Geostatistical evaluation of integrated marsh management impact on mosquito vectors using before-after-control-impact (BACI) design

PubMed Central

Rochlin, Ilia; Iwanejko, Tom; Dempsey, Mary E; Ninivaggi, Dominick V

2009-01-01

Background In many parts of the world, salt marshes play a key ecological role as the interface between the marine and the terrestrial environments. Salt marshes are also exceedingly important for public health as larval habitat for mosquitoes that are vectors of disease and significant biting pests. Although grid ditching and pesticides have been effective in salt marsh mosquito control, marsh degradation and other environmental considerations compel a different approach. Targeted habitat modification and biological control methods known as Open Marsh Water Management (OMWM) had been proposed as a viable alternative to marsh-wide physical alterations and chemical control. However, traditional larval sampling techniques may not adequately assess the impacts of marsh management on mosquito larvae. To assess the effectiveness of integrated OMWM and marsh restoration techniques for mosquito control, we analyzed the results of a 5-year OMWM/marsh restoration project to determine changes in mosquito larval production using GIS and geostatistical methods. Methods The following parameters were evaluated using "Before-After-Control-Impact" (BACI) design: frequency and geographic extent of larval production, intensity of larval production, changes in larval habitat, and number of larvicide applications. The analyses were performed using Moran's I, Getis-Ord, and Spatial Scan statistics on aggregated before and after data as well as data collected over time. This allowed comparison of control and treatment areas to identify changes attributable to the OMWM/marsh restoration modifications. Results The frequency of finding mosquito larvae in the treatment areas was reduced by 70% resulting in a loss of spatial larval clusters compared to those found in the control areas. This effect was observed directly following OMWM treatment and remained significant throughout the study period. The greatly reduced frequency of finding larvae in the treatment areas led to a significant

Enhancement of mosquito trapping efficiency by using pulse width modulated light emitting diodes.

PubMed

Liu, Yu-Nan; Liu, Yu-Jen; Chen, Yi-Chian; Ma, Hsin-Yi; Lee, Hsiao-Yi

2017-01-06

In this study, a light-driving bug zapper is presented for well controlling the diseases brought by insects, such as mosquitoes. In order to have the device efficient to trap the insect pests in off-grid areas, pulse width modulated light emitting diodes (PWM-LED) combined with a solar power module are proposed and implemented. With specific PWM electric signals to drive the LED, it is found that no matter what the ability of catching insects or the consumed power efficiency can be enhanced thus. It is demonstrated that 40% of the UV LED consumed power and 25.9% of the total load power consumption can be saved, and the trapped mosquitoes are about 250% increased when the PWM method is applied in the bug zapper experiments.

Enhancement of mosquito trapping efficiency by using pulse width modulated light emitting diodes

NASA Astrophysics Data System (ADS)

Liu, Yu-Nan; Liu, Yu-Jen; Chen, Yi-Chian; Ma, Hsin-Yi; Lee, Hsiao-Yi

2017-01-01

In this study, a light-driving bug zapper is presented for well controlling the diseases brought by insects, such as mosquitoes. In order to have the device efficient to trap the insect pests in off-grid areas, pulse width modulated light emitting diodes (PWM-LED) combined with a solar power module are proposed and implemented. With specific PWM electric signals to drive the LED, it is found that no matter what the ability of catching insects or the consumed power efficiency can be enhanced thus. It is demonstrated that 40% of the UV LED consumed power and 25.9% of the total load power consumption can be saved, and the trapped mosquitoes are about 250% increased when the PWM method is applied in the bug zapper experiments.

Changes in Sea Salt Emissions Enhance ENSO Variability

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

Yang, Yang; Russell, Lynn M.; Lou, Sijia

Two 150-year pre-industrial simulations with and without interactive sea salt emissions from the Community Earth System Model (CESM) are performed to quantify the interactions between sea salt emissions and El Niño–Southern Oscillation (ENSO). Variations in sea salt emissions over the tropical Pacific Ocean are affected by changing wind speed associated with ENSO variability. ENSO-induced interannual variations in sea salt emissions result in decreasing (increasing) aerosol optical depth (AOD) by 0.03 over the equatorial central-eastern (western) Pacific Ocean during El Niño events compared to those during La Niña events. These changes in AOD further increase (decrease) radiative fluxes into the atmospheremore » by +0.2 W m -2 (-0.4 W m -2) over the tropical eastern (western) Pacific. Thereby, sea surface temperature increases (decreases) by 0.2–0.4 K over the tropical eastern (western) Pacific Ocean during El Niño compared to La Niña events and enhances ENSO variability by 10%. The increase in ENSO amplitude is a result of systematic heating (cooling) during the warm (cold) phase, of ENSO in the eastern Pacific. Interannual variations in sea salt emissions then produce the anomalous ascent (subsidence) over the equatorial eastern (western) Pacific between El Niño and La Niña events, which is a result of heating anomalies. Due to variations in sea salt emissions, the convective precipitation is enhanced by 0.6–1.2 mm day -1 over the tropical central-eastern Pacific Ocean and weakened by 0.9–1.5 mm day -1 over the Maritime Continent during El Niño compared to La Niña events, enhancing the precipitation variability over the tropical Pacific.« less

Enhancement of mosquito trapping efficiency by using pulse width modulated light emitting diodes

PubMed Central

Liu, Yu-Nan; Liu, Yu-Jen; Chen, Yi-Chian; Ma, Hsin-Yi; Lee, Hsiao-Yi

2017-01-01

In this study, a light-driving bug zapper is presented for well controlling the diseases brought by insects, such as mosquitoes. In order to have the device efficient to trap the insect pests in off-grid areas, pulse width modulated light emitting diodes (PWM-LED) combined with a solar power module are proposed and implemented. With specific PWM electric signals to drive the LED, it is found that no matter what the ability of catching insects or the consumed power efficiency can be enhanced thus. It is demonstrated that 40% of the UV LED consumed power and 25.9% of the total load power consumption can be saved, and the trapped mosquitoes are about 250% increased when the PWM method is applied in the bug zapper experiments. PMID:28059148

Enhanced salt tolerance of alfalfa (Medicago sativa) by rstB gene transformation.

PubMed

Zhang, Wan-Jun; Wang, Tao

2015-05-01

Generating salt tolerance forage plant is essential for use of the land affected by high salinity. A salt tolerance gene rstB was used as a selectable marker gene in Agrobacterium-mediated transformation of tobacco under a selective regime of 170mM NaCl. The transgenic plants showed clear improvement in salt tolerance. To improve salt tolerance of alfalfa (Medicago sativa L.), rstB gene was introduced into alfalfa genome by Agrobacterium-mediated transformation. No abnormal phenotype was observed among the transgenic plants when compared with wild type (wt) plants. Significant enhancement of resistance to salt-shock treatment was noted on the rstB transgenic (T0) plants. Transgenic second-generation (T1) seeds showed improved germination rate and seedling growth under salt-stress condition. Hindered Na(+) accumulation, but enhanced Ca(2+) accumulation was observed on the rstB T1 plants when subjected to salt-stresses. Enhanced calcium accumulation in transgenic plants was also verified by cytohistochemical localization of calcium. Under salt-stress of 50mM NaCl, about 15% of the transgenic plants finished their life-cycle but the wt plants had no flower formation. The results demonstrated that the expression of rstB gene improved salt tolerance in transgenic alfalfa. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Dual-treatment autodissemination station with enhanced transfer of an insect growth regulator to mosquito oviposition sites.

PubMed

Wang, Yi; Suman, Devi S; Bertrand, Jacques; Dong, Limin; Gaugler, Randy

2014-08-01

The Asian tiger mosquito, Aedes albopictus (Skuse), transmits important arboviral diseases and displaces native species. This peridomestic mosquito deposits eggs in natural and artificial containers. Container larval habitats tend to be cryptic and, therefore, difficult to reach by conventional insecticide treatments. We have developed an autodissemination station that transfers the insect growth regulator, pyriproxyfen, from the station to oviposition sites. Mosquitoes visiting the station become contaminated with an oil sticker followed by pyriproxyfen powder before exiting. In a room (31 m(3) ) bioassay a single station consistently achieved 100% Ae. albopictus pupal mortality against 10 oviposition containers. In a greenhouse (200 m(3) ) assay with two stations and 12 oviposition cups, 91.7% of the cups had been contaminated as shown, and 57.1% pupal mortality was recorded. Pyriproxyfen transfer was also detected by visualizing mosquito 'tarsal prints' using a fluorescent dye. The oil and pyriproxyfen powder dual-treatment station enhanced autodissemination efficacy by increasing toxicant attachment and retention on contaminated females. The autodissemination station offers a targeted, less environmentally damaging approach to manage cryptic container species. © 2013 Society of Chemical Industry.

Nesting bird "host funnel" increases mosquito-bird contact rate.

PubMed

Caillouët, Kevin A; Riggan, Anna E; Bulluck, Lesley P; Carlson, John C; Sabo, Roy T

2013-03-01

Increases in vector-host contact rates can enhance arbovirus transmission intensity. We investigated weekly fluctuations in contact rates between mosquitoes and nesting birds using the recently described Nest Mosquito Trap (NMT). The number of mosquitoes per nestling increased from < 1 mosquito per trap night to 36.2 in the final 2 wk of the nesting season. Our evidence suggests the coincidence of the end of the avian nesting season and increasing mosquito abundances may have caused a "host funnel," concentrating host-seeking mosquitoes to the few remaining nestlings. The relative abundance of mosquitoes collected by the NMT suggests that significantly more Aedes albopictus (Skuse) and Culex pipiens (L.) /restuans (Theobald) sought nesting bird bloodmeals than were predicted by their relative abundances in CO2-baited Centers for Disease Control and Prevention light and gravid traps. Culex salinarius (Coquillett) and Culex erraticus Dyar and Knab were collected in NMTs in proportion to their relative abundances in the generic traps. Temporal host funnels and nesting bird host specificity may enhance arbovirus amplification and explain observed West Nile virus and St. Louis encephalitis virus amplification periods.

Aquatic insects of New York salt marsh associated with mosquito larval habitat and their potential utility as bioindicators.

PubMed

Rochlin, Ilia; Dempsey, Mary E; Iwanejko, Tom; Ninivaggi, Dominick V

2011-01-01

The aquatic insect fauna of salt marshes is poorly characterized, with the possible exception of biting Diptera. Aquatic insects play a vital role in salt marsh ecology, and have great potential importance as biological indicators for assessing marsh health. In addition, they may be impacted by measures to control mosquitoes such as changes to the marsh habitat, altered hydrology, or the application of pesticides. Given these concerns, the goals of this study were to conduct the first taxonomic survey of salt marsh aquatic insects on Long Island, New York, USA and to evaluate their utility for non-target pesticide impacts and environmental biomonitoring. A total of 18 species from 11 families and five orders were collected repeatedly during the five month study period. Diptera was the most diverse order with nine species from four families, followed by Coleoptera with four species from two families, Heteroptera with three species from three families, then Odonata and the hexapod Collembola with one species each. Water boatmen, Trichocorixa verticalis Fieber (Heteroptera: Corixidae) and a shore fly, Ephydra subopaca Loew (Diptera: Ephydridae), were the two most commonly encountered species. An additional six species; Anurida maritima Guérin-Méneville (Collembola: Neanuridae), Mesovelia mulsanti White (Heteroptera: Mesovelidae), Enochrus hamiltoni Horn (Coleoptera: Hydrophilidae), Tropisternus quadristriatus Horn (Coleoptera: Hydrophilidae), Dasyhelea pseudocincta Waugh and Wirth (Diptera: Ceratopogonidae), and Brachydeutera argentata Walker (Diptera: Ephydridae), were found regularly. Together with the less common Erythrodiplax berenice Drury (Odonata: Libellulidae), these nine species were identified as the most suitable candidates for pesticide and environmental impact monitoring due to abundance, position in the food chain, and extended seasonal occurrence. This study represents a first step towards developing an insect-based index of biological integrity for

Aquatic Insects of New York Salt Marsh Associated with Mosquito Larval Habitat and their Potential Utility as Bioindicators

PubMed Central

Rochlin, Ilia; Dempsey, Mary E.; Iwanejko, Tom; Ninivaggi, Dominick V.

2011-01-01

The aquatic insect fauna of salt marshes is poorly characterized, with the possible exception of biting Diptera. Aquatic insects play a vital role in salt marsh ecology, and have great potential importance as biological indicators for assessing marsh health. In addition, they may be impacted by measures to control mosquitoes such as changes to the marsh habitat, altered hydrology, or the application of pesticides. Given these concerns, the goals of this study were to conduct the first taxonomic survey of salt marsh aquatic insects on Long Island, New York, USA and to evaluate their utility for non-target pesticide impacts and environmental biomonitoring. A total of 18 species from 11 families and five orders were collected repeatedly during the five month study period. Diptera was the most diverse order with nine species from four families, followed by Coleoptera with four species from two families, Heteroptera with three species from three families, then Odonata and the hexapod Collembola with one species each. Water boatmen, Trichocorixa verticalis Fieber (Heteroptera: Corixidae) and a shore fly, Ephydra subopaca Loew (Diptera: Ephydridae), were the two most commonly encountered species. An additional six species; Anurida maritima Guérin-Méneville (Collembola: Neanuridae), Mesovelia mulsanti White (Heteroptera: Mesovelidae), Enochrus hamiltoni Horn (Coleoptera: Hydrophilidae), Tropisternus quadristriatus Horn (Coleoptera: Hydrophilidae), Dasyhelea pseudocincta Waugh and Wirth (Diptera: Ceratopogonidae), and Brachydeutera argentata Walker (Diptera: Ephydridae), were found regularly. Together with the less common Erythrodiplax berenice Drury (Odonata: Libellulidae), these nine species were identified as the most suitable candidates for pesticide and environmental impact monitoring due to abundance, position in the food chain, and extended seasonal occurrence. This study represents a first step towards developing an insectbased index of biological integrity for

Enhancing longevity of Plasmodium vivax and P. falciparum sporozoites after dissection from mosquito salivary glands.

PubMed

Lupton, Emily J; Roth, Alison; Patrapuvich, Rapatbhorn; Maher, Steve P; Singh, Naresh; Sattabongkot, Jetsumon; Adams, John H

2015-04-01

The pre-erythrocytic stages of Plasmodium vivax and Plasmodium falciparum remain challenging for experimental research in part due to limited access to sporozoites. An important factor limiting availability is the laboratory support required for producing infected mosquitoes and the ephemeral nature of isolated extracellular sporozoites. This study was undertaken to investigate methods to improve the availability of this limited resource by extending the longevity of the extracellular sporozoites after mosquito dissection. Our goal in this study was to determine whether buffer conditions more closely mimicking the insect microenvironment could prolong longevity of ex vivo P. vivax and P. falciparum sporozoites. The study compared the current standard dissection buffer RPMI1640 to Hank's Balanced Salt Solution with 1g/L glucose (HBSS-1) or 2g/L glucose (HBSS-2) and Grace's Insect Medium for ability to extend longevity of ex vivo P. vivax and P. falciparum sporozoites. The effect of each buffer on sporozoite viability was evaluated by measuring sporozoite gliding motility at 0, 4, 8, and 24h post-dissection from mosquito salivary glands. Comparisons of mean gliding percentages of ex vivo sporozoites in the different buffers and time points found that RPMI and Grace's both showed strong gliding at 0h. In contrast, by 4h post-dissection sporozoites in RPMI consistently had the lowest gliding activity, whereas sporozoites in Grace's had significantly more gliding compared to all other buffers at almost all time points. Our results indicate that P. vivax and P. falciparum sporozoites maintained in insect media rather than the standard dissection buffer RPMI and HBSS retain viability better over time. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Mosquito-disseminated pyriproxyfen yields high breeding-site coverage and boosts juvenile mosquito mortality at the neighborhood scale.

PubMed

Abad-Franch, Fernando; Zamora-Perea, Elvira; Ferraz, Gonçalo; Padilla-Torres, Samael D; Luz, Sérgio L B

2015-04-01

Mosquito-borne pathogens pose major public health challenges worldwide. With vaccines or effective drugs still unavailable for most such pathogens, disease prevention heavily relies on vector control. To date, however, mosquito control has proven difficult, with low breeding-site coverage during control campaigns identified as a major drawback. A novel tactic exploits the egg-laying behavior of mosquitoes to have them disseminate tiny particles of a potent larvicide, pyriproxyfen (PPF), from resting to breeding sites, thus improving coverage. This approach has yielded promising results at small spatial scales, but its wider applicability remains unclear. We conducted a four-month trial within a 20-month study to investigate mosquito-driven dissemination of PPF dust-particles from 100 'dissemination stations' (DSs) deployed in a 7-ha sub-area to surveillance dwellings and sentinel breeding sites (SBSs) distributed over an urban neighborhood of about 50 ha. We assessed the impact of the trial by measuring juvenile mosquito mortality and adult mosquito emergence in each SBS-month. Using data from 1,075 dwelling-months, 2,988 SBS-months, and 29,922 individual mosquitoes, we show that mosquito-disseminated PPF yielded high coverage of dwellings (up to 100%) and SBSs (up to 94.3%). Juvenile mosquito mortality in SBSs (about 4% at baseline) increased by over one order of magnitude during PPF dissemination (about 75%). This led to a >10-fold decrease of adult mosquito emergence from SBSs, from approximately 1,000-3,000 adults/month before to about 100 adults/month during PPF dissemination. By expanding breeding-site coverage and boosting juvenile mosquito mortality, a strategy based on mosquito-disseminated PPF has potential to substantially enhance mosquito control. Sharp declines in adult mosquito emergence can lower vector/host ratios, reducing the risk of disease outbreaks. This approach is a very promising complement to current and novel mosquito control strategies

Mosquito-Disseminated Pyriproxyfen Yields High Breeding-Site Coverage and Boosts Juvenile Mosquito Mortality at the Neighborhood Scale

PubMed Central

Abad-Franch, Fernando; Zamora-Perea, Elvira; Ferraz, Gonçalo; Padilla-Torres, Samael D.; Luz, Sérgio L. B.

2015-01-01

Background Mosquito-borne pathogens pose major public health challenges worldwide. With vaccines or effective drugs still unavailable for most such pathogens, disease prevention heavily relies on vector control. To date, however, mosquito control has proven difficult, with low breeding-site coverage during control campaigns identified as a major drawback. A novel tactic exploits the egg-laying behavior of mosquitoes to have them disseminate tiny particles of a potent larvicide, pyriproxyfen (PPF), from resting to breeding sites, thus improving coverage. This approach has yielded promising results at small spatial scales, but its wider applicability remains unclear. Methodology/Principal Findings We conducted a four-month trial within a 20-month study to investigate mosquito-driven dissemination of PPF dust-particles from 100 ‘dissemination stations’ (DSs) deployed in a 7-ha sub-area to surveillance dwellings and sentinel breeding sites (SBSs) distributed over an urban neighborhood of about 50 ha. We assessed the impact of the trial by measuring juvenile mosquito mortality and adult mosquito emergence in each SBS-month. Using data from 1,075 dwelling-months, 2,988 SBS-months, and 29,922 individual mosquitoes, we show that mosquito-disseminated PPF yielded high coverage of dwellings (up to 100%) and SBSs (up to 94.3%). Juvenile mosquito mortality in SBSs (about 4% at baseline) increased by over one order of magnitude during PPF dissemination (about 75%). This led to a >10-fold decrease of adult mosquito emergence from SBSs, from approximately 1,000–3,000 adults/month before to about 100 adults/month during PPF dissemination. Conclusions/Significance By expanding breeding-site coverage and boosting juvenile mosquito mortality, a strategy based on mosquito-disseminated PPF has potential to substantially enhance mosquito control. Sharp declines in adult mosquito emergence can lower vector/host ratios, reducing the risk of disease outbreaks. This approach is a very

Molecular mechanisms mediating immune priming in Anopheles gambiae mosquitos

USDA-ARS?s Scientific Manuscript database

The Anopheles gambiae immune priming response is triggered when Plasmodium ookinetes invade the mosquito midgut and the microbiota comes in direct contact with injured cells. This is a long-lasting response that confers the challenged mosquito enhanced ability to control subsequent Plasmodium infect...

Identification of mosquito repellent odours from Ocimum forskolei.

PubMed

Dekker, Teun; Ignell, Rickard; Ghebru, Maedot; Glinwood, Robert; Hopkins, Richard

2011-09-22

Native mosquito repellent plants have a good potential for integrated mosquito control in local settings. Ocimum forskolei, Lamiaceae, is used in Eritrea as a spatial mosquito repellent inside houses, either through crushing fresh plants or burning dry plants. We verified whether active repellent compounds could be identified using gas-chromatography coupled electroantennogram recordings (GC-EAD) with headspace extracts of crushed plants. EAD active compounds included (R)-(-)-linalool, (S)-(+)-1-octen-3-ol, trans-caryophyllene, naphthalene, methyl salicylate, (R)-(-)-α-copaene, methyl cinnamate and (E)-ocimene. Of these compounds (R)-(-)-linalool, methyl cinnamate and methyl salicylate reduced landing of female Aedes aegypti on human skin-odor baited tubes. The latter two are novel mosquito repellent compounds. The identification of mosquito repellent compounds contributes to deciphering the mechanisms underlying repulsion, supporting the rational design of novel repellents. The three mosquito repellent compounds identified in this study are structurally dissimilar, which may indicate involvement of different sensory neurons in repulsion. Repulsion may well be enhanced through combining different repellent plants (or their synthetic mimics), and can be a locally sustainable part in mosquito control efforts.

Mosquito Control

MedlinePlus

... Labs and Research Centers Contact Us Share Mosquito Control About Mosquitoes General Information Life Cycle Information from ... Repellent that is Right for You DEET Mosquito Control Methods Success in mosquito control: an integrated approach ...

Identification of mosquito repellent odours from Ocimum forskolei

PubMed Central

2011-01-01

Background Native mosquito repellent plants have a good potential for integrated mosquito control in local settings. Ocimum forskolei, Lamiaceae, is used in Eritrea as a spatial mosquito repellent inside houses, either through crushing fresh plants or burning dry plants. We verified whether active repellent compounds could be identified using gas-chromatography coupled electroantennogram recordings (GC-EAD) with headspace extracts of crushed plants. Results EAD active compounds included (R)-(-)-linalool, (S)-(+)-1-octen-3-ol, trans-caryophyllene, naphthalene, methyl salicylate, (R)-(-)-α-copaene, methyl cinnamate and (E)-ocimene. Of these compounds (R)-(-)-linalool, methyl cinnamate and methyl salicylate reduced landing of female Aedes aegypti on human skin-odor baited tubes. The latter two are novel mosquito repellent compounds. Conclusions The identification of mosquito repellent compounds contributes to deciphering the mechanisms underlying repulsion, supporting the rational design of novel repellents. The three mosquito repellent compounds identified in this study are structurally dissimilar, which may indicate involvement of different sensory neurons in repulsion. Repulsion may well be enhanced through combining different repellent plants (or their synthetic mimics), and can be a locally sustainable part in mosquito control efforts. PMID:21936953

Enhanced salt-induced antioxidative responses involve a contribution of polyamine biosynthesis in grapevine plants.

PubMed

Ikbal, Fatima Ezzohra; Hernández, José Antonio; Barba-Espín, Gregorio; Koussa, Tayeb; Aziz, Aziz; Faize, Mohamed; Diaz-Vivancos, Pedro

2014-06-15

The possible involvement of polyamines in the salt stress adaptation was investigated in grapevine (Vitis vinifera L.) plantlets focusing on photosynthesis and oxidative metabolism. Salt stress resulted in the deterioration of plant growth and photosynthesis, and treatment of plantlets with methylglyoxal-bis(guanylhydrazone) (MGBG), a S-adenosylmethionine decarboxylase (SAMDC) inhibitor, enhanced the salt stress effect. A decrease in PSII quantum yield (Fv/Fm), effective PSII quantum yield (Y(II)) and coefficient of photochemical quenching (qP) as well as increases in non-photochemical quenching (NPQ) and its coefficient (qN) was observed by these treatments. Salt and/or MGBG treatments also triggered an increase in lipid peroxidation and reactive oxygen species (ROS) accumulation as well as an increase of superoxide dismutase (SOD) and peroxidase (POX) activities, but not ascorbate peroxidase (APX) activity. Salt stress also resulted in an accumulation of oxidized ascorbate (DHA) and a decrease in reduced glutathione. MGBG alone or in combination with salt stress increased monodehydroascorbate reductase (MDHAR), SOD and POX activities and surprisingly no accumulation of DHA was noticed following treatment with MGBG. These salt-induced responses correlated with the maintaining of high level of free and conjugated spermidine and spermine, whereas a reduction of agmatine and putrescine levels was observed, which seemed to be amplified by the MGBG treatment. These results suggest that maintaining polyamine biosynthesis through the enhanced SAMDC activity in grapevine leaf tissues under salt stress conditions could contribute to the enhanced ROS scavenging activity and a protection of photosynthetic apparatus from oxidative damages. Copyright © 2014 Elsevier GmbH. All rights reserved.

Climatic effects on mosquito abundance in Mediterranean wetlands

PubMed Central

2014-01-01

Background The impact of climate change on vector-borne diseases is highly controversial. One of the principal points of debate is whether or not climate influences mosquito abundance, a key factor in disease transmission. Methods To test this hypothesis, we analysed ten years of data (2003–2012) from biweekly surveys to assess inter-annual and seasonal relationships between the abundance of seven mosquito species known to be pathogen vectors (West Nile virus, Usutu virus, dirofilariasis and Plasmodium sp.) and several climatic variables in two wetlands in SW Spain. Results Within-season abundance patterns were related to climatic variables (i.e. temperature, rainfall, tide heights, relative humidity and photoperiod) that varied according to the mosquito species in question. Rainfall during winter months was positively related to Culex pipiens and Ochlerotatus detritus annual abundances. Annual maximum temperatures were non-linearly related to annual Cx. pipiens abundance, while annual mean temperatures were positively related to annual Ochlerotatus caspius abundance. Finally, we modelled shifts in mosquito abundances using the A2 and B2 temperature and rainfall climate change scenarios for the period 2011–2100. While Oc. caspius, an important anthropophilic species, may increase in abundance, no changes are expected for Cx. pipiens or the salt-marsh mosquito Oc. detritus. Conclusions Our results highlight that the effects of climate are species-specific, place-specific and non-linear and that linear approaches will therefore overestimate the effect of climate change on mosquito abundances at high temperatures. Climate warming does not necessarily lead to an increase in mosquito abundance in natural Mediterranean wetlands and will affect, above all, species such as Oc. caspius whose numbers are not closely linked to rainfall and are influenced, rather, by local tidal patterns and temperatures. The final impact of changes in vector abundance on disease frequency

Evaluation of nontarget effects of methoprene applied to catch basins for mosquito control

USGS Publications Warehouse

Butler, Mari; Ginsberg, Howard S.; LeBrun, Roger A.; Gettman, Alan

2010-01-01

The mosquito larvicide methoprene is a juvenile growth hormone mimic that is widely used to control mosquito larvae in stormwater catch basins. This study addresses two concerns pertaining to methoprene's use for mosquito control. First, measurements of methoprene concentrations were made from water in catch basins that had been treated with methoprene and from an adjoining salt pond near where the treated catch basins emptied. The concentrations of methoprene in catch basins and at drainage outlets after application at the rates currently used for mosquito control in southern Rhode Island were 0.5 ppb and lower, orders of magnitude below what has been determined as detrimental to organisms other than mosquitoes. Second, the effects of methoprene on the communities that live in catch basins were evaluated both in simulated catch basins in the laboratory and in actual catch basins in the field. We found no evidence of declines in abundances of any taxa attributable to the application. Furthermore, we found no consistent changes in community-level parameters (e.g., taxonomic richness, and dominance-diversity relationships) related to methoprene application in either field or laboratory trials.

Sentinel site-enhanced near-real time surveillance documenting West Nile virus circulation in two Culex mosquito species indicating different transmission characteristics, Djibouti City, Djibouti.

PubMed

Faulde, Michael K; Spiesberger, Michael; Abbas, Babiker

2012-08-01

The Horn of Africa represents a region formerly known to be highly susceptible to mosquito-borne infectious diseases. In order to investigate whether autochthonous WNV transmission occurs in the Djibouti City area, in how far, and which of, the endemic Culex mosquito species are involved in WNV circulation activity,and whether sentinel site-enhanced near-real time surveillance (SSE-NRTS) may increase WNV detection sensitivity, mosquito vector monitoring was conducted from January 2010 to June 2012. Six monitoring locations, including two identified sentinel sites, considered most probable for potential anthroponotic and zoonotic virus circulation activity, have been continuously employed. Among the 20431 mosquitoes collected, 19069 (93.4%) were Cx. quinquefasciatus, and 1345 (6.6%) Cx. pipiens ssp. torridus. WNV lineage 2 circulation activity was detected between December 20th, 2010 and January 7th, 2011. Overall, 19 WNV RNA-positive mosquito pools were detected. Generally, urban environment-specific WNV-RNA circulation took place in Cx. pipiens ssp. torridus, whereas periurban and rural area-linked circulation was detected only in Cx. quinquefasciatus. Serological investigation data from 10 volunteers employed at the dislocated zoonotic WNV transmission sentinel site suggest that six persons (60%) had an acute, or recent, WNV infection. Results show that WNV should be considered endemic for Djibouti and sentinel site-enhanced near-real time surveillance is an elegant and highly effective epidemiological tool. In Djibouti, the endemicity level, public health impact and transmission modes of vector-borne diseases in concordance with locally optimized monitoring and control regimen deserve further investigation.

Tuneable enhancement of the salt and thermal stability of polymeric micelles by cyclized amphiphiles

PubMed Central

Honda, Satoshi; Yamamoto, Takuya; Tezuka, Yasuyuki

2013-01-01

Cyclic molecules provide better stability for their aggregates. Typically in nature, the unique cyclic cell membrane lipids allow thermophilic archaea to inhabit extreme conditions. By mimicking the biological design, the robustness of self-assembled synthetic nanostructures is expected to be improved. Here we report topology effects by cyclized polymeric amphiphiles against their linear counterparts, demonstrating a drastic enhancement in the thermal, as well as salt stability of self-assembled micelles. Furthermore, through coassembly of the linear and cyclic amphiphiles, the stability was successfully tuned for a wide range of temperatures and salt concentrations. The enhanced thermal/salt stability was exploited in a halogen exchange reaction to stimulate the catalytic activity. The mechanism for the enhancement was also investigated. These topology effects by the cyclic amphiphiles offer unprecedented opportunities in polymer materials design unattainable by traditional means. PMID:23481382

Anopheles sinensis mosquito insecticide resistance: comparison of three mosquito sample collection and preparation methods and mosquito age in resistance measurements.

PubMed

Xu, Tielong; Zhong, Daibin; Tang, Linhua; Chang, Xuelian; Fu, Fengyang; Yan, Guiyun; Zheng, Bin

2014-01-28

Insecticide resistance monitoring in malaria mosquitoes is essential for guiding the rational use of insecticides in vector control programs. Resistance bioassay is the first step for insecticide monitoring and it lays an important foundation for molecular examination of resistance mechanisms. In the literature, various mosquito sample collection and preparation methods have been used, but how mosquito sample collection and preparation methods affect insecticide susceptibility bioassay results is largely unknown. The objectives of this study were to determine whether mosquito sample collection and preparation methods affected bioassay results, which may cause incorrect classification of mosquito resistance status. The study was conducted in Anopheles sinensis mosquitoes in two study sites in central China. Three mosquito sample collection and preparation methods were compared for insecticide susceptibility, kdr frequencies and metabolic enzyme activities: 1) adult mosquitoes collected from the field; 2) F1 adults from field collected, blood-fed mosquitoes; and 3) adult mosquitoes reared from field collected larvae. Mosquito sample collection and preparation methods significantly affected mortality rates in the standard WHO tube resistance bioassay. Mortality rate of field-collected female adults was 10-15% higher than in mosquitoes reared from field-collected larvae and F1 adults from field collected blood-fed females. This pattern was consistent in mosquitoes from the two study sites. High kdr mutation frequency (85-95%) with L1014F allele as the predominant mutation was found in our study populations. Field-collected female adults consistently exhibited the highest monooxygenase and GST activities. The higher mortality rate observed in the field-collected female mosquitoes may have been caused by a mixture of mosquitoes of different ages, as older mosquitoes were more susceptible to deltamethrin than younger mosquitoes. Female adults reared from field

Enjoyment of Spicy Flavor Enhances Central Salty-Taste Perception and Reduces Salt Intake and Blood Pressure.

PubMed

Li, Qiang; Cui, Yuanting; Jin, Rongbing; Lang, Hongmei; Yu, Hao; Sun, Fang; He, Chengkang; Ma, Tianyi; Li, Yingsha; Zhou, Xunmei; Liu, Daoyan; Jia, Hongbo; Chen, Xiaowei; Zhu, Zhiming

2017-12-01

High salt intake is a major risk factor for hypertension and is associated with cardiovascular events. Most countries exhibit a traditionally high salt intake; thus, identification of an optimal strategy for salt reduction at the population level may have a major impact on public health. In this multicenter, random-order, double-blind observational and interventional study, subjects with a high spice preference had a lower salt intake and blood pressure than subjects who disliked spicy food. The enjoyment of spicy flavor enhanced salt sensitivity and reduced salt preference. Salt intake and salt preference were related to the regional metabolic activity in the insula and orbitofrontal cortex (OFC) of participants. Administration of capsaicin-the major spicy component of chili pepper-enhanced the insula and OFC metabolic activity in response to high-salt stimuli, which reversed the salt intensity-dependent differences in the metabolism of the insula and OFC. In animal study, OFC activity was closely associated with salt preference, and salty-taste information processed in the OFC was affected in the presence of capsaicin. Thus, interventions related to this region may alter the salt preference in mice through fiber fluorometry and optogenetic techniques. In conclusion, enjoyment of spicy foods may significantly reduce individual salt preference, daily salt intake, and blood pressure by modifying the neural processing of salty taste in the brain. Application of spicy flavor may be a promising behavioral intervention for reducing high salt intake and blood pressure. © 2017 American Heart Association, Inc.

Transparent hydrogel with enhanced water retention capacity by introducing highly hydratable salt

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

Bai, Yuanyuan; Xiang, Feng; Wang, Hong, E-mail: hwang@mail.xjtu.edu.cn, E-mail: suo@seas.harvard.edu

2014-10-13

Polyacrylamide hydrogels containing salt as electrolyte have been used as highly stretchable transparent electrodes in flexible electronics, but those hydrogels are easy to dry out due to water evaporation. Targeted, we try to enhance water retention capacity of polyacrylamide hydrogel by introducing highly hydratable salts into the hydrogel. These hydrogels show enhanced water retention capacity in different level. Specially, polyacrylamide hydrogel containing high content of lithium chloride can retain over 70% of its initial water even in environment with relative humidity of only 10% RH. The excellent water retention capacities of these hydrogels will make more applications of hydrogels becomemore » possible.« less

Biological Control Strategies for Mosquito Vectors of Arboviruses.

PubMed

Huang, Yan-Jang S; Higgs, Stephen; Vanlandingham, Dana L

2017-02-10

Historically, biological control utilizes predatory species and pathogenic microorganisms to reduce the population of mosquitoes as disease vectors. This is particularly important for the control of mosquito-borne arboviruses, which normally do not have specific antiviral therapies available. Although development of resistance is likely, the advantages of biological control are that the resources used are typically biodegradable and ecologically friendly. Over the past decade, the advancement of molecular biology has enabled optimization by the manipulation of genetic materials associated with biological control agents. Two significant advancements are the discovery of cytoplasmic incompatibility induced by Wolbachia bacteria, which has enhanced replacement programs, and the introduction of dominant lethal genes into local mosquito populations through the release of genetically modified mosquitoes. As various arboviruses continue to be significant public health threats, biological control strategies have evolved to be more diverse and become critical tools to reduce the disease burden of arboviruses.

Biological Control Strategies for Mosquito Vectors of Arboviruses

PubMed Central

Huang, Yan-Jang S.; Higgs, Stephen; Vanlandingham, Dana L.

2017-01-01

Historically, biological control utilizes predatory species and pathogenic microorganisms to reduce the population of mosquitoes as disease vectors. This is particularly important for the control of mosquito-borne arboviruses, which normally do not have specific antiviral therapies available. Although development of resistance is likely, the advantages of biological control are that the resources used are typically biodegradable and ecologically friendly. Over the past decade, the advancement of molecular biology has enabled optimization by the manipulation of genetic materials associated with biological control agents. Two significant advancements are the discovery of cytoplasmic incompatibility induced by Wolbachia bacteria, which has enhanced replacement programs, and the introduction of dominant lethal genes into local mosquito populations through the release of genetically modified mosquitoes. As various arboviruses continue to be significant public health threats, biological control strategies have evolved to be more diverse and become critical tools to reduce the disease burden of arboviruses. PMID:28208639

Fate of methoprene in temperate salt marsh ditches following aerial applications.

PubMed

Tonjes, David J; McElroy, Anne E; Barnes-Pohjonen, Robin K; Ninivaggi, Dominick V; Dawydiak, Walter; Greene, Gregory T; Brownawell, Bruce J

2018-06-12

Aerial applications of liquid methoprene are used in salt marshes to control mosquitoes by preventing adult emergence. Despite concern about toxicity to non-target organisms, little is known about environmental concentrations after applications, nor methoprene's persistence in salt marsh environments. Aqueous and sediment samples were collected from two marshes receiving weekly applications. Aqueous samples were collected as early as 30 min after applications and as long as nine days afterwards; sediment samples were taken within hours of application and as long as 19 days post-application. Use of time-of-flight liquid chromatography - mass spectral analysis allowed for ultra-low detection limits (0.5 ng/L) in water samples. The data show loss of nearly all methoprene from 1 m deep marsh ditches within 1 day and presence but not accumulation of methoprene in marsh sediments despite repeated applications. Methoprene concentrations observed in salt-marsh mosquito ditches were below those found to be of toxicological significance in other studies. Copyright © 2018. Published by Elsevier B.V.

Hyperpolarization of {sup 133}Cs nuclei enhanced by ion movement in a cesium salt

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

Ishikawa, Kiyoshi

2011-12-15

Hyperpolarization of {sup 133}Cs nuclei in CsCl salt is achieved through spin transfer from an optically pumped Cs vapor, with maximum polarizations of 0.1% demonstrated. Motional narrowing of the enhanced NMR line indicates that ion movement facilitates this process by transporting spin-polarized ions from the interface into the salt. The resulting NMR enhancement allows measurement of the polarization and its dynamics in real time. Based upon the NMR frequency and the longitudinal spin relaxation time, we find no evidence that the salt is contaminated by Cs metal or paramagnetic impurities. The Cs nuclear polarization reported here could be improved severalmore » orders of magnitude by intense laser heating of the entire sample.« less

Enhancing consumer liking of low salt tomato soup over repeated exposure by herb and spice seasonings.

PubMed

Ghawi, Sameer Khalil; Rowland, Ian; Methven, Lisa

2014-10-01

There is strong evidence for the link between high dietary sodium and increased risk of cardiovascular disease which drives the need to reduce salt content in foods. In this study, herb and spice blends were used to enhance consumer acceptability of a low salt tomato soup (0.26% w/w). Subjects (n = 148) scored their liking of tomato soup samples over 5 consecutive days. The first and last days were pre-and post-exposure visits where all participants rated three tomato soup samples; standard, low salt and low salt with added herbs and spices. The middle 3 days were the repeated exposure phase where participants were divided into three balanced groups; consuming the standard soup, the low salt soup, or the low salt soup with added herbs and spices. Reducing salt in the tomato soup led to a significant decline in consumer acceptability, and incorporating herbs and spices did not lead to an immediate enhancement in liking. However, inclusion of herbs and spices enhanced the perception of the salty taste of the low salt soup to the same level as the standard. Repeated exposure to the herbs and spice-modified soup led to a significant increase in the overall liking and liking of flavour, texture and aftertaste of the soup, whereas no changes in liking were observed for the standard and low salt tomato soups over repeated exposure. Moreover, a positive trend in increasing the post-exposure liking of the herbs and spices soup was observed. The findings suggest that the use of herbs and spices is a useful approach to reduce salt content in foods; however, herbs and spices should be chosen carefully to complement the food as large contrasts in flavour can polarise consumer liking. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

A Neuron-Specific Antiviral Mechanism Prevents Lethal Flaviviral Infection of Mosquitoes

PubMed Central

Xiao, Xiaoping; Zhang, Rudian; Pang, Xiaojing; Liang, Guodong; Wang, Penghua; Cheng, Gong

2015-01-01

Mosquitoes are natural vectors for many etiologic agents of human viral diseases. Mosquito-borne flaviviruses can persistently infect the mosquito central nervous system without causing dramatic pathology or influencing the mosquito behavior and lifespan. The mechanism by which the mosquito nervous system resists flaviviral infection is still largely unknown. Here we report that an Aedes aegypti homologue of the neural factor Hikaru genki (AaHig) efficiently restricts flavivirus infection of the central nervous system. AaHig was predominantly expressed in the mosquito nervous system and localized to the plasma membrane of neural cells. Functional blockade of AaHig enhanced Dengue virus (DENV) and Japanese encephalitis virus (JEV), but not Sindbis virus (SINV), replication in mosquito heads and consequently caused neural apoptosis and a dramatic reduction in the mosquito lifespan. Consistently, delivery of recombinant AaHig to mosquitoes reduced viral infection. Furthermore, the membrane-localized AaHig directly interfaced with a highly conserved motif in the surface envelope proteins of DENV and JEV, and consequently interrupted endocytic viral entry into mosquito cells. Loss of either plasma membrane targeting or virion-binding ability rendered AaHig nonfunctional. Interestingly, Culex pipien pallens Hig also demonstrated a prominent anti-flavivirus activity, suggesting a functionally conserved function for Hig. Our results demonstrate that an evolutionarily conserved antiviral mechanism prevents lethal flaviviral infection of the central nervous system in mosquitoes, and thus may facilitate flaviviral transmission in nature. PMID:25915054

Association between salt substitutes/enhancers and changes in sodium levels in fast-food restaurants: a cross-sectional analysis.

PubMed

Scourboutakos, Mary J; Murphy, Sarah A; L'Abbé, Mary R

2018-03-07

Restaurant foods have high sodium levels, and efforts have been made to promote reductions. The objective of this study was to understand if salt substitutes and enhancers are associated with changes in sodium levels in fast-food restaurants. A longitudinal database (MENU-FLIP) containing nutrition information for Canadian chain restaurants with 20 or more locations nationally was created in 2010 and updated in 2013 and 2016. In 2016, when available, ingredient lists were collected from restaurant websites and searched for the presence of salt substitutes/enhancers. Changes in sodium levels (per serving) and the prevalence of salt substitutes/enhancers in 222 foods from 12 of the leading fast-food restaurant chains were compared across 3 time points. Sixty-nine percent of foods contained a salt substitute/enhancer. Substitutes/enhancers were found in every restaurant chain ( n = 12) for which ingredient data were available. The most common substitutes/enhancers were yeast extracts (in 30% of foods), calcium chloride (28%), monosodium glutamate (14%) and potassium chloride (12%). Sodium levels in foods that contained substitutes/enhancers decreased significantly more (190 ± 42 mg/serving) over the study period than those in foods that did not contain a substitute/enhancer (40 ± 17 mg/serving, p < 0.001). Salt substitutes and enhancers are prevalent in restaurant foods and are one means by which restaurants may be lowering sodium levels in their foods. At this time, the potential consequences of these findings, if any, are uncertain. Copyright 2018, Joule Inc. or its licensors.

