochrome P450-Dependent Monooxygenases.

PubMed

Basij, M; Talebi, K; Ghadamyari, M; Hosseininaveh, V; Salami, S A

2017-02-01

Nine Bemisia tabaci (Gennadius) populations were collected from different regions of Iran. In all nine populations, only one biotype (B biotype) was detected. Susceptibilities of these populations to imidacloprid and acetamiprid were assayed. The lethal concentration 50 values (LC 50 ) for different populations showed a significant discrepancy in the susceptibility of B. tabaci to imidacloprid (3.76 to 772.06 mg l -1 ) and acetamiprid (4.96 to 865 mg l -1 ). The resistance ratio of the populations ranged from 9.72 to 205.20 for imidacloprid and 6.38 to 174.57 for acetamiprid. The synergistic effects of piperonylbutoxide (PBO) and S,S,S-tributylphosphorotrithioate (DEF) were evaluated for the susceptible (RF) and resistant (JR) populations for the determination of the involvement of cytochrome P450-dependent monooxygenase and carboxylesterase, respectively, in their resistance mechanisms. The results showed that PBO overcame the resistance of the JR population to both imidacloprid and acetamiprid, with synergistic ratios of 72.7 and 106.9, respectively. Carboxylesterase, glutathione S-transferase and cytochrome P450-dependent monooxygenase were studied biochemically, for the purpose of measuring the activity of the metabolizing enzymes in order to determine which enzymes are directly involved in neonicotinoid resistance. There was an increase in the activity of cytochrome P450-dependent monooxygenase up to 17-fold in the resistant JR population (RR = 205.20). The most plausible activity of cytochrome P450-dependent monooxygenase correlated with the resistances of imidacloprid and acetamiprid, and this suggests that cytochrome P450-dependent monooxygenase is the only enzyme system responsible for neonicotinoid resistance in the nine populations of B. tabaci.

Is agriculture driving the diversification of the Bemisia tabaci species complex (Hemiptera: Sternorrhyncha: Aleyrodidae)?: Dating, diversification and biogeographic evidence revealed.

PubMed

Boykin, Laura M; Bell, Charles D; Evans, Gregory; Small, Ian; De Barro, Paul J

2013-10-18

Humans and insect herbivores are competing for the same food crops and have been for thousands of years. Despite considerable advances in crop pest management, losses due to insects remain considerable. The global homogenisation of agriculture has supported the range expansion of numerous insect pests and has been driven in part by human-assisted dispersal supported through rapid global trade and low-cost air passenger transport. One of these pests, is the whitefly, Bemisia tabaci, a cryptic species complex that contains some of the world's most damaging pests of agriculture. The complex shows considerable genetic diversity and strong phylogeographic relationships. One consequence of the considerable impact that members of the B. tabaci complex have on agriculture, is the view that human activity, particularly in relation to agricultural practices, such as use of insecticides, has driven the diversification found within the species complex. This has been particularly so in the case of two members of the complex, Middle East-Asia Minor 1 (MEAM1) and Mediterranean (MED), which have become globally distributed invasive species. An alternative hypothesis is that diversification is due to paleogeographic and paleoclimatological changes. The idea that human activity is driving speciation within the B. tabaci complex has never been tested, but the increased interest in fossil whiteflies and the growth in molecular data have enabled us to apply a relaxed molecular clock and so estimate divergence dates for the major lineages within the B. tabaci species complex. The divergence estimates do not support the view that human activity has been a major driver of diversification. Our analysis suggests that the major lineages within the complex arose approximately 60-30 mya and the highly invasive MED and MEAM1 split from the rest of the species complex around 12 mya well before the evolution of Homo sapiens and agriculture. Furthermore, the divergence dates coincide with a period of global diversification that occurred broadly across the plant and animal kingdoms and was most likely associated with major climatic and tectonic events.

Lethal and Sublethal Effects of Clothianidin on the Development and Reproduction of Bemisia tabaci (Hemiptera: Aleyrodidae) MED and MEAM1

PubMed Central

Fang, Yong; Wang, Jinda; Luo, Chen; Wang, Ran

2018-01-01

Abstract The Bemisia tabaci (Gennadius) cryptic species complex includes important crop pests, and among them, the cryptic species Mediterranean (MED) and Middle East-Asia Minor 1 (MEAM1) cause substantial crop losses in China. The second-generation neonicotinoid clothianidin acts as an agonist of the nicotinic acetylcholine receptor in the insect nervous system and has both stomach and contact activity. In this study, the toxicity of clothianidin and five other insecticides to MED and MEAM1 was examined. The sublethal effects of clothianidin on the development and reproduction of MED and MEAM1 were also investigated. Among the six insecticides tested, clothianidin showed toxicities to both MED and MEAM1 adults with LC50 values of 5.23 and 5.18 mg/liter, respectively. The sublethal effects of clothianidin were assessed by treating MED and MEAM1 adults with the LC25 of 1.58 and 1.13 mg/liter, respectively. The LC25 treatments accelerated the development of the F1 generation but reduced survival and fecundity of both species. Our results indicate that clothianidin could be useful for the management of B. tabaci MED and MEAM1. PMID:29718499

Impacts of the Psyllid Arytinnis hakani (Homoptera: Psyllidae) on Invasive French Broom in Relation to Plant Size and Psyllid Density.

PubMed

Hogg, Brian N; Moran, Patrick J; Smith, Lincoln

2017-06-01

The impacts of weed biological control agents may vary with plant ontogeny. As plants grow, structural and chemical changes can alter plant resistance, which may reduce herbivory via chemical or structural defenses, and plant tolerance, which may enable plants to maintain fitness despite attack. Resistance and tolerance generally increase as plants grow. Nonetheless, prerelease tests of agent efficacy often overlook plant ontogeny. Here, we assess the performance and impacts of a candidate biocontrol agent, the psyllid Arytinnis hakani (Loginova), in relation to the age of its host plant, the invasive shrub French broom, Genista monspessulana. We also examined whether the psyllid can consistently kill plants when its densities are sufficiently high. Survival of psyllids to adulthood and the timing of adult emergence did not differ between plant sizes, indicating that performance of nymphs was not influenced by plant size. However, adult psyllid survival was reduced on small plants, suggesting that nymphs and adults responded differently to ontogenetic changes in plant quality. Psyllids affected the growth of small and large plants similarly; all measured plant growth parameters were lower in the presence of psyllids regardless of plant size. In a separate experiment, effects on plant survival depended on psyllid density, as higher realized densities of ∼9 psyllids per cm stem length were necessary to consistently kill plants. Thus, results suggest that the psyllid would be equally effective on a range of plant sizes, particularly at high densities, and show the potential of the psyllid to help control French broom in California. 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.

Chemical Composition and Behavioral Effects of Five Plant Essential Oils on the Green Pea Aphid Acyrthosiphon pisum (Harris) (Homoptera: Aphididae).

PubMed

Kasmi, Abir; Hammami, Majdi; Raoelison, Emmanuel G; Abderrabba, Manef; Bouajila, Jalloul; Ducamp, Christine

2017-05-01

Essential oils (EOs) from Schinus molle, Helichrysum gymnocephalum, Cedrelopsis grevei and Melaleuca viridiflora, four aromatic and medicinal plants, are commonly used in folk medicine. EOs were characterized by gas chromatography/mass spectrometry (GC/MS) and quantified by gas chromatography-flame ionization detection (GC-FID); then evaluated for their behavioral effects on adults of the green pea aphid Acyrthosiphon pisum (Harris) using a Perspex four-armed olfactometer in order to test the compatibility of their use as phytoinsecticides to control this insect pest. Our results showed that the EOs from the leaves of S. molle, M. viridiflora and C. grevei did not change aphids' behavior. However, S. molle fruits EO seemed to be attractive while H. gymnocephalum leaves EO exhibited repellency towards aphids at a dose of 10 μl. The major compounds in S. molle fruits EO were 6-epi-shyobunol (16.22%) and d-limonene (15.35%). While, in H. gymnocephalum leaves EO, 1,8-cineole was the main compound (47.4%). The difference in aphids' responses to these two EOs could be attributed to the differences in their compositions. Our findings suggest that these two EOs have potential applications for the integrated pest management of A. pisum (Harris). © 2017 Wiley-VHCA AG, Zurich, Switzerland.

Comparison of AC electronic monitoring and field data for estimating tolerance to Empoasca kraemeri (Homoptera: Cicadellidae) in common bean genotypes.

PubMed

Serrano, M S; Backus, E A; Cardona, C

2000-12-01

Two methods for estimating the tolerance of common bean genotypes to Empoasca kraemeri Ross & Moore were compared, using a yield trial carried out at Centro Internacional de Agricultura Tropical (CIAT), Cali, Colombia, versus stylet penetration tactics measured by AC electronic feeding monitors. A stylet penetration index was devised based on principal component scores of three penetration tactics identified (pulsing laceration, cell rupturing, and lancing sap ingestion), combined with knowledge of the hopperburn symptoms caused by each tactic. Tolerant genotypes, as classified by the CIAT yield index, showed significantly more unprotected yield and lower hopperburn scores than the susceptible control. They also induced performance of less pulsing laceration (the tactic considered most damaging to the plant), and more of the other two, mitigating tactics, especially cell rupturing. When index values were calculated for each genotype, stylet penetration index values matched those of the yield index for three out of five genotypes: two EMP-coded tolerant lines ('EMP 385' and 'EMP 392') and the susceptible control 'BAT 41'. Thus, for these three genotypes, all subsequent hoppereburn symptoms are predictable by the type of feeding behavior performed on them. 'Porrillo Sintético' and 'EMP 84', considered borderline genotypes by the yield index, were overestimated and underestimated respectively, by the stylet penetration index. We postulate that, for these two genotypes, plant physiological responses to feeding (either compensatory or heightened sensitivity, respectively) synergize with type of feeding performed to generate the overall hopperburn condition. This multivariate analysis of electronic monitoring data was successfully used to devise an index of resistance. The implications of using the stylet penetration index and the advantages of using electronic monitoring in a bean-breeding program are discussed.

An Opposite Pattern to the Conventional Thermal Hypothesis: Temperature-Dependent Variation in Coloration of Adults of Saccharosydne procerus (Homoptera: Delphacidae)

PubMed Central

Yin, Haichen; Shakeel, Muhammad; Kuang, Jing; Li, Jianhong

2015-01-01

Melanism is a common polymorphism in many insect species that also influences immune function. According to the thermal melanin hypothesis, ectothermic individuals from cooler environments have darker cuticles and higher polyphenol oxidase (PO) levels, which represent a better immunocompetence. In this study, the links among environmental temperature, melanism, and PO activity of Saccharosydne procerus (Matsumura) were examined. Most S. procerus have a black spot on their forewings at high temperatures in the field and in the laboratory. In PO activity assay, a positive association between PO level and temperature was found. Our results showed that a diversification of melanism occurred under different temperatures and that melanism in S. procerus presented an opposite pattern to the one proposed by the thermal hypothesis. PMID:26024474

Inheritance mode and realized heritability of resistance to imidacloprid in the brown planthopper, Nilaparvata lugens (Stål) (Homoptera: Delphacidae).

PubMed

Wang, Yan Hua; Liu, Xu Gan; Zhu, Yu Cheng; Wu, Sheng Gan; Li, Shu Yong; Chen, Wen Ming; Shen, Jin Liang

2009-06-01

The brown planthopper, Nilaparvata lugens (Stål), is a serious pest that causes enormous losses to the rice crop in Asia. The genetic basis of imidacloprid resistance was investigated in N. lugens. The resistant strain, selected for imidacloprid resistance from a field population of N. lugens collected from Nanjing, Jiangsu Province, China, showed a 964-fold resistance compared with the laboratory strain. Progenies of reciprocal crosses (F(1) and F(1)') showed similar dose-mortality responses (LC(50)) to imidacloprid, and also exhibited a similar degree of dominance (D), 0.58 for F(1) and 0.63 for F(1)'. Chi-square analyses of self-bred and backcross progenies (F(2), F(2)' and BC respectively) rejected the hypothesis for a single gene control of the resistance. The estimated realized heritability (h(2)) of imidacloprid resistance was 0.1141 in the resistant strain of N. lugens. The results showed that imidacloprid resistance in N. lugens was autosomal and was expressed as an incompletely dominant trait, probably controlled by multiple genes.

Two new species of Eretmocerus Haldeman (Hymenoptera: Aphelinidae) parasitizing Aleurolobus rhododendri Takahashi and Dialeuropora decempunctata (Quaintance & Baker) (Hemiptera: Aleyrodidae) from Taiwan

PubMed Central

Ward, Samantha E.; Shih, Yuan Tung; Ko, Chiun-Cheng

2016-01-01

Abstract Background Species of Eretmocerus Haldeman develop as primary ecto-endoparasites of whiteflies (Rose and Rosen 1992). Currently, the genus Eretmocerus comprises 86 species worldwide, of which 11 species have been previously recorded from Taiwan (Shih et al. 2015). Despite having been recently revised for Taiwan, two new species are here added to the Taiwan fauna. New information Two new species, Eretmocerus garrywardi Ward sp. nov. and Eretmocerus liangyihchoui Shih sp. nov. found parasitizing Aleurolobus rhododendri Takahashi and Dialeuropora decempunctata respectively, are described. A key to females of Eretmocerus species occurring in Taiwan is provided. PMID:27346951

Silicon influence on resistance induction against Bemisia tabaci biotype B (Genn.) (Hemiptera: Aleyrodidae) and on vegetative development in two soybean cultivars.

PubMed

Ferreira, R S; Moraes, J C; Antunes, C S

2011-01-01

The potential of populations of Bemisia tabaci (Genn.) to become resistant to insecticides has stimulated research into alternative tactics of integrated pest management such as the induction of host-plant resistance. Recent data have shown that silicon can increase the degree of resistance of host plants to insect pests. Therefore the aim of our work was to study the effects of silicon application on the vegetative development of soybean plants and on the induction of resistance to the silverleaf whitefly, B. tabaci biotype B. We performed choice and no-choice tests of oviposition preference on two soybean cultivars, IAC-19 (moderately resistant to B. tabaci biotype B) and MONSOY-8001 (susceptible), with and without application of silicon. Silicon did not affect silverleaf whitefly oviposition preferences, but caused significant mortality in nymphs. Thus, silicon increased the degree of resistance to silverleaf whitefly. Silicon decreased the production of phenolic compounds, but did not affect lignin production. However, when applied to cultivar IAC-19, it increased the production of non-protein organic nitrogen. Silicon had no effect on the vegetative development of soybean plants, but it increased the degree of resistance to the silverleaf whitefly. We conclude that silicon applications combined with cultivar IAC-19 can significantly decrease silverleaf whitefly populations, having a positive impact both on the soybean plant and on the environment.

Assessing compatibility of Isaria fumosorosea and buprofezin for mitigation of Aleurodicus rugioperculatus (Hemiptera: Aleyrodidae) - an invasive pest in the Florida landscape

USDA-ARS?s Scientific Manuscript database

A significant reduction in Rugose spiraling whitefly (RSW) population was reported for more than 5 weeks in buprofezin alone and more than 7 weeks in the combination treatments. In fall 2014 and summer 2015, the mean whitefly mortality observed during the 10 week assessment period were 52.4 and 42....

A review of the genus Tuberaleyrodes Takahashi (Hemiptera: Aleyrodidae) with description of five new species from Brunei, Hong Kong and Malaysia.

PubMed

Dubey, Anil Kumar; Martin, Jon H

2018-03-28

The whitefly genus Tuberaleyrodes Takahashi is reviewed using types and determined specimens. The generic diagnosis is redefined together with description of five new species: T. bruneiensis Dubey Martin sp. nov. from Brunei, T. crypta Dubey Martin sp. nov. from Hong Kong, and T. ordo Dubey Martin sp. nov., T. aequalis Dubey Martin sp. nov. and T. variabilis Dubey Martin sp. nov. from Malaysia. New species descriptions are accompanied with camera lucida drawings and microphotographs of holotype and paratypes. Tuberaleyrodes actinodaphnis Takahashi is elevated from its status as a variety of T. machili Takahashi to species level. Lectotypes are selected for T. actinodaphnis Takahashi Stat. nov. and T. bobuae Takahashi. Tuberaleyrodes actinodaphnis Takahashi is a new record to Taiwan. A new combination, Tuberaleyrodes glutae (Corbett) Comb. nov. is proposed for Dialeurodes glutae Corbett. Two species, T. glutae (Corbett) and Tuberaleyrodes spiniferosa (Corbett) are re-described, and placement of T. spiniferosa in the genus Tuberaleyrodes is confirmed. The genus Tuberaleyrodes is newly recorded from Borneo and Sulawesi. An identification key to puparia of Tuberaleyrodes species so far described is provided along with the countries of present records. Four plants families viz., Annonaceae, Fabaceae, Myristicaceae and Pentaphylacaeae are recorded as new hosts for Tuberaleyrodes species. New host plant records are indicated.

Tri-trophic interactions between Bt cotton, the herbivore Aphis gossypii Glover (Homoptera: Aphididae), and the predator Chrysopa pallens (Rambur) (Neuroptera: Chrysopidae).

PubMed

Guo, Jian-Ying; Wan, Fang-Hao; Dong, Liang; Lövei, Gábor L; Han, Zhao-Jun

2008-02-01

Tri-trophic impacts of transgenic Bacillus thuringiensis (Bt) cotton GK12 and NuCOTN 99B were studied using a predator, the great lacewing Chrysopa pallens (Rambur), and its prey, the cotton aphid Aphis gossypii Glover, in laboratory feeding experiments. The parental nontransgenic cotton cultivar of GK12 was used as control. The predator was fed with uniform (aphids from a single cultivar) or mixed prey (aphids from the three cotton cultivars provided on alternate days). Mortality and development of the immature stages, pupal body mass, adult sex ratio, fecundity, and egg viability of C. pallens were measured. When fed GK12-originated aphid prey, pupal body mass of C. pallens was significantly higher than that of the control, more females emerged, and these females laid significantly more eggs. Other parameters were not impacted. Females emerging from larvae maintained on NuCOTN 99B-originated prey laid fewer eggs than those maintained on GK12. Other measurements did not differ significantly between the two Bt cotton cultivars. Compared with the control, mixed feeding significantly prolonged pupal development time and increased pupal body mass and percentage of females but did not affect other parameters. These results indicate that C. pallens is sensitive to aphid prey from different cotton cultivars. Transgenic Bt cotton GK12-originated aphid prey has no adverse impact on survival, development, and fecundity of C. pallens. Between the two Bt cotton cultivars, NuCOTN 99B-originated aphid prey provided to C. pallens in the larval stage may lower female fecundity. Mixed feeding of C. pallens with the two Bt cotton-originated prey and non-Bt prey may have some adverse impacts on pupal development.

Plant virus differentially alters the plant's defense response to its closely related vectors.

PubMed

Shi, Xiaobin; Pan, Huipeng; Xie, Wen; Wu, Qingjun; Wang, Shaoli; Liu, Yang; Fang, Yong; Chen, Gong; Gao, Xiwu; Zhang, Youjun

2013-01-01

The whitefly, Bemisia tabaci (Hemiptera: Aleyrodidae), is one of the most widely distributed agricultural pests. In recent years, B. tabaci Q has invaded China, and Q has displaced B in many areas now. In a number of regions of the world, invasion by B and/or Q has been followed by outbreaks of tomato yellow leaf curl virus (TYLCV). Our previous study showed TYLCV directly and indirectly modified the feeding behavior of B. tabaci in favor of Q rather than B. In this study, we quantified the salicylic acid (SA) titers and relative gene expression of SA in tomato leaves that were infested with viruliferous or non-viruliferous B and Q. We also measured the impacts of exogenous SA on the performance of B and Q, including the effects on ovary development. SA titer was always higher in leaves that were infested with viruliferous B than with viruliferous Q, whereas the SA titer did not differ between leaves infested with non-viruliferous B and Q. The relative gene expression of SA signaling was increased by feeding of viruliferous B but was not increased by feeding of viruliferous Q. The life history traits of B and Q were adversely affected on SA-treated plants. On SA-treated plants, both B and Q had lower fecundity, shorter longevity, longer developmental time and lower survival rate than on untreated plants. Compared with whiteflies feeding on control plants, those feeding on SA-treated plants had fewer oocytes and slower ovary development. On SA-treated plants, viruliferous B had fewer oocytes than viruliferous Q. These results indicate that TYLCV tends to induce SA-regulated plant defense against B but SA-regulated plant defense against Q was reduced. In other words, Q may have a mutualistic relationship with TYLCV that results in the reduction of the plant's defense response.

Generating Within-Plant Spatial Distributions of an Insect Herbivore Based on Aggregation Patterns and Per-Node Infestation Probabilities.

PubMed

Rincon, Diego F; Hoy, Casey W; Cañas, Luis A

2015-04-01

Most predator-prey models extrapolate functional responses from small-scale experiments assuming spatially uniform within-plant predator-prey interactions. However, some predators focus their search in certain plant regions, and herbivores tend to select leaves to balance their nutrient uptake and exposure to plant defenses. Individual-based models that account for heterogeneous within-plant predator-prey interactions can be used to scale-up functional responses, but they would require the generation of explicit prey spatial distributions within-plant architecture models. The silverleaf whitefly, Bemisia tabaci biotype B (Gennadius) (Hemiptera: Aleyrodidae), is a significant pest of tomato crops worldwide that exhibits highly aggregated populations at several spatial scales, including within the plant. As part of an analytical framework to understand predator-silverleaf whitefly interactions, the objective of this research was to develop an algorithm to generate explicit spatial counts of silverleaf whitefly nymphs within tomato plants. The algorithm requires the plant size and the number of silverleaf whitefly individuals to distribute as inputs, and includes models that describe infestation probabilities per leaf nodal position and the aggregation pattern of the silverleaf whitefly within tomato plants and leaves. The output is a simulated number of silverleaf whitefly individuals for each leaf and leaflet on one or more plants. Parameter estimation was performed using nymph counts per leaflet censused from 30 artificially infested tomato plants. Validation revealed a substantial agreement between algorithm outputs and independent data that included the distribution of counts of both eggs and nymphs. This algorithm can be used in simulation models that explore the effect of local heterogeneity on whitefly-predator dynamics. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions

Temporal Dynamics of Arthropods on Six Tree Species in Dry Woodlands on the Caribbean Island of Puerto Rico

PubMed Central

Beltrán, William; Wunderle, Joseph M.