Substitution of wild-type yellow fever Asibi sequences for 17D vaccine sequences in ChimeriVax-dengue 4 does not enhance infection of Aedes aegypti mosquitoes.

PubMed

McGee, Charles E; Tsetsarkin, Konstantin; Vanlandingham, Dana L; McElroy, Kate L; Lang, Jean; Guy, Bruno; Decelle, Thierry; Higgs, Stephen

2008-03-01

To address concerns that a flavivirus vaccine/wild-type recombinant virus might have a high mosquito infectivity phenotype, the yellow fever virus (YFV) 17D backbone of the ChimeriVax-dengue 4 virus was replaced with the corresponding gene sequences of the virulent YFV Asibi strain. Field-collected and laboratory-colonized Aedes aegypti mosquitoes were fed on blood containing each of the viruses under investigation and held for 14 days after infection. Infection and dissemination rates were based on antigen detection in titrated body or head triturates. Our data indicate that, even in the highly unlikely event of recombination or substantial backbone reversion, virulent sequences do not enhance the transmissibility of ChimeriVax viruses. In light of the low-level viremias that have been observed after vaccination in human volunteers coupled with low mosquito infectivity, it is predicted that the risk of mosquito infection and transmission of ChimeriVax vaccine recombinant/revertant viruses in nature is minimal.

Substitution of Wild-Type Yellow Fever Asibi Sequences for 17D Vaccine Sequences in ChimeriVax–Dengue 4 Does Not Enhance Infection of Aedes aegypti Mosquitoes

PubMed Central

McGee, Charles E.; Tsetsarkin, Konstantin; Vanlandingham, Dana L.; McElroy, Kate L.; Lang, Jean; Guy, Bruno; Decelle, Thierry; Higgs, Stephen

2008-01-01

To address concerns that a flavivirus vaccine/wild-type recombinant virus might have a high mosquito infectivity phenotype, the yellow fever virus (YFV) 17D backbone of the ChimeriVax– dengue 4 virus was replaced with the corresponding gene sequences of the virulent YFV Asibi strain. Field-collected and laboratory-colonized Aedes aegypti mosquitoes were fed on blood containing each of the viruses under investigation and held for 14 days after infection. Infection and dissemination rates were based on antigen detection in titrated body or head triturates. Our data indicate that, even in the highly unlikely event of recombination or substantial backbone reversion, virulent sequences do not enhance the transmissibility of ChimeriVax viruses. In light of the low-level viremias that have been observed after vaccination in human volunteers coupled with low mosquito infectivity, it is predicted that the risk of mosquito infection and transmission of ChimeriVax vaccine recombinant/revertant viruses in nature is minimal. PMID:18266608

Molecular Responses to the Zika Virus in Mosquitoes.

PubMed

Alfonso-Parra, Catalina; Avila, Frank W

2018-05-03

The Zika virus (ZIKV), originally discovered in 1947, did not become a major concern until the virus swept across the Pacific and into the Americas in the last decade, bringing with it news of neurological complications and birth defects in ZIKV affected areas. This prompted researchers to dissect the molecular interactions between ZIKV and the mosquito vector in an attempt to better understand not only the changes that occur upon infection, but to also identify molecules that may potentially enhance or suppress a mosquito’s ability to become infected and/or transmit the virus. Here, we review what is currently known regarding ZIKV-mosquito molecular interactions, focusing on ZIKV infection of Aedes aegypti and Aedes albopictus , the primary species implicated in transmitting ZIKV during the recent outbreaks.

Mosquito Life Cycle

EPA Pesticide Factsheets

Knowing the stages of the mosquito's life will help you prevent mosquitoes around your home and help you choose the right pesticides for your needs, if you decide to use them. All mosquito species go through four distinct stages during their live cycle.

Novel flaviviruses from mosquitoes: Mosquito-specific evolutionary lineages within the phylogenetic group of mosquito-borne flaviviruses

PubMed Central

Huhtamo, Eili; Cook, Shelley; Moureau, Gregory; Uzcátegui, Nathalie Y.; Sironen, Tarja; Kuivanen, Suvi; Putkuri, Niina; Kurkela, Satu; Harbach, Ralph E.; Firth, Andrew E.; Vapalahti, Olli; Gould, Ernest A.; de Lamballerie, Xavier

2014-01-01

Novel flaviviruses that are genetically related to pathogenic mosquito-borne flaviviruses (MBFV) have been isolated from mosquitoes in various geographical locations, including Finland. We isolated and characterized another novel virus of this group from Finnish mosquitoes collected in 2007, designated as Ilomantsi virus (ILOV). Unlike the MBFV that infect both vertebrates and mosquitoes, the MBFV-related viruses appear to be specific to mosquitoes similar to the insect-specific flaviviruses (ISFs). In this overview of MBFV-related viruses we conclude that they differ from the ISFs genetically and antigenically. Phylogenetic analyses separated the MBFV-related viruses isolated in Africa, the Middle East and South America from those isolated in Europe and Asia. Serological cross-reactions of MBFV-related viruses with other flaviviruses and their potential for vector-borne transmission require further characterization. The divergent MBFV-related viruses are probably significantly under sampled to date and provide new information on the variety, properties and evolution of vector-borne flaviviruses. PMID:25108382

Research Contributing to Improvements in Controlling Florida's Mosquitoes and Mosquito-borne Diseases.

PubMed

Tabachnick, Walter J

2016-09-28

Research on mosquitoes and mosquito-borne diseases has contributed to improvements in providing effective, efficient, and environmentally proper mosquito control. Florida has benefitted from several research accomplishments that have increased the state's mosquito control capabilities. Research with Florida's mosquitoes has resulted in the development of ecologically sound management of mosquito impoundments on Florida's east coast. This strategy, called Rotational Impoundment Management (RIM), has improved the ability to target the delivery of pesticides and has helped to reduce non-target effects and environmental damage. Research has led to the development of an arbovirus surveillance system which includes sentinel chicken surveillance, real time use of environmental contributing factors like meteorology and hydrology to target mosquito control, as well as public health efforts to mitigate disease outbreaks to areas with risk of disease. These research driven improvements have provided substantial benefits to all of Florida. More research is needed to meet the future challenges to reduce emerging pathogens like Zika virus and the consequences of environmental changes like global climate change that are likely to influence the effects of mosquito-borne pathogens on human health and well-being.

Mosquito Biology and Mosquito-Borne Disease Awareness Among Island Communities In Malaysia.

PubMed

Shafie, Aziz; Roslan, Muhammad Aidil; Ngui, Romano; Lim, Yvonne Ai Lian; Sulaiman, Wan Yusoff Wan

2016-12-01

Mosquito-borne diseases have been increasing at an alarming rate over the past decades. In Malaysia, one finds several important mosquito-borne diseases such as Japanese encephalitis, dengue, malaria, and chikungunya. Mosquito surveillance and control programs are the most effective way of detecting and controlling mosquito-borne diseases, but these programs are less effective without an aware and well-informed general public. In 2014 we used a questionnaire to evaluate the extent of awareness of basic mosquito biology and mosquito-borne diseases in 6 villages, Kampung Masjid, Kampung Teluk Gedung, Kampung Teluk Dalam, Kampung Ujung Kelawai, Kampung Sungai Pinang Besar, and Kampung Sungai Pinang Kechil on Pangkor Island, Malaysia. A total of 1,012 individuals responded to the questionnaire, consisting of 790 Malay (78.1%), 164 Chinese (16.2%), and 58 Indian (5.7%). More than 60% (Malay = 73.7%, Chinese = 64.0%, Indian = 79.3%) of the respondents were familiar with basic mosquito biology and practiced personal protection against mosquito bites, and the association was statistically significant (P = 0.02). However, the majority of the respondents had limited knowledge on mosquito-borne diseases, and this varied significantly among the 3 ethnic groups (P = 0.0001). Our recommendations are to improve and intensify public health education outreach programs to the island residents and to encourage community participation in vector control programs.

Nest Mosquito Trap quantifies contact rates between nesting birds and mosquitoes.

PubMed

Caillouët, Kevin A; Riggan, Anna E; Rider, Mark; Bulluck, Lesley P

2012-06-01

Accurate estimates of host-vector contact rates are required for precise determination of arbovirus transmission intensity. We designed and tested a novel mosquito collection device, the Nest Mosquito Trap (NMT), to collect mosquitoes as they attempt to feed on unrestrained nesting birds in artificial nest boxes. In the laboratory, the NMT collected nearly one-third of the mosquitoes introduced to the nest boxes. We then used these laboratory data to estimate our capture efficiency of field-collected bird-seeking mosquitoes collected over 66 trap nights. We estimated that 7.5 mosquitoes per trap night attempted to feed on nesting birds in artificial nest boxes. Presence of the NMT did not have a negative effect on avian nest success when compared to occupied nest boxes that were not sampled with the trap. Future studies using the NMT may elucidate the role of nestlings in arbovirus transmission and further refine estimates of nesting bird and vector contact rates. © 2012 The Society for Vector Ecology.

Nest Mosquito Trap quantifies contact rates between nesting birds and mosquitoes

PubMed Central

Caillouët, Kevin A.; Riggan, Anna E.; Rider, Mark; Bulluck, Lesley P.

2012-01-01

Accurate estimates of host-vector contact rates are required for precise determination of arbovirus transmission intensity. We designed and tested a novel mosquito collection device, the Nest Mosquito Trap (NMT), to collect mosquitoes as they attempt to feed on unrestrained nesting birds in artificial nest boxes. In the laboratory, the NMT collected nearly one-third of the mosquitoes introduced to the nest boxes. We then used these laboratory data to estimate our capture efficiency of field-collected bird-seeking mosquitoes collected over 66 trap nights. We estimated that 7.5 mosquitoes per trap night attempted to feed on nesting birds in artificial nest boxes. Presence of the NMT did not have a negative effect on avian nest success when compared to occupied nest boxes that were not sampled with the trap. Future studies using the NMT may elucidate the role of nestlings in arbovirus transmission and further refine estimates of nesting bird and vector contact rates. PMID:22548555

Mosquito Bites

MedlinePlus

... humans. Other mosquito-borne infections include yellow fever, malaria and some types of brain infection (encephalitis). Symptoms ... carry certain diseases, such as West Nile virus, malaria, yellow fever and dengue fever. The mosquito obtains ...

Gustatory receptor neuron responds to DEET and other insect repellents in the yellow-fever mosquito, Aedes aegypti

NASA Astrophysics Data System (ADS)

Sanford, Jillian L.; Shields, Vonnie D. C.; Dickens, Joseph C.

2013-03-01

Three gustatory receptor neurons were characterized for contact chemoreceptive sensilla on the labella of female yellow-fever mosquitoes, Aedes aegypti. The neuron with the smallest amplitude spike responded to the feeding deterrent, quinine, as well as N, N-diethyl-3-methylbenzamide and other insect repellents. Two other neurons with differing spikes responded to salt (NaCl) and sucrose. This is the first report of a gustatory receptor neuron specific for insect repellents in mosquitoes and may provide a tool for screening chemicals to discover novel or improved feeding deterrents and repellents for use in the management of arthropod disease vectors.

Novel flaviviruses from mosquitoes: mosquito-specific evolutionary lineages within the phylogenetic group of mosquito-borne flaviviruses.

PubMed

Huhtamo, Eili; Cook, Shelley; Moureau, Gregory; Uzcátegui, Nathalie Y; Sironen, Tarja; Kuivanen, Suvi; Putkuri, Niina; Kurkela, Satu; Harbach, Ralph E; Firth, Andrew E; Vapalahti, Olli; Gould, Ernest A; de Lamballerie, Xavier

2014-09-01

Novel flaviviruses that are genetically related to pathogenic mosquito-borne flaviviruses (MBFV) have been isolated from mosquitoes in various geographical locations, including Finland. We isolated and characterized another novel virus of this group from Finnish mosquitoes collected in 2007, designated as Ilomantsi virus (ILOV). Unlike the MBFV that infect both vertebrates and mosquitoes, the MBFV-related viruses appear to be specific to mosquitoes similar to the insect-specific flaviviruses (ISFs). In this overview of MBFV-related viruses we conclude that they differ from the ISFs genetically and antigenically. Phylogenetic analyses separated the MBFV-related viruses isolated in Africa, the Middle East and South America from those isolated in Europe and Asia. Serological cross-reactions of MBFV-related viruses with other flaviviruses and their potential for vector-borne transmission require further characterization. The divergent MBFV-related viruses are probably significantly under sampled to date and provide new information on the variety, properties and evolution of vector-borne flaviviruses. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

Countering a bioterrorist introduction of pathogen-infected mosquitoes through mosquito control.

PubMed

Tabachnick, Walter J; Harvey, William R; Becnel, James J; Clark, Gary G; Connelly, C Roxanne; Day, Jonathan F; Linser, Paul J; Linthicum, Kenneth J

2011-06-01

The release of infected mosquitoes or other arthropods by bioterrorists, i.e., arboterrorism, to cause disease and terror is a threat to the USA. A workshop to assess mosquito control response capabilities to mount rapid and effective responses to eliminate an arboterrorism attack provided recommendations to improve capabilities in the USA. It is essential that mosquito control professionals receive training in possible responses, and it is recommended that a Council for Emergency Mosquito Control be established in each state to coordinate training, state resources, and actions for use throughout the state.

3D mosquito screens to create window double screen traps for mosquito control.

PubMed

Khattab, Ayman; Jylhä, Kaisa; Hakala, Tomi; Aalto, Mikko; Malima, Robert; Kisinza, William; Honkala, Markku; Nousiainen, Pertti; Meri, Seppo

2017-08-29

Mosquitoes are vectors for many diseases such as malaria. Insecticide-treated bed nets and indoor residual spraying of insecticides are the principal malaria vector control tools used to prevent malaria in the tropics. Other interventions aim at reducing man-vector contact. For example, house screening provides additive or synergistic effects to other implemented measures. We used commercial screen materials made of polyester, polyethylene or polypropylene to design novel mosquito screens that provide remarkable additional benefits to those commonly used in house screening. The novel design is based on a double screen setup made of a screen with 3D geometric structures parallel to a commercial mosquito screen creating a trap between the two screens. Owing to the design of the 3D screen, mosquitoes can penetrate the 3D screen from one side but cannot return through the other side, making it a unidirectional mosquito screen. Therefore, the mosquitoes are trapped inside the double screen system. The permissiveness of both sides of the 3D screens for mosquitoes to pass through was tested in a wind tunnel using the insectary strain of Anopheles stephensi. Among twenty-five tested 3D screen designs, three designs from the cone, prism, or cylinder design groups were the most efficient in acting as unidirectional mosquito screens. The three cone-, prism-, and cylinder-based screens allowed, on average, 92, 75 and 64% of Anopheles stephensi mosquitoes released into the wind tunnel to penetrate the permissive side and 0, 0 and 6% of mosquitoes to escape through the non-permissive side, respectively. A cone-based 3D screen fulfilled the study objective. It allowed capturing 92% of mosquitoes within the double screen setup inside the wind tunnel and blocked 100% from escaping. Thus, the cone-based screen effectively acted as a unidirectional mosquito screen. This 3D screen-based trap design could therefore be used in house screening as a means of avoiding infective bites and

Field evaluation of the Off! Clip-on Mosquito Repellent (metofluthrin) against Aedes albopictus and Aedes taeniorhynchus (Diptera: Culicidae) in northeastern Florida.

PubMed

Xue, Rui-De; Qualls, Whitney A; Smith, Michael L; Gaines, Marcia K; Weaver, James H; Debboun, Mustapha

2012-05-01

Repellent efficacy of the Off! Clip-on Mosquito Repellent device (S. C. Johnson and Son, Inc., Racine, WI) containing Metofluthrin was evaluated on six human volunteers against the container-breeding mosquito Aedes albopictus (Skuse) and the salt marsh mosquito Aedes taeniorhynchus (Wiedemann) at two field locations in northeastern Florida. The device repelled mosquitoes by releasing a vaporized form of the pyrethroid insecticide metofluthrin ([AI] 31.2%) and provided 70% protection from Ae. albopictus bites for > 3 h. For the second field trial, a repellent device that was used in the first trial was tested after being open for >1 wk. This device provided 79% protection from Ae. taeniorhynchus bites for 3 h. Our field results showed that the repellent device was 70 and 79% effective at repelling Ae. albopictus and Ae. taeniorhynchus from human test subjects in both field locations in northeastern Florida.

Application of biogenic carbon dioxide produced by yeast with different carbon sources for attraction of mosquitoes towards adult mosquito traps.

PubMed

Sukumaran, D; Ponmariappan, S; Sharma, Atul K; Jha, Hemendra K; Wasu, Yogesh H; Sharma, Ajay K

2016-04-01

enhance their trapping efficiency of a mosquito surveillance programme.

Agricultural chemicals: life changer for mosquito vectors in agricultural landscapes?

PubMed

Kibuthu, Tabitha W; Njenga, Sammy M; Mbugua, Amos K; Muturi, Ephantus J

2016-09-13

Although many mosquito species develop within agricultural landscapes where they are potentially exposed to agricultural chemicals (fertilizers and pesticides), the effects of these chemicals on mosquito biology remain poorly understood. This study investigated the effects of sublethal concentrations of four agricultural chemicals on the life history traits of Anopheles arabiensis and Culex quinquefasciatus mosquitoes. Field and laboratory experiments were conducted to examine how sublethal concentrations of four agricultural chemicals: an insecticide (cypermethrin), a herbicide (glyphosate), and two nitrogenous fertilizers (ammonium sulfate and diammonium phosphate) alter oviposition site selection, emergence rates, development time, adult body size, and longevity of An. arabiensis and Cx. quinquefasciatus. Both mosquito species had preference to oviposit in fertilizer treatments relative to pesticide treatments. Emergence rates for An. arabiensis were significantly higher in the control and ammonium sulfate treatments compared to cypermethrin treatment, while emergence rates for Cx. quinquefasciatus were significantly higher in the diammonium phosphate treatment compared to glyphosate and cypermethrin treatments. For both mosquito species, individuals from the ammonium sulfate and diammonium phosphate treatments took significantly longer time to develop compared to those from cypermethrin and glyphosate treatments. Although not always significant, males and females of both mosquito species tended to be smaller in the ammonium sulfate and diammonium phosphate treatments compared to cypermethrin and glyphosate treatments. There was no significant effect of the agrochemical treatments on the longevity of either mosquito species. These results demonstrate that the widespread use of agricultural chemicals to enhance crop production can have unexpected effects on the spatial distribution and abundance of mosquito vectors of malaria and lymphatic filariasis.

Research Contributing to Improvements in Controlling Florida’s Mosquitoes and Mosquito-Borne Diseases

PubMed Central

Tabachnick, Walter J.

2016-01-01

Research on mosquitoes and mosquito-borne diseases has contributed to improvements in providing effective, efficient, and environmentally proper mosquito control. Florida has benefitted from several research accomplishments that have increased the state’s mosquito control capabilities. Research with Florida’s mosquitoes has resulted in the development of ecologically sound management of mosquito impoundments on Florida’s east coast. This strategy, called Rotational Impoundment Management (RIM), has improved the ability to target the delivery of pesticides and has helped to reduce non-target effects and environmental damage. Research has led to the development of an arbovirus surveillance system which includes sentinel chicken surveillance, real time use of environmental contributing factors like meteorology and hydrology to target mosquito control, as well as public health efforts to mitigate disease outbreaks to areas with risk of disease. These research driven improvements have provided substantial benefits to all of Florida. More research is needed to meet the future challenges to reduce emerging pathogens like Zika virus and the consequences of environmental changes like global climate change that are likely to influence the effects of mosquito-borne pathogens on human health and well-being. PMID:27690112

Overexpression of the alfalfa WRKY11 gene enhances salt tolerance in soybean

PubMed Central

Wang, Youjing; Jiang, Lin; Chen, Jiaqi; Tao, Lei; An, Yimin; Cai, Hongsheng

2018-01-01

The WRKY transcription factors play an important role in the regulation of transcriptional reprogramming associated with plant abiotic stress responses. In this study, the WRKY transcription factor MsWRKY11, containing the plant-specific WRKY zinc finger DNA–binding motif, was isolated from alfalfa. The MsWRKY11 gene was detected in all plant tissues (root, stem, leaf, flower, and fruit), with high expression in root and leaf tissues. MsWRKY11 was upregulated in response to a variety of abiotic stresses, including salinity, alkalinity, cold, abscisic acid, and drought. Overexpression of MsWRKY11 in soybean enhanced the salt tolerance at the seedling stage. Transgenic soybean had a better salt-tolerant phenotype, and the hypocotyls were significantly longer than those of wild-type seeds after salt treatment. Furthermore, MsWRKY11 overexpression increased the contents of chlorophyll, proline, soluble sugar, superoxide dismutase, and catalase, but reduced the relative electrical conductivity and the contents of malonaldehyde, H2O2, and O2-. Plant height, pods per plant, seeds per plant, and 100-seed weight of transgenic MsWRKY11 soybean were higher than those of wild-type soybean, especially OX2. Results of the salt experiment showed that MsWRKY11 is involved in salt stress responses, and its overexpression improves salt tolerance in soybean. PMID:29466387

Antarctic Moss Multiprotein Bridging Factor 1c Overexpression in Arabidopsis Resulted in Enhanced Tolerance to Salt Stress

PubMed Central

Alavilli, Hemasundar; Lee, Hyoungseok; Park, Mira; Lee, Byeong-ha

2017-01-01

Polytrichastrum alpinum is one of the moss species that survives extreme conditions in the Antarctic. In order to explore the functional benefits of moss genetic resources, P. alpinum multiprotein-bridging factor 1c gene (PaMBF1c) was isolated and characterized. The deduced amino acid sequence of PaMBF1c comprises of a multiprotein-bridging factor (MBF1) domain and a helix-turn-helix (HTH) domain. PaMBF1c expression was induced by different abiotic stresses in P. alpinum, implying its roles in stress responses. We overexpressed PaMBF1c in Arabidopsis and analyzed the resulting phenotypes in comparison with wild type and/or Arabidopsis MBF1c (AtMBF1c) overexpressors. Overexpression of PaMBF1c in Arabidopsis resulted in enhanced tolerance to salt and osmotic stress, as well as to cold and heat stress. More specifically, enhanced salt tolerance was observed in PaMBF1c overexpressors in comparison to wild type but not clearly observable in AtMBF1c overexpressing lines. Thus, these results implicate the evolution of PaMBF1c under salt-enriched Antarctic soil. RNA-Seq profiling of NaCl-treated plants revealed that 10 salt-stress inducible genes were already up-regulated in PaMBF1c overexpressing plants even before NaCl treatment. Gene ontology enrichment analysis with salt up-regulated genes in each line uncovered that the terms lipid metabolic process, ion transport, and cellular amino acid biosynthetic process were significantly enriched in PaMBF1c overexpressors. Additionally, gene enrichment analysis with salt down-regulated genes in each line revealed that the enriched categories in wild type were not significantly overrepresented in PaMBF1c overexpressing lines. The up-regulation of several genes only in PaMBF1c overexpressing lines suggest that enhanced salt tolerance in PaMBF1c-OE might involve reactive oxygen species detoxification, maintenance of ATP homeostasis, and facilitation of Ca2+ signaling. Interestingly, many salt down-regulated ribosome- and

The osmolyte xylitol reduces the salt concentration of airway surface liquid and may enhance bacterial killing

NASA Astrophysics Data System (ADS)

Zabner, Joseph; Seiler, Michael P.; Launspach, Janice L.; Karp, Philip H.; Kearney, William R.; Look, Dwight C.; Smith, Jeffrey J.; Welsh, Michael J.

2000-10-01

The thin layer of airway surface liquid (ASL) contains antimicrobial substances that kill the small numbers of bacteria that are constantly being deposited in the lungs. An increase in ASL salt concentration inhibits the activity of airway antimicrobial factors and may partially explain the pathogenesis of cystic fibrosis (CF). We tested the hypothesis that an osmolyte with a low transepithelial permeability may lower the ASL salt concentration, thereby enhancing innate immunity. We found that the five-carbon sugar xylitol has a low transepithelial permeability, is poorly metabolized by several bacteria, and can lower the ASL salt concentration in both CF and non-CF airway epithelia in vitro. Furthermore, in a double-blind, randomized, crossover study, xylitol sprayed for 4 days into each nostril of normal volunteers significantly decreased the number of nasal coagulase-negative Staphylococcus compared with saline control. Xylitol may be of value in decreasing ASL salt concentration and enhancing the innate antimicrobial defense at the airway surface.

Free boundary models for mosquito range movement driven by climate warming.

PubMed

Bao, Wendi; Du, Yihong; Lin, Zhigui; Zhu, Huaiping

2018-03-01

As vectors, mosquitoes transmit numerous mosquito-borne diseases. Among the many factors affecting the distribution and density of mosquitoes, climate change and warming have been increasingly recognized as major ones. In this paper, we make use of three diffusive logistic models with free boundary in one space dimension to explore the impact of climate warming on the movement of mosquito range. First, a general model incorporating temperature change with location and time is introduced. In order to gain insights of the model, a simplified version of the model with the change of temperature depending only on location is analyzed theoretically, for which the dynamical behavior is completely determined and presented. The general model can be modified into a more realistic one of seasonal succession type, to take into account of the seasonal changes of mosquito movements during each year, where the general model applies only for the time period of the warm seasons of the year, and during the cold season, the mosquito range is fixed and the population is assumed to be in a hibernating status. For both the general model and the seasonal succession model, our numerical simulations indicate that the long-time dynamical behavior is qualitatively similar to the simplified model, and the effect of climate warming on the movement of mosquitoes can be easily captured. Moreover, our analysis reveals that hibernating enhances the chances of survival and successful spreading of the mosquitoes, but it slows down the spreading speed.

Mosquito repellents: An insight into the chronological perspectives and novel discoveries.

PubMed

Islam, Johirul; Zaman, Kamaruz; Duarah, Sanjukta; Raju, Pakalapati Srinivas; Chattopadhyay, Pronobesh

2017-03-01

Mosquito being the major medically important arthropod vector; requires utmost attention to reduce the sufferings and economic consequences of those living in the endemic regions. This is only possible by minimising the human-mosquito contact by an absolute preventing measure. However, unfortunately, such absolute measures are yet to be developed despite enormous efforts and huge investments worldwide. In the absence of vaccines for number of mosquito-borne diseases, repellents could be an attractive option for both military personal and civilians to minimise the risk of contacting different mosquito-borne diseases. However, to achieve this golden goal, the detailed knowledge of a particular repellent is must, including its mode of repellency and other relevant informations. Here, in the present article, an effort has been made to convey the best and latest information on repellents in order to enhance the knowledge of scientific community. The review offers an overview on mosquito repellents, the novel discoveries, and areas in need of attention such as novel repellent formulations and their future prospective. Copyright © 2016 Elsevier B.V. All rights reserved.

Mosquito Bite Delivery of Dengue Virus Enhances Immunogenicity and Pathogenesis in Humanized Mice

PubMed Central

Cox, Jonathan; Mota, Javier; Sukupolvi-Petty, Soila; Diamond, Michael S.

2012-01-01

Dengue viruses (DENV) are transmitted to humans by the bite of Aedes aegypti or Aedes albopictus mosquitoes, with millions of infections annually in over 100 countries. The diseases they produce, which occur exclusively in humans, are dengue fever (DF) and dengue hemorrhagic fever (DHF). We previously developed a humanized mouse model of DF in which mice transplanted with human hematopoietic stem cells produced signs of DENV disease after injection with low-passage, wild-type isolates. Using these mice, but now allowing infected A. aegypti to transmit dengue virus during feeding, we observed signs of more severe disease (higher and more sustained viremia, erythema, and thrombocytopenia). Infected mice mounted innate (gamma interferon [IFN-γ] and soluble interleukin 2 receptor alpha [sIL-2Rα]) and adaptive (anti-DENV antibodies) immune responses that failed to clear viremia until day 56, while a mosquito bite alone induced strong immunomodulators (tumor necrosis factor alpha [TNF-α], IL-4, and IL-10) and thrombocytopenia. This is the first animal model that allows an evaluation of human immunity to DENV infection after mosquito inoculation. PMID:22573866

Mosquito (Diptera: Culicidae) Habitat Surveillance by Android Mobile Devices in Guangzhou, China.

PubMed

Wu, Tai-Ping; Tian, Jun-Hua; Xue, Rui-De; Fang, Yi-Liang; Zheng, Ai-Hua

2016-12-17

In 2014, Guangzhou City, South China, suffered from its worst outbreak of dengue fever in decades. Larval mosquito habitat surveillance was carried out by using android mobile devices in four study sites in May 2015. The habitats with larval mosquitoes were recorded as photo waypoints in OruxMaps or in videos. The total number of potential mosquito habitats was 342, of which 166 (49%) were found to have mosquito larvae or pupae. Small containers were the most abundant potential habitats, accounting for 26% of the total number. More mosquito larvae and pupae, were found in small containers than in other objects holding water, for example, potted or hydroponic plants ( p < 0.05). Mosquito larvae were collected from all plastic road barriers, used tires, and underground water. Aedes albopictus larvae were found from small and large containers, stumps, among others. The overall route index (RI) was 11.3, which was 14.2 times higher than the grade C criteria of the National Patriotic Health Campaign Committee (NPHCC), China. The higher RIs were found from the bird and flower markets, schools, and underground parking lots. The results indicated that Android mobile devices are a convenient and useful tool for surveillance of mosquito habitats, and the enhancement of source reduction may benefit the prevention and control of dengue vector mosquitoes.

Mosquito (Diptera: Culicidae) Habitat Surveillance by Android Mobile Devices in Guangzhou, China

PubMed Central

Wu, Tai-Ping; Tian, Jun-Hua; Xue, Rui-De; Fang, Yi-Liang; Zheng, Ai-Hua

2016-01-01

In 2014, Guangzhou City, South China, suffered from its worst outbreak of dengue fever in decades. Larval mosquito habitat surveillance was carried out by using android mobile devices in four study sites in May 2015. The habitats with larval mosquitoes were recorded as photo waypoints in OruxMaps or in videos. The total number of potential mosquito habitats was 342, of which 166 (49%) were found to have mosquito larvae or pupae. Small containers were the most abundant potential habitats, accounting for 26% of the total number. More mosquito larvae and pupae, were found in small containers than in other objects holding water, for example, potted or hydroponic plants (p < 0.05). Mosquito larvae were collected from all plastic road barriers, used tires, and underground water. Aedes albopictus larvae were found from small and large containers, stumps, among others. The overall route index (RI) was 11.3, which was 14.2 times higher than the grade C criteria of the National Patriotic Health Campaign Committee (NPHCC), China. The higher RIs were found from the bird and flower markets, schools, and underground parking lots. The results indicated that Android mobile devices are a convenient and useful tool for surveillance of mosquito habitats, and the enhancement of source reduction may benefit the prevention and control of dengue vector mosquitoes. PMID:27999305

Sediment redistributed by coastal marsh mosquito ditching in Cape May County, New Jersey, U.S.A.

USGS Publications Warehouse

Kirby, Ronald E.; Widjeskog, Lee E.

2013-01-01

Effects of mosquito ditching on salt marsh sediment budgets have not been quantified for lack of sufficient records, but such information is necessary to provide historical context for current management objectives. We were able to do so in Cape May County New Jersey where Mosquito Extermination Commission records reported 1,493,900 m3 of spoil redistributed through ditching from1902 to 1974. The amount of spoil redistributed rose to 2,240,850 m3–22,987,800 m3 overall when ditch cleaning efforts were included. On a 54 km2 study area, 161,560 m of ditches removed as much as 99,000 m3 of material. If all such sediment stayed in the system and was deposited in open water, it would have added 0.082 mm/yr to those areas. If the sediments had accumulated only in the larger water bodies, it would have been sufficient to add 0.16 mm/yr to those areas. Alternatively, if the material had been deposited only on the marsh surface, the material displaced by mosquito ditching was capable of adding only 0.036 mm/yr. These rates are inconsequential in a system infilling at a rate of 4.4–7.4 mm/yr. Materials released by mosquito ditching thus have added to the sediment budgets of this coastal system, but shoaling of bays and sounds in recent centuries is a consequence of increases in all sediment sources including many of anthropogenic origin. Nonetheless, other consequences of ditching to the marsh (e.g., increased drainage, transport of water, and erosion of ditch banks) are not negligible in consideration of all anthropogenic effects. These data can help parameterize models of salt marsh accretion in the face of climate change.

Late season commercial mosquito trap and host seeking activity evaluation against mosquitoes in a malarious area of the Republic of Korea

PubMed Central

Burkett, Douglas A.; Lee, Kwan-Woo; Kim, Heung-Chul; Lee, Hee-Il; Lee, Jong-Soo; Shin, E-Hyun; Wirtz, Robert A.; Cho, Hae-Wol; Claborn, David M.; Coleman, Russel E.; Kim, Wan Y; Klein, Terry A.

2002-01-01

Field trials evaluating selected commercially available mosquito traps variously baited with light, carbon dioxide, and/or octenol were conducted from 18-27 September 2000 in a malarious area near Paekyeon-ri (Tongil-Chon ) and Camp Greaves in Paju County, Kyonggi Province, Republic of Korea. The host-seeking activity for common mosquito species, including the primary vector of Japanese encephalitis, Culex tritaeniorhynchus Giles, was determined using hourly aspirator collections from a human and propane lantern-baited Shannon trap during hours when temperatures exceeded 15℃. The total number of mosquitoes and number of each species captured during the test was compared using a block design. Significant differences were observed for the total number of mosquitoes collected, such that, the Mosquito MagnetTM with octenol > Shannon trap > ABC light trap with light and dry ice > Miniature Black Light trap (manufactured by John W. Hock) ≥ New Jersey Trap > ABC light trap with light only. Significant differences in numbers collected among traps were noted for several species including: Aedes vexans (Meigen), Anopheles lesteri Baisas and Hu, An. sinensis Weidemann, An. sineroides Yamada, An. yatsushiroensis Miyazaki, Culex pipiens pallens Coquillett L., Cx. orientalis Edwards and Cx. tritaeniorhynchus. Host-seeking activity for most common species showed a similar bimodal pattern. Results from these field trap evaluations can significantly enhance current vector and disease surveillance efforts especially for the primary vector of Japanese encephalitis, Cx. tritaeniorhynchus. PMID:11949213

Arbovirus Prevalence in Mosquitoes, Kenya

PubMed Central

Sutherland, Laura J.; Muiruri, Samuel; Muchiri, Eric M.; Gray, Laurie R.; Zimmerman, Peter A.; Hise, Amy G.; King, Charles H.

2011-01-01

Few studies have investigated the many mosquito species that harbor arboviruses in Kenya. During the 2006–2007 Rift Valley fever outbreak in North Eastern Province, Kenya, exophilic mosquitoes were collected from homesteads within 2 affected areas: Gumarey (rural) and Sogan-Godud (urban). Mosquitoes (n = 920) were pooled by trap location and tested for Rift Valley fever virus and West Nile virus. The most common mosquitoes trapped belonged to the genus Culex (75%). Of 105 mosquito pools tested, 22% were positive for Rift Valley fever virus, 18% were positive for West Nile virus, and 3% were positive for both. Estimated mosquito minimum infection rates did not differ between locations. Our data demonstrate the local abundance of mosquitoes that could propagate arboviral infections in Kenya and the high prevalence of vector arbovirus positivity during a Rift Valley fever outbreak. PMID:21291594

Mosquito, adult (image)

MedlinePlus

This illustration shows an adult southern house mosquito. This mosquito feeds on blood and is the carrier of many diseases, such as encephalitis, West Nile, dengue fever, yellow fever, and others. ( ...

Overexpression of GmFDL19 enhances tolerance to drought and salt stresses in soybean

PubMed Central

Li, Xiaoming; Lu, Sijia; Zhao, Xiaohui; Liu, Baohui; Guo, Changhong; Kong, Fanjiang

2017-01-01

The basic leucine zipper (bZIP) family of transcription factors plays an important role in the growth and developmental process as well as responds to various abiotic stresses, such as drought and high salinity. Our previous work identified GmFDL19, a bZIP transcription factor, as a flowering promoter in soybean, and the overexpression of GmFDL19 caused early flowering in transgenic soybean plants. Here, we report that GmFDL19 also enhances tolerance to drought and salt stress in soybean. GmFDL19 was determined to be a group A member, and its transcription expression was highly induced by abscisic acid (ABA), polyethylene glycol (PEG 6000) and high salt stresses. Overexpression of GmFDL19 in soybean enhanced drought and salt tolerance at the seedling stage. The relative plant height (RPH) and relative shoot dry weight (RSDW) of transgenic plants were significantly higher than those of the WT after PEG and salt treatments. In addition, the germination rate and plant height of the transgenic soybean were also significantly higher than that of WT plants after various salt treatments. Furthermore, we also found that GmFDL19 could reduce the accumulation of Na+ ion content and up-regulate the expression of several ABA/stress-responsive genes in transgenic soybean. We also found that GmFDL19 overexpression increased the activities of several antioxidative enzyme and chlorophyll content but reduced malondialdehyde content. These results suggested that GmFDL19 is involved in soybean abiotic stress responses and has potential utilization to improve multiple stress tolerance in transgenic soybean. PMID:28640834

Proteomic study participating the enhancement of growth and salt tolerance of bottle gourd rootstock-grafted watermelon seedlings.

PubMed

Yang, Yanjuan; Wang, Liping; Tian, Jing; Li, Jing; Sun, Jin; He, Lizhong; Guo, Shirong; Tezuka, Takafumi

2012-09-01

An insertion grafting technique to do research on salt tolerance was applied using watermelon (Citrullus lanatus [Thunb.] Mansf. cv. Xiuli) as a scion and bottle gourd (Lagenaria siceraria Standl. cv. Chaofeng Kangshengwang) as a rootstock. Rootstock-grafting significantly relieved the inhibition of growth and photosynthesis induced by salt stress in watermelon plants. Proteomic analysis revealed 40 different expressed proteins in response to rootstock-grafting and/or salt stress. These proteins were involved in Calvin cycle, amino acids biosynthesis, carbohydrate and energy metabolism, ROS defense, hormonal biosynthesis and signal transduction. Most of these proteins were up-regulated by rootstock-grafting and/or susceptible to salt stress. The enhancement of the metabolic activities of Calvin cycle, biosynthesis of amino acids, carotenoids and peroxisomes, glycolytic pathway and tricarboxylic acid cycle will probably contribute to intensify the biomass and photosynthetic capacity in rootstock-grafted seedlings under condition without salt. The accumulation of key enzymes included in these biological processes described above seems to play an important role in the enhancement of salt tolerance of rootstock-grafted seedlings. Furthermore, leucine-rich repeat transmembrane protein kinase and phospholipase may be involved in transmitting the internal and external stimuli induced by grafting and/or salt stress. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

The potential for flower nectar to allow mosquito to mosquito transmission of Francisella tularensis.

PubMed

Kenney, Adam; Cusick, Austin; Payne, Jessica; Gaughenbaugh, Anna; Renshaw, Andrea; Wright, Jenna; Seeber, Roger; Barnes, Rebecca; Florjanczyk, Aleksandr; Horzempa, Joseph

2017-01-01

Francisella tularensis is disseminated in nature by biting arthropods such as mosquitoes. The relationship between mosquitoes and F. tularensis in nature is highly ambiguous, due in part to the fact that mosquitoes have caused significant tularemia outbreaks despite being classified as a mechanical vector of F. tularensis. One possible explanation for mosquitoes being a prominent, yet mechanical vector is that these insects feed on flower nectar between blood meals, allowing for transmission of F. tularensis between mosquitoes. Here, we aimed to assess whether F. tularensis could survive in flower nectar. Moreover, we examined if mosquitoes could interact with or ingest and transmit F. tularensis from one source of nectar to another. F. tularensis exhibited robust survivability in flower nectar with concentrations of viable bacteria remaining consistent with the rich growth medium. Furthermore, F. tularensis was able to survive (albeit to a lesser extent) in 30% sucrose (a nectar surrogate) over a period of time consistent with that of a typical flower bloom. Although we observed diminished bacterial survival in the nectar surrogate, mosquitoes that fed on this material became colonized with F. tularensis. Finally, colonized mosquitoes were capable of transferring F. tularensis to a sterile nectar surrogate. These data suggest that flower nectar may be capable of serving as a temporary source of F. tularensis that could contribute to the amplification of outbreaks. Mosquitoes that feed on an infected mammalian host and subsequently feed on flower nectar could deposit some F. tularensis bacteria into the nectar in the process. Mosquitoes subsequently feeding on this nectar source could potentially become colonized by F. tularensis. Thus, the possibility exists that flower nectar may allow for vector-vector transmission of F. tularensis.

Salt at concentrations relevant to meat processing enhances Shiga toxin 2 production in Escherichia coli O157:H7.

PubMed

Harris, Shaun M; Yue, Wan-Fu; Olsen, Sarena A; Hu, Jia; Means, Warrie J; McCormick, Richard J; Du, Min; Zhu, Mei-Jun

2012-10-15

Escherichia coli (E. coli) O157:H7 remains a major food safety concern associated with meat, especially beef products. Shiga toxins (Stx) are key virulence factors produced by E. coli O157:H7 that are responsible for hemorrhagic colitis and Hemolytic Uremic Syndrome. Stx are heat stable and can be absorbed after oral ingestion. Despite the extensive study of E. coli O157:H7 survival during meat processing, little attention is paid to the production of Stx during meat processing. The objective of this study was to elucidate the effect of salt, an essential additive to processed meat, at concentrations relevant to meat processing (0%, 1%, 2%, 3%, W/V) on Stx2 production and Stx2 prophage induction by E. coli O157:H7 strains. For both E. coli O157:H7 86-24 and EDL933 strains, including 2% salt in LB broth decreased (P<0.05) E. coli O157:H7 population, but increased (P<0.05) Stx2 production (as measured relative to Log(10)CFU) compared to that of the control (1% salt). Supplementing 3% salt decreased (P<0.05) both E. coli O157:H7 number and Stx2 production. Quantitative RT-PCR indicated that stx2 mRNA expression in culture media containing 2% salt was greatly increased (P<0.05) compared to other salt concentrations. Consistent with enhanced Stx2 production and stx2 expression, the 2% salt group had highest lambdoid phage titer and stx2 prophage induction among all salt treatments. RecA is a key mediator of bacterial response to stress, which mediates prophage activation. Quantitative RT-PCR further indicated that recA mRNA expression was higher in both 2% and 3% salt than that of 0% and 1% salt treatments, indicating that stress was involved in enhanced Stx2 production. In conclusion, salt at the concentration used for meat processing enhances Stx production, a process linked to bacterial stress response and lambdoid prophage induction. Published by Elsevier B.V.

MAN, MOSQUITOES AND MICROBES.

ERIC Educational Resources Information Center

SCHOONOVER, ROBERT A.

THE CONTROL OF MOSQUITOES IS A MATTER OF INCREASING CONCERN IN THE STATE OF FLORIDA. A BRIEF DESCRIPTION OF THE LIFE CYCLE, VARIOUS SPECIES, CONTROL, AND DESCRIPTION OF DISEASES TRANSMITTED BY THE MOSQUITO WAS PRESENTED. THE ARTICLE CONCLUDED THAT MOSQUITO CONTROL IS NOT ONLY A HEALTH PROBLEM, BUT ALSO A MATTER OF IMPROVED ECONOMICS IN RELATION TO…

Malaria infectivity of xanthurenic acid-deficient anopheline mosquitoes produced by TALEN-mediated targeted mutagenesis.