2014-01-01

Abstract The seasonal dynamics of foliage arthropod populations are poorly studied in tropical dry forests despite the importance of these studies for understanding arthropod population responses to environmental change. We monitored the abundance, temporal distributions, and body size of arthropods in five naturalized alien and one native tree species to characterize arthropod seasonality in dry novel Prosopis–Leucaena woodlands in Puerto Rico. A branch clipping method was used monthly to sample foliage arthropod abundance over 39 mo. Seasonal patterns of rainfall and abundance within various arthropod taxa were highly variable from year to year. Abundance for most taxa did not show significant seasonality over the 3 yr, although most taxa had abundance peaks each year. However, Homoptera displayed high seasonality with significant temporal aggregations in each year. Formicidae, Orthoptera, and Coleoptera showed high variation in abundance between wet and dry periods, whereas Hemiptera were consistently more abundant in the wet period. Seasonal differences in mean abundance were found only in a few taxa on Tamarindus indica L. , Bucida buceras L. , Pithecellobium dulce , and (Roxburgh) Benth. Mean arthropod abundance varied among tree species, with highest numbers on Prosopis juliflora , (Swartz) De Candolle, Pi. dulce , Leucaena leucocephala , and (Lamarck) de Wit. Abundance of Araneae, Orthoptera, Coleoptera, Lepidoptera larvae, and all arthropods showed weak relationships with one or more climatic variables (rainfall, maximum temperature, or relative humidity). Body size of arthropods was usually largest during the dry periods. Overall, total foliage arthropod abundance showed no consistent seasonality among years, which may become a more common trend in dry forests and woodlands in the Caribbean if seasonality of rainfall becomes less predictable. PMID:25502036

Phytoplasma infection of a tropical root crop triggers bottom-up cascades by favoring generalist over specialist herbivores

PubMed Central

Graziosi, Ignazio; Burra, Dharani Dhar; Walter, Abigail Jan

2017-01-01

Global interest on plant-microbe-insect interactions is rapidly growing, revealing the multiple ways in which microorganisms mediate plant-herbivore interactions. Phytopathogens regularly alter whole repertoires of plant phenotypic traits, and bring about shifts in key chemical or morphological characteristics of plant hosts. Pathogens can also cause cascading effects on higher trophic levels, and eventually shape entire plant-associated arthropod communities. We tested the hypothesis that a Candidatus Phytoplasma causing cassava witches’ broom (CWB) on cassava (Manihot esculenta Grantz) is altering species composition of invasive herbivores and their associated parasitic hymenopterans. We conducted observational studies in cassava fields in eastern Cambodia to assess the effect of CWB infection on abundance of specialist and generalist mealybugs (Homoptera: Pseudococcidae), and associated primary and hyper-parasitoid species. CWB infection positively affects overall mealybug abundance and species richness at a plant- and field-level, and disproportionately favors a generalist mealybug over a specialist feeder. CWB phytoplasma infection led to increased parasitoid richness and diversity, with richness of ‘comparative’ specialist taxa being the most significantly affected. Parasitism rate did not differ among infected and uninfected plants, and mealybug host suppression was not impacted. CWB phytoplasma modifies host plant quality for sap-feeding homopterans, differentially affects success rates of two invasive species, and generates niche opportunities for higher trophic orders. By doing so, a Candidatus phytoplasma affects broader food web structure and functioning, and assumes the role of an ecosystem engineer. Our work unveils key facets of phytoplasma ecology, and sheds light upon complex multi-trophic interactions mediated by an emerging phytopathogen. These findings have further implications for invasion ecology and management. PMID:28813469

Insect emergence in relation to floods in wet meadows and swamps in the River Dalälven floodplain.

PubMed

Vinnersten, T Z Persson; Östman, Ö; Schäfer, M L; Lundström, J O

2014-08-01

Annual variation in flood frequency and hydroperiod during the vegetation season has ecological impacts on the floodplain biota. Although many insect groups may have a lower emergence during a flood event, it is poorly known how annual emergence of insects in temporary wetlands is related to the variation in hydrology. Between May and September, we studied the weekly emergence of 18 insect taxa over six consecutive years, 2002-2007, in six temporary flooded wetlands (four wet meadows and two forest swamps) in the River Dalälven floodplains, Central Sweden. We used emergence traps to collect emerging insects from terrestrial and aquatic parts of wet meadows and swamp forests. In all wetlands, the insect fauna was numerically dominated by the orders Diptera, Hymenoptera, Coleoptera and Homoptera. On a weekly basis, 9 out of the 18 insect taxa had lower emergence in weeks with flood than in weeks with no flood, whereas no taxon had a higher emergence in weeks with flood. Over the seasons, we related insect emergence to seasonal flood frequency and length of hydroperiod. The emergence of most studied taxa decreased with increasing hydroperiod, which suggests that emergence after floods do not compensate for the reduced emergence during floods. Only Culicidae and the aquatic Chironomidae sub-families Tanypodinae and Chironominae showed an increase in emergence with increasing hydroperiod, whereas Staphylinidae peaked at intermediate hydroperiod. We conclude that a hydroperiod covering up to 40% of the vegetation season has a significant negative effect on the emergence of most taxa and that only a few taxa occurring in the temporary wetlands are actually favoured by a flood regime with recurrent and unpredictable floods.

Low-Temperature Fumigation of Harvested Lettuce Using a Phosphine Generator.

PubMed

Liu, Yong-Biao

2018-02-28

A research-scale phosphine generator, QuickPHlo-R, from United Phosphorus Ltd. (Mumbai, India) was tested to determine whether it was suitable for low-temperature fumigation and oxygenated phosphine fumigation of harvested lettuce. Vacuum cooled Iceberg and Romaine lettuce (Lactuca sativa) were fumigated in 442-liter chambers at 2°C for 24 and 72 h for control of western flower thrips [Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae)] and lettuce aphid [Nasonovia ribisnigri (Mosely) (Homoptera: Aphididae)]. Oxygenated phosphine fumigation for 48 h under 60% O2 was also conducted at 2°C with Iceberg and Romaine lettuce for control of lettuce aphid. The generator completed phosphine generation in 60-90 min. Complete control of western flower thrips was achieved in 24-h treatment, and the 48-h oxygenated fumigation, and 72-h regular fumigation treatments completely controlled lettuce aphid. Lettuce quality was evaluated 14 d after fumigation. There was increased incidence of brown stains on fumigated Iceberg lettuce, and the increases were more obvious in longer (≥48 h) treatments. Both Iceberg and Romaine lettuce from all treatments and controls had good visual quality even though there was significantly higher brown stain incidence on fumigated Iceberg lettuce in ≥48-h treatment and significant differences in quality score for both Iceberg and Romaine lettuce in the 72-h treatment. The brown stains were likely due to the high sensitivity of lettuce to carbon dioxide. The study indicated that QuiPHlo-R phosphine generator has potential in low-temperature phosphine fumigation due to the quick establishment of desired phosphine levels, efficacy in pest control, and reasonable safety to product quality.

The Trouble with MEAM2: Implications of Pseudogenes on Species Delimitation in the Globally Invasive Bemisia tabaci (Hemiptera: Aleyrodidae) Cryptic Species Complex.

PubMed

Tay, Wee Tek; Elfekih, Samia; Court, Leon N; Gordon, Karl H J; Delatte, Hélène; De Barro, Paul J

2017-10-01

Molecular species identification using suboptimal PCR primers can over-estimate species diversity due to coamplification of nuclear mitochondrial (NUMT) DNA/pseudogenes. For the agriculturally important whitefly Bemisia tabaci cryptic pest species complex, species identification depends primarily on characterization of the mitochondrial DNA cytochrome oxidase I (mtDNA COI) gene. The lack of robust PCR primers for the mtDNA COI gene can undermine correct species identification which in turn compromises management strategies. This problem is identified in the B. tabaci Africa/Middle East/Asia Minor clade which comprises the globally invasive Mediterranean (MED) and Middle East Asia Minor I (MEAM1) species, Middle East Asia Minor 2 (MEAM2), and the Indian Ocean (IO) species. Initially identified from the Indian Ocean island of Réunion, MEAM2 has since been reported from Japan, Peru, Turkey and Iraq. We identified MEAM2 individuals from a Peruvian population via Sanger sequencing of the mtDNA COI gene. In attempting to characterize the MEAM2 mitogenome, we instead characterized mitogenomes of MEAM1. We also report on the mitogenomes of MED, AUS, and IO thereby increasing genomic resources for members of this complex. Gene synteny (i.e., same gene composition and orientation) was observed with published B. tabaci cryptic species mitogenomes. Pseudogene fragments matching MEAM2 partial mtDNA COI gene exhibited low frequency single nucleotide polymorphisms that matched low copy number DNA fragments (<3%) of MEAM1 genomes, whereas presence of internal stop codons, loss of expected stop codons and poor primer annealing sites, all suggested MEAM2 as a pseudogene artifact and so not a real species. © The Author 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

Efficacy of an entomopathogenic fungus, Isaria fumosorosea and an insect growth regulator against the rugose spiraling whitefly, Aleurodicus rugioperculatus Martin (Hemiptera: Aleyrodidae)

USDA-ARS?s Scientific Manuscript database

Aleurodicus rugioperculatus Martin, infamous as gumbo limbo or rugose spiraling whitefly is a new addition in the list of devastating whitefly species found in Florida. It is a newly introduced pest of Central American origin, reported first time in Florida from Miami-Dade County in 2009. Since then...

Bemisia tabaci MED (Q biotype) (Hemiptera: Aleyrodidae)is on the move in Florida to residential landscapes and may impact open field agriculture

USDA-ARS?s Scientific Manuscript database

Bemisia tabaci MED (Mediterranean) have been in the United States for approximately a dozen years spreading to 26 states since it was first detected in Arizona at a retail outlet on poinsettia in 2004. Indistinguishable morphologically from silverleaf whitefly (Bemisia tabaci MEAM1 (Middle Eastern A...

Changes in life history parameters of corn leaf aphid, Rhopalosiphum maidus (Homoptera: Aphididae), under four different elevated temperature and CO2 combinations

USDA-ARS?s Scientific Manuscript database

Biological characteristics of corn leaf aphid, Rhopalosiphum maidis (Fitch), on barley, Hordeum vulgare L., were examined for two generations under four different elevated temperature and CO2 combinations. The developmental duration for each life stage was significantly reduced under the elevated te...

Host Plant-Herbivore-Predator Interactions in Chrysoperla carnea (Neuroptera: Chrysopidae) and Myzus persicae (Homoptera: Aphididae) on Four Plant Species Under Laboratory Conditions.

PubMed

Farrokhi, Milad; Gharekhani, Gholamhossein; Iranipour, Shahzad; Hassanpour, Mahdi

2017-12-05

The common green lacewing, Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae), is a well-known biocontrol agent. The current study examined host plant-herbivore-predator interactions with C. carnea and Myzus persicae on four host plants (peach, almond, pepper, and potato). The experiments were carried out at 25 ± 1°C and 65 ± 5% RH at a photoperiod of 16:8 (L:D) h). Duration of the preadult growth period, adult longevity, fecundity, and population growth parameters were analyzed based on the age-stage, two-sex life table theory. The shortest and longest preadult developmental times of the predator were observed on the peach and potato, respectively. The highest and lowest predation rate, oviposition period, and male and female longevity of predator were also observed on the peach and potato, respectively. The lowest intrinsic rate of increase (r) and finite rate of increase (λ) were observed on the potato (0.1087 and 1.11 d-1, respectively) and the highest on the peach (0.1460 and 1.15 d-1, respectively). The maximum and minimum mean generation times (T) were 41.84 and 35.59 d in the potato and peach, respectively. Overall, peach was found to be a more appropriate host than the other host plants for development and predation fitness of C. carnea. These findings reveal that information on tritrophic interactions and subsequent life table evaluation of natural enemies improves integrated pest management programs. Published by Oxford University Press on behalf of Entomological Society of America 2017. This work is written by (a) US Government employee(s) and is in the public domain in the US.

Establishment of Lipolexis oregmae (Hymenoptera: Aphidiidae) in a classical biological control program directed against the brown citrus aphid (Homoptera: Aphididae) in Florida

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

Persad, A.B.; Hoy, M.A.; Ru Nguyen

The parasitoid Lipolexis oregmae Gahan (introduced as L. scutellaris Mackauer) was imported from Guam, evaluated in quarantine, mass reared, and released into citrus groves in Florida in a classical biological control program directed against the brown citrus aphid, Toxoptera citricida Kirkaldy. Releases of 20,200, 12,100, and 1,260 adults of L. oregmae were made throughout Florida during 2000, 2001, and 2002, respectively. To determine if L. oregmae had successfully established, surveys were conducted throughout the state beginning in the summer of 2001 and continuing through the summer of 2003. Parasitism during 2001 and 2002 was evaluated by holding brown citrus aphidsmore » in the laboratory until parasitoid adults emerged. Lipolexis oregmae was found in 10 sites in 7 counties and 4 sites in 3 counties with parasitism rates ranging from 0.7 to 3.3% in 2001 and 2002, respectively. Laboratory tests indicated that high rates of mortality occurred if field-collected parasitized aphids were held in plastic bags, so a molecular assay was used that allowed immature L. oregmae to be detected within aphid hosts immediately after collection. The molecular assay was used in 2003 with the brown citrus aphids and with other aphid species collected from citrus, weeds, and vegetables near former release sites; immatures of L. oregmae were detected in black citrus aphids, cowpea aphids, spirea aphids, and melon aphids, as well as in the brown citrus aphid, in 4 of 8 counties sampled, with parasitism ranging from 2.0 to 12.9%, indicating that L. oregmae is established and widely distributed. Samples taken in Polk County during Oct 2005 indicated that L. oregmae has persisted. The ability of L. oregmae to parasitize other aphid species on citrus, and aphids on other host plants, enhances the ability of L. oregmae to persist when brown citrus aphid populations are low. (author) [Spanish] El parasitoide Lipolexis oregmae Gahan (introducido como L. scutellaris Mackauer) fue importado de Guam, evaluado en cuarentena, criado en masa y liberado en huertos de citricos en un programa de control biologico clasico dirigido contra el afido pardo de citricos, Toxoptera citricida Kirkaldy. Se hicieron liberaciones de 20,200, 12,100, y 1,260 adultos de L. oregmae a traves de la Florida durante los anos de 2000, 2001, y 2002, respectivamente. Para determinar si L. oregmae ha logrado en establecer, se realizaron sondeos a traves del estado empezando en el verano del 2001 y continuando hasta el final del verano del 2003. El parasitismo durante 2001 y 2002 fue evaluado con el mantenimiento de individuos del afido pardo de los citricos en el laboratorio hasta que los adultos emergieron. Lipolexis oregmae fue encontrado en 10 sitios en 7 condados y con tasas de parasitismo en 4 sitios en 3 condados entre 0.7 a 3.3% en el 2001 y 2002, respectivamente. Las pruebas del laboratorio indicaron que las tasas altas de mortalidad fueron posibles si los afidos con parasitos recolectados en el campo fueron mantenidos en bolsas plasticas, entonces un ensayo molecular fue usado con lo que permitio la deteccion de inmaduros de L. oregmae dentro de los hospederos de afidos inmediatamente despues de la recoleccion. El ensayo molecular fue usado en el 2003 con individuos del afido pardo de los citricos y con otras especies de afidos recolectados sobre citricos, malezas y hortalizas cerca de los sitios donde los parasitoides fueron liberados anteriormente; inmaduros de L. oregmae fueron detectados en individuos del afido negro de los citricos, el afido del caupi, el afido spirea y el afido del melon, ademas del afido pardo de los citricos en 4 de los 8 condados muestreados, con la tasa del parasitismo entre 2.0 a12.9%, indicando que L. oregmae estaba estabecido y ampliamente distribuido. Las muestras tomadas en el Condado de Polk durante octobre del 2005 indicaron que L. oregmae ha persistido. La capacidad de L. oregmae para parasitar otras especies de afidos sobre citricos y otros afidos sobre otras plantas hospederas, incrementa la capacidad de L. oregmae para persistir cuando las poblaciones del afido pardo de los citricos estan bajas. (author)« less

Temporal dynamics of arthropods on six tree species in dry woodlands on the Caribbean Island of Puerto Rico.

PubMed

Beltrán, William; Wunderle, Joseph M

2014-01-01

The seasonal dynamics of foliage arthropod populations are poorly studied in tropical dry forests despite the importance of these studies for understanding arthropod population responses to environmental change. We monitored the abundance, temporal distributions, and body size of arthropods in five naturalized alien and one native tree species to characterize arthropod seasonality in dry novel Prosopis-Leucaena woodlands in Puerto Rico. A branch clipping method was used monthly to sample foliage arthropod abundance over 39 mo. Seasonal patterns of rainfall and abundance within various arthropod taxa were highly variable from year to year. Abundance for most taxa did not show significant seasonality over the 3 yr, although most taxa had abundance peaks each year. However, Homoptera displayed high seasonality with significant temporal aggregations in each year. Formicidae, Orthoptera, and Coleoptera showed high variation in abundance between wet and dry periods, whereas Hemiptera were consistently more abundant in the wet period. Seasonal differences in mean abundance were found only in a few taxa on Tamarindus indica L., Bucida buceras L., Pithecellobium dulce, and (Roxburgh) Benth. Mean arthropod abundance varied among tree species, with highest numbers on Prosopis juliflora, (Swartz) De Candolle, Pi. dulce, Leucaena leucocephala, and (Lamarck) de Wit. Abundance of Araneae, Orthoptera, Coleoptera, Lepidoptera larvae, and all arthropods showed weak relationships with one or more climatic variables (rainfall, maximum temperature, or relative humidity). Body size of arthropods was usually largest during the dry periods. Overall, total foliage arthropod abundance showed no consistent seasonality among years, which may become a more common trend in dry forests and woodlands in the Caribbean if seasonality of rainfall becomes less predictable. © The Author 2014. Published by Oxford University Press on behalf of the Entomological Society of America.

Vitex agnus-castus is a preferred host plant for Hyalesthes obsoletus.

PubMed

Sharon, Rakefet; Soroker, Victoria; Wesley, S Daniel; Zahavi, Tirtza; Harari, Ally; Weintraub, Phyllis G

2005-05-01

Hyalesthes obsoletus Signoret (Homoptera: Cixiidae) is a polyphagous planthopper that transmits stolbur phytoplasma (a causative agent of "yellows" disease) to various weeds, members of the Solanaceae, and wine grapes (Vitis vinifera L.) in Europe and the Middle East. Planthoppers were collected by hand vacuuming eight native plant species. Vitex agnus-castus L., a shrub in the Verbenaceae, hosted the largest number of H. obsoletus, although Olea europaea L. also served as a host for adults. Using a Y-olfactometer, we compared the planthoppers relative preference for V. agnus-castus, Convolvulus arvensis, and V. vinifera. V. agnus-castus was more attractive to both male and female H. obsoletus than the other plants. H. obsoletus antennal response was stronger to volatiles collected from V. agnuscastus than from Cabernet Sauvignon variety of V. vinifera. To determine if V. agnus-castus would serve as a reservoir for the pathogen, H. obsoletus were collected from leaf and stem samples of native V. agnus-castus, and were tested by polymerase chain reaction (PCR) for the presence of phytoplasma DNA. While 14% and 25% (2003 and 2004, respectively) of the insects tested positive for phytoplasma DNA, none of the plant samples tested positive. To determine if V. agnus-castus could serve as a host plant for the development of the planthopper, we placed emergence cages beneath field shrubs and enclosed wild-caught H. obsoletus in a cage with a potted young shrub. We found adult H. obsoletus in the emergence cases and planthopper nymphs in the soil of the potted plant. We concluded that V. agnus-castus is attractive to H. obsoletus, which seems to be refractory to phytoplasma infections and warrants further testing as a trap plant near vineyards.

ASSESSING OF HERBIVOROUS AND BENEFICIAL INSECTS ON SWITCHGRASS IN UKRAINE.

PubMed

Stefanovska, T; Kucherovska, S; Pisdlisnyuk, V

2014-01-01

A perennial switchgrass, (Panicum virgatum L.), (C4) that is native to North America has good potential for biomass production because of its wide geographic distribution and adaptability to diverse environmental conditions. Insects can significantly impact the yield and quality of biofuel crops. If switchgrass are to be grown on marginally arable land or in monoculture, it are likely to be plagued with herbivore pests and plant diseases at a rate that exceeds what would be expected if the plants were not stressed in this manner. This biofuel crop has been under evaluation for commercial growing in Ukraine for eight years. However, insect diversity and the potential impact of pests on biomass production of this feedstock have not been accessed yet. The objective of our study, started in 2011, is a survey of switch grass insects by trophic groups and determine species that have pest status at two sites in the Central part of Ukraine (Kiev and Poltava regions). In Poltava site we investigated the effect of nine varieties of switchgrass (lowland and upland) to insects' diversity. We assessed changes over time in the densities of major insects' trophic groups, identifying potential pests and natural enemies. Obtained results indicates that different life stages of herbivorous insects from Hymenoptera, Homoptera, Diptera and Coleoptera orders were present on switchgrass during the growing season. Our study results suggests that choice of variety has an impact on trophic groups' structure and number of insects from different orders on swicthgrass. Herbivores and beneficial insects were the only groups that showed significant differences across sampling dates. The highest population of herbivores insects we recorded on 'Alamo' variety for studied years, although herbivore diversity tended to increase on 'Shelter', 'Alamo' and 'Cave-in-Rock' during 2012 and 2013. 'Dacotah', 'Nebraska', 'Sunburst', 'Forestburg' and 'Carthage' showed the highest level of beneficial insects