PubMed

Yamamoto, Daisuke S; Sumitani, Megumi; Hatakeyama, Masatsugu; Matsuoka, Hiroyuki

2018-02-01

Anopheline mosquitoes are major vectors of malaria parasites. When the gametocytes of the malaria parasite are transferred from a vertebrate to mosquitoes, they differentiate into gametes, and are fertilized in the midguts of mosquitoes. Xanthurenic acid (XA), a waste product of the ommochrome synthesis pathway, has been shown to induce exflagellation during microgametogenesis in vitro; however, it currently remains unclear whether endogenous XA affects the infectivity of anopheline mosquitoes to malaria parasites in vivo due to the lack of appropriate experimental systems such as a XA-deficient line. In the present study, we produced a XA-deficient line in Anopheles stephensi using transcription activator-like effector nuclease (TALEN)-mediated gene targeting (knockout) of the kynurenine 3-monooxygenase (kmo) gene, which encodes an enzyme that participates in the ommochrome synthesis pathway. The knockout of kmo resulted in the absence of XA, and oocyst formation was inhibited in the midguts of these XA-deficient mosquitoes, which, in turn, reduced sporozoite numbers in their salivary glands. These results suggest that endogenous XA stimulates exflagellation, and enhances the infectivity of anopheline mosquitoes to malaria parasites in vivo. The XA-deficient line of the anopheline mosquito provides a useful system for analyzing and understanding the associated factors of malaria gametogenesis in the mosquito midgut.

The potential for flower nectar to allow mosquito to mosquito transmission of Francisella tularensis

PubMed Central

Payne, Jessica; Gaughenbaugh, Anna; Renshaw, Andrea; Wright, Jenna; Seeber, Roger; Barnes, Rebecca; Florjanczyk, Aleksandr; Horzempa, Joseph

2017-01-01

Francisella tularensis is disseminated in nature by biting arthropods such as mosquitoes. The relationship between mosquitoes and F. tularensis in nature is highly ambiguous, due in part to the fact that mosquitoes have caused significant tularemia outbreaks despite being classified as a mechanical vector of F. tularensis. One possible explanation for mosquitoes being a prominent, yet mechanical vector is that these insects feed on flower nectar between blood meals, allowing for transmission of F. tularensis between mosquitoes. Here, we aimed to assess whether F. tularensis could survive in flower nectar. Moreover, we examined if mosquitoes could interact with or ingest and transmit F. tularensis from one source of nectar to another. F. tularensis exhibited robust survivability in flower nectar with concentrations of viable bacteria remaining consistent with the rich growth medium. Furthermore, F. tularensis was able to survive (albeit to a lesser extent) in 30% sucrose (a nectar surrogate) over a period of time consistent with that of a typical flower bloom. Although we observed diminished bacterial survival in the nectar surrogate, mosquitoes that fed on this material became colonized with F. tularensis. Finally, colonized mosquitoes were capable of transferring F. tularensis to a sterile nectar surrogate. These data suggest that flower nectar may be capable of serving as a temporary source of F. tularensis that could contribute to the amplification of outbreaks. Mosquitoes that feed on an infected mammalian host and subsequently feed on flower nectar could deposit some F. tularensis bacteria into the nectar in the process. Mosquitoes subsequently feeding on this nectar source could potentially become colonized by F. tularensis. Thus, the possibility exists that flower nectar may allow for vector-vector transmission of F. tularensis. PMID:28486521

Tips to Prevent Mosquito Bites

MedlinePlus

... mosquitoes using insecticides. Use Structural Barriers Cover all gaps in walls, doors, and windows to prevent mosquitoes ... into pants and pants into socks to cover gaps in your clothing where mosquitoes can get to ...

Discovery of antimicrobial lipodepsipeptides produced by a Serratia sp. within mosquito microbiomes.

PubMed

Ganley, Jack; Carr, Gavin; Ioerger, Thomas; Sacchettini, James; Clardy, Jon; Derbyshire, Emily

2018-04-26

The Anopheles mosquito that harbors the Plasmodium parasite contains a microbiota that can influence both the vector and parasite. In recent years, insect-associated microbes have highlighted the untapped potential of exploiting interspecies interactions to discover bioactive compounds. In this study, we report the discovery of nonribosomal lipodepsipeptides that are produced by a Serratia sp. within the midgut and salivary glands of A. stephensi mosquitoes. The lipodepsipeptides, stephensiolides A-K, have antibiotic activity and facilitate bacterial surface motility. Bioinformatic analyses indicate that the stephensiolides are ubiquitous in nature and are likely important for Serratia spp. colonization within mosquitoes, humans, and other ecological niches. Our results demonstrate the usefulness of probing insect-microbiome interactions, enhance our understanding of the chemical ecology within Anopheles mosquitoes, and provide a secondary metabolite scaffold to further investigate this complex relationship. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Chikungunya Virus Infection of Aedes Mosquitoes.

PubMed

Wong, Hui Vern; Chan, Yoke Fun; Sam, I-Ching; Sulaiman, Wan Yusof Wan; Vythilingam, Indra

2016-01-01

In vivo infection of mosquitoes is an important method to study and characterize arthropod-borne viruses. Chikungunya virus (CHIKV) is a mosquito-borne alphavirus that is transmitted primarily by Aedes mosquitoes. In this chapter, we describe a protocol for infection of CHIKV in two species of Aedes mosquitoes, Aedes aegypti and Aedes albopictus, together with the isolation of CHIKV in different parts of the infected mosquito such as midgut, legs, wings, salivary gland, head, and saliva. This allows the study of viral infection, replication and dissemination within the mosquito vector.

Lessons from mosquitoes' painless piercing.

PubMed

Gurera, Dev; Bhushan, Bharat; Kumar, Navin

2018-05-18

Arthropods are the largest group of the living organisms. They attack other organisms by biting, stinging, or piercing and sucking. Among various medically important arthropods, which feed on living hosts, mosquitoes' piercing spread viruses which have been reported to cause the highest number of deaths annually. The primary cause of the deaths is malaria, which is spread by infected mosquitoes' piercing. This study aims at elucidating lessons from mosquitoes' painless piercing. Mosquitoes pierce using their fascicle, which is a bundle of coherently functioning six stylets. Based on experiments and available literature, it is presented that mosquitoes painlessly pierce using a combination of the numbing, the fascicle's serrated design, the vibratory actuation, and the graded and frequency-dependent mechanical properties of the labrum. Based on this understanding, a mosquito-inspired microneedle design has also been proposed. Copyright © 2018 Elsevier Ltd. All rights reserved.

Bottle gourd rootstock-grafting affects nitrogen metabolism in NaCl-stressed watermelon leaves and enhances short-term salt tolerance.

PubMed

Yang, Yanjuan; Lu, Xiaomin; Yan, Bei; Li, Bin; Sun, Jin; Guo, Shirong; Tezuka, Takafumi

2013-05-01

The plant growth, nitrogen absorption, and assimilation in watermelon (Citrullus lanatus [Thunb.] Mansf.) were investigated in self-grafted and grafted seedlings using the salt-tolerant bottle gourd rootstock Chaofeng Kangshengwang (Lagenaria siceraria Standl.) exposed to 100mM NaCl for 3d. The biomass and NO3(-) uptake rate were significantly increased by rootstock while these values were remarkably decreased by salt stress. However, compared with self-grafted plants, rootstock-grafted plants showed higher salt tolerance with higher biomass and NO3(-) uptake rate under salt stress. Salinity induced strong accumulation of nitrate, ammonium and protein contents and a significant decrease of nitrogen content and the activities of nitrate reductase (NR), nitrite reductase (NiR), glutamine synthetase (GS), and glutamate synthase (GOGAT) in leaves of self-grafted seedlings. In contrast, salt stress caused a remarkable decrease in nitrate content and the activities of GS and GOGAT, and a significant increase of ammonium, protein, and nitrogen contents and NR activity, in leaves of rootstock-grafted seedlings. Compared with that of self-grafted seedlings, the ammonium content in leaves of rootstock-grafted seedlings was much lower under salt stress. Glutamate dehydrogenase (GDH) activity was notably enhanced in leaves of rootstock-grafted seedlings, whereas it was significantly inhibited in leaves of self-grafted seedlings, under salinity stress. Three GDH isozymes were isolated by native gel electrophoresis and their expressions were greatly enhanced in leaves of rootstock-grafted seedlings than those of self-grafted seedlings under both normal and salt-stress conditions. These results indicated that the salt tolerance of rootstock-grafted seedlings might (be enhanced) owing to the higher nitrogen absorption and the higher activities of enzymes for nitrogen assimilation induced by the rootstock. Furthermore, the detoxification of ammonium by GDH when the GS/GOGAT pathway

Convergence between a mosquito-eating predator's natural diet and its prey-choice behaviour

PubMed Central

Jackson, Robert R.; Deng, Chan

2016-01-01

On the basis of 1115 records of Evarcha culicivora feeding in the field, we can characterize this East African jumping spider (Salticidae) as being distinctively stenophagic. We can also, on the basis of laboratory prey-choice experiments, characterize E. culicivora as having a specialized prey-classification system and a hierarchy of innate preferences for various categories of mosquitoes and other arthropods. Prey from the field belonged to 10 arthropod orders, but 94.5% of the prey records were dipterans. Mosquitoes were the dominant prey (80.2% of the records), with the majority (82.9%) of the mosquitoes being females, and thereafter midges were the most common prey (9.2% of the records). Preference profiles that were determined from experiments showed strong convergence with natural diet in some, but not all, instances. In experiments, E. culicivora adults appeared to distinguish between six prey categories and juveniles between seven, with blood-carrying anopheline female mosquitoes being ranked highest in preference. For adults, this was followed by blood-carrying culicine female mosquitoes and then anopheline female mosquitoes not carrying blood, but these two preferences were reversed for juveniles. Moreover, for juveniles, but not for adults, anopheline male mosquitoes seem to be a distinct prey category ranked in preference after blood-carrying culicine females and, for both adults and juveniles, preference for midges is evident when the alternatives are not mosquitoes. These findings illustrate the importance of going beyond simply specifying preferred prey categories when characterizing predators as ‘specialized’ and a need to make clear conceptual distinctions between a predator's natural diet, the prey categories that are relevant to the predator, and the predator's prey-choicebehaviour. PMID:28083103

Global climate change and its potential impact on disease transmission by salinity-tolerant mosquito vectors in coastal zones.

PubMed

Ramasamy, Ranjan; Surendran, Sinnathamby Noble

2012-01-01

Global climate change can potentially increase the transmission of mosquito vector-borne diseases such as malaria, lymphatic filariasis, and dengue in many parts of the world. These predictions are based on the effects of changing temperature, rainfall, and humidity on mosquito breeding and survival, the more rapid development of ingested pathogens in mosquitoes and the more frequent blood feeds at moderately higher ambient temperatures. An expansion of saline and brackish water bodies (water with <0.5 ppt or parts per thousand, 0.5-30 ppt and >30 ppt salt are termed fresh, brackish, and saline respectively) will also take place as a result of global warming causing a rise in sea levels in coastal zones. Its possible impact on the transmission of mosquito-borne diseases has, however, not been adequately appreciated. The relevant impacts of global climate change on the transmission of mosquito-borne diseases in coastal zones are discussed with reference to the Ross-McDonald equation and modeling studies. Evidence is presented to show that an expansion of brackish water bodies in coastal zones can increase the densities of salinity-tolerant mosquitoes like Anopheles sundaicus and Culex sitiens, and lead to the adaptation of fresh water mosquito vectors like Anopheles culicifacies, Anopheles stephensi, Aedes aegypti, and Aedes albopictus to salinity. Rising sea levels may therefore act synergistically with global climate change to increase the transmission of mosquito-borne diseases in coastal zones. Greater attention therefore needs to be devoted to monitoring disease incidence and preimaginal development of vector mosquitoes in artificial and natural coastal brackish/saline habitats. It is important that national and international health agencies are aware of the increased risk of mosquito-borne diseases in coastal zones and develop preventive and mitigating strategies. Application of appropriate counter measures can greatly reduce the potential for increased

Global Climate Change and Its Potential Impact on Disease Transmission by Salinity-Tolerant Mosquito Vectors in Coastal Zones

PubMed Central

Ramasamy, Ranjan; Surendran, Sinnathamby Noble

2012-01-01

Global climate change can potentially increase the transmission of mosquito vector-borne diseases such as malaria, lymphatic filariasis, and dengue in many parts of the world. These predictions are based on the effects of changing temperature, rainfall, and humidity on mosquito breeding and survival, the more rapid development of ingested pathogens in mosquitoes and the more frequent blood feeds at moderately higher ambient temperatures. An expansion of saline and brackish water bodies (water with <0.5 ppt or parts per thousand, 0.5–30 ppt and >30 ppt salt are termed fresh, brackish, and saline respectively) will also take place as a result of global warming causing a rise in sea levels in coastal zones. Its possible impact on the transmission of mosquito-borne diseases has, however, not been adequately appreciated. The relevant impacts of global climate change on the transmission of mosquito-borne diseases in coastal zones are discussed with reference to the Ross–McDonald equation and modeling studies. Evidence is presented to show that an expansion of brackish water bodies in coastal zones can increase the densities of salinity-tolerant mosquitoes like Anopheles sundaicus and Culex sitiens, and lead to the adaptation of fresh water mosquito vectors like Anopheles culicifacies, Anopheles stephensi, Aedes aegypti, and Aedes albopictus to salinity. Rising sea levels may therefore act synergistically with global climate change to increase the transmission of mosquito-borne diseases in coastal zones. Greater attention therefore needs to be devoted to monitoring disease incidence and preimaginal development of vector mosquitoes in artificial and natural coastal brackish/saline habitats. It is important that national and international health agencies are aware of the increased risk of mosquito-borne diseases in coastal zones and develop preventive and mitigating strategies. Application of appropriate counter measures can greatly reduce the potential for

Exploiting mosquito sugar feeding to detect mosquito-borne pathogens

PubMed Central

Hall-Mendelin, Sonja; Ritchie, Scott A.; Johansen, Cheryl A.; Zborowski, Paul; Cortis, Giles; Dandridge, Scott; Hall, Roy A.; van den Hurk, Andrew F.

2010-01-01

Arthropod-borne viruses (arboviruses) represent a global public health problem, with dengue viruses causing millions of infections annually, while emerging arboviruses, such as West Nile, Japanese encephalitis, and chikungunya viruses have dramatically expanded their geographical ranges. Surveillance of arboviruses provides vital data regarding their prevalence and distribution that may be utilized for biosecurity measures and the implementation of disease control strategies. However, current surveillance methods that involve detection of virus in mosquito populations or sero-conversion in vertebrate hosts are laborious, expensive, and logistically problematic. We report a unique arbovirus surveillance system to detect arboviruses that exploits the process whereby mosquitoes expectorate virus in their saliva during sugar feeding. In this system, infected mosquitoes captured by CO2-baited updraft box traps are allowed to feed on honey-soaked nucleic acid preservation cards within the trap. The cards are then analyzed for expectorated virus using real-time reverse transcription-PCR. In field trials, this system detected the presence of Ross River and Barmah Forest viruses in multiple traps deployed at two locations in Australia. Viral RNA was preserved for at least seven days on the cards, allowing for long-term placement of traps and continuous collection of data documenting virus presence in mosquito populations. Furthermore no mosquito handling or processing was required and cards were conveniently shipped to the laboratory overnight. The simplicity and efficacy of this approach has the potential to transform current approaches to vector-borne disease surveillance by streamlining the monitoring of pathogens in vector populations. PMID:20534559

North American Wetlands and Mosquito Control

PubMed Central

Rey, Jorge R.; Walton, William E.; Wolfe, Roger J.; Connelly, Roxanne; O’Connell, Sheila M.; Berg, Joe; Sakolsky-Hoopes, Gabrielle E.; Laderman, Aimlee D.

2012-01-01

Wetlands are valuable habitats that provide important social, economic, and ecological services such as flood control, water quality improvement, carbon sequestration, pollutant removal, and primary/secondary production export to terrestrial and aquatic food chains. There is disagreement about the need for mosquito control in wetlands and about the techniques utilized for mosquito abatement and their impacts upon wetlands ecosystems. Mosquito control in wetlands is a complex issue influenced by numerous factors, including many hard to quantify elements such as human perceptions, cultural predispositions, and political climate. In spite of considerable progress during the last decades, habitat protection and environmentally sound habitat management still remain inextricably tied to politics and economics. Furthermore, the connections are often complex, and occur at several levels, ranging from local businesses and politicians, to national governments and multinational institutions. Education is the key to lasting wetlands conservation. Integrated mosquito abatement strategies incorporate many approaches and practicable options, as described herein, and need to be well-defined, effective, and ecologically and economically sound for the wetland type and for the mosquito species of concern. The approach will certainly differ in response to disease outbreaks caused by mosquito-vectored pathogens versus quality of life issues caused by nuisance-biting mosquitoes. In this contribution, we provide an overview of the ecological setting and context for mosquito control in wetlands, present pertinent information on wetlands mosquitoes, review the mosquito abatement options available for current wetlands managers and mosquito control professionals, and outline some necessary considerations when devising mosquito control strategies. Although the emphasis is on North American wetlands, most of the material is applicable to wetlands everywhere. PMID:23222252

Trypanosomatid parasites in Austrian mosquitoes

PubMed Central

Schoener, Ellen; Uebleis, Sarah Susanne; Cuk, Claudia; Nawratil, Michaela; Obwaller, Adelheid G.; Zechmeister, Thomas; Rádrová, Jana; Zittra, Carina

2018-01-01

Trypanosomatid flagellates have not been studied in Austria in any detail. In this study, specific nested PCR, targeted on the ribosomal small subunit, was used to determine the occurrence and diversity of trypanosomatids in wild-caught mosquitoes sampled across Eastern Austria in the years 2014−2015. We collected a total of 29,975 mosquitoes of 19 species divided in 1680 pools. Of these, 298 (17.7%), representing 12 different mosquito species, were positive for trypanosomatid DNA. In total, seven trypanosomatid spp. were identified (three Trypanosoma, three Crithidia and one Herpetomonas species), with the highest parasite species diversity found in the mosquito host Coquillettidia richiardii. The most frequent parasite species belonged to the mammalian Trypanosoma theileri/cervi species complex (found in 105 pools; 6.3%). The avian species T. culicavium (found in 69 pools; 4.1%) was only detected in mosquitoes of the genus Culex, which corresponds to their preference for avian hosts. Monoxenous trypanosomatids of the genus Crithidia and Herpetomonas were found in 20 (1.3%) mosquito pools. One third (n = 98) of the trypanosomatid positive mosquito pools carried more than one parasite species. This is the first large scale study of trypanosomatid parasites in Austrian mosquitoes and our results are valuable in providing an overview of the diversity of these parasites in Austria. PMID:29672618

Repelling mosquitoes with essential oils

NASA Astrophysics Data System (ADS)

Riley, L.

2017-12-01

Mosquitoes carry diseases than can lead to serious illness and death. According to the World Health Organization, mosquitoes infect over 300 million people a year with Malaria and Dengue Fever, two life threatening diseases vectored by mosquitoes. Although insecticides are the most effective way to control mosquitoes, they are not always environmentally friendly. Therefore, alternative tactics should be considered. In this study, we looked at the repellency of various essential oils on female Aedes aegypti through a series of laboratory assays.

Synergistic enhancement in the co-gelation of salt-soluble pea proteins and whey proteins.

PubMed

Wong, Douglas; Vasanthan, Thava; Ozimek, Lech

2013-12-15

This paper investigated the enhancement of thermal gelation properties when salt-soluble pea proteins were co-gelated with whey proteins in NaCl solutions, using different blend ratios, total protein concentrations, pH, and salt concentrations. Results showed that the thermal co-gelation of pea/whey proteins blended in ratio of 2:8 in NaCl solutions showed synergistic enhancement in storage modulus, gel hardness, paste viscosity and minimum gelation concentrations. The highest synergistic enhancement was observed at pH 6.0 as compared with pH 4.0 and 8.0, and at the lower total protein concentration of 10% as compared with 16% and 22% (w/v), as well as in lower NaCl concentrations of 0.5% and 1.0% as compared with 1.5%, 2.0%, 2.5%, and 3.0% (w/v). The least gelation concentrations were also lower in the different pea/whey protein blend ratios than in pure pea or whey proteins, when dissolved in 1.0% or 2.5% (w/v) NaCl aqueous solutions. Copyright © 2013 Elsevier Ltd. All rights reserved.

Exogenous Calcium Enhances the Photosystem II Photochemistry Response in Salt Stressed Tall Fescue.

PubMed

Wang, Guangyang; Bi, Aoyue; Amombo, Erick; Li, Huiying; Zhang, Liang; Cheng, Cheng; Hu, Tao; Fu, Jinmin

2017-01-01

Calcium enhances turfgrass response to salt stress. However, little is known about PSII photochemical changes when exogenous calcium was applied in salinity-stressed turfgrass. Here, we probe into the rearrangements of PSII electron transport and endogenous ion accumulation in tall fescue ( Festuca arundinacea Schreber) treated with exogenous calcium under salt stress. Three-month-old seedlings of genotype "TF133" were subjected to the control (CK), salinity (S), salinity + calcium nitrate (SC), and salinity + ethylene glycol tetraacetic acid (SE). Calcium nitrate and ethylene glycol tetraacetic acid was used as exogenous calcium donor and calcium chelating agent respectively. At the end of a 5-day duration treatment, samples in SC regime had better photochemistry performance on several parameters than salinity only. Such as the Area (equal to the plastoquinone pool size), N (number of [Formula: see text] redox turnovers until F m is reached), ψE 0 , or δRo (Efficiencdy/probability with which a PSII trapped electron is transferred from Q A to Q B or PSI acceptors), ABS/RC (Absorbed photon flux per RC). All the above suggested that calcium enhanced the electron transfer of PSII (especially beyond [Formula: see text]) and prevented reaction centers from inactivation in salt-stressed tall fescue. Furthermore, both grass shoot and root tissues generally accumulated more C, N, Ca 2+ , and K + in the SC regime than S regime. Interrelated analysis indicated that ψE 0 , δRo, ABS/RC, C, and N content in shoots was highly correlated to each other and significantly positively related to Ca 2+ and K + content in roots. Besides, high salt increased ATP6E and CAMK2 transcription level in shoot at 1 and 5 day, respectively while exogenous calcium relieved it. In root, CAMK2 level was reduced by Salinity at 5 day and exogenous calcium recovered it. These observations involved in electron transport capacity and ion accumulation assist in understanding better the protective role

Exogenous Calcium Enhances the Photosystem II Photochemistry Response in Salt Stressed Tall Fescue

PubMed Central

Wang, Guangyang; Bi, Aoyue; Amombo, Erick; Li, Huiying; Zhang, Liang; Cheng, Cheng; Hu, Tao; Fu, Jinmin

2017-01-01

Calcium enhances turfgrass response to salt stress. However, little is known about PSII photochemical changes when exogenous calcium was applied in salinity-stressed turfgrass. Here, we probe into the rearrangements of PSII electron transport and endogenous ion accumulation in tall fescue (Festuca arundinacea Schreber) treated with exogenous calcium under salt stress. Three-month-old seedlings of genotype “TF133” were subjected to the control (CK), salinity (S), salinity + calcium nitrate (SC), and salinity + ethylene glycol tetraacetic acid (SE). Calcium nitrate and ethylene glycol tetraacetic acid was used as exogenous calcium donor and calcium chelating agent respectively. At the end of a 5-day duration treatment, samples in SC regime had better photochemistry performance on several parameters than salinity only. Such as the Area (equal to the plastoquinone pool size), N (number of QA- redox turnovers until Fm is reached), ψE0, or δRo (Efficiencdy/probability with which a PSII trapped electron is transferred from QA to QB or PSI acceptors), ABS/RC (Absorbed photon flux per RC). All the above suggested that calcium enhanced the electron transfer of PSII (especially beyond QA-) and prevented reaction centers from inactivation in salt-stressed tall fescue. Furthermore, both grass shoot and root tissues generally accumulated more C, N, Ca2+, and K+ in the SC regime than S regime. Interrelated analysis indicated that ψE0, δRo, ABS/RC, C, and N content in shoots was highly correlated to each other and significantly positively related to Ca2+ and K+ content in roots. Besides, high salt increased ATP6E and CAMK2 transcription level in shoot at 1 and 5 day, respectively while exogenous calcium relieved it. In root, CAMK2 level was reduced by Salinity at 5 day and exogenous calcium recovered it. These observations involved in electron transport capacity and ion accumulation assist in understanding better the protective role of exogenous calcium in tall fescue

Gene Drive for Mosquito Control: Where Did It Come from and Where Are We Headed?

PubMed Central

Macias, Vanessa M.; Ohm, Johanna R.; Rasgon, Jason L.

2017-01-01

Mosquito-borne pathogens place an enormous burden on human health. The existing toolkit is insufficient to support ongoing vector-control efforts towards meeting disease elimination and eradication goals. The perspective that genetic approaches can potentially add a significant set of tools toward mosquito control is not new, but the recent improvements in site-specific gene editing with CRISPR/Cas9 systems have enhanced our ability to both study mosquito biology using reverse genetics and produce genetics-based tools. Cas9-mediated gene-editing is an efficient and adaptable platform for gene drive strategies, which have advantages over innundative release strategies for introgressing desirable suppression and pathogen-blocking genotypes into wild mosquito populations; until recently, an effective gene drive has been largely out of reach. Many considerations will inform the effective use of new genetic tools, including gene drives. Here we review the lengthy history of genetic advances in mosquito biology and discuss both the impact of efficient site-specific gene editing on vector biology and the resulting potential to deploy new genetic tools for the abatement of mosquito-borne disease. PMID:28869513

Development of autochthonous microbial consortia for enhanced phytoremediation of salt-marsh sediments contaminated with cadmium.

PubMed

Teixeira, Catarina; Almeida, C Marisa R; Nunes da Silva, Marta; Bordalo, Adriano A; Mucha, Ana P

2014-09-15

Microbial assisted phytoremediation is a promising, though yet poorly explored, new remediation technique. The aim of this study was to develop autochthonous microbial consortia resistant to cadmium that could enhance phytoremediation of salt-marsh sediments contaminated with this metal. The microbial consortia were selectively enriched from rhizosediments colonized by Juncus maritimus and Phragmites australis. The obtained consortia presented similar microbial abundance but a fairly different community structure, showing that the microbial community was a function of the sediment from which the consortia were enriched. The effect of the bioaugmentation with the developed consortia on cadmium uptake, and the microbial community structure associated to the different sediments were assessed using a microcosm experiment. Our results showed that the addition of the cadmium resistant microbial consortia increased J. maritimus metal phytostabilization capacity. On the other hand, in P. australis, microbial consortia amendment promoted metal phytoextraction. The addition of the consortia did not alter the bacterial structure present in the sediments at the end of the experiments. This study provides new evidences that the development of autochthonous microbial consortia for enhanced phytoremediation of salt-marsh sediments contaminated with cadmium might be a simple, efficient, and environmental friendly remediation procedure. Development of autochthonous microbial consortia resistant to cadmium that enhanced phytoremediation by salt-marsh plants, without a long term effect on sediment bacterial diversity. Copyright © 2014 Elsevier B.V. All rights reserved.

The importance of temperature fluctuations in understanding mosquito population dynamics and malaria risk.

PubMed

Beck-Johnson, Lindsay M; Nelson, William A; Paaijmans, Krijn P; Read, Andrew F; Thomas, Matthew B; Bjørnstad, Ottar N

2017-03-01

Temperature is a key environmental driver of Anopheles mosquito population dynamics; understanding its central role is important for these malaria vectors. Mosquito population responses to temperature fluctuations, though important across the life history, are poorly understood at a population level. We used stage-structured, temperature-dependent delay-differential equations to conduct a detailed exploration of the impacts of diurnal and annual temperature fluctuations on mosquito population dynamics. The model allows exploration of temperature-driven temporal changes in adult age structure, giving insights into the population's capacity to vector malaria parasites. Because of temperature-dependent shifts in age structure, the abundance of potentially infectious mosquitoes varies temporally, and does not necessarily mirror the dynamics of the total adult population. In addition to conducting the first comprehensive theoretical exploration of fluctuating temperatures on mosquito population dynamics, we analysed observed temperatures at four locations in Africa covering a range of environmental conditions. We found both temperature and precipitation are needed to explain the observed malaria season in these locations, enhancing our understanding of the drivers of malaria seasonality and how temporal disease risk may shift in response to temperature changes. This approach, tracking both mosquito abundance and age structure, may be a powerful tool for understanding current and future malaria risk.

Do NIR spectra collected from laboratory-reared mosquitoes differ from those collected from wild mosquitoes?

USDA-ARS?s Scientific Manuscript database

Do near infrared spectra from lab-reared mosquitoes differ from spectra from wild mosquitoes? Near infrared spectroscopy (NIRS) can classify the age of lab-reared mosquitoes as younger or older than seven days with accuracy greater than 80%. Hence, it has been proposed in several studies as a comple...

Enhanced oral bioavailability of vinpocetine through mechanochemical salt formation: physico-chemical characterization and in vivo studies.

PubMed

Hasa, Dritan; Voinovich, Dario; Perissutti, Beatrice; Grassi, Mario; Bonifacio, Alois; Sergo, Valter; Cepek, Cinzia; Chierotti, Michele R; Gobetto, Roberto; Dall'Acqua, Stefano; Invernizzi, Sergio

2011-08-01

Enhancing oral bioavailability of vinpocetine by forming its amorphous citrate salt through a solvent-free mechanochemical process, in presence of micronised crospovidone and citric acid. The impact of formulation and process variables (amount of polymer and citric acid, and milling time) on vinpocetine solubilization kinetics from the coground was studied through an experimental design. The best performing samples were characterized by employing a multidisciplinary approach, involving Differential scanning calorimetry, X-ray diffraction, Raman imaging/spectroscopy, X-ray photoelectron spectroscopy, solid-state NMR spectroscopy, porosimetry and in vivo studies on rats to ascertain the salt formation, their solid-state characteristics and oral bioavailability in comparison to vinpocetine citrate salt (Oxopocetine(®)). The analyses attested that the mechanochemical process is a viable way to produce in absence of solvents vinpocetine citrate salt in an amorphous state. From the in vivo studies on rats the obtained salt was four times more bioavailable than its physical mixture and bioequivalent to the commercial salt produced by conventional synthetic process implying the use of solvent.

DEVELOPMENT OF AN INSOLUBLE SALT SIMULANT TO SUPPORT ENHANCED CHEMICAL CLEANING TESTS

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

Eibling, R

The closure process for high level waste tanks at the Savannah River Site will require dissolution of the crystallized salts that are currently stored in many of the tanks. The insoluble residue from salt dissolution is planned to be removed by an Enhanced Chemical Cleaning (ECC) process. Development of a chemical cleaning process requires an insoluble salt simulant to support evaluation tests of different cleaning methods. The Process Science and Engineering section of SRNL has been asked to develop an insoluble salt simulant for use in testing potential ECC processes (HLE-TTR-2007-017). An insoluble salt simulant has been developed based uponmore » the residues from salt dissolution of saltcake core samples from Tank 28F. The simulant was developed for use in testing SRS waste tank chemical cleaning methods. Based on the results of the simulant development process, the following observations were developed: (1) A composition based on the presence of 10.35 grams oxalate and 4.68 grams carbonate per 100 grams solids produces a sufficiently insoluble solids simulant. (2) Aluminum observed in the solids remaining from actual waste salt dissolution tests is probably precipitated from sodium aluminate due to the low hydroxide content of the saltcake. (3) In-situ generation of aluminum hydroxide (by use of aluminate as the Al source) appears to trap additional salts in the simulant in a manner similar to that expected for actual waste samples. (4) Alternative compositions are possible with higher oxalate levels and lower carbonate levels. (5) The maximum oxalate level is limited by the required Na content of the insoluble solids. (6) Periodic mixing may help to limit crystal growth in this type of salt simulant. (7) Long term storage of an insoluble salt simulant is likely to produce a material that can not be easily removed from the storage container. Production of a relatively fresh simulant is best if pumping the simulant is necessary for testing purposes. The

Overexpression of GsZFP1 enhances salt and drought tolerance in transgenic alfalfa (Medicago sativa L.).

PubMed

Tang, Lili; Cai, Hua; Ji, Wei; Luo, Xiao; Wang, Zhenyu; Wu, Jing; Wang, Xuedong; Cui, Lin; Wang, Yang; Zhu, Yanming; Bai, Xi

2013-10-01

GsZFP1 encodes a Cys2/His2-type zinc-finger protein. In our previous study, when GsZFP1 was heterologously expressed in Arabidopsis, the transgenic Arabidopsis plants exhibited enhanced drought and cold tolerance. However, it is still unknown whether GsZFP1 is also involved in salt stress. GsZFP1 is from the wild legume Glycine soja. Therefore, the aims of this study were to further elucidate the functions of the GsZFP1 gene under salt and drought stress in the forage legume alfalfa and to investigate its biochemical and physiological functions under these stress conditions. Our data showed that overexpression of GsZFP1 in alfalfa resulted in enhanced salt tolerance. Under high salinity stress, greater relative membrane permeability and malondialdehyde (MDA) content were observed and more free proline and soluble sugars accumulated in transgenic alfalfa than in the wild-type (WT) plants; in addition, the transgenic lines accumulated less Na(+) and more K(+) in both the shoots and roots. Overexpression of GsZFP1 also enhanced the drought tolerance of alfalfa. The fold-inductions of stress-responsive marker gene expression, including MtCOR47, MtRAB18, MtP5CS, and MtRD2, were greater in transgenic alfalfa than those of WT under drought stress conditions. In conclusion, the transgenic alfalfa plants generated in this study could be used for farming in salt-affected as well as arid and semi-arid areas. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

MosquitoMap and the Mal-area calculator: new web tools to relate mosquito species distribution with vector borne disease

PubMed Central

2010-01-01

Background Mosquitoes are important vectors of diseases but, in spite of various mosquito faunistic surveys globally, there is a need for a spatial online database of mosquito collection data and distribution summaries. Such a resource could provide entomologists with the results of previous mosquito surveys, and vector disease control workers, preventative medicine practitioners, and health planners with information relating mosquito distribution to vector-borne disease risk. Results A web application called MosquitoMap was constructed comprising mosquito collection point data stored in an ArcGIS 9.3 Server/SQL geodatabase that includes administrative area and vector species x country lookup tables. In addition to the layer containing mosquito collection points, other map layers were made available including environmental, and vector and pathogen/disease distribution layers. An application within MosquitoMap called the Mal-area calculator (MAC) was constructed to quantify the area of overlap, for any area of interest, of vector, human, and disease distribution models. Data standards for mosquito records were developed for MosquitoMap. Conclusion MosquitoMap is a public domain web resource that maps and compares georeferenced mosquito collection points to other spatial information, in a geographical information system setting. The MAC quantifies the Mal-area, i.e. the area where it is theoretically possible for vector-borne disease transmission to occur, thus providing a useful decision tool where other disease information is limited. The Mal-area approach emphasizes the independent but cumulative contribution to disease risk of the vector species predicted present. MosquitoMap adds value to, and makes accessible, the results of past collecting efforts, as well as providing a template for other arthropod spatial databases. PMID:20167090

MosquitoMap and the Mal-area calculator: new web tools to relate mosquito species distribution with vector borne disease.

PubMed

Foley, Desmond H; Wilkerson, Richard C; Birney, Ian; Harrison, Stanley; Christensen, Jamie; Rueda, Leopoldo M

2010-02-18

Mosquitoes are important vectors of diseases but, in spite of various mosquito faunistic surveys globally, there is a need for a spatial online database of mosquito collection data and distribution summaries. Such a resource could provide entomologists with the results of previous mosquito surveys, and vector disease control workers, preventative medicine practitioners, and health planners with information relating mosquito distribution to vector-borne disease risk. A web application called MosquitoMap was constructed comprising mosquito collection point data stored in an ArcGIS 9.3 Server/SQL geodatabase that includes administrative area and vector species x country lookup tables. In addition to the layer containing mosquito collection points, other map layers were made available including environmental, and vector and pathogen/disease distribution layers. An application within MosquitoMap called the Mal-area calculator (MAC) was constructed to quantify the area of overlap, for any area of interest, of vector, human, and disease distribution models. Data standards for mosquito records were developed for MosquitoMap. MosquitoMap is a public domain web resource that maps and compares georeferenced mosquito collection points to other spatial information, in a geographical information system setting. The MAC quantifies the Mal-area, i.e. the area where it is theoretically possible for vector-borne disease transmission to occur, thus providing a useful decision tool where other disease information is limited. The Mal-area approach emphasizes the independent but cumulative contribution to disease risk of the vector species predicted present. MosquitoMap adds value to, and makes accessible, the results of past collecting efforts, as well as providing a template for other arthropod spatial databases.

Heritability of Attractiveness to Mosquitoes

PubMed Central

Fernández-Grandon, G. Mandela; Gezan, Salvador A.; Armour, John A. L.; Pickett, John A.; Logan, James G.

2015-01-01

Female mosquitoes display preferences for certain individuals over others, which is determined by differences in volatile chemicals produced by the human body and detected by mosquitoes. Body odour can be controlled genetically but the existence of a genetic basis for differential attraction to insects has never been formally demonstrated. This study investigated heritability of attractiveness to mosquitoes by evaluating the response of Aedes aegypti (=Stegomyia aegypti) mosquitoes to odours from the hands of identical and non-identical twins in a dual-choice assay. Volatiles from individuals in an identical twin pair showed a high correlation in attractiveness to mosquitoes, while non-identical twin pairs showed a significantly lower correlation. Overall, there was a strong narrow-sense heritability of 0.62 (SE 0.124) for relative attraction and 0.67 (0.354) for flight activity based on the average of ten measurements. The results demonstrate an underlying genetic component detectable by mosquitoes through olfaction. Understanding the genetic basis for attractiveness could create a more informed approach to repellent development. PMID:25901606

Modeling habitat and environmental factors affecting mosquito abundance in Chesapeake, Virginia

NASA Astrophysics Data System (ADS)

Bellows, Alan Scott

summarizes the preprocessing steps and analyses used in the HSIs and the dynamic, weather-based, model generated in Chapters II and III. The purpose of this chapter is to provide the reader and potential users with the necessary protocols for modeling the spatial and temporal abundances and distributions of mosquitoes, with emphasis on Culiseta melanura, in a real-world landscape of the mid-Atlantic region. This chapter also provides enhancements that could easily be incorporated into an environmentally sensitive integrated pest management program.

Ocular Manifestations of Mosquito-Transmitted Diseases.

PubMed

Karesh, James W; Mazzoli, Robert A; Heintz, Shannon K

2018-03-01

Of the 3,548 known mosquito species, about 100 transmit human diseases. Mosquitoes are distributed globally throughout tropical and temperate regions where standing water sources are available for egg laying and the maturation of larva. Female mosquitoes require blood meals for egg production. This is the main pathway for disease transmission. Mosquitoes carry several pathogenic organisms responsible for significant ocular pathology and vision loss including West Nile, Rift Valley, chikungunya, dengue viruses, various encephalitis viruses, malarial parasites, Francisella tularensis, microfilarial parasites, including Dirofilaria, Wuchereria, and Brugia spp., and human botfly larvae. Health care providers may not be familiar with many of these mosquito-transmitted diseases or their associated ocular findings delaying diagnosis, treatment, and recovery of visual function. This article aims to provide an overview of the ocular manifestations associated with mosquito-transmitted diseases.

RNA interference of GhPEPC2 enhanced seed oil accumulation and salt tolerance in Upland cotton.

PubMed

Zhao, Yanpeng; Huang, Yi; Wang, Yumei; Cui, Yupeng; Liu, Zhengjie; Hua, Jinping

2018-06-01

Phosphoenolpyruvate carboxylase (PEPCase) mainly produces oxaloacetic acid for tricarboxylic acid (TCA) cycle. Here we reported that GhPEPC2 silencing with PEPC2-RNAi vector could regulate oil and protein accumulation in cottonseeds. In GhPEPC2 transgenic plants, PEPCase activities in immature embryos were significantly reduced, and the oil content in seed kernel was increased 7.3 percentages, whereas total proteins decreased 5.65 percentages. Compared to wild type, agronomical traits of transgenic plant were obviously unaffected. Furthermore, gene expression profile of GhPEPC2 transgenic seeds were investigated using RNA-seq, most lipid synthesis related genes were up-regulated, but amino acid metabolic related genes were down-regulated. In addition, the GhPEPC2 transgenic cotton seedlings were stressed using sodium salts at seedling stage, and the salt tolerance was significantly enhanced. Our observations of GhPEPC2 in cotton would shade light on understanding the regulation of oil content, protein accumulation and salt tolerance enhancement in other plants. Copyright © 2018 Elsevier B.V. All rights reserved.

Mosquito Consumption by Insectivorous Bats: Does Size Matter?

PubMed Central

Gonsalves, Leroy; Bicknell, Brian; Law, Brad; Webb, Cameron; Monamy, Vaughan

2013-01-01

Insectivorous bats have often been touted as biological control for mosquito populations. However, mosquitoes generally represent only a small proportion of bat diet. Given the small size of mosquitoes, restrictions imposed on prey detectability by low frequency echolocation, and variable field metabolic rates (FMR), mosquitoes may not be available to or profitable for all bats. This study investigated whether consumption of mosquitoes was influenced by bat size, which is negatively correlated with echolocation frequency but positively correlated with bat FMR. To assess this, we investigated diets of five eastern Australian bat species (Vespadelus vulturnus Thomas, V. pumilus Gray, Miniopterus australis Tomes, Nyctophilus gouldi Tomes and Chalinolobus gouldii Gray) ranging in size from 4-14 g in coastal forest, using molecular analysis of fecal DNA. Abundances of potential mosquito and non-mosquito prey were concurrently measured to provide data on relative prey abundance. Aedes vigilax was locally the most abundant mosquito species, while Lepidoptera the most abundant insect order. A diverse range of prey was detected in bat feces, although members of Lepidoptera dominated, reflecting relative abundance at trap sites. Consumption of mosquitoes was restricted to V. vulturnus and V. pumilus, two smaller sized bats (4 and 4.5 g). Although mosquitoes were not commonly detected in feces of V. pumilus, they were present in feces of 55 % of V. vulturnus individuals. To meet nightly FMR requirements, Vespadelus spp. would need to consume ~600-660 mosquitoes on a mosquito-only diet, or ~160-180 similar sized moths on a moth-only diet. Lower relative profitability of mosquitoes may provide an explanation for the low level of mosquito consumption among these bats and the absence of mosquitoes in feces of larger bats. Smaller sized bats, especially V. vulturnus, are likely to be those most sensitive to reductions in mosquito abundance and should be monitored during mosquito

Plant extracts as potential mosquito larvicides

PubMed Central

Ghosh, Anupam; Chowdhury, Nandita; Chandra, Goutam

2012-01-01

Mosquitoes act as a vector for most of the life threatening diseases like malaria, yellow fever, dengue fever, chikungunya ferver, filariasis, encephalitis, West Nile Virus infection, etc. Under the Integrated Mosquito Management (IMM), emphasis was given on the application of alternative strategies in mosquito control. The continuous application of synthetic insecticides causes development of resistance in vector species, biological magnification of toxic substances through the food chain and adverse effects on environmental quality and non target organisms including human health. Application of active toxic agents from plant extracts as an alternative mosquito control strategy was available from ancient times. These are non-toxic, easily available at affordable prices, biodegradable and show broad-spectrum target-specific activities against different species of vector mosquitoes. In this article, the current state of knowledge on phytochemical sources and mosquitocidal activity, their mechanism of action on target population, variation of their larvicidal activity according to mosquito species, instar specificity, polarity of solvents used during extraction, nature of active ingredient and promising advances made in biological control of mosquitoes by plant derived secondary metabolites have been reviewed. PMID:22771587

Plant extracts as potential mosquito larvicides.

PubMed

Ghosh, Anupam; Chowdhury, Nandita; Chandra, Goutam

2012-05-01

Mosquitoes act as a vector for most of the life threatening diseases like malaria, yellow fever, dengue fever, chikungunya ferver, filariasis, encephalitis, West Nile Virus infection, etc. Under the Integrated Mosquito Management (IMM), emphasis was given on the application of alternative strategies in mosquito control. The continuous application of synthetic insecticides causes development of resistance in vector species, biological magnification of toxic substances through the food chain and adverse effects on environmental quality and non target organisms including human health. Application of active toxic agents from plant extracts as an alternative mosquito control strategy was available from ancient times. These are non-toxic, easily available at affordable prices, biodegradable and show broad-spectrum target-specific activities against different species of vector mosquitoes. In this article, the current state of knowledge on phytochemical sources and mosquitocidal activity, their mechanism of action on target population, variation of their larvicidal activity according to mosquito species, instar specificity, polarity of solvents used during extraction, nature of active ingredient and promising advances made in biological control of mosquitoes by plant derived secondary metabolites have been reviewed.

General Information about Mosquitoes

MedlinePlus

... they can use without posing unreasonable risk to human health and the environment. State and local government agencies play a critical role in protecting public health from mosquito-borne ... use of pesticides for mosquito control is appropriate for their area. ...

Mosquitoes: A Resource Book for the Classroom.

ERIC Educational Resources Information Center

Gillmor, Mary S.; And Others

This booklet was written for anyone interested in growing mosquitoes and experimenting with them. There are three major sections: (1) rationale for studying mosquitoes, (2) raising mosquitoes, and (3) some scientific findings. The first section describes basic information about mosquitoes. The second section includes information about materials,…

Mineral resource of the month: salt

USGS Publications Warehouse

Kostick, Dennis S.

2010-01-01

The article presents information on various types of salt. Rock salt is either found from underground halite deposits or near the surface. Other types of salt include solar salt, salt brine, and vacuum pan salt. The different uses of salt are also given including its use as a flavor enhancer, as a road deicing agent, and to manufacture sodium hydroxide.

Human disease causing viruses vectored by mosquitoes

USDA-ARS?s Scientific Manuscript database

There are a number of disease-causing viruses transmitted to people primarily through the bite of infected mosquitoes. Female mosquitoes take blood meals to produce eggs (Fig. 1). A mosquito that bites an infected animal may pick up a virus within the blood meal. If the mosquito is the appropriate s...

Post-hurricane Rita mosquito surveillance and the efficacy of Air Force aerial applications for mosquito control in east Texas.

PubMed

Breidenbaugh, Mark S; Haagsma, Karl A; Walker, Wes W; Sanders, David M

2008-06-01

Post-Hurricane Rita mosquito surveillance was carried out in 4 east Texas counties to determine mosquito abundance, species composition, and need for mosquito control. Subsequently, aerial applications of naled (Dibrom) for mosquito control were made by the Air Force Aerial Spray Flight, while continued surveillance documented the efficacy of the applications. Psorophora columbiae was the predominant species in landing counts. Twenty-two mosquito species were represented in light trap collections with Aedes atlanitcus/tormentor, Culex nigripalpus, Ae. vexans, and Ps. columbiae making up 91% of the total. A total of 102,001 ha (252,052 acres) were aerially treated based on high mosquito abundance, exposure of first responders and residents to nuisance biting, and local interruption of electric utilities. A significant 90% decline in mosquito abundance was observed posttreatment.

Aquatic insect predators and mosquito control.

PubMed

Shaalan, Essam Abdel-Salam; Canyon, Deon V

2009-12-01

Mosquitoes are serious biting pests and obligate vectors of many vertebrate pathogens. Their immature larval and pupal life stages are a common feature in most tropical and many temperate water bodies and often form a significant proportion of the biomass. Control strategies rely primarily on the use of larvicides and environmental modification to reduce recruitment and adulticides during periods of disease transmission. Larvicides are usually chemical but can involve biological toxins, agents or organisms. The use of insect predators in mosquito control has been exploited in a limited fashion and there is much room for further investigation and implementation. Insects that are recognized as having predatorial capacity with regard to mosquito prey have been identified in the Orders Odonata, Coleoptera, Diptera (primarily aquatic predators), and Hemiptera (primarily surface predators). Although their capacity is affected by certain biological and physical factors, they could play a major role in mosquito control. Furthermore, better understanding for the mosquitoes-predators relationship(s) could probably lead to satisfactory reduction of mosquito-borne diseases by utilizing either these predators in control programs, for instance biological and/or integrated control, or their kairomones as mosquitoes' ovipoisting repellents. This review covers the predation of different insect species on mosquito larvae, predator-prey-habitat relationships, co-habitation developmental issues, survival and abundance, oviposition avoidance, predatorial capacity and integrated vector control.

Mosquito repellents in frog skin

PubMed Central

Williams, C.R; Smith, B.P.C; Best, S.M; Tyler, M.J

2006-01-01

The search for novel insect repellents has been driven by health concerns over established synthetic compounds such as diethyl-m-toluamide (DEET). Given the diversity of compounds known from frog skin and records of mosquito bite and ectoparasite infestation, the presence of mosquito repellents in frogs seemed plausible. We investigated frog skin secretions to confirm the existence of mosquito repellent properties. Litoria caerulea secretions were assessed for mosquito repellency by topical application on mice. The secretions provided protection against host-seeking Culex annulirostris mosquitoes. Olfactometer tests using aqueous washes of skin secretions from L. caerulea and four other frog species were conducted to determine whether volatile components were responsible for repellency. Volatiles from Litoria rubella and Uperoleia mjobergi secretions were repellent to C. annulirostris, albeit not as repellent as a DEET control. The demonstration of endogenous insect repellents in amphibians is novel, and demonstrates that many aspects of frog chemical ecology remain unexplored. PMID:17148373

Allethrin-Based Mosquito Control Device Causing Knockdown, Morbidity, and Mortality in Four Species of Field-Caught Mosquitoes (Diptera: Culicidae).

PubMed

Bibbs, Christopher S; Fulcher, Ali; Xue, Rui-De

2015-07-01

A mosquito control device marketed for spatial repellency, the ThermaCELL Mosquito Repellent Appliance, was evaluated in semifield trials against multiple field-caught species of mosquito. Using paper and mesh cages, mosquito test groups of at least 30 mosquitoes were suspended in a 2,337 cubic foot outdoor space while two ThermaCELL repellent devices were active. After 30 min of treatment, cages were moved to the laboratory to observe knockdown, morbidity, and mortality for 24 h. Species tested included Aedes atlanticus Dyar and Knab (98% average mortality), Psorophora ferox Humboldt (97% average mortality), Psorophora columbiae Dyar and Knab (96% average mortality), and Aedes taeniorhynchus Wiedemann (84% average mortality). The repellent devices showed effectiveness with high knockdown and mortality across all species tested. Mosquito control devices like the ThermaCELL Mosquito Repellent Appliance may have further practical applications to help combat viral exposures by limiting host mosquitoes. Such devices may provide a functional alternative to DEET dependence in the current state of mosquito management. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Metal salt catalysts for enhancing hydrogen spillover

DOEpatents

Yang, Ralph T; Wang, Yuhe

2013-04-23

A composition for hydrogen storage includes a receptor, a hydrogen dissociating metal doped on the receptor, and a metal salt doped on the receptor. The hydrogen dissociating metal is configured to spill over hydrogen to the receptor, and the metal salt is configured to increase a rate of the spill over of the hydrogen to the receptor.

Efficacy of Mosquito Traps for Collecting Potential West Nile Mosquito Vectors in a Natural Mediterranean Wetland

PubMed Central

Roiz, David; Roussel, Marion; Muñoz, Joaquin; Ruiz, Santiago; Soriguer, Ramón; Figuerola, Jordi

2012-01-01

Surveillance, research, and control of mosquito-borne diseases such as West Nile virus require efficient methods for sampling mosquitoes. We compared the efficacy of BG-Sentinel and Centers for Disease Control and Prevention (CDC)-CO2 traps in terms of the abundances of host-seeking and blood-fed female mosquitoes and the origin of mosquito bloodmeals. Our results indicate that BG-Sentinel traps that use CO2 and attractants are as effective as CDC-CO2 traps for Culex mosquito species, Ochlerotatus caspius, and they are also highly efficient at capturing Anopheles atroparvus host-seeking and blood-fed females with or without CO2. The CDC-CO2 trap is the least efficient method for capturing blood-fed females. BG-Sentinel traps with attractants and CO2 were significantly better at capturing mosquitoes that had fed on mammals than the unbaited BG-Sentinel and CDC-CO2 traps in the cases of An. atroparvus and Cx. theileri. These results may help researchers to optimize trapping methods by obtaining greater sample sizes and saving time and money. PMID:22492149

Mechanism of salt-induced activity enhancement of a marine-derived laccase, Lac15.

PubMed

Li, Jie; Xie, Yanan; Wang, Rui; Fang, Zemin; Fang, Wei; Zhang, Xuecheng; Xiao, Yazhong

2018-04-01

Laccase (benzenediol: oxygen oxidoreductases, EC1.10.3.2) is a multi-copper oxidase capable of oxidizing a variety of phenolic and other aromatic organic compounds. The catalytic power of laccase makes it an attractive candidate for potential applications in many areas of industry including biodegradation of organic pollutants and synthesis of novel drugs. Most laccases are vulnerable to high salt and have limited applications. However, some laccases are not only tolerant to but also activated by certain concentrations of salt and thus have great application potential. The mechanisms of salt-induced activity enhancement of laccases are unclear as yet. In this study, we used dynamic light scattering, size exclusion chromatography, analytical ultracentrifugation, intrinsic fluorescence emission, circular dichroism, ultraviolet-visible light absorption, and an enzymatic assay to investigate the potential correlation between the structure and activity of the marine-derived laccase, Lac15, whose activity is promoted by low concentrations of NaCl. The results showed that low concentrations of NaCl exert little influence on the protein structure, which was partially folded in the absence of the salt; moreover, the partially folded rather than the fully folded state seemed to be favorable for enzyme activity, and this partially folded state was distinctive from the so-called 'molten globule' occasionally observed in active enzymes. More data indicated that salt might promote laccase activity through mechanisms involving perturbation of specific local sites rather than a change in global structure. Potential binding sites for chloride ions and their roles in enzyme activity promotion are proposed.

Salt fortified with diethylcarbamazine (DEC) as an effective intervention for lymphatic filariasis, with lessons learned from salt iodization programmes.

PubMed

Houston, R

2000-01-01

DEC-fortified salt has been used successfully as a principal public health tool to eliminate lymphatic filariasis (LF) in China and, less extensively, in several other countries. Studies from 1967 to the present conducted in Brazil, Japan, Tanzania, India, China, and Taiwan involving administration of DEC salt for 18 days to 1 year, have shown this intervention to be effective for both bancroftian and brugian filariasis, as measured by reductions in both microfilarial density and positivity, and in some studies through reduction in mosquito positivity rates as well. Furthermore, studies suggest specific advantages from using DEC salt, including lack of side effects, particularly for bancroftian filariasis, and ability to reduce prevalence below 1% when used in conjunction with standard regimens of DEC tablets. However, use of DEC salt as a control tool suffers from a concern that health authorities might find it difficult to manage a programme involving a commodity such as salt. In the past decade, the very successful global efforts to eliminate iodine deficiency through universal salt iodization have demonstrated that partnership with the salt industry can be both successful and effective as a public health tool. Use of DEC salt can be most successfully implemented in areas in which (a) there is adequate governmental support for its use and for elimination of filariasis, (b) filariasis-endemic areas are clearly defined, (c) political leaders, health officials and the salt industry agree that DEC salt is an appropriate intervention, (d) the salt industry is well-organized and has known distribution patterns, (e) a successful national salt iodization effort exists, (f) a monitoring system exists that ensures adequacy of salt iodine content during production and that can also measure household coverage, and (g) measurement of impact on transmission of LF with the new antigen or filarial DNA detection methods can be established. There are advantages and disadvantages

Load-bearing ability of the mosquito tarsus on water surfaces arising from its flexibility

NASA Astrophysics Data System (ADS)

Kong, X. Q.; Liu, J. L.; Zhang, W. J.; Qu, Y. D.

2015-03-01

Mosquitoes possess a remarkable ability to stand effortlessly and walk freely on water surfaces because their six legs provide a large force to support the body weight. This study is focused on the role of the tarsus (the distal segment of the mosquito leg) because it was observed that normally only the tarsi make contact with water. The maximum value of the supporting force of the tarsus (6 mm long) in contact with water is estimated as 492 ± 5 μN, nearly 20 times the body weight of the mosquito, whereas the value for the whole leg (11 mm) is about 23 times the body weight. We demonstrate that the huge force provided by the tarsus originates from its flexibility, which ensures that the leg does not easily pierce the water. Adjustment of the initial stepping angle of the tarsus assists the mosquito to control the supporting force. These findings help to illustrate how mosquitoes stand or walk on water with only their tarsi in nearly horizontal contact with the water surface. Besides enhancing our understanding of mechanisms underlying "walking on water" by semi-aquatic insects, these investigations could provide inspiration for the biomimetic design of miniature robotics.

Cloning of a cystatin gene from sugar beet M14 that can enhance plant salt tolerance.

PubMed

Wang, Yuguang; Zhan, Yanan; Wu, Chuan; Gong, Shilong; Zhu, Ning; Chen, Sixue; Li, Haiying

2012-08-01

An open reading frame encoding a cysteine protease inhibitor, cystatin was isolated from the buds of sugar beet monosomic addition line M14 (BvM14) using 5'-/3'-RACE method. It encoded a polypeptide of 104 amino acids with conserved G and PW motifs, the consensus phytocystatin sequence LARFAV and the active site QVVAG. The protein showed significant homology to other plant cystatins. BvM14-cystatin was expressed ubiquitously in roots, stems, leaves and flower tissues with relatively high abundance in developing stems and roots. It was found to be localized in the nucleus, cytoplasm and plasma membrane. Recombinant BvM14-cystatin expressed in Escherichia coli was purified and it exhibited cysteine protease inhibitor activity. Salt-stress treatment induced BvM14-cystatin transcript levels in the M14 seedlings. Homozygous Arabidopsis plants over-expressing BvM14-cystatin showed enhanced salt tolerance. Taken together, these data improved understanding of the functions of BvM14-cystatin and highlighted the possibility of employing the cystatin in engineering plants for enhanced salt tolerance. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Mosquito Oviposition Behavior and Vector Control

PubMed Central

Day, Jonathan F.

2016-01-01

The burden of gene transfer from one mosquito generation to the next falls on the female and her eggs. The selection of an oviposition site that guarantees egg and larval survival is a critical step in the reproductive process. The dangers associated with ephemeral aquatic habitats, lengthy droughts, freezing winters, and the absence of larval nutrition makes careful oviposition site selection by a female mosquito extremely important. Mosquito species exhibit a remarkable diversity of oviposition behaviors that ensure eggs are deposited into microenvironments conducive for successful larval development and the emergence of the next mosquito generation. An understanding of mosquito oviposition behavior is necessary for the development of surveillance and control opportunities directed against specific disease vectors. For example, Aedes aegypti Linnaeus is the vector of viruses causing important human diseases including yellow fever, dengue, chikungunya, and Zika. The preference of this species to oviposit in natural and artificial containers has facilitated the development of Ae. aegypti-specific surveillance and toxic oviposition traps designed to detect and control this important vector species in and around disease foci. A better understanding of the wide diversity of mosquito oviposition behavior will allow the development of new and innovative surveillance and control devices directed against other important mosquito vectors of human and animal disease. PMID:27869724

Avian Plasmodium in Eastern Austrian mosquitoes.

PubMed

Schoener, Ellen; Uebleis, Sarah Susanne; Butter, Julia; Nawratil, Michaela; Cuk, Claudia; Flechl, Eva; Kothmayer, Michael; Obwaller, Adelheid G; Zechmeister, Thomas; Rubel, Franz; Lebl, Karin; Zittra, Carina; Fuehrer, Hans-Peter

2017-09-29

Insect vectors, namely mosquitoes (Diptera: Culicidae), are compulsory for malaria parasites (Plasmodium spp.) to complete their life cycle. Despite this, little is known about vector competence of different mosquito species for the transmission of avian malaria parasites. In this study, nested PCR was used to determine Plasmodium spp. occurrence in pools of whole individuals, as well as the diversity of mitochondrial cytochrome b gene sequences in wild-caught mosquitoes sampled across Eastern Austria in 2013-2015. A total of 45,749 mosquitoes in 2628 pools were collected, of which 169 pools (6.43%) comprising 9 mosquito species were positive for avian Plasmodium, with the majority of positives in mosquitoes of Culex pipiens s.l./Culex torrentium. Six different avian Plasmodium lineages were found, the most common were Plasmodium vaughani SYAT05, Plasmodium sp. Linn1 and Plasmodium relictum SGS1. In 2014, mosquitoes of the Culex pipiens complex were genetically identified and Culex pipiens f. pipiens presented with the highest number of avian Plasmodium positives (n = 37; 16.74%). Despite this, the minimum infection rate (MIR) was highest in Culex torrentium (5.36%) and Culex pipiens f. pipiens/f. molestus hybrids (5.26%). During 2014 and 2015, seasonal and annual changes in Plasmodium lineage distribution were also observed. In both years P. vaughani SYAT05 dominated at the beginning of the sampling period to be replaced later in the year by P. relictum SGS1 (2014) and Plasmodium sp. Linn1 (2015). This is the first large-scale study of avian Plasmodium parasites in Austrian mosquitoes. These results are of special interest, because molecular identification of the taxa of the Cx. pipiens complex and Cx. torrentium enabled the determination of Plasmodium prevalence in the different mosquito taxa and hybrids of this complex. Since pools of whole insects were used, it is not possible to assert any vector competence in any of the examined mosquitoes, but the results

Mosquitoes in Moose Country: A Mosquito Survey of Northern Minnesota.

PubMed

Kinsley, A C; Moon, R D; Johnson, K; Carstensen, M; Neitzel, D; Craft, M E

2016-06-01

An adult mosquito survey was conducted at 12 sites using carbon dioxide traps in northern Minnesota throughout the summer of 2012. Specimens were counted, identified to species, sorted into pools, and tested for eastern equine encephalitis (EEEV) and West Nile virus (WNV). Our findings extend the known range of Culiseta melanura, Anopheles barberi, and An. quadrimaculatus and document the presence and abundance of 27 other mosquito taxa in the region. None of the pools tested positive for EEEV or WNV.

Entomopathogenic fungi for mosquito control: A review

PubMed Central

Scholte, Ernst-Jan; Knols, Bart G.J.; Samson, Robert A.; Takken, Willem

2004-01-01

Fungal diseases in insects are common and widespread and can decimate their populations in spectacular epizootics. Virtually all insect orders are susceptible to fungal diseases, including Dipterans. Fungal pathogens such as Lagenidium, Coelomomyces and Culicinomyces are known to affect mosquito populations, and have been studied extensively. There are, however, many other fungi that infect and kill mosquitoes at the larval and/or adult stage. The discovery, in 1977, of the selective mosquito-pathogenic bacterium Bacillus thuringiensis Berliner israelensis (Bti) curtailed widespread interest in the search for other suitable biological control agents. In recent years interest in mosquito-killing fungi is reviving, mainly due to continuous and increasing levels of insecticide resistance and increasing global risk of mosquito-borne diseases. This review presents an update of published data on mosquito-pathogenic fungi and mosquito-pathogen interactions, covering 13 different fungal genera. Notwithstanding the potential of many fungi as mosquito control agents, only a handful have been commercialized and are marketed for use in abatement programs. We argue that entomopathogenic fungi, both new and existing ones with renewed/improved efficacies may contribute to an expansion of the limited arsenal of effective mosquito control tools, and that they may contribute in a significant and sustainable manner to the control of vector-borne diseases such as malaria, dengue and filariasis. PMID:15861235

Escaping blood-fed malaria mosquitoes minimize tactile detection without compromising on take-off speed.

PubMed

Muijres, F T; Chang, S W; van Veen, W G; Spitzen, J; Biemans, B T; Koehl, M A R; Dudley, R

2017-10-15

To escape after taking a blood meal, a mosquito must exert forces sufficiently high to take off when carrying a load roughly equal to its body weight, while simultaneously avoiding detection by minimizing tactile signals exerted on the host's skin. We studied this trade-off between escape speed and stealth in the malaria mosquito Anopheles coluzzii using 3D motion analysis of high-speed stereoscopic videos of mosquito take-offs and aerodynamic modeling. We found that during the push-off phase, mosquitoes enhanced take-off speed using aerodynamic forces generated by the beating wings in addition to leg-based push-off forces, whereby wing forces contributed 61% of the total push-off force. Exchanging leg-derived push-off forces for wing-derived aerodynamic forces allows the animal to reduce peak force production on the host's skin. By slowly extending their long legs throughout the push-off, mosquitoes spread push-off forces over a longer time window than insects with short legs, thereby further reducing peak leg forces. Using this specialized take-off behavior, mosquitoes are capable of reaching take-off speeds comparable to those of similarly sized fruit flies, but with weight-normalized peak leg forces that were only 27% of those of the fruit flies. By limiting peak leg forces, mosquitoes possibly reduce the chance of being detected by the host. The resulting combination of high take-off speed and low tactile signals on the host might help increase the mosquito's success in escaping from blood-hosts, which consequently also increases the chance of transmitting vector-borne diseases, such as malaria, to future hosts. © 2017. Published by The Company of Biologists Ltd.

Mosquitoes established in Lhasa city, Tibet, China

PubMed Central

2013-01-01

Background In 2009, residents of Lhasa city, Tibet Autonomous Region (TAR), China reported large numbers of mosquitoes and bites from these insects. It is unclear whether this was a new phenomenon, which species were involved, and whether these mosquitoes had established themselves in the local circumstances. Methods The present study was undertaken in six urban sites of Chengguan district Lhasa city, Tibet. Adult mosquitoes were collected by bed net trap, labor hour method and light trap in August 2009 and August 2012. The trapped adult mosquitoes were initially counted and identified according to morphological criteria, and a proportion of mosquitoes were examined more closely using a multiplex PCR assay. Results 907 mosquitoes of the Culex pipiens complex were collected in this study. Among them, 595 were females and 312 were males. There was no significant difference in mosquito density monitored by bed net trap and labor hour method in 2009 and 2012. Of 105 mosquitoes identified by multiplex PCR, 36 were pure mosquitoes (34.29%) while 69 were hybrids (65.71%). The same subspecies of Culex pipiens complex were observed by bed net trap, labor hour method and light trap in 2009 and 2012. Conclusion The local Culex pipiens complex comprises the subspecies Cx. pipiens pipiens, Cx. pipiens pallens, Cx. pipiens quinquefasciatus and its hybrids. Mosquitoes in the Cx. pipiens complex, known to be, potentially, vectors of periodic filariasis and encephalitis, are now present from one season to the next, and appear to be established in Lhasa City, TAR. PMID:24060238

Rickettsia Species in African Anopheles Mosquitoes

PubMed Central

Socolovschi, Cristina; Pages, Frédéric; Ndiath, Mamadou O.; Ratmanov, Pavel; Raoult, Didier

2012-01-01

Background There is higher rate of R. felis infection among febrile patients than in healthy people in Sub-Saharan Africa, predominantly in the rainy season. Mosquitoes possess a high vectorial capacity and, because of their abundance and aggressiveness, likely play a role in rickettsial epidemiology. Methodology/Principal Findings Quantitative and traditional PCR assays specific for Rickettsia genes detected rickettsial DNA in 13 of 848 (1.5%) Anopheles mosquitoes collected from Côte d’Ivoire, Gabon, and Senegal. R. felis was detected in one An. gambiae molecular form S mosquito collected from Kahin, Côte d’Ivoire (1/77, 1.3%). Additionally, a new Rickettsia genotype was detected in five An. gambiae molecular form S mosquitoes collected from Côte d’Ivoire (5/77, 6.5%) and one mosquito from Libreville, Gabon (1/88, 1.1%), as well as six An. melas (6/67, 9%) mosquitoes collected from Port Gentil, Gabon. A sequence analysis of the gltA, ompB, ompA and sca4 genes indicated that this new Rickettsia sp. is closely related to R. felis. No rickettsial DNA was detected from An. funestus, An. arabiensis, or An. gambiae molecular form M mosquitoes. Additionally, a BLAST analysis of the gltA sequence from the new Rickettsia sp. resulted in a 99.71% sequence similarity to a species (JQ674485) previously detected in a blood sample of a Senegalese patient with a fever from the Bandafassi village, Kedougou region. Conclusion R. felis was detected for the first time in An. gambiae molecular form S, which represents the major African malaria vector. The discovery of R. felis, as well as a new Rickettsia species, in mosquitoes raises new issues with respect to African rickettsial epidemiology that need to be investigated, such as bacterial isolation, the degree of the vectorial capacity of mosquitoes, the animal reservoirs, and human pathogenicity. PMID:23118963

Mosquito Lagoon environmental resources inventory

NASA Technical Reports Server (NTRS)

Provancha, Jane A.; Hall, Carlton R.; Oddy, Donna M.

1992-01-01

This document provides a synopsis of biotic and abiotic data collected in the Mosquito Lagoon area in relation to water quality. A holistic ecological approach was used in this review to allow for summaries of climate, land use, vegetation, geohydrology, water quality, fishes, sea turtles, wading birds, marine mammals, invertebrates, shellfish, and mosquito control. The document includes a bibliographic database list of 157 citations that have references to the Mosquito Lagoon, many of which were utilized in development of the text.

Salt-enhanced chemical weathering of building materials and bacterial mineralization of calcium carbonate as a treatment

NASA Astrophysics Data System (ADS)

Schiro, M.; Ruiz-Agudo, E.; Jroundi, F.; Gonzalez-Muñoz, M. T.; Rodriguez-Navarro, C.

2012-04-01

Salt weathering is an important mechanism contributing to the degradation and loss of stone building materials. In addition to the physical weathering resulting from crystallization pressure, the presence of salts in solution greatly enhances the chemical weathering potential of pore waters. Flow through experiments quantify the dissolution rates of calcite and quartz grains (63-125 micrometer diameter) when subjected to 1.0 ionic strength solutions of MgSO4, MgCl, Na2SO4 or NaCl. Results indicate that the identity of the cation is the primary control over the dissolution rate of both calcite and quartz substrates, with salt-enhanced dissolution occurring most rapidly in Mg2+ bearing solutions. It has been observed that weathering rates of rocks in nature, as well as building stones, are slowed down by naturally occurring or artificially produced patinas. These tend to be bacterially produced, durable mineralized coatings that lend some degree of protection to the underlying stone surface [1]. Our research shows that bacterially produced carbonate coatings can be quite effective at reducing chemical weathering of stone by soluble salts. The calcite-producing-bacteria used in this study were isolated from stone monuments in Granada, Spain [2] and cultivated in an organic-rich culture medium on a variety of artificial and natural substrates (including limestone, marble, sandstone, quartz, calcite single crystals, glass cover-slips, and sintered porous glass). Scanning electron microscopy (FESEM) was used to image bacterial calcite growth and biofilm formation. In-situ atomic force microscopy (AFM) enabled calculation of dissolution rates of untreated and bacterially treated surfaces. 2D-XRD showed the mineralogy and crystallographic orientation of bacterial calcium carbonate. Results indicate that bacterially produced calcite crystals form a coherent, mechanically resistant surface layer in perfect crystallographic continuity with the calcite substrate (self

Repellent action of neem cream against mosquitoes.

PubMed

Dua, V K; Nagpal, B N; Sharma, V P

1995-06-01

Neem cream was used as mosquito repellent to provide protection against Aedes albopictus, Ae. aegypti, Culex quinquefasciatus, Anopheles culicifacies and An. subpictus mosquitoes. The application of neem cream on exposed body parts @2.0 gm/person showed 78 (range 65-95), 89 (range 66-100) and 94.4 (range 66-100) per cent protection against Aedes, Culex and Anopheles mosquitoes respectively. Significant difference was observed between neem cream treated and untreated group of population for Aedes mosquitoes (p < 0.001). Application of neem cream was found to be a safe and suitable alternative to insecticide impregnated coils for personal protection against mosquitoes and one application was 68% effective for four hours.

Overexpression of a novel soybean gene modulating Na+ and K+ transport enhances salt tolerance in transgenic tobacco plants.

PubMed

Chen, Huatao; He, Hui; Yu, Deyue

2011-01-01

Salt is an important factor affecting the growth and development of soybean in saline soil. In this study, a novel soybean gene encoding a transporter (GmHKT1) was identified and its function analyzed using transgenic plants. GmHKT1 encoded a protein of 419 amino acids, with a potential molecular mass of 47.06 kDa and a predicted pI value of 8.59. Comparison of the genomic and cDNA sequences of GmHKT1 identified no intron. The deduced amino acid sequence of GmHKT1 showed 38-49% identity with other plant HKT-like sequences. RT-PCR analysis showed that the expression of GmHKT1 was upregulated by salt stress (150 mM NaCl) in roots and leaves but not in stems. Overexpression of GmHKT1 significantly enhanced the tolerance of transgenic tobacco plants to salt stress, compared with non-transgenic plants. To investigate the role of GmHKT1 in K(+) and Na(+) transport, we compared K(+) and Na(+) accumulation in roots and shoots of wild-type and transgenic tobacco plants. The results suggested that GmHKT1 is a transporter that affected K(+) and Na(+) transport in roots and shoots, and regulated Na(+) /K(+) homeostasis in these organs. Our findings suggest that GmHKT1 plays an important role in response to salt stress and would be useful in engineering crop plants for enhanced tolerance to salt stress. Copyright © Physiologia Plantarum 2010.

Acclimation of hydrogen peroxide enhances salt tolerance by activating defense-related proteins in Panax ginseng C.A. Meyer.

PubMed

Sathiyaraj, Gayathri; Srinivasan, Sathiyaraj; Kim, Yu-Jin; Lee, Ok Ran; Parvin, Shonana; Balusamy, Sri Renuka Devi; Khorolragchaa, Atlanzul; Yang, Deok Chun

2014-06-01

The effect of exogenously applied hydrogen peroxide on salt stress tolerance was investigated in Panax ginseng. Pretreatment of ginseng seedlings with 100 μM H2O2 increased the physiological salt tolerance of the ginseng plant and was used as the optimum concentration to induce salt tolerance capacity. Treatment with exogenous H2O2 for 2 days significantly enhanced salt stress tolerance in ginseng seedlings by increasing the activities of ascorbate peroxidase, catalase and guaiacol peroxidase and by decreasing the concentrations of malondialdehyde (MDA) and endogenous H2O2 as well as the production rate of superoxide radical (O2(-)). There was a positive physiological effect on the growth and development of salt-stressed seedlings by exogenous H2O2 as measured by ginseng dry weight and both chlorophyll and carotenoid contents. Exogenous H2O2 induced changes in MDA, O2(-), antioxidant enzymes and antioxidant compounds, which are responsible for increases in salt stress tolerance. Salt treatment caused drastic declines in ginseng growth and antioxidants levels; whereas, acclimation treatment with H2O2 allowed the ginseng seedlings to recover from salt stress by up-regulation of defense-related proteins such as antioxidant enzymes and antioxidant compounds.

Risk Factors for Mosquito House Entry in the Lao PDR

PubMed Central

Hiscox, Alexandra; Khammanithong, Phasouk; Kaul, Surinder; Sananikhom, Pany; Luthi, Ruedi; Brey, Paul T.; Lindsay, Steve W.

2013-01-01

Background Construction of the Nam Theun 2 hydroelectric project and flooding of a 450 km2 area of mountain plateau in south-central Lao PDR resulted in the resettlement of 6,300 people to newly built homes. We examined whether new houses would have altered risk of house entry by mosquitoes compared with traditional homes built from poorer construction materials. Methodology/Principal Findings Surveys were carried out in the Nam Theun 2 resettlement area and a nearby traditional rice farming area in 2010. Mosquitoes were sampled in bedrooms using CDC light traps in 96 resettlement houses and 96 traditional houses and potential risk factors for mosquito house entry were recorded. Risk of mosquito house entry was more than twice as high in traditional bamboo houses compared with those newly constructed from wood (Putative Japanese Encephalitis (JE) vector incidence rate ratio (IRR) = 2.26, 95% CI 1.38–3.70, P = 0.001; Anopheline IRR = 2.35, 95% CI: 1.30–4.23, P = 0.005). Anophelines were more common in homes with cattle compared against those without (IRR = 2.32, 95% CI: 1.29–4.17, P = 0.005).Wood smoke from cooking fires located under the house or indoors was found to be protective against house entry by both groups of mosquito, compared with cooking in a separate room beside the house (Putative JE vector IRR = 0.43, 95% CI: 0.26–0.73, P = 0.002; Anopheline IRR = 0.22, 95% CI: 0.10–0.51, P<0.001). Conclusions/Significance Construction of modern wooden homes should help reduce human-mosquito contact in the Lao PDR. Reduced mosquito contact rates could lead to reduced transmission of diseases such as JE and malaria. Cattle ownership was associated with increased anopheline house entry, so zooprophylaxis for malaria control is not recommended in this area. Whilst wood smoke was protective against putative JE vector and anopheline house entry we do not recommend indoor cooking since smoke inhalation can enhance respiratory

New Innovations in Biological Control of Mosquitoes.

USDA-ARS?s Scientific Manuscript database

Biological control of mosquitoes is a component of an integrated pest management strategy and includes general predators, parasites and pathogens. Pathogens of mosquitoes include bacteria, viruses, fungi and protists. The most successful group for applied mosquito control include the bacteria Baci...

Update on the American Mosquito Control Association

USDA-ARS?s Scientific Manuscript database

The American Mosquito Control Association in a non-profit scientific organization dedicated to promoting the highest standard in professional mosquito control. It is comprised of more than 1300 members representing students, scientists, regulators, industry, mosquito control employees and many other...

The transcriptome of the mosquito Aedes fluviatilis (Diptera: Culicidae), and transcriptional changes associated with its native Wolbachia infection.

PubMed

Caragata, E P; Pais, F S; Baton, L A; Silva, J B L; Sorgine, M H F; Moreira, L A

2017-01-03

Wolbachia is a bacterial endosymbiont that naturally infects a wide range of insect species, and causes drastic changes to host biology. Stable infections of Wolbachia in mosquitoes can inhibit infection with medically important pathogens such as dengue virus and malaria-causing Plasmodium parasites. However, some native Wolbachia strains can enhance infection with certain pathogens, as is the case for the mosquito Aedes fluviatilis, where infection with Plasmodium gallinaceum is enhanced by the native wFlu Wolbachia strain. To better understand the biological interactions between mosquitoes and native Wolbachia infections, and to investigate the process of pathogen enhancement, we used RNA-Seq to generate the transcriptome of Ae. fluviatilis with and without Wolbachia infection. In total, we generated 22,280,160 Illumina paired-end reads from Wolbachia-infected and uninfected mosquitoes, and used these to make a de novo transcriptome assembly, resulting in 58,013 contigs with a median sequence length of 443 bp and an N50 of 2454 bp. Contigs were annotated through local alignments using BlastX, and associated with both gene ontology and KEGG orthology terms. Through baySeq, we identified 159 contigs that were significantly upregulated due to Wolbachia infection, and 98 that were downregulated. Critically, we saw no changes to Toll or IMD immune gene transcription, but did see evidence that wFlu infection altered the expression of several bacterial recognition genes, and immune-related genes that could influence Plasmodium infection. wFlu infection also had a widespread effect on a number of host physiological processes including protein, carbohydrate and lipid metabolism, and oxidative stress. We then compared our data set with transcriptomic data for other Wolbachia infections in Aedes aegypti, and identified a core set of 15 gene groups associated with Wolbachia infection in mosquitoes. While the scale of transcriptional changes associated with wFlu infection

Significant Enhancement in the Thermoelectric Properties of PEDOT:PSS Films through a Treatment with Organic Solutions of Inorganic Salts.

PubMed

Fan, Zeng; Du, Donghe; Yu, Zhimeng; Li, Pengcheng; Xia, Yijie; Ouyang, Jianyong

2016-09-07

Conducting polymers have promising thermoelectric application because they have many advantages including abundant elements, mechanical flexibility, and nontoxicity. The thermoelectric properties of conducting polymers strongly depend on their chemical structure and microstructure. Here, we report a novel and facile method to significantly enhance the thermoelectric properties of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) ( PSS) films through a treatment with organic solutions of inorganic salts. N,N-Dimethylformamide (DMF) and a common inorganic salt like zinc chloride (ZnCl2) are used as the solvent and solute of the solutions, respectively. The treatments can significantly increase both the Seebeck coefficient and electrical conductivity of the PSS films. The thermoelectric properties of the PSS films are sensitive to the experimental conditions, such as the salt concentration, treatment temperature, and the cation of the salts. After treatment at the optimal experimental conditions, the PSS films can exhibit a Seebeck coefficient of 26.1 μV/K and an electrical conductivity of over 1400 S/cm at room temperature. The corresponding power factor is 98.2 μW/(m·K(2)). The mechanism for the enhancement in the thermoelectric properties is attributed to the segregation of some PSSH chains from PSS and the conformation change of PEDOT chains as a result of the synergetic effects of inorganic salts and DMF.

Measurement of landing mosquito density on humans

USDA-ARS?s Scientific Manuscript database

In conventional vector surveillance systems, adult mosquito density and the rate of human-mosquito contact is estimated from the mosquito numbers captured in mechanical traps. However, the design of the traps, their placement in the habitat and operating time, microclimate, and other environmental ...

Blood Feeding and Insulin-like Peptide 3 Stimulate Proliferation of Hemocytes in the Mosquito Aedes aegypti

PubMed Central

Castillo, Julio; Brown, Mark R.; Strand, Michael R.

2011-01-01

All vector mosquito species must feed on the blood of a vertebrate host to produce eggs. Multiple cycles of blood feeding also promote frequent contacts with hosts, which enhance the risk of exposure to infectious agents and disease transmission. Blood feeding triggers the release of insulin-like peptides (ILPs) from the brain of the mosquito Aedes aegypti, which regulate blood meal digestion and egg formation. In turn, hemocytes serve as the most important constitutive defense in mosquitoes against pathogens that enter the hemocoel. Prior studies indicated that blood feeding stimulates hemocytes to increase in abundance, but how this increase in abundance is regulated is unknown. Here, we determined that phagocytic granulocytes and oenocytoids express the A. aegypti insulin receptor (AaMIR). We then showed that: 1) decapitation of mosquitoes after blood feeding inhibited hemocyte proliferation, 2) a single dose of insulin-like peptide 3 (ILP3) sufficient to stimulate egg production rescued proliferation, and 3) knockdown of the AaMIR inhibited ILP3 rescue activity. Infection studies indicated that increased hemocyte abundance enhanced clearance of the bacterium Escherichia coli at lower levels of infection. Surprisingly, however, non-blood fed females better survived intermediate and high levels of E. coli infection than blood fed females. Taken together, our results reveal a previously unrecognized role for the insulin signaling pathway in regulating hemocyte proliferation. Our results also indicate that blood feeding enhances resistance to E. coli at lower levels of infection but reduces tolerance at higher levels of infection. PMID:21998579

Reception of odors and repellents in mosquitoes

PubMed Central

Ray, Anandasankar

2015-01-01

Mosquitoes use their sense of smell to find hosts, nectar, and oviposition sites, and to avoid repellents. A small number of mosquito species are adapted to feed on humans and have a major impact on public health by transmitting malaria, dengue, filariasis, etc. The application of odorants for behavioral control has not been fully realized yet due to complexity of the mosquito olfactory system. Recent progress in molecular and computational tools has enabled rigorous investigations of the mosquito olfactory system function and has started to reveal how specific receptors contribute to attractive and aversive behaviors. Here we discuss recent advances in linking odors to receptors and in exploiting this knowledge in finding attractants and repellents for mosquitoes. PMID:26202080

2nd International Forum for Surveillance and Control of Mosquitoes and Mosquito-borne Diseases

USDA-ARS?s Scientific Manuscript database

The Entomological Society of China (ESC) and Beijing Institute of Microbiology and Epidemiology (BIME) hosted the 2nd International Forum for Surveillance and Control of Mosquitoes and Mosquito-borne Diseases in Beijing, China, May 23-27, 2011. The theme of the Forum was “Impact of global climate ch...

On the relationship between the specific heat enhancement of salt-based nanofluids and the ionic exchange capacity of nanoparticles.

PubMed

Mondragón, Rosa; Juliá, J Enrique; Cabedo, Luis; Navarrete, Nuria

2018-05-14

Nanoparticles have been used in thermal applications to increase the specific heat of the molten salts used in Concentrated Solar Power plants for thermal energy storage. Although several mechanisms for abnormal enhancement have been proposed, they are still being investigated and more research is necessary. However, this nanoparticle-salt interaction can also be found in chemical applications in which nanoparticles have proved suitable to be used as an adsorbent for nitrate removal given their high specific surface, reactivity and ionic exchange capacity. In this work, the ionic exchange capacity mechanism for the nanoparticles functionalization phenomenon was evaluated. The ionic exchange capacity of silica and alumina nanoparticles dispersed in lithium, sodium and potassium nitrates was measured. Fourier-transform infrared spectroscopy tests confirmed the adsorption of nitrate ions on the nanoparticle surface. A relationship between the ionic exchange capacity of nanoparticles and the specific heat enhancement of doped molten salts was proposed for the first time.

Factors influencing infection and transmission of Anopheles gambiae densovirus (AgDNV) in mosquitoes.

PubMed

Barik, Tapan K; Suzuki, Yasutsugu; Rasgon, Jason L

2016-01-01

Anopheles gambiae densovirus (AgDNV) is a potential microbial agent for paratransgenesis and gene transduction in An. gambiae , the major vector of human malaria in sub-Saharan Africa. Understanding the interaction between AgDNV and An. gambiae is critical for using AgDNV in a basic and applied manner for Anopheles gene manipulation. Here, we tested the effects of mosquito age, sex, blood feeding status, and potential for horizontal transmission using an enhanced green fluorescent protein (EGFP) reporter AgDNV system. Neither mosquito age at infection nor feeding regime affected viral titers. Female mosquitoes were more permissive to viral infection than males. Despite low viral titers, infected males were able to venereally transmit virus to females during mating, where the virus was localized with the transferred sperm in the spermathecae. These findings will be useful for designing AgDNV-based strategies to manipulate Anopheles gambiae .

Exotic mosquito threats require strategic surveillance and response planning.

PubMed

Webb, Cameron E; Doggett, Stephen L

2016-12-14

Mosquito-borne diseases caused by endemic pathogens such as Ross River, Barmah Forest and Murray Valley encephalitis viruses are an annual concern in New South Wales (NSW), Australia. More than a dozen mosquito species have been implicated in the transmission of these pathogens, with each mosquito occupying a specialised ecological niche that influences their habitat associations, host feeding preferences and the environmental drivers of their abundance. The NSW Arbovirus Surveillance and Mosquito Monitoring Program provides an early warning system for potential outbreaks of mosquito-borne disease by tracking annual activity of these mosquitoes and their associated pathogens. Although the program will effectively track changes in local mosquito populations that may increase with a changing climate, urbanisation and wetland rehabilitation, it will be less effective with current surveillance methodologies at detecting or monitoring changes in exotic mosquito threats, where different surveillance strategies need to be used. Exotic container-inhabiting mosquitoes such as Aedes aegypti and Ae. albopictus pose a threat to NSW because they are nuisance-biting pests and vectors of pathogens such as dengue, chikungunya and Zika viruses. International movement of humans and their belongings have spread these mosquitoes to many regions of the world. In recent years, these two mosquitoes have been detected by the Australian Government Department of Agriculture and Water Resources at local airports and seaports. To target the detection of these exotic mosquitoes, new trapping technologies and networks of surveillance locations are required. Additionally, incursions of these mosquitoes into urban areas of the state will require strategic responses to minimise substantial public health and economic burdens to local communities.