Comparative Proteomic Analysis of Susceptible and Resistant Rice Plants during Early Infestation by Small Brown Planthopper

PubMed Central

Dong, Yan; Fang, Xianping; Yang, Yong; Xue, Gang-Ping; Chen, Xian; Zhang, Weilin; Wang, Xuming; Yu, Chulang; Zhou, Jie; Mei, Qiong; Fang, Wang; Yan, Chengqi; Chen, Jianping

2017-01-01

The small brown planthopper (Laodelphax striatellus Fallén, Homoptera, Delphacidae-SBPH) is one of the major destructive pests of rice (Oryza sativa L.). Understanding on how rice responds to SBPH infestation will contribute to developing strategies for SBPH control. However, the response of rice plant to SBPH is poorly understood. In this study, two contrasting rice genotypes, Pf9279-4 (SBPH-resistant) and 02428 (SBPH-susceptible), were used for comparative analysis of protein profiles in the leaf sheath of rice plants in responses to SBPH infestation. One hundred and thirty-two protein spots that were differentially expressed between the resistant and susceptible rice lines were identified with significant intensity differences (≥2-fold, P < 0.05) at 0, 6, and 12 h after SBPH infestation. Protein expression profile analysis in the leaf sheath of SBPH-resistant and SBPH-susceptible rice lines after SBPH infestation showed that proteins induced by SBPH feeding were involved mainly in stress response, photosynthesis, protein metabolic process, carbohydrate metabolic process, energy metabolism, cell wall-related proteins, amino acid metabolism and transcriptional regulation. Gene expression analysis of 24 differentially expressed proteins (DEPs) showed that more than 50% DEPs were positively correlated with their mRNA levels. Analysis of some physiological indexes mainly involved in the removal of oxygen reactive species showed that the levels of superoxide dismutase (SOD) and glutathione (GSH) were considerably higher in Pf9279-4 than 02428 during SBPH infestation. The catalase (CAT) activity and hydroxyl radical inhibition were lower in Pf9279-4 than 02428. Analysis of enzyme activities indicates that Pf9279-4 rice plants defend against SBPH through the activation of the pathway of the salicylic acid (SA)-dependent systemic acquired resistance. In conclusion, this study provides some insights into the molecular networks involved on cellular and physiological

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

Horn, Scott; Hanula, James, L.

Abstract This study determined if short-term removal of coarse woody debris would reduce prey available to red-cockaded woodpeckers (Picoides borealis Vieillot) and other bark-foraging birds at the Savannah River Site in Aiken and Barnwell counties, SC. All coarse woody debris was removed from four 9-ha plots of mature loblolly pine (Pinus taeda L.) in 1997 and again in 1998. We sampled arthropods in coarse woody debris removal and control stands using crawl traps that captured arthropods crawling up tree boles, burlap bands wrapped around trees, and cardboard panels placed on the ground. We captured 27 orders and 172 families ofmore » arthropods in crawl traps whereas 20 arthropod orders were observed under burlap bands and cardboard panels. The most abundant insects collected from crawl traps were aphids (Homoptera: Aphididae) and ants (Hymenoptera: Forrnicidae). The greatest biomass was in the wood cockroaches (Blattaria: Blattellidae), caterpillars (Lepidoptera) in the Family Noctuidae, and adult weevils (Coleoptera: Curculionidae). The most common group observed underneath cardboard panels was lsoptera (termites), and the most common taxon under burlap bands was wood cockroaches. Overall, arthropod abundance and biomass captured in crawl traps was similar in control and removal plots. In contrast, we observed more arthropods under burlap bands (mean & SE; 3,021.5 k 348.6, P= 0.03) and cardboard panels (3,537.25 k 432.4, P= 0.04) in plots with coarse woody debris compared with burlap bands (2325 + 171.3) and cardboard panels (2439.75 + 288.9) in plots where coarse woody debris was removed. Regression analyses showed that abundance beneath cardboard panels was positively correlated with abundance beneath burlap bands demonstrating the link between abundance on the ground with that on trees. Our results demonstrate that short-term removal of coarse woody debris from pine forests reduced overall arthropod availability to bark-foraging birds.« less

Evaluation of larvicidal and nymphicidal potential of plant extracts against Anopheles subpictus Grassi, Culex tritaeniorhynchus Giles and Aphis gossypii Glover.

PubMed

Bagavan, A; Kamaraj, C; Rahuman, A Abdul; Elango, G; Zahir, A Abduz; Pandiyan, G

2009-04-01

The acetone, chloroform, ethyl acetate, hexane and methanol extracts of peel and leaf extracts of Citrus sinensis, Ocimum canum, Ocimum sanctum and Rhinacanthus nasutus were tested against fourth instar larvae of malaria vector, Anopheles subpictus Grassi, Japanese encephalitis vector, Culex tritaeniorhynchus Giles (Diptera: Culicidae) and feeding deterrence to nymphs of cotton pest, Aphis gossypii Glover (Homoptera: Aphididae). The larval and nymph mortality were observed after 24 h of exposure. All extracts showed moderate larvicidal and nymphicidal effects; however, the highest mortality was found in peel chloroform extract of C. sinensis, leaf ethyl acetate extracts of O. canum and O. sanctum and leaf chloroform extract of R. nasutus against the larvae of A. subpictus (LC(50) = 58.25, 88.15, 21.67 and 40.46 ppm; LC(90) = 298.31, 528.70, 98.34 and 267.20 ppm), peel methanol extract of C. sinensis, leaf methanol extract of O. canum, ethyl acetate extracts of O. sanctum and R. nasutus against the larvae of C. tritaeniorhynchus (LC(50) = 38.15, 72.40, 109.12 and 39.32 ppm; LC(90) = 184.67, 268.93, 646.62 and 176.39 ppm), peel hexane extract of C. sinensis, leaf methanol extracts of O. canum and R. nasutus and leaf ethyl acetate extract of O. sanctum against the nymph of A. gossypii (LC(50) = 162.89, 80.99, 73.27 and 130.19 ppm; LC(90) = 595.40, 293.33, 338.74 and 450.90 ppm), respectively. These results suggest that the peel methanol extracts of C. sinensis and O. canum, ethyl acetate leaf extract of O. sanctum and leaf chloroform and ethyl acetate extract of R. nasutus have the potential to be used as an ideal eco-friendly approach for the control of the A. subpictus, C. tritaeniorhynchus and A. gossypii.

Use of fluorescence, a novel technique to determine reduction in Bemisia tabaci (Hemiptera: Aleyrodidae) nymph feeding when exposed to Benevia and other insecticides.

PubMed

Cameron, Rachel; Lang, Edward B; Annan, I Billy; Portillo, Hector E; Alvarez, Juan M

2013-04-01

The sweet potato whitefly, Bemisia tabaci (Gennadius), is an economically important pest in the United States and other countries. Growers in many places rely on the use of insecticides to reduce populations of B. tabaci. However, insecticides may take a few days to cause B. tabaci mortality and some do not reduce feeding before death. Earlier reduction of feeding of whiteflies would decrease the physiological effects on plants, reduce the production of sooty mold and potentially reduce the transmission of viruses. Measuring the reduction in feeding after the exposure of B. tabaci to an insecticide has proven difficult. This series of laboratory experiments demonstrate the usefulness of fluorescence in determining B. tabaci feeding cessation. Fluorescein sodium salt is systemically transported in the xylem from the roots to the plant leaves and absorbed by B. tabaci nymphs feeding on these plants. Nymphs start fluorescing shortly after the cotton plant root system is submerged in the fluorescein sodium salt. Using this novel technique, the effect of three insecticides with different modes of action, cyantraniliprole, imidacloprid, and spirotetramat on B. tabaci was evaluated and compared to determine reduction in feeding. Results indicate that B. tabaci nymphs feeding on a plant treated with Benevia have a significant reduction of feeding when compared with nymphs feeding on plants treated with imidacloprid or spirotetramat. Both Benevia and spirotetramat caused significant nymphal mortality by 48 h after exposure. This novel technique will be useful to demonstrate the feeding cessation or reduction in feeding produced by different insecticides in several sucking insect groups.

Microsatellite markers reveal a predominant sugarcane aphid (Homoptera: Aphididae) clone is found on sorghum in seven states and one territory of the USA

USDA-ARS?s Scientific Manuscript database

The sugarcane aphid, Melanaphis sacchari, has become a serious pest causing severe economic losses to sorghum grown in the southern United States (U.S.). Since its original detection in four states in 2013, M. sacchari on sorghum has now, for 2016, spread to 19 states. The presence of one or multip...

Influence of substrate type and temperature on the developmental morphology of Pandora neoaphidis (Zygomycetes: entomophthorales), a pathogen of the tobacco aphid (Homoptera: aphididae).

PubMed

Dara, S K; Semtner, P J

1998-09-01

Developmental morphology of Pandora neoaphidis was observed on the surfaces of the tobacco aphid, Myzus nicotianae, tobacco leaves (Nicotiana tabacum), and glass coverslips at 13 and 20 degrees C for 12 and 24 h postinoculation. Pandora neoaphidis responded similarly on the two living substrates, but differed on the inert coverslips. The proportions of ellipsoid conidia (primary and secondary) were similar on all substrates. Higher proportions of appressoria and lower proportions of round secondary conidia and germinating conidia occurred on the aphids and leaves than on the coverslips. Appressoria predominated over round secondary conidia and germinating conidia on the living substrates at 20 degrees C, but the opposite was seen at 13 degrees C. The proportions of ellipsoid conidia were similar at both temperatures. On coverslips, the proportions of appressoria and round secondary conidia were similar at both temperatures. However, the proportions of germinating and ellipsoid conidia were higher at 13 and 20 degrees C, respectively. Copyright 1998 Academic Press.

Scymnus (Pullus) suturalis Thunberg (Coleoptera: Coccinellidae): New locality records and a report on feeding on hemlock woolly adelgid, Adelges tsugae Annand (Homoptera: Adelgidae)

Treesearch

S.M. Lyon; M.E. Montgomery

1995-01-01

Scymnus (Pullus) suturalis Thunberg is a Palearctic species that occurs on conifers, where it is reported to feed on aphids (I. Hodek. 1973. Biology of Coccinellidae. Academia, Czechoslovak Academy of Science. Prague). The occurrence of S. suturalis in North America was first reported by R.D. Gordon (1982. Proc. Entomol. Soc. Wash...

Molecular dynamics of detoxification and toxin-tolerance genes in brown planthopper (Nilaparvata lugens Stål., Homoptera: Delphacidae) feeding on resistant rice plants.

PubMed

Yang, Zhifan; Zhang, Futie; He, Qing; He, Guangcun

2005-06-01

To investigate the molecular response of brown planthopper, Nilaparvata lugens (BPH) to BPH-resistant rice plants, we isolated cDNA fragments of the genes encoding for carboxylesterase (CAR), trypsin (TRY), cytochrome P450 monooxygenase (P450), NADH-quinone oxidoreductase (NQO), acetylcholinesterase (ACE), and Glutathione S-transferase (GST). Expression profiles of the genes were monitored on fourth instar nymphs feeding on rice varieties with different resistance levels. Northern blot hybridization showed that, compared with BPH reared on susceptible rice TN1, expression of the genes for P450 and CAR was apparently up-regulated and TRY mRNA decreased in BPH feeding on a highly resistant rice line B5 and a moderately resistant rice variety MH63, respectively. Two transcripts of GST increased in BPH feeding on B5; but in BPH feeding on MH63, this gene was inducible and its expression reached a maximum level at 24 h, and then decreased slightly. The expression of NQO gene was enhanced in BPH on B5 plants but showed a constant expression in BPH on MH63 plants. No difference in ACE gene expression among BPH on different rice plants was detected by the RT-PCR method. The results suggest these genes may play important roles in the defense response of BPH to resistant rice.

Increased survival and prolonged longevity mainly contribute to the temperature-adaptive evolutionary strategy in invasive Bemisia tabaci (Hemiptera: Aleyrodidae) Middle East Asia Minor 1.

PubMed

Lü, Zhi-Chuang; Gao, Qing-Lei; Wan, Fang-Hao; Yu, Hao; Guo, Jian-Ying

2014-10-15

With increasing global climate change, analyses of stress-inducing conditions have important significance in ecological adaptation and the biological distribution of species. To reveal the difference in temperature-adaptive strategy between Turpan and Beijing populations of Bemisia tabaci (Gennadius) Middle East Asia Minor 1 (MEAM1) under high-temperature stress conditions, we compared thermal tolerance and life history traits between Beijing and Turpan populations of MEAM1 after exposure to different heat shock treatments for different times. The experimental design reflected the nature of heat stress conditions suffered by MEAM1. The results showed that eggs, red-eyed pupae, and adults of the Turpan population were more heat tolerant than those of the Beijing population under the same stress conditions. Additionally, it was found that longevity and F1 adult survival rate were significantly higher in the Turpan population than in the Beijing population after heat shock stress, but egg number and F1 female ratio were not significantly different between Turpan population and Beijing population. Overall, it was suggested that heat tolerance and longevity traits were the most relevant for climate characteristics and not reproductive traits, and improved heat tolerance and prolonged longevity were important adaptive strategies that helped MEAM1 to survive in harsh high-temperature conditions such as Turpan arid desert climate. The present results provided further insight into the modes of heat tolerance and the ways in which survival and longevity traits respond to environmental selection pressures. © The Author 2014. Published by Oxford University Press on behalf of the Entomological Society of America.

Biochemical evaluation of interactions between synergistic molecules and phase I enzymes involved in insecticide resistance in B- and Q-type Bemisia tabaci (Hemiptera: Aleyrodidae).

PubMed

Panini, Michela; Tozzi, Francesco; Zimmer, Christoph T; Bass, Chris; Field, Linda; Borzatta, Valerio; Mazzoni, Emanuele; Moores, Graham

2017-09-01

Metabolic resistance is an important consideration in the whitefly Bemisia tabaci, where an esterase-based mechanism has been attributed to pyrethroid resistance and over-expression of the cytochrome P450, CYP6CM1, has been correlated to resistance to imidacloprid and other neonicotinoids. In vitro interactions between putative synergists and CYP6CM1, B and Q-type esterases were investigated, and structure-activity relationship analyses allowed the identification of chemical structures capable of acting as inhibitors of esterase and oxidase activities. Specifically, methylenedioxyphenyl (MDP) moieties with a polyether chain were preferable for optimum inhibition of B-type esterase, whilst corresponding dihydrobenzofuran structures were potent for the Q-esterase variation. Potent inhibition of CYP6CM1 resulted from structures which contained an alkynyl chain with a terminal methyl group. Synergist candidates could be considered for field control of B. tabaci, especially to abrogate neonicotinoid resistance. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

The study and analysis of the mating behavior and sound production of male cicada Psalmocharias alhageos (Kol.) (Homoptera:Cicadidae) to make disruption in mating.

PubMed

Zamanian, H; Mehdipour, M; Ghaemi, N

2008-09-01

Psalmocharias alhageos is an important pest of vine in most parts of Iran, Afghanistan, Pakistan, southern areas of Russia, Turkey and Iraq. This cicada is spread in most provinces in Iran such as Esfahan, Hamedan, Qazvin, Markazi, Lorestan, Qom, Kerman, Tehran and Kordestan. In addition to vine, this insect damages some other fruit trees, such as apple, sour cherry, quince, peach, pomegranate and pear trees and some non-fruit trees, namely white poplar, ash, elm, eglantine, silk and black poplar trees. The nymphs of cicada damage the trees by feeding on root, adult insects on young bud and by oviposition under branch barks. Nourishing root by nymph leads to the weakness of the tree and hinder its growth. The high density oviposition of adult insects inside young barks causes withering of branches. The resulted damage on vine products is 40% which is one of the most important factors in product reduction in vineyard. This research was conducted in Takestan in Qazvin. It was conducted for the first time to study the behaviors of the mates of this vine cicada in order to manage it. Two systems were used to record the sound of male cicada called analog voice-recorder and digital voice recorder. To analyze the recorded sound of the male cicada we used of spectrum analyzer, digital storage oscilloscope and protens 7 computer softwares. We could call the attention of natural enemies an disturb the male insect's attracting sound by producing natural and artificial sound in the range of 1-6 kHz in two different ripeness status of the fruits and could prevent mating and oviposition of female cicadas.

Interactive Effects of Southern Rice Black-Streaked Dwarf Virus Infection of Host Plant and Vector on Performance of the Vector, Sogatella furcifera (Homoptera: Delphacidae).

PubMed

Lei, Wenbin; Liu, Danfeng; Li, Pei; Hou, Maolin

2014-10-01

Performance of insect vectors can be influenced by the viruses they transmit, either directly by infection of the vectors or indirectly via infection of the host plants. Southern rice black-streaked dwarf virus (SRBSDV) is a propagative virus transmitted by the white-backed planthopper, Sogatella furcifera (Hovath). To elucidate the influence of SRBSDV on the performance of white-backed planthopper, life parameters of viruliferous and nonviruliferous white-backed planthopper fed rice seedlings infected or noninfected with SRBSDV were measured using a factorial design. Regardless of the infection status of the rice plant host, viruliferous white-backed planthopper nymphs took longer to develop from nymph to adult than did nonviruliferous nymphs. Viruliferous white-backed planthopper females deposited fewer eggs than nonviruliferous females and both viruliferous and nonviruliferous white-backed planthopper females laid fewer eggs on infected than on noninfected plants. Longevity of white-backed planthopper females was also affected by the infection status of the rice plant and white-backed planthopper. Nonviruliferous white-backed planthopper females that fed on infected rice plants lived longer than the other three treatment groups. These results indicate that the performance of white-backed planthopper is affected by SRBSDV either directly (by infection of white-backed planthopper) or indirectly (by infection of rice plant). The extended development of viruliferous nymphs and the prolonged life span of nonviruliferous adults on infected plants may increase their likelihood of transmitting virus, which would increase virus spread. © 2014 Entomological Society of America.

Contribution to our knowledge of the whitefly genus Aleuroclava Singh (Hemiptera: Aleyrodidae) in China, including Taiwan and Hong Kong, with descriptions of two new species.

PubMed

Wang, Ji-Rui; Du, Yu-Zhou

2016-07-15

Two new whitefly species, Aleuroclava sterculiae sp. nov., collected from Sterculia nobilis (Malvales: Sterculiaceae) of Qingxiu hill park (Guangxi, China), and Aleuroclava rosae sp. nov., collected from Stranvaesia sp. (Rosales: Rosaceae) of Maoer Mountain (Guangxi, China), are described with morphology, line illustrations, photographs and scanning electron microscope (SEM) images. In addition, two other whitefly species, Aleuroclava lefroyi (Sundararaj & David) and Aleuroclava manii (David), are reported as new to the fauna of China, and are discussed. An identification key to Aleuroclava species known from Mainland China, Taiwan and Hong Kong is provided. The specimens are deposited in the Insect Collection of Yangzhou University (YZU).

The Entomopathogenic Fungal Endophytes Purpureocillium lilacinum (Formerly Paecilomyces lilacinus) and Beauveria bassiana Negatively Affect Cotton Aphid Reproduction under Both Greenhouse and Field Conditions

PubMed Central

Castillo Lopez, Diana; Zhu-Salzman, Keyan; Ek-Ramos, Maria Julissa; Sword, Gregory A.

2014-01-01

The effects of two entomopathogenic fungal endophytes, Beauveria bassiana and Purpureocillium lilacinum (formerly Paecilomyces lilacinus), were assessed on the reproduction of cotton aphid, Aphis gossypii Glover (Homoptera:Aphididae), through in planta feeding trials. In replicate greenhouse and field trials, cotton plants (Gossypium hirsutum) were inoculated as seed treatments with two concentrations of B. bassiana or P. lilacinum conidia. Positive colonization of cotton by the endophytes was confirmed through potato dextrose agar (PDA) media plating and PCR analysis. Inoculation and colonization of cotton by either B. bassiana or P. lilacinum negatively affected aphid reproduction over periods of seven and 14 days in a series of greenhouse trials. Field trials were conducted in the summers of 2012 and 2013 in which cotton plants inoculated as seed treatments with B. bassiana and P. lilacinum were exposed to cotton aphids for 14 days. There was a significant overall effect of endophyte treatment on the number of cotton aphids per plant. Plants inoculated with B. bassiana had significantly lower numbers of aphids across both years. The number of aphids on plants inoculated with P. lilacinum exhibited a similar, but non-significant, reduction in numbers relative to control plants. We also tested the pathogenicity of both P. lilacinum and B. bassiana strains used in the experiments against cotton aphids in a survival experiment where 60% and 57% of treated aphids, respectively, died from infection over seven days versus 10% mortality among control insects. Our results demonstrate (i) the successful establishment of P. lilacinum and B. bassiana as endophytes in cotton via seed inoculation, (ii) subsequent negative effects of the presence of both target endophytes on cotton aphid reproduction using whole plant assays, and (iii) that the P. lilacinum strain used is both endophytic and pathogenic to cotton aphids. Our results illustrate the potential of using these

The entomopathogenic fungal endophytes Purpureocillium lilacinum (formerly Paecilomyces lilacinus) and Beauveria bassiana negatively affect cotton aphid reproduction under both greenhouse and field conditions.