Natural colonization and adaptation of a mosquito species in Galápagos and its implications for disease threats to endemic wildlife

PubMed Central

Bataille, Arnaud; Cunningham, Andrew A.; Cedeño, Virna; Patiño, Leandro; Constantinou, Andreas; Kramer, Laura D.; Goodman, Simon J.

2009-01-01

Emerging infectious diseases of wildlife have been recognized as a major threat to global biodiversity. Endemic species on isolated oceanic islands, such as the Galápagos, are particularly at risk in the face of introduced pathogens and disease vectors. The black salt-marsh mosquito (Aedes taeniorhynchus) is the only mosquito widely distributed across the Galápagos Archipelago. Here we show that this mosquito naturally colonized the Galápagos before the arrival of man, and since then it has evolved to represent a distinct evolutionary unit and has adapted to habitats unusual for its coastal progenitor. We also present evidence that A. taeniorhynchus feeds on reptiles in Galápagos in addition to previously reported mammal and bird hosts, highlighting the important role this mosquito might play as a bridge-vector in the transmission and spread of extant and newly introduced diseases in the Galápagos Islands. These findings are particularly pertinent for West Nile virus, which can cause significant morbidity and mortality in mammals (including humans), birds, and reptiles, and which recently has spread from an introductory focus in New York to much of the North and South American mainland and could soon reach the Galápagos Islands. Unlike Hawaii, there are likely to be no highland refugia free from invading mosquito-borne diseases in Galápagos, suggesting bleak outcomes to possible future pathogen introduction events. PMID:19502421

GLOBE Goes GO with Mosquitoes

NASA Astrophysics Data System (ADS)

Boger, R. A.; Low, R.

2016-12-01

The GLOBE Mosquito Larvae protocol and a new citizen science initiative, GLOBE Observers (GO), were both launched in Summer 2016. While the GLOBE Mosquito Larvae Protocol and associated educational materials target K-16 student inquiry and research, the GO protocol version is simplified to enable citizen scientists of all ages from all walks of life to participate. GO allows citizen scientists to collect and submit environmental data through an easy-to-use smart phone app available for both Apple and Android mobile devices. GO mosquito asks for photos of larvae mosquito genus or species, location, and type of water source (e.g., container or pond) where the larvae were found. To initiate the new mosquito GLOBE/GO opportunities, workshops have been held in Barbuda, Thailand, West Indies, US Gulf Coast, New York City, and at the GLOBE Annual Meeting in Colorado. Through these venues, the protocols have been refined and a field campaign has been initiated so that GO and GLOBE citizen scientists (K-16 students and all others) can contribute data. Quality assurance measures are taken through the online training required to participate and the validation of identification by other citizen sciences and mosquito experts. Furthermore, initial research is underway to develop optical recognition software starting with the species that carry the Zika virus (Aedes aegypti and A. albopictus). With this launch, we plan to move forward by providing opportunities throughout the world to engage people in meaningful environmental and public health data collection and to promote citizen scientists to become agents of change in their communities.

Thule AB, Greenland, Mosquito Survey and Arbovirus Surveillance, 2012

DTIC Science & Technology

2013-11-21

July 2012. One species of mosquitoes, Aedes impiger, was collected and more than 3000 were processed for virus testing. Active mosquito breeding...of mosquitoes, Aedes impiger, was collected and more than 3000 were processed for virus testing. Active mosquito breeding sites were located...were characterized by DNA sequencing. 4. FINDINGS: a. One species of mosquito, Aedes impiger, was found throughout the Thule area

Host-feeding patterns of mosquito species in Germany.

PubMed

Börstler, Jessica; Jöst, Hanna; Garms, Rolf; Krüger, Andreas; Tannich, Egbert; Becker, Norbert; Schmidt-Chanasit, Jonas; Lühken, Renke

2016-06-03

Mosquito-borne pathogens are of growing importance in many countries of Europe including Germany. At the same time, the transmission cycles of most mosquito-borne pathogens (e.g. viruses or filarial parasites) are not completely understood. There is especially a lack of knowledge about the vector capacity of the different mosquito species, which is strongly influenced by their host-feeding patterns. While this kind of information is important to identify the relevant vector species, e.g. to direct efficient control measures, studies about the host-feeding patterns of mosquito species in Germany are scarce and outdated. Between 2012 and 2015, 775 blood-fed mosquito specimens were collected. Sampling was conducted with Heavy Duty Encephalitis Vector Survey traps, Biogents Sentinel traps, gravid traps, hand-held aspirators, sweep nets, and human-bait collection. The host species for each mosquito specimen was identified with polymerase chain reactions and subsequent Sanger sequencing of the cytochrome b gene. A total of 32 host species were identified for 23 mosquito species, covering 21 mammalian species (including humans) and eleven bird species. Three mosquito species accounted for nearly three quarters of all collected blood-fed mosquitoes: Aedes vexans (363 specimens, 46.8 % of all mosquito specimens), Culex pipiens pipiens form pipiens (100, 12.9 %) and Ochlerotatus cantans (99, 12.8 %). Non-human mammals dominated the host species (572 specimens, 73.8 % of all mosquito specimens), followed by humans (152, 19.6 %) and birds (51, 6.6 %). The most common host species were roe deer (Capreolus capreolus; 258 mosquito specimens, 33.3 % of all mosquito specimens, 65 % of all mosquito species), humans (Homo sapiens; 152, 19.6 %, 90 %), cattle (Bos taurus; 101, 13.0 %, 60 %), and wild boar (Sus scrofa; 116, 15.0 %, 50 %). There were no statistically significant differences in the spatial-temporal host-feeding patterns of the three most common mosquito

Hydrology and Mosquito Population Dynamics around a Hydropower Reservoir in Africa

NASA Astrophysics Data System (ADS)

Endo, N.; Eltahir, E. A.

2013-12-01

Malaria is associated with dams because their reservoirs provide mosquitoes, the vector of malaria, with permanent breeding sites. The risk of contracting malaria is likely to be enhanced following the increasing trend of hydropower dam construction to satisfy the expanding energy needs in developing countries. A close examination of its adverse health impacts is critical in the design, construction, and operation phases. We will present results of extensive field studies in 2012 and 2013 around the Koka Reservoir, Ethiopia. The results uncover the importance of reservoir management especially after the rainy seasons. Furthermore, we show the capability of a newly modified hydrology, entomology and malaria transmission simulator, HYDREMATS (Bomblies et al, 2008), and its potential as a tool for evaluating environmental management strategies to control malaria. HYDREMATS was developed to represent how the hydrology in nearby villages is impacted by the reservoir system, and the role of different types of vector ecologies associated with different Anopheles mosquito species. The hydrology component of HYDREMATS simulates three different mosquito breeding habitats: rain-fed pools, groundwater pools, and shoreline water. The entomology component simulates the life cycles of An. funestus and An. arabiensis, the two main vectors around the reservoir. The model was calibrated over the 2012-2013 period. The impact of reservoir water level management on the mosquito population is explored based on numerical model simulations and field experiments.

Looking Backward, Looking Forward: The Long, Torturous Struggle with Mosquitoes.

PubMed

Patterson, Gordon M

2016-10-19

The American anti-mosquito movement grew out of the discovery of the role of mosquitoes in transferring pathogens and public concern about pest and nuisance mosquitoes in the late 1800s. In the 20th century, organized mosquito control in the United States passed through three eras: mechanical, chemical, and integrated mosquito control. Mosquito control in the 21st century faces the challenge of emerging pathogens, invasive mosquito species, and balancing concerns about the environment with effective control strategies.

Field evaluation of New Mountain Sandalwood Mosquito Sticks and New Mountain Sandalwood Botanical Repellent against mosquitoes in North Queensland, Australia.

PubMed

Ritchie, Scott A; Williams, Craig R; Montgomery, Brian L

2006-03-01

The mosquito repellent efficacy of New Mountain Sandalwood Mosquito Sticks (containing 0.5% w/w essential oils) and New Mountain Sandalwood Botanical Repellent (containing soybean and geranium oils) was assessed. Tests were conducted in the field with 4 volunteers in a wooded area near Cairns, North Queensland, Australia. Predominant biting species were Verrallina funerea and Ve. lineata. A pair of burning Mosquito Sticks immediately upwind of the subject (acting as an area repellent) provided a 73.1% mean reduction in mosquito landing and probing over the 3-h test period. The Botanical Repellent and a DEET-based control were both 100% effective in preventing mosquito probing for 3 h. These data are consistent with other studies of area repellents in that such products provide significant protection from mosquito bites, albeit inferior to the protection provided by topically applied repellents.

'Repel all biters': an enhanced collection of endophilic Anopheles gambiae and Anopheles arabiensis in CDC light-traps, from the Kagera Region of Tanzania, in the presence of a combination mosquito net impregnated with piperonyl butoxide and permethrin.

PubMed

LeClair, Corey; Cronery, Judith; Kessy, Enock; Tomás, Elsa V E; Kulwa, Yohannes; Mosha, Franklin W; Rowland, Mark; Protopopoff, Natacha; Derek Charlwood, J

2017-08-15

Mosquito nets containing synergists designed to overcome metabolic resistance mechanisms in vectors have been developed. These may enhance excitability in the mosquitoes and affect how they respond to CDC light-traps. Investigating the behaviour of vectors of disease in relation to novel mosquito nets is, therefore, essential for the design of sampling and surveillance systems. In an initial experiment in Muleba, Tanzania, nine bedrooms from three housing clusters were sampled. CDC light-traps were operated indoors next to occupied untreated nets (UTN), Olyset ® long lasting insecticidal net (LLIN) and Olyset Plus ® LLIN containing piperonyl butoxide (PBO) synergist. Nets were rotated daily between the nine rooms over nine nights. A further series of experiments using the nets on alternate nights in a single room was undertaken during the short rains. Anopheles gambiae s.l. were collected in CDC light-traps, a window-trap and Furvela tent-trap. Anopheles gambiae s.l. were identified to species by polymerase chain reaction (PCR). In the initial experiment 97.7% of the 310 An. gambiae s.l. were An. gambiae s.s., the remainder being Anopheles arabiensis. The number of mosquitoes collected from 81 light-trap collections was greater in the presence of an Olyset [density rate ratio 1.81, 95% CI (1.22-2.67), p = 0.003] relative to an UTN. In a second experiment, in the wet season 84% of the 180 An. gambiae s.l. identified were An. arabiensis. The number of An. gambiae s.l. collected from a light-trap compared to a tent-trap was significantly higher when an Olyset Plus net was used compared to an UTN. Survival of the mosquitoes in the window trap was not reduced by the use of an Olyset Plus net in the bedroom relative to an Olyset net. Mosquitoes entering bedrooms, even those susceptible to pyrethroids, were not killed by contact with an Olyset Plus LLIN. The enhanced numbers of An. gambiae or An. arabiensis collected in light-traps when a treated net is used requires

Mosquito bite anaphylaxis: immunotherapy with whole body extracts.

PubMed

McCormack, D R; Salata, K F; Hershey, J N; Carpenter, G B; Engler, R J

1995-01-01

Adverse reactions to mosquito bites have been recognized for some time. These usually consist of large local swellings and redness, generalized urticaria, angioedema and less easily definable responses such as nausea, dizziness, headaches, and lethargy. We report two patients who experienced systemic anaphylaxis from mosquito bites. Both were skin tested and given immunotherapy using whole body mosquito extracts. Skin testing using whole body mosquito extracts was positive to Aedes aegypti at 1/1,000 weight/volume (wt/vol) in one patient and to Aedes aegypti at 1/100,000 wt/vol, and Culex pipiens at 1/10,000 wt/vol in the other. Skin testing of ten volunteers without a history of adverse reactions to mosquito bites was negative. Immunotherapy using these extracts resulted in resolution of adverse reactions to mosquito bites in one patient and a decrease in reactions in the other. Immunotherapy with whole body mosquito extracts is a viable treatment option that can play a role in patients with mosquito bite-induced anaphylaxis. It may also result in severe side effects and one must determine the benefit versus risks for each individual patient.

[Mosquitoes as vectors for exotic pathogens in Germany].

PubMed

Becker, N; Krüger, A; Kuhn, C; Plenge-Bönig, A; Thomas, S M; Schmidt-Chanasit, J; Tannich, E

2014-05-01

As a result of intensified globalization of international trade and of substantial travel activities, mosquito-borne exotic pathogens are becoming an increasing threat for Europe. In Germany some 50 different mosquito species are known, several of which have vector competence for pathogens. During the last few years a number of zoonotic arboviruses that are pathogenic for humans have been isolated from mosquitoes in Germany including Usutu, Sindbis and Batai viruses. In addition, filarial worms, such as Dirofilaria repens have been repeatedly detected in mosquitoes from the federal state of Brandenburg. Other pathogens, in particular West Nile virus, are expected to emerge sooner or later in Germany as the virus is already circulating in neighboring countries, e.g. France, Austria and the Czech Republic. In upcoming years the risk for arbovirus transmission might increase in Germany due to increased occurrence of new so-called "invasive" mosquito species, such as the Asian bush mosquito Ochlerotatus japonicus or the Asian tiger mosquito Aedes albopictus. These invasive species are characterized by high vector competence for a broad range of pathogens and a preference for human blood meals. For risk assessment, a number of mosquito and pathogen surveillance projects have been initiated in Germany during the last few years; however, mosquito control strategies and plans of action have to be developed and put into place to allow early and efficient action against possible vector-borne epidemics.

Controlling Mosquitoes at the Larval Stage

EPA Pesticide Factsheets

Larvicides target larvae in the breeding habitat before they can mature into adult mosquitoes and disperse. Larvicide treatment of breeding habitats help reduce the adult mosquito population in nearby areas.

Wolbachia and dengue virus infection in the mosquito Aedes fluviatilis (Diptera: Culicidae).

PubMed

Silva, Jéssica Barreto Lopes; Magalhães Alves, Debora; Bottino-Rojas, Vanessa; Pereira, Thiago Nunes; Sorgine, Marcos Henrique Ferreira; Caragata, Eric Pearce; Moreira, Luciano Andrade

2017-01-01

Dengue represents a serious threat to human health, with billions of people living at risk of the disease. Wolbachia pipientis is a bacterial endosymbiont common to many insect species. Wolbachia transinfections in mosquito disease vectors have great value for disease control given the bacterium's ability to spread into wild mosquito populations, and to interfere with infections of pathogens, such as dengue virus. Aedes fluviatilis is a mosquito with a widespread distribution in Latin America, but its status as a dengue vector has not been clarified. Ae. fluviatilis is also naturally infected by the wFlu Wolbachia strain, which has been demonstrated to enhance infection with the avian malarial parasite Plasmodium gallinaceum. We performed experimental infections of Ae. fluviatilis with DENV-2 and DENV-3 isolates from Brazil via injection or oral feeding to provide insight into its competence for the virus. We also examined the effect of the native Wolbachia infection on the virus using a mosquito line where the wFlu infection had been cleared by antibiotic treatment. Through RT-qPCR, we observed that Ae. fluviatilis could become infected with both viruses via either method of infection, although at a lower rate than Aedes aegypti, the primary dengue vector. We then detected DENV-2 and DENV-3 in the saliva of injected mosquitoes, and observed that injection of DENV-3-infected saliva produced subsequent infections in naïve Ae. aegypti. However, across our data we observed no difference in prevalence of infection and viral load between Wolbachia-infected and -uninfected mosquitoes, suggesting that there is no effect of wFlu on dengue virus. Our results highlight that Ae. fluviatilis could potentially serve as a dengue vector under the right circumstances, although further testing is required to determine if this occurs in the field.

Wolbachia and dengue virus infection in the mosquito Aedes fluviatilis (Diptera: Culicidae)

PubMed Central

Silva, Jéssica Barreto Lopes; Magalhães Alves, Debora; Bottino-Rojas, Vanessa; Pereira, Thiago Nunes; Sorgine, Marcos Henrique Ferreira; Caragata, Eric Pearce

2017-01-01

Dengue represents a serious threat to human health, with billions of people living at risk of the disease. Wolbachia pipientis is a bacterial endosymbiont common to many insect species. Wolbachia transinfections in mosquito disease vectors have great value for disease control given the bacterium’s ability to spread into wild mosquito populations, and to interfere with infections of pathogens, such as dengue virus. Aedes fluviatilis is a mosquito with a widespread distribution in Latin America, but its status as a dengue vector has not been clarified. Ae. fluviatilis is also naturally infected by the wFlu Wolbachia strain, which has been demonstrated to enhance infection with the avian malarial parasite Plasmodium gallinaceum. We performed experimental infections of Ae. fluviatilis with DENV-2 and DENV-3 isolates from Brazil via injection or oral feeding to provide insight into its competence for the virus. We also examined the effect of the native Wolbachia infection on the virus using a mosquito line where the wFlu infection had been cleared by antibiotic treatment. Through RT-qPCR, we observed that Ae. fluviatilis could become infected with both viruses via either method of infection, although at a lower rate than Aedes aegypti, the primary dengue vector. We then detected DENV-2 and DENV-3 in the saliva of injected mosquitoes, and observed that injection of DENV-3-infected saliva produced subsequent infections in naïve Ae. aegypti. However, across our data we observed no difference in prevalence of infection and viral load between Wolbachia-infected and -uninfected mosquitoes, suggesting that there is no effect of wFlu on dengue virus. Our results highlight that Ae. fluviatilis could potentially serve as a dengue vector under the right circumstances, although further testing is required to determine if this occurs in the field. PMID:28732048

Visualization of house-entry behaviour of malaria mosquitoes.

PubMed

Spitzen, Jeroen; Koelewijn, Teun; Mukabana, W Richard; Takken, Willem

2016-04-25

Malaria mosquitoes often blood feed indoors on human hosts. The mosquitoes predominantly enter houses via open eaves. Host-seeking is odour-driven, and finding a host depends on the quality of the odour plume and whether the route towards the host is free of obstructions. Little is known about in-flight behaviour of mosquitoes during house entry. This semi-field study visualizes mosquito house entry in three dimensions (3D) and offers new insights for optimizing vector control interventions. The approach and house entry of Anopheles gambiae sensu stricto was studied in a semi-field set-up using video-recorded flight tracks and 3D analysis. Behavioural parameters of host-seeking female mosquitoes were visualized with respect to their position relative to the eave as well as whether a mosquito would enter or not. Host odour was standardized using an attractive synthetic blend in addition to CO2. The study was conducted in western Kenya at the Thomas Odhiambo Campus of the International Centre of Insect Physiology and Ecology, Mbita. The majority of host-seeking An. gambiae approached a house with a flight altitude at eave level, arriving within a horizontal arc of 180°. Fifty-five per cent of mosquitoes approaching a house did not enter or made multiple attempts before passing through the eave. During approach, mosquitoes greatly reduced their speed and the flight paths became more convoluted. As a result, mosquitoes that passed through the eave spent more than 80 % of the observed time within 30 cm of the eave. Mosquitoes that exited the eave departed at eave level and followed the edge of the roof (12.5 %) or quickly re-entered after exiting (9.6 %). The study shows that host-seeking mosquitoes, when entering a house, approach the eave in a wide angle to the house at eave level. Less than 25 % of approaching mosquitoes entered the house without interruption, whereas 12.5 % of mosquitoes that had entered left the house again within the time of observation

Mosquito populations dynamics associated with climate variations.

PubMed

Wilke, André Barretto Bruno; Medeiros-Sousa, Antônio Ralph; Ceretti-Junior, Walter; Marrelli, Mauro Toledo

2017-02-01

Mosquitoes are responsible for the transmission of numerous serious pathogens. Members of the Aedes and Culex genera, which include many important vectors of mosquito-borne diseases, are highly invasive and adapted to man-made environments. They are spread around the world involuntarily by humans and are highly adapted to urbanized environments, where they are exposed to climate-related abundance drivers. We investigated Culicidae fauna in two urban parks in the city of São Paulo to analyze the correlations between climatic variables and the population dynamics of mosquitoes in these urban areas. Mosquitoes were collected monthly over one year, and sampling sufficiency was evaluated after morphological identification of the specimens. The average monthly temperature and accumulated rainfall for the collection month and previous month were used to explain climate-related abundance drivers for the six most abundant species (Aedes aegypti, Aedes albopictus, Aedes fluviatilis, Aedes scapularis, Culex nigripalpus and Culex quinquefasciatus) and then analyzed using generalized linear statistical models and the Akaike Information Criteria corrected for small samples (AICc). The strength of evidence in favor of each model was evaluated using Akaike weights, and the explanatory model power was measured by McFadden's Pseudo-R 2 . Associations between climate and mosquito abundance were found in both parks, indicating that predictive models based on climate variables can provide important information on mosquito population dynamics. We also found that this association is species-dependent. Urbanization processes increase the abundance of a few mosquito species that are well adapted to man-made environments and some of which are important vectors of pathogens. Predictive models for abundance based on climate variables may help elucidate the population dynamics of urban mosquitoes and their impact on the risk of disease transmission, allowing better predictive scenarios to be

Scorpion neurotoxin AaIT-expressing Beauveria bassiana enhances the virulence against Aedes albopictus mosquitoes.

PubMed

Deng, Sheng-Qun; Cai, Qun-Di; Deng, Ming-Zhi; Huang, Qiang; Peng, Hong-Juan

2017-12-01

To improve the insecticidal efficacy of this entomopathogen Beauveria bassiana, the fungus was genetically modified to express an insect-specific scorpion neurotoxin AaIT. The virulence of the recombinant B. bassiana strain (Bb-AaIT) against Aedes albopictus adults (which occurs via penetration through the cuticle during spore germination or by conidia ingestion), and the larvae (by conidia ingestion) was measured with bioassays. The median lethal concentration (LC 50 ) of Bb-AaIT against A. albopictus larvae was 313.3-fold lower on day 4 and 11.3-fold lower on day 10 than that of the wild type (WT). Through conidia feeding or body contact, Bb-AaIT killed 50% of adult female mosquitoes at 3.9- or 1.9-fold reduced concentrations on day 4 and at 2.1- or 2.4-fold reduced concentrations on day 10. Compared with the results for the WT, the median lethal time (LT 50 ) of Bb-AaIT was reduced by 28.6% at 1 × 10 7 conidia ml -1 and 34.3% at 1 × 10 6 conidia ml -1 in the larvae bioassay by conidia ingestion, while it decreased 32.3% at 1 × 10 7 conidia ml -1 by conidia ingestion and 24.2% at 1 × 10 8 conidia ml -1 by penetrating through the cuticle in the adult bioassay. All the differences were significant. Our findings indicated that Bb-AaIT had higher virulence and faster action than the WT in killing the larval and adult mosquitoes, and therefore, it is valuable for development as a commercial mosquito pesticide.

Lay perceptions of kala-azar, mosquitoes and bed nets in Bihar, India.

PubMed

Mishra, Rabindra N; Singh, S P; Vanlerberghe, Veerle; Sundar, Shyam; Boelaert, Marleen; Lefèvre, Pierre

2010-07-01

To describe the lay perception of kala-azar (KA) in an endemic area of Muzaffarpur District, Bihar, India: local names, symptoms, affected persons, perceived severity and modes of transmission, as well as perceived mosquito nuisance, modes of protection and use of bed nets. We held 16 focus group discussions (FGD) in eight remote villages with altogether 157 participants in March 2008. Separate FGDs were held according to gender, socio-economic status (SES) and with key informants. Kala-azar is most commonly named pilahi. Poor people were said to be the most affected. Knowledge about symptoms was satisfactory. Fever and prolonged fever were the most stated symptoms. KA was perceived as a life-threatening disease with a heavy economic burden. Mosquito bites were perceived as the main mode of transmission but in lower socio-economic groups, non-vector-related explanations were also provided. The main modes of protection from mosquitoes mentioned were the use of fumes and bed nets. Season was the strongest factor influencing the use of bed nets and non-affordability for not owning them. Although the sand fly is not recognised as the vector, the relatively good awareness of disease transmission by mosquitoes and the nuisance caused by their high density might be an entry point for adopting preventive measures to protect from mosquito bite and thereby indirectly preventing from KA. Educational campaigns targeted to the poorer segments of society are needed to enhance knowledge about KA, its mode of transmission, risks of getting infected and to increase bed net use.

AN IMPROVED TRAP TO CAPTURE ADULT CONTAINER-INHABITING MOSQUITOES

PubMed Central

BARRERA, ROBERTO; MACKAY, ANDREW J.; AMADOR, MANUEL

2015-01-01

Although dengue viruses are thought to be transmitted by Aedes aegypti in Puerto Rico, Aedes mediovittatus, the Caribbean tree hole mosquito, is also a potential vector. This species is native to the Greater Antilles and has been shown to be a competent vector of dengue viruses in the laboratory. Consequently, it has been suggested that Ae. mediovittatus could be acting as a secondary vector or virus reservoir. This study was part of an ongoing investigation into this, and it aimed to determine whether BG-Sentinel traps (BGS traps) could be used to collect adults of this mosquito and could be modified to increase the number of captures of this species in the field. We conducted experiments to test the relative attractiveness of BGS traps to Ae. mediovittatus and Ae. aegypti and explored the effects of chemical lures (BG-Lure, CO2, octenol) and optical properties (color, size) on the capture rates of BGS traps in a large, outdoor cage in San Juan city, Puerto Rico. We also conducted field tests to compare modified BGS traps with the original traps in a rural community in Patillas municipality, Puerto Rico. Results obtained from the large, outdoor cage experiments indicated that trap captures of both mosquito species could be significantly enhanced by using black instead of white BGS traps combined with BG-Lure. Field experiments revealed that the modified traps captured a significantly greater number of Ae. aegypti, Ae. mediovittatus, and Culex quinquefasciatus, with greater sensitivity for the latter 2 species, and also captured a larger number of mosquito species and a smaller ratio of Ae. aegypti to Ae. mediovittatus, with greater than expected species co-occurrences. PMID:24551969

The SlNAC8 gene of the halophyte Suaeda liaotungensis enhances drought and salt stress tolerance in transgenic Arabidopsis thaliana.

PubMed

Wu, Dandan; Sun, Yinghao; Wang, Hongfei; Shi, He; Su, Mingxing; Shan, Hongyan; Li, Tongtong; Li, Qiuli

2018-07-01

NAC (NAM, ATAF1/2 and CUC) transcription factors play an important role in resisting abiotic stress in plants. In this study, a novel NAC gene, designated SlNAC8 from Suaeda liaotungensis K. was characterized. SlNAC8 protein is localized in the nucleus, and the yeast one-hybrid screening showed that it contains an activation domain in its C-terminus and functions as a transcriptional activator. Gene expression analysis revealed that it is induced by drought and salt stress. Arabidopsis plants overexpressing SlNAC8 demonstrated enhanced tolerance to drought and salt stress, showing significant advantages in seed germination, root growth, shoot growth, and survival rate compared with controls. Moreover, transgenic plants had a significantly higher proline concentration, antioxidant enzyme activity (superoxide dismutase, peroxidase, and catalase), and level of chlorophyll fluorescence than wild-type, and a significantly lower malondialdehyde concentration and electrolyte leakage under drought and salt stress. The overexpression of SlNAC8 in transgenic plants also enhanced the expression of stress-responsive genes such as RD20, GSTF6, COR47, RD29A, RD29B, and NYC1. In summary, SlNAC8, as a transcription factor, may change the physiological-biochemical characteristic of plants by regulating the expression of stress-responsive genes and enhance the drought and salt stress tolerance of plants. SlNAC8 can be utilized for developing drought and salinity tolerance in crop plants through genetic engineering. Copyright © 2018 Elsevier B.V. All rights reserved.

Beer Consumption Increases Human Attractiveness to Malaria Mosquitoes

PubMed Central

Lefèvre, Thierry; Gouagna, Louis-Clément; Dabiré, Kounbobr Roch; Elguero, Eric; Fontenille, Didier; Renaud, François; Costantini, Carlo; Thomas, Frédéric

2010-01-01

Background Malaria and alcohol consumption both represent major public health problems. Alcohol consumption is rising in developing countries and, as efforts to manage malaria are expanded, understanding the links between malaria and alcohol consumption becomes crucial. Our aim was to ascertain the effect of beer consumption on human attractiveness to malaria mosquitoes in semi field conditions in Burkina Faso. Methodology/Principal Findings We used a Y tube-olfactometer designed to take advantage of the whole body odour (breath and skin emanations) as a stimulus to gauge human attractiveness to Anopheles gambiae (the primary African malaria vector) before and after volunteers consumed either beer (n = 25 volunteers and a total of 2500 mosquitoes tested) or water (n = 18 volunteers and a total of 1800 mosquitoes). Water consumption had no effect on human attractiveness to An. gambiae mosquitoes, but beer consumption increased volunteer attractiveness. Body odours of volunteers who consumed beer increased mosquito activation (proportion of mosquitoes engaging in take-off and up-wind flight) and orientation (proportion of mosquitoes flying towards volunteers' odours). The level of exhaled carbon dioxide and body temperature had no effect on human attractiveness to mosquitoes. Despite individual volunteer variation, beer consumption consistently increased attractiveness to mosquitoes. Conclusions/Significance These results suggest that beer consumption is a risk factor for malaria and needs to be integrated into public health policies for the design of control measures. PMID:20209056

Spatial model for transmission of mosquito-borne diseases

NASA Astrophysics Data System (ADS)

Kon, Cynthia Mui Lian; Labadin, Jane

2015-05-01

In this paper, a generic model which takes into account spatial heterogeneity for the dynamics of mosquito-borne diseases is proposed. The dissemination of the disease is described by a system of reaction-diffusion partial differential equations. Host human and vector mosquito populations are divided into susceptible and infectious classes. Diffusion is considered to occur in all classes of both populations. Susceptible humans are infected when bitten by infectious mosquitoes. Susceptible mosquitoes bite infectious humans and become infected. The biting rate of mosquitoes is considered to be density dependent on the total human population in different locations. The system is solved numerically and results are shown.

Vaccination against mosquito borne viral infections: current status.

PubMed

Wiwanitkit, Viroj

2007-12-01

Mosquito borne infectious diseases are among important group of diseases worldwide. Vaccination is available for some tropical mosquito-borne diseases, especially for Japanese encephalitis virus infection and yellow fever. There are also several attempts to develop new vaccines for the other mosquito-borne diseases such as malaria, dengue infection and West Nile virus infection. In this article, the author reviews the issues on vaccination of some important tropical mosquito borne infectious diseases.

Studies on mosquito biting risk among migratory rice farmers in rural south-eastern Tanzania and development of a portable mosquito-proof hut.

PubMed

Swai, Johnson K; Finda, Marceline F; Madumla, Edith P; Lingamba, Godfrey F; Moshi, Irene R; Rafiq, Mohamed Y; Majambere, Silas; Okumu, Fredros O

2016-11-22

Subsistence rice farmers in south-eastern Tanzania are often migratory, spending weeks or months tending to crops in distant fields along the river valleys and living in improvised structures known as Shamba huts, not fully protected from mosquitoes. These farmers also experience poor access to organized preventive and curative services due to long distances. Mosquito biting exposure in these rice fields, relative to main village residences was assessed, then a portable mosquito-proof hut was developed and tested for protecting these migratory farmers. Pair-wise mosquito surveys were conducted in four villages in Ulanga district, south-eastern Tanzania in 20 randomly-selected Shamba huts located in the distant rice fields and in 20 matched houses within the main villages, to assess biting densities and Plasmodium infection rates. A portable mosquito-proof hut was designed and tested in semi-field and field settings against Shamba hut replicas, and actual Shamba huts. Also, semi-structured interviews were conducted, timed-participant observations, and focus-group discussions to assess experiences and behaviours of the farmers regarding mosquito-bites and the mosquito-proof huts. There were equal numbers of mosquitoes in Shamba huts and main houses [RR (95% CI) 27 (25.1-31.2), and RR (95% CI) 30 (27.5-33.4)], respectively (P > 0.05). Huts having >1 occupant had more mosquitoes than those with just one occupant, regardless of site [RR (95% CI) 1.57 (1.30-1.9), P < 0.05]. Open eaves [RR (95% CI) 1.15 (1.08-1.23), P < 0.05] and absence of window shutters [RR (95% CI) 2.10 (1.91-2.31), P < 0.05] increased catches of malaria vectors. All Anopheles mosquitoes caught were negative for Plasmodium. Common night-time outdoor activities in the fields included cooking, eating, fetching water or firewood, washing dishes, bathing, and storytelling, mostly between 6 and 11 p.m., when mosquitoes were also biting most. The prototype hut provided 100% protection in semi

Mosquito Records from Mexico: The Mosquitoes (Diptera: Culicidae) of Tamaulipas State.

PubMed

Ortega-Morales, Aldo I; Zavortink, Thomas J; Huerta-Jiménez, Herón; Sánchez-Rámos, Francisco J; Valdés-Perezgasga, Ma Teresa; Reyes-Villanueva, Filiberto; Siller-Rodríguez, Quetzaly K; Fernandez-Salas, Ildefonso

2015-03-01

To document the diversity and distribution of mosquito species inhabiting the Mexican state of Tamaulipas, collection trips were conducted to all physiographic regions (Grand Northamerican Plains, Coastal Plain of North Gulf, and Sierra Madre Oriental) and subregions across the state. Additionally, we re-examined mosquito specimens in two Mexican entomological collections: the Collection of Insects and Mites of Medical Importance and the Collection of Arthropods of Medical Importance. In total, 3,931 specimens were collected. These represent the two Culicidae subfamilies Anophelinae and Culicinae, 10 tribes, 17 genera, 27 subgenera, 80 named species, and 2 undescribed species. Of these, 3 tribes, 6 genera, 7 subgenera, and 20 species are new records for the mosquito fauna of Tamaulipas. Fourteen species recorded in the historical records were not found in collections made for this study. Taxonomic notes, new distribution limits, and comments about the medical importance of some of the species collected are reported. © The Author 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Recent Enhancements to the NASA Langley Structural Acoustics Loads and Transmission (SALT) Facility

NASA Technical Reports Server (NTRS)

Rizzi, Stephen A.; Cabell, Randolph H.; Allen, Albert R.

2013-01-01

The Structural Acoustics Loads and Transmission (SALT) facility at the NASA Langley Research Center is comprised of an anechoic room and a reverberant room, and may act as a transmission loss suite when test articles are mounted in a window connecting the two rooms. In the latter configuration, the reverberant room acts as the noise source side and the anechoic room as the receiver side. The noise generation system used for qualification testing in the reverberant room was previously shown to achieve a maximum overall sound pressure level of 141 dB. This is considered to be marginally adequate for generating sound pressure levels typically required for launch vehicle payload qualification testing. Recent enhancements to the noise generation system increased the maximum overall sound pressure level to 154 dB, through the use of two airstream modulators coupled to 35 Hz and 160 Hz horns. This paper documents the acoustic performance of the enhanced noise generation system for a variety of relevant test spectra. Additionally, it demonstrates the capability of the SALT facility to conduct transmission loss and absorption testing in accordance with ASTM and ISO standards, respectively. A few examples of test capabilities are shown and include transmission loss testing of simple unstiffened and built up structures and measurement of the diffuse field absorption coefficient of a fibrous acoustic blanket.

Citizen Science as a Tool for Mosquito Control.

PubMed

Jordan, Rebecca C; Sorensen, Amanda E; Ladeau, Shannon

2017-09-01

In this paper, we share our findings from a 2-year citizen science program called Mosquito Stoppers. This pest-oriented citizen science project is part of a larger coupled natural-human systems project seeking to understand the fundamental drivers of mosquito population density and spatial variability in potential exposure to mosquito-borne pathogens in a matrix of human construction, urban renewal, and individual behaviors. Focusing on residents in West Baltimore, participants were recruited through neighborhood workshops and festivals. Citizen scientists participated in yard surveys of potential mosquito habitat and in evaluating mosquito nuisance. We found that citizen scientists, with minimal education and training, were able to accurately collect data that reflect trends found in a comparable researcher-generated database.

The urban mosquito hazard today

PubMed Central

Mattingly, P. F.

1963-01-01

Of all the main types of mosquito living to a greater or lesser extent in association with man—urban invaders, infiltrators and colonizers—the most formidable and successful is probably Culex fatigans. Able to use man-made breeding-places, breeding freely in highly contaminated water and possessing the genetical and physiological plasticity to resist insecticides, this mosquito has increased extensively in urban environments in recent years. Considering that it merits greater study than it has hitherto received, the author discusses its principal characteristics in relation to those of other man-associated mosquitos and suggests a number of lines of research which should be followed for the development of effective control methods. PMID:20604163

"Bird biting" mosquitoes and human disease: a review of the role of Culex pipiens complex mosquitoes in epidemiology.

PubMed

Farajollahi, Ary; Fonseca, Dina M; Kramer, Laura D; Marm Kilpatrick, A

2011-10-01

The transmission of vector-borne pathogens is greatly influenced by the ecology of their vector, which is in turn shaped by genetic ancestry, the environment, and the hosts that are fed on. One group of vectors, the mosquitoes in the Culex pipiens complex, play key roles in the transmission of a range of pathogens including several viruses such as West Nile and St. Louis encephalitis viruses, avian malaria (Plasmodium spp.), and filarial worms. The Cx. pipiens complex includes Culex pipiens pipiens with two forms, pipiens and molestus, Culex pipiens pallens, Culex quinquefasciatus, Culex australicus, and Culex globocoxitus. While several members of the complex have limited geographic distributions, Cx. pipienspipiens and Cx. quinquefasciatus are found in all known urban and sub-urban temperate and tropical regions, respectively, across the world, where they are often principal disease vectors. In addition, hybrids are common in areas of overlap. Although gaps in our knowledge still remain, the advent of genetic tools has greatly enhanced our understanding of the history of speciation, domestication, dispersal, and hybridization. We review the taxonomy, genetics, evolution, behavior, and ecology of members of the Cx. pipiens complex and their role in the transmission of medically important pathogens. The adaptation of Cx. pipiens complex mosquitoes to human-altered environments led to their global distribution through dispersal via humans and, combined with their mixed feeding patterns on birds and mammals (including humans), increased the transmission of several avian pathogens to humans. We highlight several unanswered questions that will increase our ability to control diseases transmitted by these mosquitoes. Copyright © 2011 Elsevier B.V. All rights reserved.

Mosquitoes of field and forest: the scale of habitat segregation in a diverse mosquito assemblage.

PubMed

Reiskind, M H; Griffin, R H; Janairo, M S; Hopperstad, K A

2017-03-01

Knowledge of the distribution of arthropod vectors across a landscape is important in determining the risk for vector-borne disease. This has been well explored for ticks, but not for mosquitoes, despite their importance in the transmission of a variety of pathogens. This study examined the importance of habitat, habitat edges, and the scale at which mosquito abundance and diversity vary in a rural landscape by trapping along transects from grassland areas into forest patches. Significant patterns of vector diversity and distinct mosquito assemblages across habitats were found. The scale of individual species' responses to habitat edges was often dramatic, with several species rarely straying even 10 m from the edge. The present results suggest blood-seeking mosquito species are faithful to certain habitats, which has consequences for patterns of vector diversity and risk for pathogen transmission. This implies that analysts of risk for pathogen transmission and foci of control, and developers of land management strategies should assess habitat at a finer scale than previously considered. © 2016 The Royal Entomological Society.

rAed a 4: A New 67-kDa Aedes aegypti Mosquito Salivary Allergen for the Diagnosis of Mosquito Allergy.

PubMed

Peng, Zhikang; Caihe, Li; Beckett, Andrew N; Guan, Qingdong; James, Anthony A; Simons, F Estelle R

2016-01-01

Accurate diagnosis of mosquito allergy has been hampered by the laborious task of obtaining mosquito salivary allergens. We have previously studied 3 recombinant (r) Aedes aegypti mosquito salivary allergens: rAed a 1, rAed a 2 and rAed a 3. Here, we report the expression, purification, identification and evaluation of rAed a 4, a 67-kDa α-glucosidase. rAed a 4 was expressed using a baculovirus/insect cell system, purified by a combination of anion- and cation-exchange chromatography, and identified by immunoblotting. A. aegypti saliva extract was prepared in our laboratory. An indirect enzyme-linked immunosorbent assay (ELISA) was developed to measure rAed a 4-specific immunoglobulin E (IgE) and IgG antibodies in sera from 13 individuals with a positive mosquito-bite test from a laboratory-reared mosquito. Sera from 18 individuals with a negative bite test served as controls. Purified rAed a 4 bound to the IgE in mosquito-allergic sera, as detected by ELISA and immunoblotting. The binding of rAed a 4 to IgE could be inhibited in a dose-dependent manner by the addition of an A. aegypti extract. Mosquito-allergic individuals had significantly higher mean levels of rAed a 4-specific IgE and IgG than controls. Using the mean of the controls ± 2 SD as a cut-off level, 46% of the 13 allergic individuals had a positive IgE, while none of the controls was positive (p < 0.001). Aed a 4 is a major allergen in mosquito saliva. Its recombinant form has the hydrolase function and can be used for the diagnosis of mosquito allergy. © 2016 S. Karger AG, Basel.

Distribution of mosquitoes and mosquito-borne arboviruses in Yunnan Province near the China-Myanmar-Laos border.

PubMed

Wang, Jinglin; Zhang, Hailin; Sun, Xiaohong; Fu, Shihong; Wang, Huanqin; Feng, Yun; Wang, Huanyu; Tang, Qing; Liang, Guo-Dong

2011-05-01

Economic development and increased tourism in the southern region of Yunnan Province in China, adjacent to several countries in Southeast Asia, has increased the likelihood of import and export of vectors and vector-borne diseases. We report the results of surveillance of mosquitoes and mosquito-borne arboviruses along the border of China-Myanmar-Laos in 2005 and 2006, and information associating several arboviruses with infections and possibly disease in local human populations. Seventeen mosquito species representing four genera were obtained, and 14 strains of mosquito-borne viruses representing six viruses in five genera were isolated from Culex tritaeniorhynchus. In addition, IgM against Japanese encephalitis virus, Sindbis virus, Yunnan orbivirus and novel Banna virus was detected in acute-phase serum samples obtained from hospitalized patients with fever and encephalitis near the areas where the viruses were isolated. This investigation suggests that Japanese encephalitis virus, Sindbis virus, and lesser-known arboviruses circulate and may be infecting humans in the China-Myanmar-Laos border region.

MosquitoNet: investigating the use of UAV and artificial neural networks for integrated mosquito management

NASA Astrophysics Data System (ADS)

Case, E.; Ren, Y.; Shragai, T.; Erickson, D.

2017-12-01

Integrated mosquito control is expensive and resource intensive, and changing climatic factors are predicted to expand the habitable range of disease-carrying mosquitoes into new regions in the United States. Of particular concern in the northeastern United States are aedes albopictus, an aggressive, invasive species of mosquito that can transmit both native and exotic disease. Ae. albopictus prefer to live near human populations and breed in artificial containers with as little as two millimeters of standing water, exponentially increasing the difficulty of source control in suburban and urban areas. However, low-cost unmanned aerial vehicles (UAVs) can be used to photograph large regions at centimeter-resolution, and can image containers of interest in suburban neighborhoods. While proofs-of-concepts have been shown using UAVs to identify naturally occurring bodies of water, they have not been used to identify mosquito habitat in more populated areas. One of the primary challenges is that post-processing high-resolution aerial imagery is still time intensive, often labelled by hand or with programs built for satellite imagery. Artificial neural networks have been highly successful at image recognition tasks; in the past five years, convolutional neural networks (CNN) have surpassed or aided trained humans in identification of skin cancer, agricultural crops, and poverty levels from satellite imagery. MosquitoNet, a dual classifier built from the Single Shot Multibox Detector and VGG16 architectures, was trained on UAV­­­­­ aerial imagery taken during a larval study in Westchester County in southern New York State in July and August 2017. MosquitoNet was designed to assess the habitat risk of suburban properties by automating the identification and counting of containers like tires, toys, garbage bins, flower pots, etc. The SSD-based architecture marked small containers and other habitat indicators while the VGG16-based architecture classified the type of

Spectral and spatial characterization of rice field mosquito habitat

NASA Technical Reports Server (NTRS)

Wood, Byron L.; Beck, Louisa R.; Washino, Robert K.; Palchick, Susan M.; Sebesta, Paul D.

1991-01-01

Irrigated rice provides an ideal breeding habitat for Anopheles free-borni, the western malaria mosquito, throughout California. In a 1985 study, it was determined that early-season rice canopy development, as monitored using remotely sensed data, could be used to distinguish between high and low mosquito producing rice fields. This distinction could be made over two months prior to peak mosquito production. It was found that high-producing fields were located in an area characterized by a diversity of land use, including livestock pastures, whereas the low-producing fields were in an area devoted almost exclusively to the cultivation of rice. The ability to distinguish between high and low mosquito producing fields prior to peak mosquito production is important in terms of mosquito habitat surveillance and control.

Spermidine-mediated hydrogen peroxide signaling enhances the antioxidant capacity of salt-stressed cucumber roots.

PubMed

Wu, Jianqiang; Shu, Sheng; Li, Chengcheng; Sun, Jin; Guo, Shirong

2018-07-01

Hydrogen peroxide (H 2 O 2 ) is a key signaling molecule that mediates a variety of physiological processes and defense responses against abiotic stress in higher plants. In this study, our aims are to clarify the role of H 2 O 2 accumulation induced by the exogenous application of spermidine (Spd) to cucumber (Cucumis sativus) seedlings in regulating the antioxidant capacity of roots under salt stress. The results showed that Spd caused a significant increase in endogenous polyamines and H 2 O 2 levels, and peaked at 2 h after salt stress. Spd-induced H 2 O 2 accumulation was blocked under salt stress by pretreatment with a H 2 O 2 scavenger and respective inhibitors of cell wall peroxidase (CWPOD; EC: 1.11.1.7), polyamine oxidase (PAO; EC: 1.5.3.11) and NADPH oxidase (NOX; EC: 1.6.3.1); among these three inhibitors, the largest decrease was found in response to the addition of the inhibitor of polyamine oxidase. In addition, we observed that exogenous Spd could increase the activities of the enzymes superoxide dismutase (SOD; EC: 1.15.1.1), peroxidase (POD; EC: 1.11.1.7) and catalase (CAT; EC: 1.11.1.6) as well as the expression of their genes in salt-stressed roots, and the effects were inhibited by H 2 O 2 scavengers and polyamine oxidase inhibitors. These results suggested that, by regulating endogenous PAs-mediated H 2 O 2 signaling in roots, Spd could enhance antioxidant enzyme activities and reduce oxidative damage; the main source of H 2 O 2 was polyamine oxidation, which was associated with improved tolerance and root growth recovery of cucumber under salt stress. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Ionomic and metabolic responses to neutral salt or alkaline salt stresses in maize (Zea mays L.) seedlings.

PubMed

Guo, Rui; Shi, LianXuan; Yan, Changrong; Zhong, Xiuli; Gu, FengXue; Liu, Qi; Xia, Xu; Li, Haoru

2017-02-10

Soil salinity and alkalinity present a serious threat to global agriculture. However, most of the studies have focused on neutral salt stress, and the information on the metabolic responses of plants to alkaline salt stress is limited. This investigation aimed at determining the influence of neutral salt and alkaline salt stresses on the content of metal elements and metabolites in maize plant tissues, by using mixtures of various proportions of NaCl, NaHCO 3 , Na 2 SO 4 , and Na 2 CO 3 . We found that alkaline salt stress suppressed more pronouncedly the photosynthesis and growth of maize plants than salinity stress. Under alkaline salt stress conditions, metal ions formed massive precipitates, which ultimately reduced plant nutrient availability. On the other hand, high neutral salt stress induced metabolic changes in the direction of gluconeogenesis leading to the enhanced formation of sugars as a reaction contributing to the mitigation of osmotic stress. Thus, the active synthesis of sugars in shoots was essential to the development of salt tolerance. However, the alkaline salt stress conditions characterized by elevated pH values suppressed substantially the levels of photosynthesis, N metabolism, glycolysis, and the production of sugars and amino acids. These results indicate the presence of different defensive mechanisms responsible for the plant responses to neutral salt and alkaline salt stresses. In addition, the increased concentration of organic acids and enhanced metabolic energy might be potential major factors that can contribute to the maintenance intracellular ion balance in maize plants and counteract the negative effects of high pH under alkaline salt stress.

Climate change and mosquito-borne disease.

PubMed Central

Reiter, P

2001-01-01

Global atmospheric temperatures are presently in a warming phase that began 250--300 years ago. Speculations on the potential impact of continued warming on human health often focus on mosquito-borne diseases. Elementary models suggest that higher global temperatures will enhance their transmission rates and extend their geographic ranges. However, the histories of three such diseases--malaria, yellow fever, and dengue--reveal that climate has rarely been the principal determinant of their prevalence or range; human activities and their impact on local ecology have generally been much more significant. It is therefore inappropriate to use climate-based models to predict future prevalence. PMID:11250812

Adult vector control, mosquito ecology and malaria transmission

PubMed Central

Brady, Oliver J.; Godfray, H. Charles J.; Tatem, Andrew J.; Gething, Peter W.; Cohen, Justin M.; McKenzie, F. Ellis; Alex Perkins, T.; Reiner, Robert C.; Tusting, Lucy S.; Scott, Thomas W.; Lindsay, Steven W.; Hay, Simon I.; Smith, David L.

2015-01-01

Background Standard advice regarding vector control is to prefer interventions that reduce the lifespan of adult mosquitoes. The basis for this advice is a decades-old sensitivity analysis of ‘vectorial capacity’, a concept relevant for most malaria transmission models and based solely on adult mosquito population dynamics. Recent advances in micro-simulation models offer an opportunity to expand the theory of vectorial capacity to include both adult and juvenile mosquito stages in the model. Methods In this study we revisit arguments about transmission and its sensitivity to mosquito bionomic parameters using an elasticity analysis of developed formulations of vectorial capacity. Results We show that reducing adult survival has effects on both adult and juvenile population size, which are significant for transmission and not accounted for in traditional formulations of vectorial capacity. The elasticity of these effects is dependent on various mosquito population parameters, which we explore. Overall, control is most sensitive to methods that affect adult mosquito mortality rates, followed by blood feeding frequency, human blood feeding habit, and lastly, to adult mosquito population density. Conclusions These results emphasise more strongly than ever the sensitivity of transmission to adult mosquito mortality, but also suggest the high potential of combinations of interventions including larval source management. This must be done with caution, however, as policy requires a more careful consideration of costs, operational difficulties and policy goals in relation to baseline transmission. PMID:25733562

Adult vector control, mosquito ecology and malaria transmission.

PubMed

Brady, Oliver J; Godfray, H Charles J; Tatem, Andrew J; Gething, Peter W; Cohen, Justin M; McKenzie, F Ellis; Alex Perkins, T; Reiner, Robert C; Tusting, Lucy S; Scott, Thomas W; Lindsay, Steven W; Hay, Simon I; Smith, David L

2015-03-01

Standard advice regarding vector control is to prefer interventions that reduce the lifespan of adult mosquitoes. The basis for this advice is a decades-old sensitivity analysis of 'vectorial capacity', a concept relevant for most malaria transmission models and based solely on adult mosquito population dynamics. Recent advances in micro-simulation models offer an opportunity to expand the theory of vectorial capacity to include both adult and juvenile mosquito stages in the model. In this study we revisit arguments about transmission and its sensitivity to mosquito bionomic parameters using an elasticity analysis of developed formulations of vectorial capacity. We show that reducing adult survival has effects on both adult and juvenile population size, which are significant for transmission and not accounted for in traditional formulations of vectorial capacity. The elasticity of these effects is dependent on various mosquito population parameters, which we explore. Overall, control is most sensitive to methods that affect adult mosquito mortality rates, followed by blood feeding frequency, human blood feeding habit, and lastly, to adult mosquito population density. These results emphasise more strongly than ever the sensitivity of transmission to adult mosquito mortality, but also suggest the high potential of combinations of interventions including larval source management. This must be done with caution, however, as policy requires a more careful consideration of costs, operational difficulties and policy goals in relation to baseline transmission. © The Author 2015. Published by Oxford University Press on behalf of Royal Society of Tropical Medicine and Hygiene.

Transgenic Mosquitoes - Fact or Fiction?

PubMed

Wilke, André B B; Beier, John C; Benelli, Giovanni

2018-06-01

Technologies for controlling mosquito vectors based on genetic manipulation and the release of genetically modified mosquitoes (GMMs) are gaining ground. However, concrete epidemiological evidence of their effectiveness, sustainability, and impact on the environment and nontarget species is lacking; no reliable ecological evidence on the potential interactions among GMMs, target populations, and other mosquito species populations exists; and no GMM technology has yet been approved by the WHO Vector Control Advisory Group. Our opinion is that, although GMMs may be considered a promising control tool, more studies are needed to assess their true effectiveness, risks, and benefits. Overall, several lines of evidence must be provided before GMM-based control strategies can be used under the integrated vector management framework. Copyright © 2018 Elsevier Ltd. All rights reserved.

Blood-feeding ecology of mosquitoes in zoos.

PubMed

Tuten, H C; Bridges, W C; Paul, K S; Adler, P H

2012-12-01

To determine if the unique host assemblages in zoos influence blood-feeding by mosquitoes (Diptera: Culicidae), a sampling programme was conducted in Greenville and Riverbanks Zoos, South Carolina, U.S.A., from April 2009 to October 2010. A total of 4355 female mosquitoes of 14 species were collected, of which 106 individuals of nine species were blood-fed. The most common taxa were Aedes albopictus (Skuse), Aedes triseriatus (Say), Anopheles punctipennis (Say), Culex erraticus (Dyar & Knab), Culex pipiens complex (L.) and Culex restuans (Theobald). Molecular analyses (cytochrome b) of bloodmeals revealed that mosquitoes fed on captive animals, humans and wildlife, and took mixed bloodmeals. Host species included one amphibian, 16 birds, 10 mammals (including humans) and two reptiles. Minimum dispersal distances after feeding on captive hosts ranged from 15.5 m to 327.0 m. Mosquito-host associations generally conformed to previous accounts, indicating that mosquito behaviour inside zoos reflects that outside zoos. However, novel variation in host use, including new, exotic host records, warrants further investigation. Zoos, thus, can be used as experiment environments in which to study mosquito behaviour, and the findings extrapolated to non-zoo areas, while providing medical and veterinary benefits to zoo animals, employees and patrons. © 2012 The Authors. Medical and Veterinary Entomology © 2012 The Royal Entomological Society.

A solar-thermal energy harvesting scheme: enhanced heat capacity of molten HITEC salt mixed with Sn/SiOx core-shell nanoparticles

NASA Astrophysics Data System (ADS)

Lai, Chih-Chung; Chang, Wen-Chih; Hu, Wen-Liang; Wang, Zhiming M.; Lu, Ming-Chang; Chueh, Yu-Lun

2014-04-01

We demonstrated enhanced solar-thermal storage by releasing the latent heat of Sn/SiOx core-shell nanoparticles (NPs) embedded in a eutectic salt. The microstructures and chemical compositions of Sn/SiOx core-shell NPs were characterized. In situ heating XRD provides dynamic crystalline information about the Sn/SiOx core-shell NPs during cyclic heating processes. The latent heat of ~29 J g-1 for Sn/SiOx core-shell NPs was measured, and 30% enhanced heat capacity was achieved from 1.57 to 2.03 J g-1 K-1 for the HITEC solar salt without and with, respectively, a mixture of 5% Sn/SiOx core-shell NPs. In addition, an endurance cycle test was performed to prove a stable operation in practical applications. The approach provides a method to enhance energy storage in solar-thermal power plants.We demonstrated enhanced solar-thermal storage by releasing the latent heat of Sn/SiOx core-shell nanoparticles (NPs) embedded in a eutectic salt. The microstructures and chemical compositions of Sn/SiOx core-shell NPs were characterized. In situ heating XRD provides dynamic crystalline information about the Sn/SiOx core-shell NPs during cyclic heating processes. The latent heat of ~29 J g-1 for Sn/SiOx core-shell NPs was measured, and 30% enhanced heat capacity was achieved from 1.57 to 2.03 J g-1 K-1 for the HITEC solar salt without and with, respectively, a mixture of 5% Sn/SiOx core-shell NPs. In addition, an endurance cycle test was performed to prove a stable operation in practical applications. The approach provides a method to enhance energy storage in solar-thermal power plants. Electronic supplementary information (ESI) available: Detailed experimental results are included for the following: SEM images of the HITEC molten salt with and without a mixture of Sn/SiOx core-shell NPs; statistical diameter distribution of pure Sn and Sn/SiOx core-shell NPs; the HAADF image and EDS linescan profile of a Sn/SiOx core-shell NP; XRD analysis for Sn NPs annealing at different heating

Seasonal and Daily Activity Patterns of Mosquito (Diptera: Culicidae) Vectors of Pathogens in Northeastern Italy.

PubMed

Montarsi, Fabrizio; Mazzon, Luca; Cazzin, Stefania; Ciocchetta, Silvia; Capelli, Gioia

2015-01-01

The seasonal and daily activity of mosquito vectors of pathogens affecting animals and humans were studied in northeastern Italy at a site within the Po River Delta Park. A CDC-CO2 trap and a gravid trap were operated at 2-h intervals for 24 h every 15 d from May to October 2010. Overall, 5,788 mosquitoes comprising six species were collected, namely Culex pipiens L. (75.1% of total), Aedes caspius (Pallas) (15.2%), Aedes vexans (Meigen) (6.9%), Anopheles maculipennis s.l. Meigen (2.6%), Culiseta annulata (Schrank) (0.2%), and Culex modestus Ficalbi (<0.1%). The relative abundance of these species increased from May until the beginning of July and then decreased, disappearing at the beginning of October. The diel host-seeking patterns and oviposition site-seeking patterns were species specific and were differentially affected by the ecological variables recorded at the day and hour of mosquito collection or two weeks before collection. Knowledge of the seasonal and daily host-seeking patterns of mosquitoes highlights the time periods of the day and the seasons of potential exposure for animals and humans to mosquito-borne pathogens, therefore delineating the best time for the application of preventive measures. Furthermore, knowledge of the oviposition site-seeking activity of the mosquitoes optimizes the capture of gravid females, thereby enhancing the likelihood of detecting pathogens. © The Author 2015. Published by Oxford University Press on behalf of the Entomological Society of America.For Permissions, please e-mail: journals.permissions@oup.com.

High salt intake enhances swim stress-induced PVN vasopressin cell activation and active stress coping.

PubMed

Mitchell, N C; Gilman, T L; Daws, L C; Toney, G M

2018-07-01

Stress contributes to many psychiatric disorders; however, responsivity to stressors can vary depending on previous or current stress exposure. Relatively innocuous heterotypic (differing in type) stressors can summate to result in exaggerated neuronal and behavioral responses. Here we investigated the ability of prior high dietary sodium chloride (salt) intake, a dehydrating osmotic stressor, to enhance neuronal and behavioral responses of mice to an acute psychogenic swim stress (SS). Further, we evaluated the contribution of the osmo-regulatory stress-related neuropeptide arginine vasopressin (VP) in the hypothalamic paraventricular nucleus (PVN), one of only a few brain regions that synthesize VP. The purpose of this study was to determine the impact of high dietary salt intake on responsivity to heterotypic stress and the potential contribution of VPergic-mediated neuronal activity on high salt-induced stress modulation, thereby providing insight into how dietary (homeostatic) and environmental (psychogenic) stressors might interact to facilitate psychiatric disorder vulnerability. Salt loading (SL) with 4% saline for 7 days was used to dehydrate and osmotically stress mice prior to exposure to an acute SS. Fluid intake and hematological measurements were taken to quantify osmotic dehydration, and serum corticosterone levels were measured to index stress axis activation. Immunohistochemistry (IHC) was used to stain for the immediate early gene product c-Fos to quantify effects of SL on SS-induced activation of neurons in the PVN and extended amygdala - brain regions that are synaptically connected and implicated in responding to osmotic stress and in modulation of SS behavior, respectively. Lastly, the role of VPergic PVN neurons and VP type 1 receptor (V1R) activity in the amygdala in mediating effects of SL on SS behavior was evaluated by quantifying c-Fos activation of VPergic PVN neurons and, in functional experiments, by nano-injecting the V1R selective

Using Repellent Products to Protect against Mosquito-Borne Illnesses

MedlinePlus

... Illnesses More Information CDC-Avoid Mosquito Bites CDC-Dengue CDC-Zika Virus CDC-Mosquito bite prevention for ... how to protect against the mosquitoes that transmit dengue, Zika, and other viral diseases ( Aedes albopictus and ...

Zika virus: Endemic and epidemic ranges of Aedes mosquito transmission.

PubMed

Attaway, David F; Waters, Nigel M; Geraghty, Estella M; Jacobsen, Kathryn H

As evidence linking Zika virus with serious health complications strengthens, public health officials and clinicians worldwide need to know which locations are likely to be at risk for autochthonous Zika infections. We created risk maps for epidemic and endemic Aedes-borne Zika virus infections globally using a predictive analysis method that draws on temperature, precipitation, elevation, land cover, and population density variables to identify locations suitable for mosquito activity seasonally or year-round. Aedes mosquitoes capable of transmitting Zika and other viruses are likely to live year-round across many tropical areas in the Americas, Africa, and Asia. Our map provides an enhanced global projection of where vector control initiatives may be most valuable for reducing the risk of Zika virus and other Aedes-borne infections. Copyright © 2016 King Saud Bin Abdulaziz University for Health Sciences. Published by Elsevier Ltd. All rights reserved.

Copper enhances the activity and salt resistance of mixed methane-oxidizing communities.

PubMed

van der Ha, David; Hoefman, Sven; Boeckx, Pascal; Verstraete, Willy; Boon, Nico

2010-08-01

Effluents of anaerobic digesters are an underestimated source of greenhouse gases, as they are often saturated with methane. A post-treatment with methane-oxidizing bacterial consortia could mitigate diffuse emissions at such sites. Semi-continuously fed stirred reactors were used as model systems to characterize the influence of the key parameters on the activity of these mixed methanotrophic communities. The addition of 140 mg L(-1) NH (4) (+) -N had no significant influence on the activity nor did a temperature increase from 28 degrees C to 35 degrees C. On the other hand, addition of 0.64 mg L(-1) of copper(II) increased the methane removal rate by a factor of 1.5 to 1.7 since the activity of particulate methane monooxygenase was enhanced. The influence of different concentrations of NaCl was also tested, as effluents of anaerobic digesters often contain salt levels up to 10 g NaCl L(-1). At a concentration of 11 g NaCl L(-1), almost no methane-oxidizing activity was observed in the reactors without copper addition. Yet, reactors with copper addition exhibited a sustained activity in the presence of NaCl. A colorimetric test based on naphthalene oxidation showed that soluble methane monooxygenase was inhibited by copper, suggesting that the particulate methane monooxygenase was the active enzyme and thus more salt resistant. The results obtained demonstrate that the treatment of methane-saturated effluents, even those with increased ammonium (up to 140 mg L(-1) NH (4) (+) -N) and salt levels, can be mitigated by implementation of methane-oxidizing microbial consortia.

Pathogenesis of Dengue Vaccine Viruses in Mosquitoes.

DTIC Science & Technology

1980-01-01

1973). Sabin (1948) showed that attenuated dpngiie, passed through mosquitoes, did not revert to pathogenicity frnr man. -7- Thus even if the vaccine ...AD-A138 518 PATHOGENESIS OF DENGUE VACCINE YIRUSES IN MOSQUITOES 1/ (U) YALE UNIV NEW HAVEN CONN SCHOOL OF MEDICINE B J BEATY ET AL. 9i JAN 80 DRND7...34 ’ UNCLASSIFIED 0{) AD 0Pathogenesis of dengue vaccine viruses in mosquitoes -First Annual Report Barry I. Beaty, Ph.D. Thomas H. G

Mosquito Surveillance for Prevention and Control of Emerging Mosquito-Borne Diseases in Portugal — 2008–2014

PubMed Central

Osório, Hugo C.; Zé-Zé, Líbia; Amaro, Fátima; Alves, Maria J.

2014-01-01

Mosquito surveillance in Europe is essential for early detection of invasive species with public health importance and prevention and control of emerging pathogens. In Portugal, a vector surveillance national program—REVIVE (REde de VIgilância de VEctores)—has been operating since 2008 under the custody of Portuguese Ministry of Health. The REVIVE is responsible for the nationwide surveillance of hematophagous arthropods. Surveillance for West Nile virus (WNV) and other flaviviruses in adult mosquitoes is continuously performed. Adult mosquitoes—collected mainly with Centre for Disease Control light traps baited with CO2—and larvae were systematically collected from a wide range of habitats in 20 subregions (NUTS III). Around 500,000 mosquitoes were trapped in more than 3,000 trap nights and 3,500 positive larvae surveys, in which 24 species were recorded. The viral activity detected in mosquito populations in these years has been limited to insect specific flaviviruses (ISFs) non-pathogenic to humans. Rather than emergency response, REVIVE allows timely detection of changes in abundance and species diversity providing valuable knowledge to health authorities, which may take control measures of vector populations reducing its impact on public health. This work aims to present the REVIVE operation and to expose data regarding mosquito species composition and detected ISFs. PMID:25396768

Heterosis Increases Fertility, Fecundity, and Survival of Laboratory-Produced F1 Hybrid Males of the Malaria Mosquito Anopheles coluzzii

PubMed Central

Ekechukwu, Nkiru E.; Baeshen, Rowida; Traorè, Sékou F.; Coulibaly, Mamadou; Diabate, Abdoulaye; Catteruccia, Flaminia; Tripet, Frédéric

2015-01-01

The success of vector control strategies aiming to decrease disease transmission via the release of sterile or genetically-modified male mosquitoes critically depends on mating between laboratory-reared males and wild females. Unfortunately, mosquito colonization, laboratory rearing, and genetic manipulations can all negatively affect male competitiveness. Heterosis is commonly used to produce domestic animals with enhanced vigor and homogenous genetic background and could therefore potentially improve the mating performance of mass-reared male mosquitoes. Here, we produced enhanced hybrid males of the malaria mosquito Anopheles coluzzii by crossing two strains colonized >35 and 8 years ago. We compared the amount of sperm and mating plug proteins they transferred to females, as well as their insemination rate, reproductive success and longevity under various experimental conditions. Across experiments, widespread adaptations to laboratory mating were detected in the older strain. In large-group mating experiments, no overall hybrid advantage in insemination rates and the amount of sperm and accessory gland proteins transferred to females was detected. Despite higher sperm activity, hybrid males did not appear more fecund. However, individual-male mating and laboratory-swarm experiments revealed that hybrid males, while inseminating fewer females than older inbred males, were significantly more fertile, producing larger mating plugs and drastically increasing female fecundity. Heterotic males also showed increased longevity. These results validate the use of heterosis for creating hybrid males with improved fitness from long-established inbred laboratory strains. Therefore, this simple approach could facilitate disease control strategies based on male mosquito releases with important ultimate benefits to human health. PMID:26497140

Intricate predatory decisions by a mosquito-specialist spider from Malaysia

PubMed Central

Jackson, Robert R.; Li, Daiqin; Woon, Jeremy R. W.; Hashim, Rosli; Cross, Fiona R.

2014-01-01

Paracyrba wanlessi is a southeast Asian jumping spider (Salticidae) that lives in the hollow internodes of fallen bamboo and preys on the larvae, pupae and adults of mosquitoes. In contrast to Evarcha culicivora, an East African salticid that is also known for actively targeting mosquitoes as preferred prey, there was no evidence of P. wanlessi choosing mosquitoes on the basis of species, sex or diet. However, our findings show that P. wanlessi chooses mosquitoes significantly more often than a variety of other prey types, regardless of whether the prey are in or away from water, and regardless of whether the mosquitoes are adults or juveniles. Moreover, a preference for mosquito larvae, pupae and adults is expressed regardless of whether test spiders are maintained on a diet of terrestrial or aquatic prey and regardless of whether the diet includes or excludes mosquitoes. Congruence of an environmental factor (in water versus away from water) with prey type (aquatic versus terrestrial mosquitoes) appeared to be important and yet, even when the prey were in the incongruent environment, P. wanlessi continued to choose mosquitoes more often than other prey. PMID:26064534

Low-salt diet enhances vascular reactivity and Ca(2+) entry in pregnant rats with normal and reduced uterine perfusion pressure.

PubMed

Giardina, Jena B; Cockrell, Kathy L; Granger, Joey P; Khalil, Raouf A

2002-02-01

Salt moderation is often recommended to prevent excessive increases in blood pressure during pregnancy, particularly in women who are prone to pregnancy-induced hypertension; however, the vascular effects of low dietary salt intake during pregnancy are unclear. We investigated whether a low-salt diet during pregnancy alters the mechanisms of vascular smooth muscle contraction. Active stress and (45)Ca(2+) influx were measured in endothelium-denuded aortic strips of virgin and normal pregnant Sprague-Dawley rats and a hypertensive pregnant rat model produced by reduction in uterine perfusion pressure (RUPP), fed either a normal-sodium (NS, 1% NaCl) or low-sodium diet (LS, 0.2% NaCl) for 7 days. The mean arterial pressure was as follows: virgin/NS 108 +/- 8, virgin/LS 117 +/- 7, pregnant/NS 102 +/- 3, pregnant/LS 117 +/- 4, RUPP/NS 119 +/- 3, and RUPP/LS 133 +/- 6 mm Hg. Phenylephrine (Phe) caused concentration-dependent increases in active stress and (45)Ca(2+) influx that were greater in RUPP rats than in normal pregnant or virgin rats and were enhanced in pregnant/LS and RUPP/LS compared with pregnant/NS and RUPP/NS, respectively. High KCl (16 to 96 mmol/L), which stimulates Ca(2+) entry from the extracellular space, also caused increases in active stress that were greater in RUPP than in normal pregnant, in pregnant/LS than in pregnant/NS, and in RUPP/LS than in RUPP/NS rats. The Phe-induced (45)Ca(2+) influx--active stress relation was greater in RUPP/NS than in pregnant/NS and was enhanced in pregnant/LS and RUPP/LS compared with pregnant/NS and RUPP/NS, respectively. In Ca(2+)-free (2 mmol/L ethylene glycol bis(beta-aminoethylether)-N,N,N',N'-tetra-acetic acid) Krebs, stimulation of intracellular Ca(2+) release by Phe (10(-5) mol/L) or caffeine (25 mmol/L) caused a transient contraction that was not significantly different in all groups of rats. Thus, a low-salt diet in pregnant and RUPP rats is associated with increases in vascular reactivity that involves Ca

Parasites resistant to the antimalarial atovaquone fail to transmit by mosquitoes.

PubMed

Goodman, Christopher D; Siregar, Josephine E; Mollard, Vanessa; Vega-Rodríguez, Joel; Syafruddin, Din; Matsuoka, Hiroyuki; Matsuzaki, Motomichi; Toyama, Tomoko; Sturm, Angelika; Cozijnsen, Anton; Jacobs-Lorena, Marcelo; Kita, Kiyoshi; Marzuki, Sangkot; McFadden, Geoffrey I

2016-04-15

Drug resistance compromises control of malaria. Here, we show that resistance to a commonly used antimalarial medication, atovaquone, is apparently unable to spread. Atovaquone pressure selects parasites with mutations in cytochrome b, a respiratory protein with low but essential activity in the mammalian blood phase of the parasite life cycle. Resistance mutations rescue parasites from the drug but later prove lethal in the mosquito phase, where parasites require full respiration. Unable to respire efficiently, resistant parasites fail to complete mosquito development, arresting their life cycle. Because cytochrome b is encoded by the maternally inherited parasite mitochondrion, even outcrossing with wild-type strains cannot facilitate spread of resistance. Lack of transmission suggests that resistance will be unable to spread in the field, greatly enhancing the utility of atovaquone in malaria control. Copyright © 2016, American Association for the Advancement of Science.

Mosquito Bites

MedlinePlus

... spreading to the United States. One factor is climate change, which makes the conditions in some parts of ... United States. How can I prevent mosquito bites? Use an insect ... DEET, picaridin, IR3535, oil of lemon eucalyptus, or para-menthane-diol. It ...

Mosquito-borne viruses circulating in Kinshasa, Democratic Republic of the Congo.

PubMed

Mbanzulu, Kennedy Makola; Wumba, Roger; Mukendi, Jean-Pierre Kambala; Zanga, Josué Kikana; Shija, Fortunate; Bobanga, Thierry Lengu; Aloni, Michel Ntetani; Misinzo, Gerald

2017-04-01

Diseases caused by mosquito-borne viruses are among the most important emerging diseases that threaten human and animal health, particularly in Africa. However, little attention has been paid to these diseases in the Democratic Republic of the Congo (DRC). The present cross-sectional study was undertaken between March and May 2014 to investigate the presence of mosquito-borne viruses in mosquitoes collected from five municipalities of Kinshasa, DRC. Mosquitoes were collected using BG-Sentinel traps and battery-powered aspirators. Female mosquitoes were pooled according to their genera and sampling locations, preserved in RNAlater, and later screened for viruses using reverse transcription PCR (RT-PCR) assays. A total of 2922 mosquitoes were collected and 29 pools of female mosquitoes, containing approximately 30 mosquitoes each, were tested. Twelve of the 29 (41.4%) mosquito pools were found to be infected with at least one arbovirus, with eight (27.5%) pools positive for Alphavirus, nine (31%) for Flavivirus, and five (17.2%) for Bunyaviridae. Chikungunya, o'nyong'nyong, and Rift valley fever viruses were detected. The present study shows that mosquitoes in Kinshasa carry mosquito-borne viruses that may have serious public health implications. Further investigations on the presence of mosquito-borne viruses in the human and livestock populations of Kinshasa and DRC are recommended. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

Diversity and function of bacterial microbiota in the mosquito holobiont

PubMed Central

2013-01-01

Mosquitoes (Diptera: Culicidae) have been shown to host diverse bacterial communities that vary depending on the sex of the mosquito, the developmental stage, and ecological factors. Some studies have suggested a potential role of microbiota in the nutritional, developmental and reproductive biology of mosquitoes. Here, we present a review of the diversity and functions of mosquito-associated bacteria across multiple variation factors, emphasizing recent findings. Mosquito microbiota is considered in the context of possible extended phenotypes conferred on the insect hosts that allow niche diversification and rapid adaptive evolution in other insects. These kinds of observations have prompted the recent development of new mosquito control methods based on the use of symbiotically-modified mosquitoes to interfere with pathogen transmission or reduce the host life span and reproduction. New opportunities for exploiting bacterial function for vector control are highlighted. PMID:23688194

Maternal Germline-Specific Genes in the Asian Malaria Mosquito Anopheles stephensi: Characterization and Application for Disease Control

PubMed Central

Biedler, James K.; Qi, Yumin; Pledger, David; Macias, Vanessa M.; James, Anthony A.; Tu, Zhijian

2014-01-01

Anopheles stephensi is a principal vector of urban malaria on the Indian subcontinent and an emerging model for molecular and genetic studies of mosquito biology. To enhance our understanding of female mosquito reproduction, and to develop new tools for basic research and for genetic strategies to control mosquito-borne infectious diseases, we identified 79 genes that displayed previtellogenic germline-specific expression based on RNA-Seq data generated from 11 life stage–specific and sex-specific samples. Analysis of this gene set provided insights into the biology and evolution of female reproduction. Promoters from two of these candidates, vitellogenin receptor and nanos, were used in independent transgenic cassettes for the expression of artificial microRNAs against suspected mosquito maternal-effect genes, discontinuous actin hexagon and myd88. We show these promoters have early germline-specific expression and demonstrate 73% and 42% knockdown of myd88 and discontinuous actin hexagon mRNA in ovaries 48 hr after blood meal, respectively. Additionally, we demonstrate maternal-specific delivery of mRNA and protein to progeny embryos. We discuss the application of this system of maternal delivery of mRNA/miRNA/protein in research on mosquito reproduction and embryonic development, and for the development of a gene drive system based on maternal-effect dominant embryonic arrest. PMID:25480960

Conditioning Individual Mosquitoes to an Odor: Sex, Source, and Time

PubMed Central

Sanford, Michelle R.; Tomberlin, Jeffery K.

2011-01-01

Olfactory conditioning of mosquitoes may have important implications for vector-pathogen-host dynamics. If mosquitoes learn about specific host attributes associated with pathogen infection, it may help to explain the heterogeneity of biting and disease patterns observed in the field. Sugar-feeding is a requirement for survival in both male and female mosquitoes. It provides a starting point for learning research in mosquitoes that avoids the confounding factors associated with the observer being a potential blood-host and has the capability to address certain areas of close-range mosquito learning behavior that have not previously been described. This study was designed to investigate the ability of the southern house mosquito, Culex quinquefasciatus Say to associate odor with a sugar-meal with emphasis on important experimental considerations of mosquito age (1.2 d old and 3–5 d old), sex (male and female), source (laboratory and wild), and the time between conditioning and testing (<5 min, 1 hr, 2.5 hr, 5 hr, 10 hr, and 24 hr). Mosquitoes were individually conditioned to an odor across these different experimental conditions. Details of the conditioning protocol are presented as well as the use of binary logistic regression to analyze the complex dataset generated from this experimental design. The results suggest that each of the experimental factors may be important in different ways. Both the source of the mosquitoes and sex of the mosquitoes had significant effects on conditioned responses. The largest effect on conditioning was observed in the lack of positive response following conditioning for females aged 3–5 d derived from a long established colony. Overall, this study provides a method for conditioning experiments involving individual mosquitoes at close range and provides for future discussion of the relevance and broader questions that can be asked of olfactory conditioning in mosquitoes. PMID:21887384

Dengue subgenomic flaviviral RNA disrupts immunity in mosquito salivary glands to increase virus transmission

PubMed Central

Manuel, Menchie; Shan, Chao; Manokaran, Gayathri; Bradrick, Shelton S.; Missé, Dorothée; Shi, Pei-Yong

2017-01-01

Globally re-emerging dengue viruses are transmitted from human-to-human by Aedes mosquitoes. While viral determinants of human pathogenicity have been defined, there is a lack of knowledge of how dengue viruses influence mosquito transmission. Identification of viral determinants of transmission can help identify isolates with high epidemiological potential. Additionally, mechanistic understanding of transmission will lead to better understanding of how dengue viruses harness evolution to cycle between the two hosts. Here, we identified viral determinants of transmission and characterized mechanisms that enhance production of infectious saliva by inhibiting immunity specifically in salivary glands. Combining oral infection of Aedes aegypti mosquitoes and reverse genetics, we identified two 3’ UTR substitutions in epidemic isolates that increased subgenomic flaviviral RNA (sfRNA) quantity, infectious particles in salivary glands and infection rate of saliva, which represents a measure of transmission. We also demonstrated that various 3’UTR modifications similarly affect sfRNA quantity in both whole mosquitoes and human cells, suggesting a shared determinism of sfRNA quantity. Furthermore, higher relative quantity of sfRNA in salivary glands compared to midgut and carcass pointed to sfRNA function in salivary glands. We showed that the Toll innate immune response was preferentially inhibited in salivary glands by viruses with the 3’UTR substitutions associated to high epidemiological fitness and high sfRNA quantity, pointing to a mechanism for higher saliva infection rate. By determining that sfRNA is an immune suppressor in a tissue relevant to mosquito transmission, we propose that 3’UTR/sfRNA sequence evolution shapes dengue epidemiology not only by influencing human pathogenicity but also by increasing mosquito transmission, thereby revealing a viral determinant of epidemiological fitness that is shared between the two hosts. PMID:28753642

Effects of Zika Virus Strain and Aedes Mosquito Species on Vector Competence.

PubMed

Ciota, Alexander T; Bialosuknia, Sean M; Zink, Steven D; Brecher, Matthew; Ehrbar, Dylan J; Morrissette, Madeline N; Kramer, Laura D

2017-07-01

In the Western Hemisphere, Zika virus is thought to be transmitted primarily by Aedes aegypti mosquitoes. To determine the extent to which Ae. albopictus mosquitoes from the United States are capable of transmitting Zika virus and the influence of virus dose, virus strain, and mosquito species on vector competence, we evaluated multiple doses of representative Zika virus strains in Ae. aegypti and Ae. albopictus mosquitoes. Virus preparation (fresh vs. frozen) significantly affected virus infectivity in mosquitoes. We calculated 50% infectious doses to be 6.1-7.5 log 10 PFU/mL; minimum infective dose was 4.2 log 10 PFU/mL. Ae. albopictus mosquitoes were more susceptible to infection than Ae. aegypti mosquitoes, but transmission efficiency was higher for Ae. aegypti mosquitoes, indicating a transmission barrier in Ae. albopictus mosquitoes. Results suggest that, although Zika virus transmission is relatively inefficient overall and dependent on virus strain and mosquito species, Ae. albopictus mosquitoes could become major vectors in the Americas.

Effects of Zika Virus Strain and Aedes Mosquito Species on Vector Competence

PubMed Central

Bialosuknia, Sean M.; Zink, Steven D.; Brecher, Matthew; Ehrbar, Dylan J.; Morrissette, Madeline N.; Kramer, Laura D.

2017-01-01

In the Western Hemisphere, Zika virus is thought to be transmitted primarily by Aedes aegypti mosquitoes. To determine the extent to which Ae. albopictus mosquitoes from the United States are capable of transmitting Zika virus and the influence of virus dose, virus strain, and mosquito species on vector competence, we evaluated multiple doses of representative Zika virus strains in Ae. aegypti and Ae. albopictus mosquitoes. Virus preparation (fresh vs. frozen) significantly affected virus infectivity in mosquitoes. We calculated 50% infectious doses to be 6.1–7.5 log10 PFU/mL; minimum infective dose was 4.2 log10 PFU/mL. Ae. albopictus mosquitoes were more susceptible to infection than Ae. aegypti mosquitoes, but transmission efficiency was higher for Ae. aegypti mosquitoes, indicating a transmission barrier in Ae. albopictus mosquitoes. Results suggest that, although Zika virus transmission is relatively inefficient overall and dependent on virus strain and mosquito species, Ae. albopictus mosquitoes could become major vectors in the Americas. PMID:28430564

The excess salt appetite of humans is not due to sodium loss in adulthood.

PubMed

Leshem, Micah

2009-09-07

In seeking the determinants of high salt intake, studies in rat have shown that sodium depletion in utero, neonatally, or in maturity, permanently enhances salt appetite. In humans too, salt appetite is permanently enhanced after perinatal sodium loss, but it is not known if sodium loss in adults also enhances salt intake. If it does, it might contribute to high sodium intake and its associated pathologies. Therefore, using methods that revealed the perinatal determinants of sodium appetite, here we evaluated whether salt appetite is enhanced in adults with a varied history of sodium loss. We find that putative sodium loss due to hyperhidrosis, hemorrhage, dehydration, or breastfeeding, does not increase salt appetite significantly. The findings contrast with the many studies showing enduring enhancement of salt appetite by perinatal sodium loss in humans, and suggest that lifelong salt appetite is established very early in development. In turn this counsels very early intervention to prevent lifelong excess sodium intake.

Plant-Mediated Effects on Mosquito Capacity to Transmit Human Malaria

PubMed Central

Hien, Domonbabele F. d. S.; Roche, Benjamin; Diabaté, Abdoulaye; Yerbanga, Rakiswende S.; Cohuet, Anna; Yameogo, Bienvenue K.; Gouagna, Louis-Clément; Hopkins, Richard J.; Ouedraogo, Georges A.; Simard, Frédéric; Ignell, Rickard; Lefevre, Thierry

2016-01-01

The ecological context in which mosquitoes and malaria parasites interact has received little attention, compared to the genetic and molecular aspects of malaria transmission. Plant nectar and fruits are important for the nutritional ecology of malaria vectors, but how the natural diversity of plant-derived sugar sources affects mosquito competence for malaria parasites is unclear. To test this, we infected Anopheles coluzzi, an important African malaria vector, with sympatric field isolates of Plasmodium falciparum, using direct membrane feeding assays. Through a series of experiments, we then examined the effects of sugar meals from Thevetia neriifolia and Barleria lupilina cuttings that included flowers, and fruit from Lannea microcarpa and Mangifera indica on parasite and mosquito traits that are key for determining the intensity of malaria transmission. We found that the source of plant sugar meal differentially affected infection prevalence and intensity, the development duration of the parasites, as well as the survival and fecundity of the vector. These effects are likely the result of complex interactions between toxic secondary metabolites and the nutritional quality of the plant sugar source, as well as of host resource availability and parasite growth. Using an epidemiological model, we show that plant sugar source can be a significant driver of malaria transmission dynamics, with some plant species exhibiting either transmission-reducing or -enhancing activities. PMID:27490374

ABP9, a maize bZIP transcription factor, enhances tolerance to salt and drought in transgenic cotton.

PubMed

Wang, Chunling; Lu, Guoqing; Hao, Yuqiong; Guo, Huiming; Guo, Yan; Zhao, Jun; Cheng, Hongmei

2017-09-01

ABP9 , encoding a bZIP transcription factor from maize, enhances tolerance to multiple stresses and may participate in the ABA signaling pathway in transgenic cotton by altering physiological and biochemical processes and stress-related gene expression. Abiotic stresses, such as soil salinity and drought, negatively affect growth, development, and yield in cotton. Gene ABP9, which encodes a bZIP transcription factor, binds to the abscisic acid (ABA)-responsive-element (ABRE2) motif of the maize catalase1 gene. Its expression significantly improves tolerance in Arabidopsis to multiple abiotic stresses, but little is known about its role in cotton. In the present study, the ABP9 gene was introduced into upland cotton (Gossypium hirsutum L.) cultivar R15 by Agrobacterium tumefaciens-mediated transformation, and 12 independent transgenic cotton lines were obtained. Cotton plants over-expressing ABP9 have enhanced tolerance to salt and osmotic stress. Under stress, they developed better root systems in a greenhouse and higher germination, reduced stomatal aperture, and stomatal density in a growth chamber. Under drought conditions, survival rate and relative water content (RWC) of transgenic cotton were higher than those of R15 plants. Under salt and osmotic stresses, chlorophyll, proline, and soluble sugar contents significantly increased in transgenic cotton leaves and the malondialdehyde (MDA) content was lower than in R15. Overexpression of ABP9 also enhanced oxidative stress tolerance, reduced cellular levels of reactive oxygen species (ROS) through increased activities of antioxidative enzymes, and alleviated oxidative damage to cell. Interestingly, ABP9 over-expressing cotton was more sensitive to exogenous ABA than R15 at seed germination, root growth, stomatal aperture, and stomatal density. Moreover, ABP9 overexpression upregulated significantly the transcription levels of stress-related genes such as GhDBP2, GhNCED2, GhZFP1, GhERF1, GhHB1, and GhSAP1 under

Mosquitoes of Guam and the Northern Marianas: distribution, checklists, and notes on mosquito-borne pathogens.