PubMed

Castillo Lopez, Diana; Zhu-Salzman, Keyan; Ek-Ramos, Maria Julissa; Sword, Gregory A

2014-01-01

The effects of two entomopathogenic fungal endophytes, Beauveria bassiana and Purpureocillium lilacinum (formerly Paecilomyces lilacinus), were assessed on the reproduction of cotton aphid, Aphis gossypii Glover (Homoptera:Aphididae), through in planta feeding trials. In replicate greenhouse and field trials, cotton plants (Gossypium hirsutum) were inoculated as seed treatments with two concentrations of B. bassiana or P. lilacinum conidia. Positive colonization of cotton by the endophytes was confirmed through potato dextrose agar (PDA) media plating and PCR analysis. Inoculation and colonization of cotton by either B. bassiana or P. lilacinum negatively affected aphid reproduction over periods of seven and 14 days in a series of greenhouse trials. Field trials were conducted in the summers of 2012 and 2013 in which cotton plants inoculated as seed treatments with B. bassiana and P. lilacinum were exposed to cotton aphids for 14 days. There was a significant overall effect of endophyte treatment on the number of cotton aphids per plant. Plants inoculated with B. bassiana had significantly lower numbers of aphids across both years. The number of aphids on plants inoculated with P. lilacinum exhibited a similar, but non-significant, reduction in numbers relative to control plants. We also tested the pathogenicity of both P. lilacinum and B. bassiana strains used in the experiments against cotton aphids in a survival experiment where 60% and 57% of treated aphids, respectively, died from infection over seven days versus 10% mortality among control insects. Our results demonstrate (i) the successful establishment of P. lilacinum and B. bassiana as endophytes in cotton via seed inoculation, (ii) subsequent negative effects of the presence of both target endophytes on cotton aphid reproduction using whole plant assays, and (iii) that the P. lilacinum strain used is both endophytic and pathogenic to cotton aphids. Our results illustrate the potential of using these

Climate Risk Modelling of Balsam Woolly Adelgid Damage Severity in Subalpine Fir Stands of Western North America.

PubMed

Hrinkevich, Kathryn H; Progar, Robert A; Shaw, David C

2016-01-01

The balsam woolly adelgid (Adelges piceae (Ratzeburg) (Homoptera: Adelgidae)) (BWA) is a nonnative, invasive insect that threatens Abies species throughout North America. It is well established in the Pacific Northwest, but continues to move eastward through Idaho and into Montana and potentially threatens subalpine fir to the south in the central and southern Rocky Mountains. We developed a climatic risk model and map that predicts BWA impacts to subalpine fir using a two-step process. Using 30-year monthly climate normals from sites with quantitatively derived BWA damage severity index values, we built a regression model that significantly explained insect damage. The sites were grouped into two distinct damage categories (high damage and mortality versus little or no mortality and low damage) and the model estimates for each group were used to designate distinct value ranges for four climatic risk categories: minimal, low, moderate, and high. We then calculated model estimates for each cell of a 4-kilometer resolution climate raster and mapped the risk categories over the entire range of subalpine fir in the western United States. The spatial variation of risk classes indicates a gradient of climatic susceptibility generally decreasing from the Olympic Peninsula in Washington and the Cascade Range in Oregon and Washington moving eastward, with the exception of some high risk areas in northern Idaho and western Montana. There is also a pattern of decreasing climatic susceptibility from north to south in the Rocky Mountains. Our study provides an initial step for modeling the relationship between climate and BWA damage severity across the range of subalpine fir. We showed that September minimum temperature and a metric calculated as the maximum May temperature divided by total May precipitation were the best climatic predictors of BWA severity. Although winter cold temperatures and summer heat have been shown to influence BWA impacts in other locations, these

Testing the Enemies Hypothesis in Peach Orchards in Two Different Geographic Areas in Eastern China: The Role of Ground Cover Vegetation

PubMed Central

Wan, Nian-Feng; Ji, Xiang-Yun; Jiang, Jie-Xian

2014-01-01

Many studies have supported the enemies hypothesis, which suggests that natural enemies are more efficient at controlling arthropod pests in polyculture than in monoculture agro-ecosystems. However, we do not yet have evidence as to whether this hypothesis holds true in peach orchards over several geographic locations. In the two different geographic areas in eastern China (Xinchang a town in the Shanghai municipality, and Hudai, a town in Jiangsu Province) during a continuous three-year (2010–2012) investigation, we sampled arthropod pests and predators in Trifolium repens L. and in tree canopies of peach orchards with and without the ground cover plant T. repens. No significant differences were found in the abundances of the main groups of arthropod pests and predators in T. repens between Hudai and Xinchang. The abundance, richness, Simpson's index, Shannon-Wiener index, and Pielou evenness index of canopy predators in ground cover areas increased by 85.5, 27.5, 3.5, 16.7, and 7.9% in Xinchang, and by 87.0, 27.6, 3.5, 17.0 and 8.0% in Hudai compared to those in the controls, respectively. The average abundance of Lepidoptera, Coleoptera, Homoptera, true bugs and Acarina canopy pests in ground cover areas decreased by 9.2, 10.2, 17.2, 19.5 and 14.1% in Xinchang, and decreased by 9.5, 8.2, 16.8, 20.1 and 16.6% in Hudai compared to that in control areas, respectively. Our study also found a higher density of arthropod species resources in T. repens, as some omnivorous pests and predators residing in T. repens could move between the ground cover and the orchard canopy. In conclusion, ground cover in peach orchards supported the enemies hypothesis, as indicated by the fact that ground cover T. repens promoted the abundance and diversity of predators and reduced the number of arthropod pests in tree canopies in both geographical areas. PMID:24963719

[Effect of pine plantations on soil arthropods in a high Andean forest].

PubMed

León-Gamboa, Alba Lucía; Ramos, Carolina; García, Mary Ruth

2010-09-01

One of the most common problems in the Colombian mountains has been the replacement of native vegetation by pine plantations. Soil arthropods are a fundamental component of forest ecosystem, since they participate in the organic matter fragmentation, previous to decomposition. This role is more valuable in high altitude environments, where low temperatures limit the dynamics of biological processes, where the effects of pine plantations on soil arthropods are still not well-known. In a remnant of high-andean forest (Neusa - Colombia) and a pine plantation of about 50 years-old, it was evaluated the composition, richness and abundance of arthropods at surface (S), organic horizon (O) and mineral horizon (A) of soil, to establish the differences associated to the soil use transformation. It was used "Pitfall" sampling to register the movement of the epigeous fauna, and extraction by funnel Berlese for determining the fauna density from O and A horizons. The Shannon and Simpson indexes estimated the diversity at different places and horizons, and the trophic structure of the community was evaluated. Overall, there were collected 38 306 individuals from forest and 17 386 individuals from pine plantation, mainly distributed in Collembola (42.4%), Acari (27%), Diptera (17.6%) and Coleoptera (4.6%). The most important differences were given in the surface, where the mobilization in forest (86 individuals/day) almost triplicates the one in pine plantation (33 individuals/day). The differences in composition were given in Collembola, Araneae, Hemiptera, Homoptera and Hymenoptera. The dynamics of richness and abundance along the year had significant high values in the native forest than in the pine plantation. The general trophic structure was dominated by saprophagous (75%), followed by predators (14%) and phytophagous (9%), but in two layers of the pine plantation soil (S and O) this structural pattern was not given. Based on the results, it was concluded that pine

Anopheles gambiae feeding and survival on honeydew and extra-floral nectar of peridomestic plants.

PubMed

Gary, R E; Foster, W A

2004-06-01

It is widely believed that the malaria vector Anopheles gambiae Giles (Diptera: Culicidae) rarely or never feeds on sugar in nature. If so, the need for supplemental blood-feeding may be increased and this would help to explain why it is such an efficient malaria vector. Nonetheless, both sexes of this mosquito species readily imbibe and digest sugar solutions, and sugar is a staple of laboratory colonies. In this study, we investigated whether An. gambiae will feed on the extra-floral nectar of three common peridomestic plants in Africa, and on honeydew of the mealybug Pseudococcus longispinus (Targioni-Tozetti) (Hemiptera: Homoptera: Pseudococcidae), and how this affects survivorship. We found that both males and females of An. gambiae provided with vegetative parts of cassava (Manihot esculenta Crantz) survived as well (x = 26.3 and 19.2 days, respectively) as they did on 50% sucrose solution (x = 29.7 and 24.3 days, respectively) and much longer than they did on water alone (x = 1.8 days, both sexes). Females provided with mealybug honeydew also lived substantially longer (x = 16.5 days) than those on water alone. Males and females provided with vegetative parts of castorbean (Ricinus communis L.) also survived much longer (x = 12.7 and 7.8 days, respectively) than on water, but those provided with flowering lantana (Lantana camara L.) did not. Anthrone tests of females after one night of exposure to these potential energy sources confirmed that they obtained fructose from cassava, from mealybug honeydew, and from non-flowering castorbean, but not from lantana or from castorbean lacking its petiolar nectaries. Previous laboratory studies had shown that sugar availability affects the survival and biting frequency of An. gambiae. It now appears that this mosquito can locate natural sources of plant sugar readily and utilize them effectively. Nectar-producing plants in the domestic environment may play a significant role in this mosquito's energy budget and

[Genetic variability of the Bemisia tabaci (Gennadius) biotype B (Hemiptera: Aleyrodidae) in vegetable crops in São Luís, state of Maranhão, Brazil].

PubMed

Da Silva, Maria C; De Lemos, Raimunda N S; Lima, Luzia H C; Gourlart Filho, Luiz R; Pereira, Silma R F

2009-01-01

The RAPD technique is widely used to investigate the distinct genetic characteristics of the complex Bemisia tabaci (Gennadius), which is currently constituted of approximately 41 biotypes. The objective of this research was to characterize populations of whitefly collected in crops of agricultural producing areas in São Luís, MA, like okra, beans and pepper, using RAPD molecular markers. Females from nine whitefly populations were analyzed and compared with B. tabaci biotype B taken from poinsettia culture of Embrapa Genetic Resources and Biotechnology (Brasília, DF). Twelve out of the 20 primers tested produced specific band patterns suitable to confirm that the evaluated specimens belong to the biotype B of B. tabaci, despite the high percentage of detected polymorphism. The analysis of the 96 RAPD molecular markers generated indicated that the populations on okra, beans and pepper were grouped according to the host cultures, sharing 80, 76 and 45% of genetic similarity, respectively, when compared with the control population of B. tabaci biotype B. A lower selective pressure was observed with the population of whitefly collected on pepper and minor genetic variability in the whitefly populations collected on okra and bean, when compared with the control population.

Insect growth regulator effects of azadirachtin and neem oil on survivorship, development and fecundity of Aphis glycines (Homoptera: Aphididae) and its predator, Harmonia axyridis (Coleoptera: Coccinellidae).

PubMed

Kraiss, Heidi; Cullen, Eileen M

2008-06-01

Aphis glycines Matsumura, an invasive insect pest in North American soybeans, is fed upon by a key biological control agent, Harmonia axyridis Pallas. Although biological control is preferentially relied upon to suppress insect pests in organic agriculture, approved insecticides, such as neem, are periodically utilized to reduce damaging pest populations. The authors evaluated direct spray treatments of two neem formulations, azadirachtin and neem seed oil, under controlled conditions for effects on survivorship, development time and fecundity in A. glycines and H. axyridis. Both azadirachtin and neem seed oil significantly increased aphid nymphal mortality (80 and 77% respectively) while significantly increasing development time of those surviving to adulthood. First-instar H. axyridis survival to adulthood was also significantly reduced by both neem formulations, while only azadirachtin reduced third-instar survivorship. Azadirachtin increased H. axyridis development time to adult when applied to both instars, while neem oil only increased time to adult when applied to first instar. Neither neem formulation affected the fecundity of either insect. Results are discussed within the context of future laboratory and field studies aimed at clarifying if neem-derived insecticides can be effectively integrated with biological control for soybean aphid management in organic soybeans. Copyright (c) 2008 Society of Chemical Industry.