PubMed

Rueda, Leopoldo M; Pecor, James E; Reeves, Will K; Wolf, Stephen P; Nunn, Peter V; Rabago, Rosanna Y; Gutierrez, Teresa L; Debboun, Mustapha

2011-01-01

This report includes the distribution records and updated checklists of the mosquitoes known to occur in Guam and nearby selected islands (ie, Saipan, Tinian, Rota), based on our field collections from various localities during 2010, published reports, and accessioned specimens deposited in the US National Museum of Natural History, Smithsonian Institution, Washington, DC. The status of common and potential mosquito vectors and their borne-pathogens are also noted.

Functional characterization of three MicroRNAs of the Asian Tiger Mosquito, Aedes albopictus

PubMed Central

2013-01-01

expressed miRNAs by the miRNA inhibitors in specific developmental stages had considerable effects on development, but enhancement of their gain of function was not observed on knock-in of these specific miRNAs. Hence, our study indicates that an optimal level of endogenous expression of miRNA is indispensable for the normal development and maintenance of the vectorial population density and pathogen transmissibility of this mosquito vector. PMID:23924583

Control of Malaria Vector Mosquitoes by Insecticide-Treated Combinations of Window Screens and Eave Baffles.

PubMed

Killeen, Gerry F; Masalu, John P; Chinula, Dingani; Fotakis, Emmanouil A; Kavishe, Deogratius R; Malone, David; Okumu, Fredros

2017-05-01

We assessed window screens and eave baffles (WSEBs), which enable mosquitoes to enter but not exit houses, as an alternative to indoor residual spraying (IRS) for malaria vector control. WSEBs treated with water, the pyrethroid lambda-cyhalothrin, or the organophosphate pirimiphos-methyl, with and without a binding agent for increasing insecticide persistence on netting, were compared with IRS in experimental huts. Compared with IRS containing the same insecticide, WSEBs killed similar proportions of Anopheles funestus mosquitoes that were resistant to pyrethroids, carbamates and organochlorines and greater proportions of pyrethroid-resistant, early exiting An. arabiensis mosquitoes. WSEBs with pirimiphos-methyl killed greater proportions of both vectors than lambda-cyhalothrin or lambda-cyhalothrin plus pirimiphos-methyl and were equally efficacious when combined with binding agent. WSEBs required far less insecticide than IRS, and binding agents might enhance durability. WSEBs might enable affordable deployment of insecticide combinations to mitigate against physiologic insecticide resistance and improve control of behaviorally resistant, early exiting vectors.

Plasmodium infection decreases fecundity and increases survival of mosquitoes.

PubMed

Vézilier, J; Nicot, A; Gandon, S; Rivero, A

2012-10-07

Long-lived mosquitoes maximize the chances of Plasmodium transmission. Yet, in spite of decades of research, the effect of Plasmodium parasites on mosquito longevity remains highly controversial. On the one hand, many studies report shorter lifespans in infected mosquitoes. On the other hand, parallel (but separate) studies show that Plasmodium reduces fecundity and imply that this is an adaptive strategy of the parasite aimed at redirecting resources towards longevity. No study till date has, however, investigated fecundity and longevity in the same individuals to see whether this prediction holds. In this study, we follow for both fecundity and longevity in Plasmodium-infected and uninfected mosquitoes using a novel, albeit natural, experimental system. We also explore whether the genetic variations that arise through the evolution of insecticide resistance modulate the effect of Plasmodium on these two life-history traits. We show that (i) a reduction in fecundity in Plasmodium-infected mosquitoes is accompanied by an increase in longevity; (ii) this increase in longevity arises through a trade-off between reproduction and survival; and (iii) in insecticide-resistant mosquitoes, the slope of this trade-off is steeper when the mosquito is infected by Plasmodium (cost of insecticide resistance).

Effect of Maillard Reacted Peptides on Human Salt Taste and the Amiloride-Insensitive Salt Taste Receptor (TRPV1t)

PubMed Central

Katsumata, Tadayoshi; Nakakuki, Hiroko; Tokunaga, Chikara; Fujii, Noboru; Egi, Makoto; Phan, Tam-Hao T.; Mummalaneni, Shobha; DeSimone, John A.

2008-01-01

Maillard reacted peptides (MRPs) were synthesized by conjugating a peptide fraction (1000–5000 Da) purified from soy protein hydrolyzate with galacturonic acid, glucosamine, xylose, fructose, or glucose. The effect of MRPs was investigated on human salt taste and on the chorda tympani (CT) taste nerve responses to NaCl in Sprague–Dawley rats, wild-type, and transient receptor potential vanilloid 1 (TRPV1) knockout mice. MRPs produced a biphasic effect on human salt taste perception and on the CT responses in rats and wild-type mice in the presence of NaCl + benzamil (Bz, a blocker of epithelial Na+ channels), enhancing the NaCl response at low concentrations and suppressing it at high concentrations. The effectiveness of MRPs as salt taste enhancers varied with the conjugated sugar moiety: galacturonic acid = glucosamine > xylose > fructose > glucose. The concentrations at which MRPs enhanced human salt taste were significantly lower than the concentrations of MRPs that produced increase in the NaCl CT response. Elevated temperature, resiniferatoxin, capsaicin, and ethanol produced additive effects on the NaCl CT responses in the presence of MRPs. Elevated temperature and ethanol also enhanced human salt taste perception. N-(3-methoxyphenyl)-4-chlorocinnamid (a blocker of TRPV1t) inhibited the Bz-insensitive NaCl CT responses in the absence and presence of MRPs. TRPV1 knockout mice demonstrated no Bz-insensitive NaCl CT response in the absence or presence of MRPs. The results suggest that MRPs modulate human salt taste and the NaCl + Bz CT responses by interacting with TRPV1t. PMID:18603652

A CIPK protein kinase targets sucrose transporter MdSUT2.2 at Ser254 for phosphorylation to enhance salt tolerance.

PubMed

Ma, Qi-Jun; Sun, Mei-Hong; Kang, Hui; Lu, Jing; You, Chun-Xiang; Hao, Yu-Jin

2018-05-23

Soil salinity is one of the major abiotic stressors that negatively affect crop growth and yield. Salt stress can regulate antioxidants and the accumulation of osmoprotectants. In the study, a sucrose transporter MdSUT2.2 was identified in apple. Overexpression of MdSUT2.2 gene increased salt tolerance in the transgenic apple, compared with the WT control 'Gala'. In addition, it was found that protein MdSUT2.2 was phosphorylated at Ser 254 site in response to salt. A DUAL membrane yeast hybridization system through an apple cDNA library demonstrated that a protein kinase MdCIPK13 interacted with MdSUT2.2. A series of transgenic analysis in apple calli showed that MdCIPK13 was required for the salt-induced phosphorylation of MdSUT2.2 protein and enhanced its stability and transport activity. Finally, it was found that MdCIPK13 improved salt resistance in an MdSUT2.2-dependent manner. These findings had enriched our understanding of the molecular mechanisms underlying abiotic stress. This article is protected by copyright. All rights reserved.

Immobilization of alginate-encapsulated Bacillus thuringiensis var. israelensis containing different multivalent counterions for mosquito control.

PubMed

Prabakaran, G; Hoti, S L

2008-08-01

Immobilized techniques have been used widely for the controlled release formulation of mosquitoes. Among the microbial formulations, polymeric matrices play an important role in the controlled release of microbial pesticide at rates sufficiently effective to kill mosquitoes in the field. The advantage of these matrices is that they enhance the stability of both spores and toxin against pH, temperature variations, and UV irradiation. The disadvantage of using calcium alginate beads is that they are unstable upon contact with phosphate of potassium or sodium ions rich in the mosquito habitats. To overcome these problems, attempts were made to encapsulate Bacillus thuringiensis var. israelensis within alginate by using different multivalent counterions, namely, calcium chloride, zinc sulfate, copper sulfate, cobalt chloride, and ferric chloride, and the beads formed were tested for its mosquito larvicidal activity. Among all the beads tested, zinc alginate beads resulted in maximum larvicidal activity of 98% (+/-1.40 SE) against Culex quinquefasciatus IIIrd instar larvae and maximum spore count of 3.36 x 10(5) (+/-5291.50 SE) CFU/ml. Zinc alginate beads maintained their structure for up to 48 h when shaken vigorously on a rotary shaker at 180 rpm in the presence of 10 mM potassium phosphate buffer (pH 6.8 +/- 0.1). In conclusion, our results suggest that the use of zinc sulfate as counterions to encapsulate B. thuringiensis var. israelensis within alginate may be a potent mosquito control program in the habitats where more phosphate ions are present.

Hofmeister series salts enhance purification of plasmid DNA by non-ionic detergents

PubMed Central

Lezin, George; Kuehn, Michael R.; Brunelli, Luca

2011-01-01

Ion-exchange chromatography is the standard technique used for plasmid DNA purification, an essential molecular biology procedure. Non-ionic detergents (NIDs) have been used for plasmid DNA purification, but it is unclear whether Hofmeister series salts (HSS) change the solubility and phase separation properties of specific NIDs, enhancing plasmid DNA purification. After scaling-up NID-mediated plasmid DNA isolation, we established that NIDs in HSS solutions minimize plasmid DNA contamination with protein. In addition, large-scale NID/HSS solutions eliminated LPS contamination of plasmid DNA more effectively than Qiagen ion-exchange columns. Large-scale NID isolation/NID purification generated increased yields of high quality DNA compared to alkali isolation/column purification. This work characterizes how HSS enhance NID-mediated plasmid DNA purification, and demonstrates that NID phase transition is not necessary for LPS removal from plasmid DNA. Specific NIDs such as IGEPAL CA-520 can be utilized for rapid, inexpensive and efficient laboratory-based large-scale plasmid DNA purification, outperforming Qiagen-based column procedures. PMID:21351074

Emerging mosquito species in Germany-a synopsis after 6 years of mosquito monitoring (2011-2016).

PubMed

Kampen, Helge; Schuhbauer, Astrid; Walther, Doreen

2017-12-01

Globalisation and climate change are the main drivers of invasion of non-endemic regions by mosquitoes. Mass transportation of people, animals and goods facilitate accidental long-distance displacement while climate warming supports active spread and establishment of thermophilic species. In the framework of a mosquito-monitoring programme, eight non-indigenous culicid species have been registered in Germany since 2011, with four of them being more or less efficient vectors of disease agents and another four now considered established. The eight newly emerged species include Aedes albopictus, Ae. japonicus, Ae. aegypti, Ae. koreicus, Ae. berlandi, Ae. pulcritarsis, Anopheles petragnani and Culiseta longiareolata. We here review recent findings and at the same time present new findings of specimens of non-native mosquito species in Germany.

Genetic approaches to interfere with malaria transmission by vector mosquitoes

PubMed Central

Wang, Sibao; Jacobs-Lorena, Marcelo

2013-01-01

Malaria remains one of the world’s most devastating diseases, causing over one million deaths every year. The most vulnerable stages of Plasmodium development in the vector mosquito occur in the midgut lumen, making the midgut a prime target for intervention. Mosquito transgenesis and paratransgenesis are two novel strategies that aim at rendering the vector incapable of sustaining Plasmodium development. Mosquito transgenesis involves direct genetic engineering of the mosquito itself for delivery of anti-Plasmodium effector molecules. Conversely, paratransgenesis involves the genetic modification of mosquito symbionts for expression of anti-pathogen effector molecules. Here we consider both genetic manipulation strategies for rendering mosquitoes refractory to Plasmodium infection, and discuss challenges for the translation of laboratory findings to field applications. PMID:23395485

Modulation of Host Learning in Aedes aegypti Mosquitoes.

PubMed

Vinauger, Clément; Lahondère, Chloé; Wolff, Gabriella H; Locke, Lauren T; Liaw, Jessica E; Parrish, Jay Z; Akbari, Omar S; Dickinson, Michael H; Riffell, Jeffrey A

2018-02-05

How mosquitoes determine which individuals to bite has important epidemiological consequences. This choice is not random; most mosquitoes specialize in one or a few vertebrate host species, and some individuals in a host population are preferred over others. Mosquitoes will also blood feed from other hosts when their preferred is no longer abundant, but the mechanisms mediating these shifts between hosts, and preferences for certain individuals within a host species, remain unclear. Here, we show that olfactory learning may contribute to Aedes aegypti mosquito biting preferences and host shifts. Training and testing to scents of humans and other host species showed that mosquitoes can aversively learn the scent of specific humans and single odorants and learn to avoid the scent of rats (but not chickens). Using pharmacological interventions, RNAi, and CRISPR gene editing, we found that modification of the dopamine-1 receptor suppressed their learning abilities. We further show through combined electrophysiological and behavioral recordings from tethered flying mosquitoes that these odors evoke changes in both behavior and antennal lobe (AL) neuronal responses and that dopamine strongly modulates odor-evoked responses in AL neurons. Not only do these results provide direct experimental evidence that olfactory learning in mosquitoes can play an epidemiological role, but collectively, they also provide neuroanatomical and functional demonstration of the role of dopamine in mediating this learning-induced plasticity, for the first time in a disease vector insect. Copyright © 2017 Elsevier Ltd. All rights reserved.

microRNA profiles and functions in mosquitoes

PubMed Central

Zhou, Shuisen; Wang, Jingwen; Hu, Wei

2018-01-01

Mosquitoes are incriminated as vectors for many crippling diseases, including malaria, West Nile fever, Dengue fever, and other neglected tropical diseases (NTDs). microRNAs (miRNAs) can interact with multiple target genes to elicit biological functions in the mosquitoes. However, characterization and function of individual miRNAs and their potential targets have not been fully determined to date. We conducted a systematic review of published literature following PRISMA guidelines. We summarize the information about miRNAs in mosquitoes to better understand their metabolism, development, and responses to microorganisms. Depending on the study, we found that miRNAs were dysregulated in a species-, sex-, stage-, and tissue/organ-specific manner. Aberrant miRNA expressions were observed in development, metabolism, host-pathogen interactions, and insecticide resistance. Of note, many miRNAs were down-regulated upon pathogen infection. The experimental studies have expanded the identification of miRNA target from the 3′ untranslated regions (UTRs) of mRNAs of mosquitoes to the 5′ UTRs of mRNAs of the virus. In addition, we discuss current trends in mosquito miRNA research and offer suggestions for future studies. PMID:29718912

The ecology of Anopheles mosquitoes under climate change: case studies from the effects of deforestation in East African highlands.

PubMed

Afrane, Yaw A; Githeko, Andrew K; Yan, Guiyun

2012-02-01

Climate change is expected to lead to latitudinal and altitudinal temperature increases. High-elevation regions such as the highlands of Africa and those that have temperate climate are most likely to be affected. The highlands of Africa generally exhibit low ambient temperatures. This restricts the distribution of Anopheles mosquitoes, the vectors of malaria, filariasis, and O'nyong'nyong fever. The development and survival of larval and adult mosquitoes are temperature dependent, as are mosquito biting frequency and pathogen development rate. Given that various Anopheles species are adapted to different climatic conditions, changes in climate could lead to changes in species composition in an area that may change the dynamics of mosquito-borne disease transmission. It is important to consider the effect of climate change on rainfall, which is critical to the formation and persistence of mosquito breeding sites. In addition, environmental changes such as deforestation could increase local temperatures in the highlands; this could enhance the vectorial capacity of the Anopheles. These experimental data will be invaluable in facilitating the understanding of the impact of climate change on Anopheles. © 2012 New York Academy of Sciences.

Effects of landscape anthropization on mosquito community composition and abundance

NASA Astrophysics Data System (ADS)

Ferraguti, Martina; Martínez-de La Puente, Josué; Roiz, David; Ruiz, Santiago; Soriguer, Ramón; Figuerola, Jordi

2016-07-01

Anthropogenic landscape transformation has an important effect on vector-borne pathogen transmission. However, the effects of urbanization on mosquito communities are still only poorly known. Here, we evaluate how land-use characteristics are related to the abundance and community composition of mosquitoes in an area with endemic circulation of numerous mosquito-borne pathogens. We collected 340 829 female mosquitoes belonging to 13 species at 45 localities spatially grouped in 15 trios formed by 1 urban, 1 rural and 1 natural area. Mosquito abundance and species richness were greater in natural and rural areas than in urban areas. Environmental factors including land use, vegetation and hydrological characteristics were related to mosquito abundance and community composition. Given the differing competences of each species in pathogen transmission, these results provide valuable information on the transmission potential of mosquito-borne pathogens that will be of great use in public and animal health management by allowing, for instance, the identification of the priority areas for pathogen surveillance and vector control.

Effects of landscape anthropization on mosquito community composition and abundance

PubMed Central

Ferraguti, Martina; Martínez-de la Puente, Josué; Roiz, David; Ruiz, Santiago; Soriguer, Ramón; Figuerola, Jordi

2016-01-01

Anthropogenic landscape transformation has an important effect on vector-borne pathogen transmission. However, the effects of urbanization on mosquito communities are still only poorly known. Here, we evaluate how land-use characteristics are related to the abundance and community composition of mosquitoes in an area with endemic circulation of numerous mosquito-borne pathogens. We collected 340 829 female mosquitoes belonging to 13 species at 45 localities spatially grouped in 15 trios formed by 1 urban, 1 rural and 1 natural area. Mosquito abundance and species richness were greater in natural and rural areas than in urban areas. Environmental factors including land use, vegetation and hydrological characteristics were related to mosquito abundance and community composition. Given the differing competences of each species in pathogen transmission, these results provide valuable information on the transmission potential of mosquito-borne pathogens that will be of great use in public and animal health management by allowing, for instance, the identification of the priority areas for pathogen surveillance and vector control. PMID:27373794

First molecular identification of Dirofilaria spp. (Onchocercidae) in mosquitoes from Serbia.

PubMed

Kurucz, Kornélia; Kepner, Anett; Krtinic, Bosiljka; Zana, Brigitta; Földes, Fanni; Bányai, Krisztián; Oldal, Miklós; Jakab, Ferenc; Kemenesi, Gábor

2016-08-01

Dirofilariosis is a common and widespread veterinary health issue in several European countries with notable zoonotic potential. The causative agents are Dirofilaria immitis and Dirofilaria repens nematoda species which are transmitted by different mosquito vectors. Similar to other mosquito-borne infections, the knowledge about mosquito species involved in disease transmission is crucial for the complex understanding of local transmission cycles. Since there is no available data on mosquito species, potentially involved in disease transmission from Serbia, 6369 female mosquito individuals were retrospectively tested for Dirofilaria nematodes, collected from 13 localities in Vojvodina province, Serbia, in 2013. Altogether, 8.33 % of tested pools showed positivity, composed of five mosquito species, mainly, Culex pipiens and Aedes vexans. D. immitis and D. repens were both detected from multiple localities, during the whole period of mosquito breeding season, which provides the first data on local transmission characteristics regarding mosquitoes from the Balkans.

Darker eggs of mosquitoes resist more to dry conditions: Melanin enhances serosal cuticle contribution in egg resistance to desiccation in Aedes, Anopheles and Culex vectors.

PubMed

Farnesi, Luana C; Vargas, Helena C M; Valle, Denise; Rezende, Gustavo L

2017-10-01

Mosquito vectors lay their white eggs in the aquatic milieu. During early embryogenesis water passes freely through the transparent eggshell, which at this moment is composed of exochorion and endochorion. Within two hours the endochorion darkens via melanization but even so eggs shrink and perish if removed from moisture. However, during mid-embryogenesis, cells of the extraembryonic serosa secrete the serosal cuticle, localized right below the endochorion, becoming the third and innermost eggshell layer. Serosal cuticle formation greatly reduces water flow and allows egg survival outside the water. The degree of egg resistance to desiccation (ERD) at late embryogenesis varies among different species: Aedes aegypti, Anopheles aquasalis and Culex quinquefasciatus eggs can survive in a dry environment for ≥ 72, 24 and 5 hours, respectively. In some adult insects, darker-body individuals show greater resistance to desiccation than lighter ones. We asked if egg melanization enhances mosquito serosal cuticle-dependent ERD. Species with higher ERD at late embryogenesis exhibit more melanized eggshells. The melanization-ERD hypothesis was confirmed employing two Anopheles quadrimaculatus strains, the wild type and the mutant GORO, with a dark-brown and a golden eggshell, respectively. In all cases, serosal cuticle formation is fundamental for the establishment of an efficient ERD but egg viability outside the water is much higher in mosquitoes with darker eggshells than in those with lighter ones. The finding that pigmentation influences egg water balance is relevant to understand the evolutionary history of insect egg coloration. Since eggshell and adult cuticle pigmentation ensure insect survivorship in some cases, they should be considered regarding species fitness and novel approaches for vector or pest insects control.

Darker eggs of mosquitoes resist more to dry conditions: Melanin enhances serosal cuticle contribution in egg resistance to desiccation in Aedes, Anopheles and Culex vectors

PubMed Central

Farnesi, Luana C.; Vargas, Helena C. M.; Valle, Denise

2017-01-01

Mosquito vectors lay their white eggs in the aquatic milieu. During early embryogenesis water passes freely through the transparent eggshell, which at this moment is composed of exochorion and endochorion. Within two hours the endochorion darkens via melanization but even so eggs shrink and perish if removed from moisture. However, during mid-embryogenesis, cells of the extraembryonic serosa secrete the serosal cuticle, localized right below the endochorion, becoming the third and innermost eggshell layer. Serosal cuticle formation greatly reduces water flow and allows egg survival outside the water. The degree of egg resistance to desiccation (ERD) at late embryogenesis varies among different species: Aedes aegypti, Anopheles aquasalis and Culex quinquefasciatus eggs can survive in a dry environment for ≥ 72, 24 and 5 hours, respectively. In some adult insects, darker-body individuals show greater resistance to desiccation than lighter ones. We asked if egg melanization enhances mosquito serosal cuticle-dependent ERD. Species with higher ERD at late embryogenesis exhibit more melanized eggshells. The melanization-ERD hypothesis was confirmed employing two Anopheles quadrimaculatus strains, the wild type and the mutant GORO, with a dark-brown and a golden eggshell, respectively. In all cases, serosal cuticle formation is fundamental for the establishment of an efficient ERD but egg viability outside the water is much higher in mosquitoes with darker eggshells than in those with lighter ones. The finding that pigmentation influences egg water balance is relevant to understand the evolutionary history of insect egg coloration. Since eggshell and adult cuticle pigmentation ensure insect survivorship in some cases, they should be considered regarding species fitness and novel approaches for vector or pest insects control. PMID:29084225

Aedes mosquito saliva modulates Rift Valley fever virus pathogenicity.

PubMed

Le Coupanec, Alain; Babin, Divya; Fiette, Laurence; Jouvion, Grégory; Ave, Patrick; Misse, Dorothee; Bouloy, Michèle; Choumet, Valerie

2013-01-01

Rift Valley fever (RVF) is a severe mosquito-borne disease affecting humans and domestic ruminants. Mosquito saliva contains compounds that counteract the hemostatic, inflammatory, and immune responses of the host. Modulation of these defensive responses may facilitate virus infection. Indeed, Aedes mosquito saliva played a crucial role in the vector's capacity to effectively transfer arboviruses such as the Cache Valley and West Nile viruses. The role of mosquito saliva in the transmission of Rift Valley fever virus (RVFV) has not been investigated. Using a murine model, we explored the potential for mosquitoes to impact the course of RVF disease by determining whether differences in pathogenesis occurred in the presence or absence of mosquito saliva and salivary gland extract. C57BL/6NRJ male mice were infected with the ZH548 strain of RVFV via intraperitoneal or intradermal route, or via bites from RVFV-exposed mosquitoes. The virus titers in mosquitoes and mouse organs were determined by plaque assays. After intraperitoneal injection, RVFV infection primarily resulted in liver damage. In contrast, RVFV infection via intradermal injection caused both liver and neurological symptoms and this route best mimicked the natural infection by mosquitoes. Co-injections of RVFV with salivary gland extract or saliva via intradermal route increased the mortality rates of mice, as well as the virus titers measured in several organs and in the blood. Furthermore, the blood cell counts of infected mice were altered compared to those of uninfected mice. Different routes of infection determine the pattern in which the virus spreads and the organs it targets. Aedes saliva significantly increases the pathogenicity of RVFV.

NtLTP4, a lipid transfer protein that enhances salt and drought stresses tolerance in Nicotiana tabacum.

PubMed

Xu, Yang; Zheng, Xinxin; Song, Yunzhi; Zhu, Lifei; Yu, Zipeng; Gan, Liming; Zhou, Shumei; Liu, Hongmei; Wen, Fujiang; Zhu, Changxiang

2018-06-11

Lipid transfer proteins (LTPs), a class of small, ubiquitous proteins, play critical roles in various environmental stresses. However, their precise biological functions remain unknown. Here we isolated an extracellular matrix-localised LTP, NtLTP4, from Nicotiana tabacum. The overexpression of NtLTP4 in N. tabacum enhanced resistance to salt and drought stresses. Upon exposure to high salinity, NtLTP4-overexpressing lines (OE lines) accumulated low Na + levels. Salt-responsive genes, including Na + /H + exchangers (NHX1) and high-affinity K + transporter1 (HKT1), were dramatically higher in OE lines than in wild-type lines. NtLTP4 might regulate transcription levels of NHX1 and HKT1 to alleviate the toxicity of Na + . Interestingly, OE lines enhanced the tolerance of N. tabacum to drought stress by reducing the transpiration rate. Moreover, NtLTP4 could increase reactive oxygen species (ROS)-scavenging enzyme activity and expression levels to scavenge excess ROS under drought and high salinity conditions. We used a two-hybrid yeast system and screened seven putative proteins that interact with NtLTP4 in tobacco. An MAPK member, wound-induced protein kinase, was confirmed to interact with NtLTP4 via co-immunoprecipitation and a firefly luciferase complementation imaging assay. Taken together, this is the first functional analysis of NtLTP4, and proves that NtLTP4 positively regulates salt and drought stresses in N. tabacum.

Mini Review: Mode of Action of Mosquito Repellents

DTIC Science & Technology

2013-01-01

Mini review: Mode of action of mosquito repellents Joseph C. Dickens ⇑, Jonathan D. Bohbot United States Department of Agriculture, Agricultural...Modulation a b s t r a c t The mode of action of mosquito repellents remains a controversial topic. However, electrophysiological studies and molecular...annoyance that can disrupt outdoor activities. The use of repellents decreases contacts between mosquitoes and their hosts, and may even lower the rate of

Effect of Salt Reduction on Consumer Acceptance and Sensory Quality of Food

PubMed Central

Hoppu, Ulla; Hopia, Anu; Pohjanheimo, Terhi; Rotola-Pukkila, Minna; Mäkinen, Sari; Pihlanto, Anne

2017-01-01

Reducing salt (NaCl) intake is an important public health target. The food industry and catering services are searching for means to reduce the salt content in their products. This review focuses on options for salt reduction in foods and the sensory evaluation of salt-reduced foods. Simple salt reduction, mineral salts and flavor enhancers/modifiers (e.g., umami compounds) are common options for salt reduction. In addition, the modification of food texture and odor-taste interactions may contribute to enhanced salty taste perception. Maintaining consumer acceptance of the products is a challenge, and recent examples of the consumer perception of salt-reduced foods are presented. PMID:29186893

The effect of salt replacers and flavor enhancer on the processing characteristics and consumer acceptance of turkey sausages.

PubMed

Pietrasik, Zeb; Gaudette, Nicole J

2015-07-01

Producing high-quality processed meats that contain reduced amounts of sodium chloride is a major challenge facing industry owing to the importance of sodium chloride toward the functional, microbial stability and sensory properties of these products. In order to create reduced sodium alternatives, a number of commercial salt replacers and flavor enhancers have entered the market; however, their ability to be applied in processed meats requires investigation. In this study, two salt replacers (Ocean's Flavor - OF45, OF60) and one flavor enhancer (Fonterra™ Savoury Powder - SP) were evaluated for their ability to effectively reduce sodium while maintaining the functional and sensory properties of turkey sausages. Functionality via instrumental measures (yield, purge loss, pH, expressible moisture, proximate composition, sodium content, color, texture), safety (microbiological assessment) and consumer acceptability were obtained on all samples. All non-control treatments resulted in products with sodium chloride contents below Canada's Health Check™ Program target for processed meats. There was no detrimental effect on water binding and texture in treatments when NaCl was substituted with OF60 sea salt replacers. Sodium reduction had no negative effect on the shelf life of the turkey sausages with up to 60 days of refrigerated storage. Consumer acceptability for all attributes did not differ significantly, except for aftertaste, which scored lowest for OF45 compared with the control (regular NaCl content). This work demonstrated that salt replacers could potentially substitute for NaCl in smoked turkey sausages; however, further flavor optimization may be required to suppress undesirable levels of bitterness elicited by some of these ingredients. © 2014 Society of Chemical Industry.

Traditional use of indigenous mosquito-repellents to protect humans against mosquitoes and other insect bites in a rural community of Cameroon.

PubMed

Ntonifor, N N; Ngufor, C A; Kimbi, H K; Oben, B O

2006-10-01

To document and test the efficacy of indigenous traditional personal protection methods against mosquito bites and general nuisance. A prospective study based on a survey and field evaluation of selected plant-based personal protection methods against mosquito bites. Bolifamba, a rural setting of the Mount Cameroon region. A structured questionnaire was administered to 179 respondents and two anti-mosquito measures were tested under field conditions. Identified traditional anti-mosquito methods used by indigenes of Bolifamba. Two plants tested under field conditions were found to be effective. Of the 179 respondents, 88 (49.16%) used traditional anti-mosquito methods; 57 (64.77%) used plant-based methods while 31 (35.2%) used various petroleum oils. The rest of the respondents, 91 (50.8%) used conventional personal protection methods. Reasons for using traditional methods were because they were available, affordable and lack of known more effective alternatives. The demerits of these methods were: labourious to implement, stain dresses, produce a lot of smoke/ repulsive odours when used; those of conventional methods were lack of adequate information about them, high cost and non-availability. When the two most frequently used plants, Saccharum officinarium and Ocimum basilicum were evaluated under field conditions, each gave a better protection than the control. Most plants used against mosquitoes in the area are known potent mosquito repellents but others identified in the study warrant further research. The two tested under field conditions were effective though less than the commonly used commercial diethyltoluamide.

Into the environment of mosquito-borne disease: A spatial analysis of vector distribution using traditional and remotely sensed methods

NASA Astrophysics Data System (ADS)

Brown, Heidi E.

mosquito and human disease surveillance data by providing spatially explicit, line resolution information about environmental factors relevant to vector-borne disease processes. Together, surveillance and remotely sensed environmental data facilitate improved description and modeling of disease transmission. Remote sensing can be used to develop predictive maps of mosquito distribution in relation to disease risk. This has implications for increased accuracy of mosquito control efforts. The projects presented in this dissertation enhance current public health capacities by examining the applications of spatial modeling with respect to mosquito-borne disease.

Effects of mosquito larvicide on mallard ducklings and prey

USGS Publications Warehouse

Miles, A.K.; Lawler, S.P.; Dritz, D.; Spring, S.

2002-01-01

We determined the effects of a commonly used mosquito (Culicidae) larvicide (California Golden Bear Oil??, also GB-1111) on body mass and survival of mallard (Anas platyrhynchos) ducklings and on target and nontarget invertebrates. Field studies conducted on natural ponds located in salt marshes in south San Francisco Bay indicated that GB-1111 had an initial impact on potential invertebrate prey of birds that dissipated rapidly 3 days post-spray. Over-spray, spray drift, or treatment of more extensive areas would likely delay recovery of nontarget prey. Ducklings held intermittently on the ponds over an 8-day period showed no significant effects of weight loss due to invertebrate prey depletion, although initial effects of exposure to GB-1111 were observed (i.e., matting of feathers and mild hypothermia). These results emphasize the importance of avoiding application of GB-1111 during cold temperatures and adherence to recommended use of this larvicide. Otherwise, GB-1111 had a short-term impact on wetland communities.

Mosquito larvicidal activity of botanical-based mosquito repellents.

PubMed

Zhu, Junwei; Zeng, Xiaopeng; O'Neal, Megan; Schultz, Gretchen; Tucker, Brad; Coats, Joel; Bartholomay, Lyric; Xue, Rui-De

2008-03-01

The larvicidal activity of 4 plant essential oils--innamon oil, lemon eucalyptus oil, sandalwood oil, and turmeric oil--previously reported as insect repellents was evaluated in the laboratory against 4th instars of Aedes albopictus, Ae. aegypti, and Culex pipiens. Sandalwood oil appeared to be the most effective of the larvicides, killing larvae of all 3 mosquito species in relatively short times. The values of LT50 and LT90 at the application dosage (0.2 mg/ml) were 1.06 +/- 0.11 and 3.24 +/- 0.14 h for Ae. aegypti, 1.82 +/- 0.06 and 3.33 +/- 0.48 h for Ae. albopictus, and 1.55 +/- 0.07 and 3.91 +/- 0.44 h for Cx. pipiens, respectively. Chemical compositions of these essential oils were also studied, and the lavicidal activity of their major ingredient compounds was compared with that of each of the essential oils. The acute toxicity of the 4 essential oils to fathead minnows was also evaluated. The safe use of these natural plant essential oils in future applications of mosquito control was discussed.

Dietary Salt Exacerbates Experimental Colitis.

PubMed

Tubbs, Alan L; Liu, Bo; Rogers, Troy D; Sartor, R Balfour; Miao, Edward A

2017-08-01

The Western diet is characterized by high protein, sugar, fat, and low fiber intake, and is widely believed to contribute to the incidence and pathogenesis of inflammatory bowel disease (IBD). However, high sodium chloride salt content, a defining feature of processed foods, has not been considered as a possible environmental factor that might drive IBD. We set out to bridge this gap. We examined murine models of colitis on either a high salt diet (HSD) or a low salt diet. We demonstrate that an HSD exacerbates inflammatory pathology in the IL-10-deficient murine model of colitis relative to mice fed a low salt diet. This was correlated with enhanced expression of numerous proinflammatory cytokines. Surprisingly, sodium accumulated in the colons of mice on an HSD, suggesting a direct effect of salt within the colon. Similar to the IL-10-deficient model, an HSD also enhanced cytokine expression during infection by Salmonella typhimurium This occurred in the first 3 d of infection, suggesting that an HSD potentiates an innate immune response. Indeed, in cultured dendritic cells we found that high salt media potentiates cytokine expression downstream of TLR4 activation via p38 MAPK and SGK1. A third common colitis model, administration of dextran sodium sulfate, was hopelessly confounded by the high sodium content of the dextran sodium sulfate. Our results raise the possibility that high dietary salt is an environmental factor that drives increased inflammation in IBD. Copyright © 2017 by The American Association of Immunologists, Inc.

“Looking over the Backyard Fence”: Householders and Mosquito Control

PubMed Central

Mainali, Samir; Lamichhane, Ram Sharan; Clark, Kim; Beatty, Shelley; Fatouros, Maria; Neville, Peter; Oosthuizen, Jacques

2017-01-01

(1) Background: Vector-borne diseases are a significant public health problem in Western Australia. Mosquitoes are responsible for the transmission of a number of pathogens and may pose a serious nuisance problem. Prevention efforts in the State are multi-faceted and include physical, chemical, and cultural control methods for restricting mosquito breeding. This is less complex where breeding areas are located within public open spaces. In Australia’s developed urban areas, breeding sites are, however, frequently located within private residential landholdings, where the scope of public health officials to act is constrained by law and practicality. Consequently, mosquito prevention in these locations is predominantly the responsibility of the residents. This research addressed a gap, both in understanding the degree to which “backyard” mosquito breeding has the potential to contribute to local mosquito problems, and in assessing what residents “think and do” about mosquito control within their home environment. (2) Methods: The study was conducted in the Town of Bassendean, a metropolitan Local Government Area of Perth, Western Australia, in close proximity to two natural, productive mosquito breeding sites, namely Ashfield Flats and Bindaring Park. A total of 150 householders were randomly surveyed during the summer of 2015–2016, to gauge residents’ knowledge, attitudes, and practices (KAP (knowledge, attitudes, and practices) Survey) in regards to mosquitoes, their breeding and ecology, and avoidance or minimization strategies. The survey comprised nine questions covering residents’ knowledge (3 questions), attitudes (3 questions), and practices (3 questions), as well as additional questions regarding the basic demographics of the resident. Larvae were collected from backyard containers and reared to adults for species identification. A series of Encephalitis Vector Surveillance carbon dioxide (EVS CO2) traps were also deployed, to assess adult

Mosquito (Diptera: culicidae) fauna of qom province, iran.

PubMed

Saghafipour, A; Abai, Mr; Farzinnia, B; Nafar, R; Ladonni, H; Azari-Hamidian, S

2012-01-01

There is very little information about the mosquito fauna of Qom Province, central Iran. By now only three species; Anopheles claviger, An. multicolor, and An. superpictus have been reported in the province. To study mosquito fauna and providing a primary checklist, an investigation was carried out on a collection of mosquitoes in this province. TO STUDY THE MOSQUITO (DIPTERA: Culicidae) fauna, larval collections were carried out from different habitats on 19 occasions using the standard dipping technique during spring and summer 2008 and 2009. In total, 371 mosquito larvae were collected and morphologically identified including 14 species representing four genera: Anopheles claviger, An. marteri, An. turkhudi, An. superpictus, Culex arbieeni, Cx. hortensis, Cx. mimeticus, Cx. modestus, Cx. pipiens, Cx. territans, Cx. theileri, Culiseta longiareolata, Cs. subochrea, and Ochlerotatus caspius s.l. All species except for An. claviger and An. superpictus were collected for the first time in the province. All larvae were found in natural habitats. The association occasions and percentages of the mosquito larvae in Qom Province were discussed. There are some potential or proven vectors of different human and domesticated animal pathogens in Qom Province. The ecology of these species and the unstudied areas of Qom Province need to be investigated extensively.

Mosquito (Diptera: Culicidae) Fauna of Qom Province, Iran

PubMed Central

Saghafipour, A; Abai, MR; Farzinnia, B; Nafar, R; Ladonni, H; Azari-Hamidian, S

2012-01-01

Background There is very little information about the mosquito fauna of Qom Province, central Iran. By now only three species; Anopheles claviger, An. multicolor, and An. superpictus have been reported in the province. To study mosquito fauna and providing a primary checklist, an investigation was carried out on a collection of mosquitoes in this province. Methods: To study the mosquito (Diptera: Culicidae) fauna, larval collections were carried out from different habitats on 19 occasions using the standard dipping technique during spring and summer 2008 and 2009. Results: In total, 371 mosquito larvae were collected and morphologically identified including 14 species representing four genera: Anopheles claviger, An. marteri, An. turkhudi, An. superpictus, Culex arbieeni, Cx. hortensis, Cx. mimeticus, Cx. modestus, Cx. pipiens, Cx. territans, Cx. theileri, Culiseta longiareolata, Cs. subochrea, and Ochlerotatus caspius s.l. All species except for An. claviger and An. superpictus were collected for the first time in the province. All larvae were found in natural habitats. The association occasions and percentages of the mosquito larvae in Qom Province were discussed. Conclusion: There are some potential or proven vectors of different human and domesticated animal pathogens in Qom Province. The ecology of these species and the unstudied areas of Qom Province need to be investigated extensively. PMID:23293779

Tropical Mosquito Assemblages Demonstrate ‘Textbook’ Annual Cycles

PubMed Central

Franklin, Donald C.; Whelan, Peter I.

2009-01-01

Background Annual biological rhythms are often depicted as predictably cyclic, but quantitative evaluations are few and rarely both cyclic and constant among years. In the monsoon tropics, the intense seasonality of rainfall frequently drives fluctuations in the populations of short-lived aquatic organisms. However, it is unclear how predictably assemblage composition will fluctuate because the intensity, onset and cessation of the wet season varies greatly among years. Methodology/Principal Findings Adult mosquitoes were sampled using EVS suction traps baited with carbon dioxide around swamplands adjacent to the city of Darwin in northern Australia. Eleven sites were sampled weekly for five years, and one site weekly for 24 years, the sample of c. 1.4 million mosquitoes yielding 63 species. Mosquito abundance, species richness and diversity fluctuated seasonally, species richness being highly predictable. Ordination of assemblage composition demonstrated striking annual cycles that varied little from year to year. The mosquito assemblage was temporally structured by a succession of species peaks in abundance. Conclusion/Significance Ordination provided strong visual representation of annual rhythms in assemblage composition and the means to evaluate variability among years. Because most mosquitoes breed in shallow freshwater which fluctuates with rainfall, we did not anticipate such repeatability; we conclude that mosquito assemblage composition appears adapted to predictable elements of the rainfall. PMID:20011531

Integrating the Public in Mosquito Management: Active Education by Community Peers Can Lead to Significant Reduction in Peridomestic Container Mosquito Habitats

PubMed Central

Healy, Kristen; Hamilton, George; Crepeau, Taryn; Healy, Sean; Unlu, Isik; Farajollahi, Ary; Fonseca, Dina M.

2014-01-01

Mosquito species that utilize peridomestic containers for immature development are commonly aggressive human biters, and because they often reach high abundance, create significant nuisance. One of these species, the Asian tiger mosquito Aedes albopictus, is an important vector of emerging infectious diseases, such as dengue, chikungunya, and Zika fevers. Integrated mosquito management (IMM) of Ae. albopictus is particularly difficult because it requires access to private yards in urban and suburban residences. It has become apparent that in the event of a public health concern due to this species, homeowners will have to be active participants in the control process by reducing mosquito habitats in their properties, an activity known as source reduction. However, limited attempts at quantifying the effect of source reduction by homeowners have had mixed results. Of note, many mosquito control programs in the US have some form of education outreach, however the primary approach is often passive focusing on the distribution of education materials as flyers. In 2010, we evaluated the use of active community peer education in a source reduction program, using AmeriCorps volunteers. The volunteers were mobilized over a 4-week period, in two areas with approximately 1,000 residences each in urban Mercer and suburban Monmouth counties in New Jersey, USA. The volunteers were first provided training on peridomestic mosquitoes and on basic approaches to reducing the number of container habitats for mosquito larvae in backyards. Within the two treatment areas the volunteers successfully engaged 758 separate homes. Repeated measures analysis of variance showed a significant reduction in container habitats in the sites where the volunteers actively engaged the community compared to untreated control areas in both counties. Our results suggest that active education using community peer educators can be an effective means of source reduction, and a critical tool in the arsenal

Using mobile phones as acoustic sensors for high-throughput mosquito surveillance.

PubMed

Mukundarajan, Haripriya; Hol, Felix Jan Hein; Castillo, Erica Araceli; Newby, Cooper; Prakash, Manu

2017-10-31

The direct monitoring of mosquito populations in field settings is a crucial input for shaping appropriate and timely control measures for mosquito-borne diseases. Here, we demonstrate that commercially available mobile phones are a powerful tool for acoustically mapping mosquito species distributions worldwide. We show that even low-cost mobile phones with very basic functionality are capable of sensitively acquiring acoustic data on species-specific mosquito wingbeat sounds, while simultaneously recording the time and location of the human-mosquito encounter. We survey a wide range of medically important mosquito species, to quantitatively demonstrate how acoustic recordings supported by spatio-temporal metadata enable rapid, non-invasive species identification. As proof-of-concept, we carry out field demonstrations where minimally-trained users map local mosquitoes using their personal phones. Thus, we establish a new paradigm for mosquito surveillance that takes advantage of the existing global mobile network infrastructure, to enable continuous and large-scale data acquisition in resource-constrained areas.