Pre shipping dip treatments using soap, natural oils, and Isaria fumosorosea: potential biopesticides for mitigating the spread of whitefly Bemisia tabaci (Hemiptera: Aleyrodidae) invasive insects on ornamental plants

USDA-ARS?s Scientific Manuscript database

The whitefly Bemisia tabaci (Hemiptera: Aleyodidae) is an invasive insect pest affecting different crops including vegetables, fruits, cereals, and ornamentals. The efficacy of some products such as commercial soap, natural oils and Preferal® (based on the entomopathogenic fungus Isaria fumosorosea ...

What is the phylogenetic signal limit from mitogenomes? The reconciliation between mitochondrial and nuclear data in the Insecta class phylogeny

PubMed Central

2011-01-01

Background Efforts to solve higher-level evolutionary relationships within the class Insecta by using mitochondrial genomic data are hindered due to fast sequence evolution of several groups, most notably Hymenoptera, Strepsiptera, Phthiraptera, Hemiptera and Thysanoptera. Accelerated rates of substitution on their sequences have been shown to have negative consequences in phylogenetic inference. In this study, we tested several methodological approaches to recover phylogenetic signal from whole mitochondrial genomes. As a model, we used two classical problems in insect phylogenetics: The relationships within Paraneoptera and within Holometabola. Moreover, we assessed the mitochondrial phylogenetic signal limits in the deeper Eumetabola dataset, and we studied the contribution of individual genes. Results Long-branch attraction (LBA) artefacts were detected in all the datasets. Methods using Bayesian inference outperformed maximum likelihood approaches, and LBA was avoided in Paraneoptera and Holometabola when using protein sequences and the site-heterogeneous mixture model CAT. The better performance of this method was evidenced by resulting topologies matching generally accepted hypotheses based on nuclear and/or morphological data, and was confirmed by cross-validation and simulation analyses. Using the CAT model, the order Strepsiptera was recovered as sister to Coleoptera for the first time using mitochondrial sequences, in agreement with recent results based on large nuclear and morphological datasets. Also the Hymenoptera-Mecopterida association was obtained, leaving Coleoptera and Strepsiptera as the basal groups of the holometabolan insects, which coincides with one of the two main competing hypotheses. For the Paraneroptera, the currently accepted non-monophyly of Homoptera was documented as a phylogenetic novelty for mitochondrial data. However, results were not satisfactory when exploring the entire Eumetabola, revealing the limits of the phylogenetic

[Characteristics of floor litter and soil arthropod community in different types ot subtropical forest in Ailao Mountain of Yunnan, Southwest China].

PubMed

Yang, Zhao; Yang, Xiao-Dong

2011-11-01

By using line transect method, an investigation was conducted on the floor litter and soil arthropod community in a mid mountain wet evergreen broad-leaved forest, a mossy dwarf forest, and a Populus bonatii forest in Ailao Mountain of Yunnan in April (dry and hot season), June (rainy season), and December (dry and cold season), 2005. In both dry and rainy seasons, the existing floor litter mass, C storage, and C/N ratio in the three forests all increased in the order of mossy dwarf forest > P. bonatii forest > evergreen broad-leaved forest, but the N storage had less difference. In the floor litter layer of the forests, Acari and Collembola were the dominant groups of soil arthropod community, while Diptera larvae, Coleoptera, ants, and Homoptera were the common groups. The Sorenson coefficients of soil arthropod community in the three forests were extremely great. No significant differences were observed in the soil arthropod density (ind x m(-2)) in the floor litter layer among the three forests, but the relative density (ind x g(-1)) of soil arthropods was higher in the evergreen broad-leaved forest and P. bonatii forest than in the mossy dwarf forest. In the three forests, the density of soil arthropods was significantly higher in dry season than in rainy season, but the Shannon diversity index had less difference. There were significant positive correlations between the existing floor litter mass and the individual density (ind x m(-2)) and dominant groups of soil arthropod communities in dry and hot season (April), but negative correlations between the existing floor litter mass and the relative density (ind x g(-1)) of soil arthropod communities and Acari in dry and cold season (December). The individual densities of Collembola and Coleoptera also had positive correlations with the N storage of the existing floor litter mass in the three forests. It was considered that the floor litter and the development of soil arthropod community in the litter layer of

Effect of an alternate weed host, hairy nightshade, Solanum sarrachoides, on the biology of the two most important potato leafroll virus (Luteoviridae: Polerovirus) vectors, Myzus persicae and Macrosiphum euphorbiae (Aphididae: Homoptera).

PubMed

Srinivasan, Rajagopalbabu; Alvarez, Juan M; Bosque-Pérez, Nilsa A; Eigenbrode, Sanford D; Novy, Richard G

2008-04-01

Hairy nightshade, Solanum sarrachoides (Sendtner), is a ubiquitous weed in potato agro-ecosystems and nonagricultural lands of southeastern Idaho and the Pacific Northwest. This weed increases the complexity of the Potato leafroll virus (PLRV) (Luteoviridae: Polervirus)-potato pathosystem by serving as aphid and virus reservoir. Previous field studies showed higher densities of green peach aphid, Myzus persicae (Sulzer), and potato aphid, Macrosiphum euphorbiae (Thomas), the two most important vectors of PLRV, on S. sarrachoides compared with potato plants in the same fields. Some of the S. sarrachoides plants sampled in these surveys tested positive for PLRV. Viral infections can alter the physiology of plant hosts and aphid performance on such plants. To understand better the potential effects of S. sarrachoides on the PLRV-potato-aphid pathosystem, the life histories of M. persicae and M. euphorbiae were compared on virus-free and PLRV-infected S. sarrachoides and potato. Individual nymphs of each aphid species were held in clip cages on plants from each treatment to monitor their development, survival, and reproductive output. Nymphal survival for both aphids across plant species was higher on S. sarrachoides than on potato, and, within plant species, it was higher on PLRV-infected plants than on noninfected plants. With a few exceptions, similar patterns occurred for fecundity, reproductive periods, adult longevity, and intrinsic rate of increase. The enhanced performance of aphids on S. sarrachoides and on PLRV-infected plants could alter the vector population dynamics and thus the PLRV-disease epidemiology in fields infested with this weed.

Study of microarthropod communities to assess soil quality in different managed vineyards

NASA Astrophysics Data System (ADS)

Gagnarli, Elena; Vignozzi, Nadia; Valboa, Giuseppe; Bouneb, Mabrouk; Corino, Lorenzo; Goggioli, Donatella; Guidi, Silvia; Lottero, Mariarosa; Tarchi, Franca; Simoni, Sauro

2014-05-01

conventional/IPM management). The mites represented about 50% of the arthropodofauna recorded, collembolans 30%, and 20% other microarthropods (Blattaria, Chilopoda, Coleoptera, Diplopoda, Diplura, Diptera, Hemiptera, Hymenoptera, Isopoda, Homoptera, Pauropoda, Protura, Pseudoscopionida, Psocoptera, Symphyla, Thysanoptera). The mesofauna abundance was affected by the type of management (P=0.015) and soil texture (P=0.029). At the identification level considered, the biological indices calculated showed no substantial differences between different crop managements (H'=1.26, D=0.97 in organic vineyard, H'=1.30, D=0.89 in IPM vineyard). The analysis of microarthropod communities by QBSar, however, showed higher values in organic compared to IPM managed vineyards (QBSar 199 vs 98 in 2011 and 205 vs 188 in 2012, respectively) which are close to figures characteristic of preserved soils.

Ground-based hyperspectral remote sensing to discriminate biotic stress in cotton crop

NASA Astrophysics Data System (ADS)

Nigam, Rahul; Kot, Rajsi; Sandhu, Sandeep S.; Bhattacharya, Bimal K.; Chandi, Ravinder S.; Singh, Manjeet; Singh, Jagdish; Manjunath, K. R.

2016-05-01

in warm weather, and populations can build up quickly in situations where natural enemies are ineffective and when weather and host plants favor outbreaks. Large colonies often develop on the undersides of leaves. The most common pest species such as greenhouse white fly (Trialeurodes vaporariorum) and sweet potato white fly (Bemisia tabaci) have a wide host range that includes many weeds and crops. White flies normally lay their tiny oblong eggs on the undersides of leaves. The eggs hatch, and the young white flies gradually increase in size through four nymphal stages called instars. The first nymphal stage (crawler) is barely visible even with a hand lens. The crawlers move around for several hours before settling to begin feeding. Later nymphal stages are immobile, oval, and flattened, with greatly reduced legs and antennae, like small scale insects. The winged adult emerges from the last nymphal stage (sometimes called a pupa, although whiteflies don't have a true complete metamorphosis). All stages feed by sucking plant juices from leaves and excreting excess liquid as drops of honeydew as they feed. White flies use their piercing, needle like mouthparts to suck sap from phloem, the food-conducting tissues in plant stems and leaves. Large populations can cause leaves to turn yellow, appear dry, or fall off plants. Like aphids, white flies excrete sugary liquid called honeydew, so leaves may be sticky or covered with black sooty mold that grows on honeydew. The honeydew attracts ants, which interfere with the activities of natural enemies that may control white flies and other pests. High white fly infestation was reported at several locations in Punjab during year 2015. The application of non-destructive methods to detect vegetation stress at an early stage of its development is very important for pest management in commercially important crops. Earlier few studies have been done to characterize reflectance spectra of nutrient stress nitrogen deficiency and

Grassland birds wintering at U.S. Navy facilities in southern Texas

USGS Publications Warehouse

Woodin, Marc C.; Skoruppa, Mary Kay; Bryan, Pearce D.; Ruddy, Amanda J.; Hickman, Graham C.

2010-01-01

transects during the study were Species of Conservation Concern: Le Conte’s Sparrow, Sedge Wren (Cistothorus platensis), Grasshopper Sparrow (Ammodramus savannarum), Long-billed Curlew (Numenius americanus), Sprague’s Pipit (Anthus spragueii), Cassin’s Sparrow (Aimophila cassinii), and Loggerhead Shrike (Lanius ludovicianus). Native grasslands consistently supported greater bird species richness than exotic grasslands. In one winter, exotic grasslands supported more birds than native grasslands.Native grasslands were determined to have more forb cover, more bare ground, and greater plant species richness than exotic grasslands, whereas exotic grasslands were characterized by more grass cover and relatively greater vegetation density during dry years. Not only did these individual measures differ between native and exotic grasslands, but components of variation also differed. In native grasslands, grass density and cover contributed more to variation, whereas in exotic grasslands, non-grass vegetation was a greater component of variation. Total bird numbers and bird species richness in native grasslands were related to the principal component that contained a measure of litter cover. Total bird numbers and bird species richness in exotic grasslands indicated no significant relationships with any of the principal components of variation.The two most common insect orders in native grasslands were Hymenoptera and Coleoptera, which accounted for 42 percent of all insects. The two most common insect orders in exotic grasslands were Hemiptera and Homoptera, which accounted for about 80 percent of all insects. Insect family richness was greater in exotic grasslands than in native grasslands in two of four seasons. Proportions of arachnid families were similar in native and exotic grasslands, but arachnid family richness was greater in exotic grasslands than in native grasslands.Abundance of seeds was greater in exotic than in native grasslands. However, seed diversity was