Using mobile phones as acoustic sensors for high-throughput mosquito surveillance

PubMed Central

Mukundarajan, Haripriya; Hol, Felix Jan Hein; Castillo, Erica Araceli; Newby, Cooper

2017-01-01

The direct monitoring of mosquito populations in field settings is a crucial input for shaping appropriate and timely control measures for mosquito-borne diseases. Here, we demonstrate that commercially available mobile phones are a powerful tool for acoustically mapping mosquito species distributions worldwide. We show that even low-cost mobile phones with very basic functionality are capable of sensitively acquiring acoustic data on species-specific mosquito wingbeat sounds, while simultaneously recording the time and location of the human-mosquito encounter. We survey a wide range of medically important mosquito species, to quantitatively demonstrate how acoustic recordings supported by spatio-temporal metadata enable rapid, non-invasive species identification. As proof-of-concept, we carry out field demonstrations where minimally-trained users map local mosquitoes using their personal phones. Thus, we establish a new paradigm for mosquito surveillance that takes advantage of the existing global mobile network infrastructure, to enable continuous and large-scale data acquisition in resource-constrained areas. PMID:29087296

Does Zika virus infection affect mosquito response to repellents?

PubMed Central

Leal, Walter S.; Barbosa, Rosângela M. R.; Zeng, Fangfang; Faierstein, Gabriel B.; Tan, Kaiming; Paiva, Marcelo H. S.; Guedes, Duschinka R. D.; Crespo, Mônica M.; Ayres, Constância F. J.

2017-01-01

The World Health Organization (WHO) recommends that people travelling to or living in areas with Zika virus (ZIKV) outbreaks or epidemics adopt prophylactic measures to reduce or eliminate mosquito bites, including the use of insect repellents. It is, however, unknown whether repellents are effective against ZIKV-infected mosquitoes, in part because of the ethical concerns related to exposing a human subject’s arm to infected mosquitoes in the standard arm-in-cage assay. We used a previously developed, human subject-free behavioural assay, which mimics a human subject to evaluate the top two recommended insect repellents. Our measurements showed that DEET provided significantly higher protection than picaridin provided against noninfected, host-seeking females of the southern house mosquito, Culex quinquefasciatus, and the yellow fever mosquito, Aedes aegypti. When tested at lower doses, we observed a significant reduction in DEET-elicited protection against ZIKV-infected yellow fever mosquitoes from old and recent laboratory colonies. The reduction in protection is more likely associated with aging than the virus infection and could be compensated by applying a 5x higher dose of DEET. A substantial protection against ZIKV-infected and old noninfected mosquitoes was achieved with 5% DEET, which corresponds approximately to a 30% dose in the conventional arm-in-cage assays. PMID:28205633

Avian phenotypic traits related to feeding preferences in two Culex mosquitoes

NASA Astrophysics Data System (ADS)

Yan, Jiayue; Gangoso, Laura; Martínez-de la Puente, Josué; Soriguer, Ramón; Figuerola, Jordi

2017-10-01

Host choice by mosquitoes affects the transmission dynamics of vector-borne infectious diseases. Although asymmetries in mosquito attraction to vertebrate species have been reported, the relative importance of host characteristics in mosquito blood-feeding behavior is still poorly studied. Here, we investigate the relationship between avian phenotypic traits—in particular, morphometry, plumage coloration, and nesting and roosting behavior—and the blood-feeding patterns in two common Culex mosquito species on a North American avian community. Forage ratios of the mosquito species were unrelated to the phylogenetic relationships among bird species. Culex pipiens fed preferably on birds with lighter-colored plumage and longer tarsi; furthermore, solitary roosting avian species were both bitten by Cx. pipiens and Cx. restuans more often than expected. These associations may be explained by greater mosquito attraction towards larger birds with a greater color contrast against the background. Although communally roosting birds may release more cues and attract more mosquitoes, individuals may in fact receive fewer bites due to the encounter-dilution effect. Mosquito feeding behavior is a highly complex phenomenon, and our results may improve understanding of the non-random interaction between birds and mosquitoes in natural communities.

UV light and urban pollution: bad cocktail for mosquitoes?

PubMed

Tetreau, Guillaume; Chandor-Proust, Alexia; Faucon, Frédéric; Stalinski, Renaud; Akhouayri, Idir; Prud'homme, Sophie M; Régent-Kloeckner, Myriam; Raveton, Muriel; Reynaud, Stéphane

2014-01-01

Mosquito breeding sites consist of water pools, which can either be large open areas or highly covered ponds with vegetation, thus with different light exposures combined with the presence in water of xenobiotics including polycyclic aromatic hydrocarbons (PAHs) generated by urban pollution. UV light and PAHs are abiotic factors known to both affect the mosquito insecticide resistance status. Nonetheless, their potential combined effects on the mosquito physiology have never been investigated. The present article aims at describing the effects of UV exposure alongside water contamination with two major PAH pollutants (fluoranthene and benzo[a]pyrene) on a laboratory population of the yellow fever mosquito Aedes aegypti. To evaluate the effects of PAH exposure and low energetic UV (UV-A) irradiation on mosquitoes, different parameters were measured including: (1) The PAH localization and its impact on cell mortality by fluorescent microscopy; (2) The detoxification capacities (cytochrome P450, glutathione-S-transferase, esterase); (3) The responses to oxidative stress (Reactive Oxygen Species-ROS) and (4) The tolerance of mosquito larvae to a bioinsecticide (Bacillus thuringiensis subsp. israelensis-Bti) and to five chemical insecticides (DDT, imidacloprid, permethrin, propoxur and temephos). Contrasting effects regarding mosquito cell mortality, detoxification and oxidative stress were observed as being dependent on the pollutant considered, despite the fact that the two PAHs belong to the same family. Moreover, UV is able to modify pollutant effects on mosquitoes, including tolerance to three insecticides (imidacloprid, propoxur and temephos), cell damage and response to oxidative stress. Taken together, our results suggest that UV and pollution, individually or in combination, are abiotic parameters that can affect the physiology and insecticide tolerance of mosquitoes; but the complexity of their direct effect and of their interaction will require further

Non-Genetic Determinants of Mosquito Competence for Malaria Parasites

PubMed Central

Lefèvre, Thierry; Vantaux, Amélie; Dabiré, Kounbobr R.; Mouline, Karine; Cohuet, Anna

2013-01-01

Understanding how mosquito vectors and malaria parasites interact is of fundamental interest, and it also offers novel perspectives for disease control. Both the genetic and environmental contexts are known to affect the ability of mosquitoes to support malaria development and transmission, i.e., vector competence. Although the role of environment has long been recognized, much work has focused on host and parasite genetic effects. However, the last few years have seen a surge of studies revealing a great diversity of ways in which non-genetic factors can interfere with mosquito-Plasmodium interactions. Here, we review the current evidence for such environmentally mediated effects, including ambient temperature, mosquito diet, microbial gut flora, and infection history, and we identify additional factors previously overlooked in mosquito-Plasmodium interactions. We also discuss epidemiological implications, and the evolutionary consequences for vector immunity and parasite transmission strategies. Finally, we propose directions for further research and argue that an improved knowledge of non-genetic influences on mosquito-Plasmodium interactions could aid in implementing conventional malaria control measures and contribute to the design of novel strategies. PMID:23818841

Novel Methods for Mosquito Control using RNAi.

USDA-ARS?s Scientific Manuscript database

The discovery and development of novel insecticides for vector control is a primary focus of toxicology research conducted at the Mosquito and Fly Research Unit, Gainesville, FL. Targeting critical genes/proteins in mosquitoes using RNA interference (RNAi) is being investigated as a method to devel...

An innovative mosquito trap for testing attractants

USDA-ARS?s Scientific Manuscript database

We describe a simple trap modification for testing or using attractants to collect flying mosquitoes. The trap also can test the effectiveness of spatial repellents. The proposed design may facilitate standardized testing of mosquito attractants and repellents. The trap uses a standard Centers f...

Review: artificial container-breeding mosquitoes and cemeteries: a perfect match.

PubMed

Vezzani, Darío

2007-02-01

Artificial container-breeding mosquitoes, such as Aedes aegypti, Ae. albopictus, and Culex pipiens, are well-recognized vectors of diseases throughout the world. Cemeteries are considered major sources of mosquitoes and the results of more than 30 studies concerning mosquitoes in cemeteries have been published over the last decade. The characteristics of these environments in regard to the availability of resources for mosquito development were discussed. Also, studies about early detection of Aedes vectors, ecological issues, and mosquito control performed in cemeteries were reviewed. Among 31 mosquito species found breeding in cemeteries from 16 countries, the invasive Ae. aegypti and Ae. albopictus were the most frequent ones. Species of the genus Ochlerotatus, Culex, Toxorhynchites, Culiseta, Armigeres, Lutzia, Uranotaenia, and Tripteroides were also reported. Overall, cemeteries are highly suitable habitats for artificial container-breeding mosquitoes due to the great availability of the different resources that they need (i.e. sugar substances, blood, shelter and water-filled containers). In addition, these places are mostly ideal settings to perform studies in urbanized areas because of high mosquito abundance, heterogeneity of macro- and microhabitats, and an easier access in comparison with private premises. However, the feasibility of a cemetery as a study area must be evaluated in each case considering the objectives of the study and cemetery characteristics.

National Mosquito (Diptera: Culicidae) Survey in The Netherlands 2010-2013.

PubMed

Ibañez-Justicia, A; Stroo, A; Dik, M; Beeuwkes, J; Scholte, E J

2015-03-01

From 2010 onwards, a nationwide mosquito monitoring scheme has been conducted in The Netherlands with the aim of gaining crucial information about mosquito (Diptera: Culicidae) species composition, geographical distributions, biodiversity, and habitat preferences. The results of this study are based on 778 randomly sampled mosquito locations. These are divided into three main habitat types: urban, rural-agricultural, and natural areas. Twenty-seven mosquito species were found: 26 indigenous and 1 exotic, Aedes japonicus japonicus (Theobald, 1901). The preliminary results are presented here, with details of their species distribution and seasonality. Monitoring the temporal and spatial distribution of mosquitoes is an essential step in the risk analysis of emerging mosquito-borne diseases. © The Author 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Distribution of Aedes mosquitoes in the Kilimanjaro Region of northern Tanzania.

PubMed

Hertz, Julian T; Lyaruu, Lucille J; Ooi, Eng Eong; Mosha, Franklin W; Crump, John A

2016-05-01

Little is known about the presence and distribution of Aedes mosquitoes in northern Tanzania despite the occurence of viruses transmitted by these mosquitoes such as Chikungunya virus (CHIKV) and Dengue virus (DENV) in the region. Adult and larval mosquitoes were collected from rural and urban settings across a wide range of altitudes in the Kilimanjaro Region using the Mosquito Magnet CO2 Trap for collection of adults and old tires for breeding of larvae. Polymerase chain reaction assays were performed on captured adult mosquitoes to detect the presence of CHIKV and DENV. A total of 2609 Aedes aegypti adult mosquitoes were collected; no other Aedes species larvae were found. Mosquito yields were significantly higher in urban settings than rural settings (26.5 vs. 1.9 mosquitoes per day, p = 0.037). A total of 6570 Ae. aegypti larvae were collected from old tires; no other Aedes species larvae were found. Of the 2609 adult mosquitoes collected, none tested positive for CHIKV or DENV. As far as we are aware, this paper reports for the first time the presence of Ae. aegypti in the Kilimanjaro Region of northern Tanzania. Although CHIKV and DENV were not isolated from any of the collected mosquitoes in this study, the apparent absence of other Aedes species in the area suggests that Ae. aegypti is the primary local vector of these infections.

Pesticide-Free Device a Fatal Attraction for Mosquitoes

NASA Technical Reports Server (NTRS)

2005-01-01

Are those pesky mosquitoes getting more entertainment out of your family picnic than you are? If the answer is yes, then it is time to reclaim your backyard with assistance from an unlikely partner. Nowadays, NASA is developing tools to track and predict the spread of the West Nile Virus on a global scale, but several years ago, the Space Agency carved out some time to collaborate with an outdoor products manufacturer in order to help control mosquito populations on a local level. The technology resulting from this union leveraged a space-age heat blanket to attract mosquitoes, which would then be eliminated without the use of harmful pesticides or chemicals. technical assistance from NASA and is an environmentally safe way to reduce the mosquito population.

Comparative evaluation of the efficiency of the BG-Sentinel trap, CDC light trap and Mosquito-oviposition trap for the surveillance of vector mosquitoes.

PubMed

Li, Yiji; Su, Xinghua; Zhou, Guofa; Zhang, Hong; Puthiyakunnon, Santhosh; Shuai, Shufen; Cai, Songwu; Gu, Jinbao; Zhou, Xiaohong; Yan, Guiyun; Chen, Xiao-Guang

2016-08-12

The surveillance of vector mosquitoes is important for the control of mosquito-borne diseases. To identify a suitable surveillance tool for the adult dengue vector Aedes albopictus, the efficacy of the BG-Sentinel trap, CDC light trap and Mosquito-oviposition trap (MOT) on the capture of vector mosquitoes were comparatively evaluated in this study. The capture efficiencies of the BG-Sentinel trap, CDC light trap and Mosquito-oviposition trap for common vector mosquitoes were tested in a laboratory setting, through the release-recapture method, and at two field sites of Guangzhou, China from June 2013 to May 2014. The captured mosquitoes were counted, species identified and compared among the three traps on the basis of species. In the release-recapture experiments in a laboratory setting, the BG-Sentinel trap caught significantly more Aedes albopictus and Culex quinquefasciatus than the CDC light trap and Mosquito-ovitrap, except for Anopheles sinensis. The BG-Sentinel trap had a higher efficacy in capturing female rather than male Ae. albopictus and Cx. quinquefasciatus, but the capture in CDC light traps displayed no significant differences. In the field trial, BG-Sentinel traps collected more Aedes albopictus than CDC light traps and MOTs collected in both urban and suburban areas. The BG-Sentinel trap was more sensitive for monitoring the population density of Aedes albopictus than the CDC light trap and MOT during the peak months of the year 2013. However, on an average, CDC light traps captured significantly more Cx. quinquefasciatus than BG-Sentinel traps. The population dynamics of Cx. quinquefasciatus displayed a significant seasonal variation, with the lowest numbers in the middle of the year. This study indicates that the BG-Sentinel trap is more effective than the commonly used CDC light trap and MOT in sampling adult Aedes albopictus and Culex quinquefasciatus. We recommend its use in the surveillance of dengue vector mosquitoes in China.

Seeing is believing: the nocturnal malarial mosquito Anopheles coluzzii responds to visual host-cues when odour indicates a host is nearby.

PubMed

Hawkes, Frances; Gibson, Gabriella

2016-06-03

The immediate aim of our study was to analyse the behaviour of the malarial mosquito Anopheles coluzzii (An. gambiae species complex) near a human host with the ultimate aim of contributing to our fundamental understanding of mosquito host-seeking behaviour and the overall aim of identifying behaviours that could be exploited to enhance sampling and control strategies. Based on 3D video recordings of individual host-seeking females in a laboratory wind-tunnel, we found that despite being a nocturnal species, An. coluzzii is highly responsive to a visually conspicuous object, but only in the presence of host-odour. Female mosquitoes approached and abruptly veered away from a dark object, which suggests attraction to visual cues plays a role in bringing mosquitoes to the source of host odour. It is worth noting that the majority of our recorded flight tracks consisted of highly stereotyped 'dipping' sequences near the ground, which have been mentioned in the literature, but never before quantified. Our quantitative analysis of female mosquito flight patterns within ~1.5 m of a host has revealed highly relevant information about responsiveness to visual objects and flight height that could revolutionise the efficacy of sampling traps; the capturing device of a trap should be visually conspicuous and positioned near the ground where the density of host-seeking mosquitoes would be greatest. These characteristics are not universally present in current traps for malarial mosquitoes. The characterisation of a new type of flight pattern that is prevalent in mosquitoes suggests that there is still much that is not fully understood about mosquito flight behaviour.

The Interaction between Arbuscular Mycorrhizal Fungi and Endophytic Bacteria Enhances Plant Growth of Acacia gerrardii under Salt Stress

PubMed Central

Hashem, Abeer; Abd_Allah, Elsayed F.; Alqarawi, Abdulaziz A.; Al-Huqail, Asma A.; Wirth, Stephan; Egamberdieva, Dilfuza

2016-01-01

Microbes living symbiotically in plant tissues mutually cooperate with each other by providing nutrients for proliferation of the partner organism and have a beneficial effect on plant growth. However, few studies thus far have examined the interactive effect of endophytic bacteria and arbuscular mycorrhizal fungi (AMF) in hostile conditions and their potential to improve plant stress tolerance. In this study, we investigated how the synergistic interactions of endophytic bacteria and AMF affect plant growth, nodulation, nutrient acquisition and stress tolerance of Acacia gerrardii under salt stress. Plant growth varied between the treatments with both single inoculants and was higher in plants inoculated with the endophytic B. subtilis strain than with AMF. Co-inoculated A. gerrardii had a significantly greater shoot and root dry weight, nodule number, and leghemoglobin content than those inoculated with AMF or B. subtilis alone under salt stress. The endophytic B. subtilis could alleviate the adverse effect of salt on AMF colonization. The differences in nitrate and nitrite reductase and nitrogenase activities between uninoculated plants and those inoculated with AMF and B. subtilis together under stress were significant. Both inoculation treatments, either B. subtilis alone or combined with AMF, enhanced the N, P, K, Mg, and Ca contents and phosphatase activities in salt-stressed A. gerrardii tissues and reduced Na and Cl concentration, thereby protecting salt-stressed plants from ionic and osmotic stress-induced changes. In conclusion, our results indicate that endophytic bacteria and AMF contribute to a tripartite mutualistic symbiosis in A. gerrardii and are coordinately involved in the plant adaptation to salt stress tolerance. PMID:27486442

Cross-correlation map analyses show weather variation influences on mosquito abundance patterns in Saginaw County, Michigan, 1989-2005.

PubMed

Chuang, Ting-Wu; Ionides, Edward L; Knepper, Randall G; Stanuszek, William W; Walker, Edward D; Wilson, Mark L

2012-07-01

Weather is important determinant of mosquito abundance that, in turn, influences vectorborne disease dynamics. In temperate regions, transmission generally is seasonal as mosquito abundance and behavior varies with temperature, precipitation, and other meteorological factors. We investigated how such factors affected species-specific mosquito abundance patterns in Saginaw County, MI, during a 17-yr period. Systematic sampling was undertaken at 22 trapping sites from May to September, during 1989-2005, for 19,228 trap-nights and 300,770 mosquitoes in total. Aedes vexans (Meigen), Culex pipiens L. and Culex restuans Theobald, the most abundant species, were analyzed. Weather data included local daily maximum temperature, minimum temperature, total precipitation, and average relative humidity. In addition to standard statistical methods, cross-correlation mapping was used to evaluate temporal associations with various lag periods between weather variables and species-specific mosquito abundances. Overall, the average number of mosquitoes was 4.90 per trap-night for Ae. vexans, 2.12 for Cx. pipiens, and 1.23 for Cx. restuans. Statistical analysis of the considerable temporal variability in species-specific abundances indicated that precipitation and relative humidity 1 wk prior were significantly positively associated with Ae. vexans, whereas elevated maximum temperature had a negative effect during summer. Cx. pipiens abundance was positively influenced by the preceding minimum temperature in the early season but negatively associated with precipitation during summer and with maximum temperature in July and August. Cx. restuans showed the least weather association, with only relative humidity 2-24 d prior being linked positively during late spring-early summer. The recently developed analytical method applied in this study could enhance our understanding of the influences of weather variability on mosquito population dynamics.

Effect of ebastine on mosquito bites.

PubMed

Reunala, T; Brummer-Korvenkontio, H; Petman, L; Palosuo, T; Sarna, S

1997-07-01

Mosquito bites usually cause wealing and delayed bite papules. Cetirizine decreases wealing, bite papules and pruritus but the effect of other antihistamines on mosquito bites is unknown. We studied the effect of ebastine in 30 mosquito bite-sensitive adult subjects. Ebastine 10 mg or 20 mg and placebo were given for 4 days in a cross-over fashion. Aedes aegypti bites were given on forearms. The size of the bite lesions and pruritus (visual analogue score) were measured at 15 min, 2, 6, and 24 h after the bites. Twenty-five subjects were evaluable in the study. At 15 min ebastine decreased significantly the size of the bite lesion (p = 0.0017) and pruritus (p<0.0001). The effects of 10 mg and 20 mg of ebastine were similar. No significant effect was found at 2, 6 or 24 h, but when the measurements at all four time points were compiled the size of the bite lesion and pruritus score decreased significantly. Sedation occurred during ebastine treatment in 6 (21%) and during placebo treatment in 2 (7%) subjects. The present results show that prophylactically given ebastine is effective against immediate mosquito bite symptoms.

Advances in mosquito dynamics modeling

NASA Astrophysics Data System (ADS)

Wijaya, Karunia Putra; Götz, Thomas; Soewono, Edy

2016-11-01

It is preliminarily known that Aedes mosquitoes are very close to humans and their dwellings, also give rises to a broad spectrum of diseases: dengue, yellow fever, chikungunya. In this paper, we explore a multi-age-class model for mosquito population secondarily classified into indoor-outdoor dynamics. We accentuate a novel design for the model in which periodicity of the affecting time-varying environmental condition is taken into account. Application of the optimal control with collocated measure as apposed to the widely-used prototypic smooth time-continuous measure is also considered. Using two approaches: least-square and maximum likelihood, we estimate several involving undetermined parameters. We analyze the model enforceability to biological point of view such as existence, uniqueness, positivity and boundedness of solution trajectory, also existence and stability of (non)trivial periodic solution(s) by means of the basic mosquito offspring number. Some numerical tests are brought along at the rest of the paper as a compact realistic visualization of the model.

Effects of lambda-cyhalothrin on mosquito larvae and predatory aquatic insects.

PubMed

Lawler, Sharon P; Dritz, Deborah A; Christiansen, Julie A; Cornel, Anthony J

2007-03-01

Agricultural insecticides can affect mosquito production in rice fields by controlling mosquitoes, disrupting biological control or contributing to selection of insecticide resistance. The duration of insecticidal activity of the pyrethroid lambda-cyhalothrin was quantified on predatory insects in rice fields and on three kinds of mosquito larva: a pyrethroid-susceptible strain of Culex tarsalis Coquillet, a pyrethroid-resistant strain of Cx pipiens L. (sensu lato) and non-resistant Cx pipiens s.l. Lambda-cyhalothrin killed most caged, susceptible mosquitoes for up to 21 days. It killed fewer resistant Cx pipiens s.l., but suppressed their survival for over a week. Lambda-cyhalothrin suppressed field populations of predatory insects through day 29. Agricultural use of lambda-cyhalothrin can provide incidental mosquito control. However, the pyrethroid persisted in sediment and gradually decreased in activity, which could contribute to selection of pyrethroid-resistant mosquitoes. Because caged mosquitoes showed good survival before predators recovered, disruption of biological control is possible. It is therefore advisable for growers and mosquito control agencies to communicate about pesticide use. Copyright 2006 Society of Chemical Industry.

Combinations of fluorinated solvents with imide salts or methide salts for electrolytes

DOEpatents

Tikhonov, Konstantin; Yip, Ka Ki; Lin, Tzu-Yuan; Lei, Norman; Guerrero-Zavala, Guillermo; Kwong, Kristie W

2015-11-10

Provided are electrochemical cells and electrolytes used to build such cells. The electrolytes include imide salts and/or methide salts as well as fluorinated solvents capable of maintaining single phase solutions at between about -30.degree. C. to about 80.degree. C. The fluorinated solvents, such as fluorinated carbonates, fluorinated esters, and fluorinated esters, are less flammable than their non-fluorinated counterparts and improve safety characteristics of cells containing these solvents. The amount of fluorinated solvents in electrolytes may be between about 30% and 80% by weight not accounting weight of the salts. Linear and cyclic imide salts, such as LiN(SO.sub.2CF.sub.2CF.sub.3).sub.2, and LiN(SO.sub.2CF.sub.3).sub.2, as well as methide salts, such as LiC(SO.sub.2CF.sub.3).sub.3 and LiC(SO.sub.2CF.sub.2CF.sub.3).sub.3, may be used in these electrolytes. Fluorinated alkyl groups enhance solubility of these salts in the fluorinated solvents. In some embodiments, the electrolyte may also include a flame retardant, such as a phosphazene, and/or one or more ionic liquids.

Measurement, analysis, and depiction of activity in adult mosquito populations

USDA-ARS?s Scientific Manuscript database

Globalization, open trading practices, and climate change increase the likelihood of introduction of exotic mosquito species. These mosquitoes may harbor disease agents that threaten public and animal health. Successful containment and eradication of exotic mosquito species and (in the case of exo...

Potential for Waterborne and Invertebrate Transmission of West Nile Virus in the Great Salt Lake, Utah.

PubMed

Lund, Melissa; Shearn-Bochsler, Valerie; Dusek, Robert J; Shivers, Jan; Hofmeister, Erik

2017-07-15

In November and December of 2013, a large mortality event involving 15,000 to 20,000 eared grebes ( Podiceps nigricollis ) occurred at the Great Salt Lake (GSL), UT. The onset of the outbreak in grebes was followed by a mortality event in >86 bald eagles ( Haliaeetus leucocephalus ). During the die-off, West Nile virus (WNV) was detected by reverse transcription-PCR (RT-PCR) or viral culture in the carcasses of grebes and eagles submitted to the National Wildlife Health Center. However, no activity of mosquitoes, the primary vectors of WNV, was detected by the State of Utah's WNV monitoring program. The transmission of WNV has rarely been reported during the winter in North America in the absence of known mosquito activity; however, the size of this die-off, the habitat in which it occurred, and the species involved are unique. We experimentally investigated whether WNV could survive in water with a high salt content, as found at the GSL, and whether brine shrimp, the primary food of migrating eared grebes on the GSL, could have played a role in the transmission of WNV to feeding birds. We found that WNV can survive up to 72 h at 4°C in water containing 30 to 150 ppt NaCl, and brine shrimp incubated with WNV in 30 ppt NaCl may adsorb WNV to their cuticle and, through feeding, infect epithelial cells of their gut. Both mechanisms may have potentiated the WNV die-off in migrating eared grebes on the GSL. IMPORTANCE Following a major West Nile virus die-off of eared grebes and bald eagles at the Great Salt Lake (GSL), UT, in November to December 2013, this study assessed the survival of West Nile virus (WNV) in water as saline as that of the GSL and whether brine shrimp, the major food for migrating grebes, could have played a role as a vector for the virus. While mosquitoes are the major vector of WNV, under certain circumstances, transmission may occur through contaminated water and invertebrates as food. Copyright © 2017 American Society for Microbiology.

Inhibition of Malaria Infection in Transgenic Anopheline Mosquitoes Lacking Salivary Gland Cells

PubMed Central

Kasashima, Katsumi; Sezutsu, Hideki; Matsuoka, Hiroyuki

2016-01-01

Malaria is an important global public health challenge, and is transmitted by anopheline mosquitoes during blood feeding. Mosquito vector control is one of the most effective methods to control malaria, and population replacement with genetically engineered mosquitoes to block its transmission is expected to become a new vector control strategy. The salivary glands are an effective target tissue for the expression of molecules that kill or inactivate malaria parasites. Moreover, salivary gland cells express a large number of molecules that facilitate blood feeding and parasite transmission to hosts. In the present study, we adapted a functional deficiency system in specific tissues by inducing cell death using the mouse Bcl-2-associated X protein (Bax) to the Asian malaria vector mosquito, Anopheles stephensi. We applied this technique to salivary gland cells, and produced a transgenic strain containing extremely low amounts of saliva. Although probing times for feeding on mice were longer in transgenic mosquitoes than in wild-type mosquitoes, transgenic mosquitoes still successfully ingested blood. Transgenic mosquitoes also exhibited a significant reduction in oocyst formation in the midgut in a rodent malaria model. These results indicate that mosquito saliva plays an important role in malaria infection in the midgut of anopheline mosquitoes. The dysfunction in the salivary glands enabled the inhibition of malaria transmission from hosts to mosquito midguts. Therefore, salivary components have potential in the development of new drugs or genetically engineered mosquitoes for malaria control. PMID:27598328

Overexpression of a partial fragment of the salt-responsive gene OsNUC1 enhances salt adaptation in transgenic Arabidopsis thaliana and rice (Oryza sativa L.) during salt stress.

PubMed

Sripinyowanich, Siriporn; Chamnanmanoontham, Nontalee; Udomchalothorn, Thanikarn; Maneeprasopsuk, Somporn; Santawee, Panudda; Buaboocha, Teerapong; Qu, Li-Jia; Gu, Hongya; Chadchawan, Supachitra

2013-12-01

The rice (Oryza sativa L.) nucleolin gene, OsNUC1, transcripts were expressed in rice leaves, flowers, seeds and roots but differentially expressed within and between two pairs of salt-sensitive and salt-resistant rice lines when subjected to salt stress. Salt-resistant lines exhibited higher OsNUC1 transcript expression levels than salt-sensitive lines during 0.5% (w/v) NaCl salt stress for 6d. Two sizes of OsNUC1 full-length cDNA were found in the rice genome database and northern blot analysis confirmed their existence in rice tissues. The longer transcript (OsNUC1-L) putatively encodes for a protein with a serine rich N-terminal, RNA recognition motifs in the central domain and a glycine- and arginine-rich repeat in the C-terminal domain, while the shorter one (OsNUC1-S) putatively encodes for the similar protein without the N-terminus. Without salt stress, OsNUC1-L expressing Arabidopsis thaliana Atnuc1-L1 plants displayed a substantial but incomplete revertant phenotype, whereas OsNUC1-S expression only induced a weak effect. However, under 0.5% (w/v) NaCl salt stress they displayed a higher relative growth rate, longer root length and a lower H2O2 level than the wild type plants, suggesting a higher salt resistance. Moreover, they displayed elevated AtSOS1 and AtP5CS1 transcript levels. We propose that OsNUC1-S plays an important role in salt resistance during salt stress, a new role for nucleolin in plants. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Hey! A Mosquito Bit Me! (For Kids)

MedlinePlus

... Staying Safe Videos for Educators Search English Español Hey! A Mosquito Bit Me! KidsHealth / For Kids / Hey! A Mosquito Bit Me! Print en español ¡Ay! ¡ ... your skin. More on this topic for: Kids Hey! A Flea Bit Me! Hey! A Scorpion Stung ...

Current status of genome editing in vector mosquitoes: A review.

PubMed

Reegan, Appadurai Daniel; Ceasar, Stanislaus Antony; Paulraj, Michael Gabriel; Ignacimuthu, Savarimuthu; Al-Dhabi, Naif Abdullah

2017-01-16

Mosquitoes pose a major threat to human health as they spread many deadly diseases like malaria, dengue, chikungunya, filariasis, Japanese encephalitis and Zika. Identification and use of novel molecular tools are essential to combat the spread of vector borne diseases. Genome editing tools have been used for the precise alterations of the gene of interest for producing the desirable trait in mosquitoes. Deletion of functional genes or insertion of toxic genes in vector mosquitoes will produce either knock-out or knock-in mutants that will check the spread of vector-borne diseases. Presently, three types of genome editing tools viz., zinc finger nuclease (ZFN), transcription activator-like effector nucleases (TALEN) and clustered regulatory interspaced short palindromic repeats (CRISPR) and CRISPR associated protein 9 (Cas9) are widely used for the editing of the genomes of diverse organisms. These tools are also applied in vector mosquitoes to control the spread of vector-borne diseases. A few studies have been carried out on genome editing to control the diseases spread by vector mosquitoes and more studies need to be performed with the utilization of more recently invented tools like CRISPR/Cas9 to combat the spread of deadly diseases by vector mosquitoes. The high specificity and flexibility of CRISPR/Cas9 system may offer possibilities for novel genome editing for the control of important diseases spread by vector mosquitoes. In this review, we present the current status of genome editing research on vector mosquitoes and also discuss the future applications of vector mosquito genome editing to control the spread of vectorborne diseases.

[Strengthening Effects of Sodium Salts on Washing Kerosene Contaminated Soil with Surfactants].

PubMed

Huang, Zhao-lu; Chen, Quan-yuan; Zhou, Juan; Xie, Mo-han

2015-05-01

The impact of sodium salt on kerosene contaminated soil washing with surfactants was investigated. The results indicated that sodium silicate greatly enhanced the washing efficiency of SDS. Sodium tartrate can largely enhance the washing efficiency of SDBS and Brij35. Sodium salts can enhance the washing efficiency on kerosene contaminated with TX-100. No significant differences were observed between different sodium salts. Sodium salt of humic acid and sodium silicate had similar enhancement on kerosene contaminated soil washing with saponin. Sodium humate can be a better choice since its application can also improve soil quality. The enhancement of sodium silicate on kerosene contaminated soil washing with Tw-80 increased with the increase of Tw-80 dosage. However, the impact of sodium chloride and sodium tartrate was opposite to sodium silicate. Sodium salts can reduce surface tension and critical micelle concentration of ionic surfactants to enhance the washing. Sodium salts can also reduce re-adsorption of oil to soil with nonionic surfactants to enhance the washing. Kerosene contamination can increase the contact angle of soil, which indicated the increase of hydrophilicity of soil. Washing with surfactants can reduce the hydrophilicitiy of soil according to contact angle measurement, which indicated that kerosene contaminated soil remediation with surfactant can also benefit nutrient and water transportation in the contaminated soil.

A solar-thermal energy harvesting scheme: enhanced heat capacity of molten HITEC salt mixed with Sn/SiO(x) core-shell nanoparticles.

PubMed

Lai, Chih-Chung; Chang, Wen-Chih; Hu, Wen-Liang; Wang, Zhiming M; Lu, Ming-Chang; Chueh, Yu-Lun

2014-05-07

We demonstrated enhanced solar-thermal storage by releasing the latent heat of Sn/SiO(x) core-shell nanoparticles (NPs) embedded in a eutectic salt. The microstructures and chemical compositions of Sn/SiO(x) core-shell NPs were characterized. In situ heating XRD provides dynamic crystalline information about the Sn/SiO(x) core-shell NPs during cyclic heating processes. The latent heat of ∼29 J g(-1) for Sn/SiO(x) core-shell NPs was measured, and 30% enhanced heat capacity was achieved from 1.57 to 2.03 J g(-1) K(-1) for the HITEC solar salt without and with, respectively, a mixture of 5% Sn/SiO(x) core-shell NPs. In addition, an endurance cycle test was performed to prove a stable operation in practical applications. The approach provides a method to enhance energy storage in solar-thermal power plants.

Use of Encapsulated Zinc Particles in a Eutectic Chloride Salt to Enhance Thermal Energy Storage Capacity for Concentrated Solar Power

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

Cingarapu, Sreeram; Singh, Dileep; Timofeeva, Elena V.

2015-08-01

Concentrated Solar Power (CSP) is considered as a viable large-scale renewable energy source to produce electricity. However, current costs to produce electricity from CSP are not cost competitive as compared to the traditional energy generation technologies based on fossil fuels and nuclear. It is envisioned that development of high efficiency and high heat capacity thermal storage fluids will increase system efficiency, reduce structural storage volume, and hence, contribute to reducing costs. Particularly, with respect to CSP, current high temperature energy storage fluids, such as molten salts, are relatively limited in terms of their thermal energy storage capacity and thermal conductivity.more » The current work explores possibility of boosting the thermal storage capacity of molten salts through latent heat of added phase change materials. We studied the advantage Of adding coated Zn micron-sized particles to alkali chloride salt eutectic for enhanced thermal energy storage. Zinc particles (0.6 mu m and 5 mu m) obtained from commercial source were coated with an organo-phosphorus shell to improve chemical stability and to prevent individual particles from coalescing with one another during melt/freeze cycles. Thermal cycling tests (200 melt/freeze cycles) showed that coated Zn particles have good thermal stability and are chemically inert to alkali chloride salt eutectic in both N-2 and in air atmospheres. Elemental mapping of the cross-sectional view of coated Zn particles from the composite after thermal cycles showed no signs of oxidation, agglomeration or other type of particle degradation. The measured enhancement in volumetric thermal storage capacity of the composite with just similar to 10 vol% of coated Zn particles over the base chloride salt eutectic varies from 15% to 34% depending on cycling temperature range (Delta T = 50 degrees C -100 degrees C. (C) 2015 Elsevier Ltd. All rights reserved.« less

Evaluating the effects of mosquito control adulticides on honey bees

USDA-ARS?s Scientific Manuscript database

While mosquito control adulticides can be effective in rapidly reducing mosquito populations during times of high arbovirus transmission, the impacts of these control measures on pollinators has been of recent interest. The purpose of our study was to evaluate mosquito and honey bee mortality using ...

Landing response of Aedes (Stegomyia) polynesiensis mosquitoes to coloured targets.

PubMed

Chambers, E W; Bossin, H C; Ritchie, S A; Russell, R C; Dobson, S L

2013-09-01

Aedes polynesiensis Marks (Diptera: Culicidae) is the primary vector of lymphatic filariasis (LF) in the island countries and territories of the South Pacific. In the development of a novel control tool, the response of Ae. polynesiensis to six different colours (three solid fabrics, two patterned fabrics and a plastic tarp) was measured using a digital photographic system. Adult mosquitoes were placed into an environmental chamber and allowed to choose between a white target and one of six experimental targets. Mosquito landing frequency and landing duration were calculated. Adult female Ae. polynesiensis preferred all of the experimental targets to the white control target. Mosquito landing frequency was highest for the solid targets (black, navy blue and red) followed in turn by the two colour pattern targets and the polyethylene target. Mosquito landing duration was greater for experimental targets when compared with white control targets. Mosquito landing frequencies did not change over time during the course of the assay. The response of male Ae. polynesiensis was also measured when exposed to a 100% cotton black target. Male mosquitoes preferred the black target to the white control target, although at levels lower than that observed in female mosquitoes. The results suggest that future investigations evaluating the visual responses of Ae. polynesiensis mosquitoes are warranted, with a special emphasis on semi-field and field-based experiments. © 2013 The Royal Entomological Society.

Zika mosquito vectors: the jury is still out.

PubMed

Leal, Walter S

2016-01-01

After a 40-year hiatus, the International Congress of Entomology (ICE 2016) convened in Orlando, Florida (September 25-30, 2016). One of the symposia at ICE 2016, the Zika Symposium, covered multiple aspects of the Zika epidemic, including epidemiology, sexual transmission, genetic tools for reducing transmission, and particularly vector competence. While there was a consensus among participants that the yellow fever mosquito, Aedes aegypti , is a vector of the Zika virus, there is growing evidence indicating that the range of mosquito vectors might be wider than anticipated. In particular, three independent groups from Canada, China, and Brazil presented and discussed laboratory and field data strongly suggesting that the southern house mosquito, Culex quinquefasciatus , also known as the common mosquito, is highly likely to be a vector in certain environments.

Preventive dietary potassium supplementation in young salt-sensitive Dahl rats attenuates development of salt hypertension by decreasing sympathetic vasoconstriction.

PubMed

Zicha, J; Dobešová, Z; Behuliak, M; Kuneš, J; Vaněčková, I

2011-05-01

Increased potassium intake attenuates the development of salt-dependent hypertension, but the detailed mechanisms of blood pressure (BP) reduction are still unclear. The aims of our study were (i) to elucidate these mechanisms, (ii) to compare preventive potassium effects in immature and adult animals and (iii) to evaluate the therapeutic effects of dietary potassium supplementation in rats with established salt hypertension.   Young (4-week-old) and adult (24-week-old) female salt-sensitive Dahl rats were fed a high-salt diet (5% NaCl) or a high-salt diet supplemented with 3% KCl for 5 weeks. The participation of vasoconstrictor (renin-angiotensin and sympathetic nervous systems) and vasodilator systems [prostanoids, Ca(2+) -activated K(+) channels, nitric oxide (NO)] was evaluated using a sequential blockade of these systems. Preventive potassium supplementation attenuated the development of severe salt hypertension in young rats, whereas it had no effects on BP in adult rats with moderate hypertension. Enhanced sympathetic vasoconstriction was responsible for salt hypertension in young rats and its attenuation for potassium-induced BP reduction. Conversely, neither salt hypertension nor its potassium-induced attenuation were associated with significant changes of the vasodilator systems studied. The relative deficiency of vasodilator action of NO and Ca(2+) -activated K(+) channels in salt hypertensive Dahl rats was not improved by potassium supplementation. The attenuation of enhanced sympathetic vasoconstriction is the principal mechanism of antihypertensive action exerted by preventive potassium supplementation in immature Dahl rats. Dietary potassium supplementation has no preventive effects on BP in adult salt-loaded animals or no therapeutic effects on established salt hypertension in young rats. © 2011 The Authors. Acta Physiologica © 2011 Scandinavian Physiological Society.

Guppies as predators of common mosquito larvae in Malaysia.

PubMed

Saleeza, S N R; Norma-Rashid, Y; Sofian-Azirun, M

2014-03-01

Observation on predation activities of guppies (Poecilia reticulata) on the larvae of three species of mosquito, namely Aedes albopictus, Aedes aegypti, and Culex quinquefasciatus was carried out under laboratory conditions. Male and female guppies were used as predators for predation experiments on the 4th instars of mosquito larvae. The daily feeding rates comparing male and female guppies on mosquito larvae were different; the female guppies consumed more mosquito larvae than male guppies did. The daily feeding rates of female guppies were 121.3 for Ae. aegypti, 105.6 for Ae. albopictus, and 72.3 for Cx. quinquefasciatus. The daily feeding rates of male guppies were 98.6 for Ae. aegypti, 73.6 for Ae. albopictus, and 47.6 for Cx. quinquefasciatus. In terms of prey preference, there was greater preference towards mosquito larvae of Ae. aegypti, followed by Ae. albopictus, and the least preferred was Cx. quinquefasciatus. Male and female guppies consumed more mosquito larvae during lights on (day time) compared with lights off (night time). The water volume, prey species, number of fish predators available, prey densities, and prey's sex also influenced the predation activities.

Mosquito Vectors and the Globalization of Plasmodium falciparum Malaria.

PubMed

Molina-Cruz, Alvaro; Zilversmit, Martine M; Neafsey, Daniel E; Hartl, Daniel L; Barillas-Mury, Carolina

2016-11-23

Plasmodium falciparum malaria remains a devastating public health problem. Recent discoveries have shed light on the origin and evolution of Plasmodium parasites and their interactions with their vertebrate and mosquito hosts. P. falciparum malaria originated in Africa from a single horizontal transfer between an infected gorilla and a human, and became global as the result of human migration. Today, P. falciparum malaria is transmitted worldwide by more than 70 different anopheline mosquito species. Recent studies indicate that the mosquito immune system can be a barrier to malaria transmission and that the P. falciparum Pfs47 gene allows the parasite to evade mosquito immune detection. Here, we review the origin and globalization of P. falciparum and integrate this history with analysis of the biology, evolution, and dispersal of the main mosquito vectors. This new perspective broadens our understanding of P. falciparum population structure and the dispersal of important parasite genetic traits.

Improving crop salt tolerance.

PubMed

Flowers, T J

2004-02-01

Salinity is an ever-present threat to crop yields, especially in countries where irrigation is an essential aid to agriculture. Although the tolerance of saline conditions by plants is variable, crop species are generally intolerant of one-third of the concentration of salts found in seawater. Attempts to improve the salt tolerance of crops through conventional breeding programmes have met with very limited success, due to the complexity of the trait: salt tolerance is complex genetically and physiologically. Tolerance often shows the characteristics of a multigenic trait, with quantitative trait loci (QTLs) associated with tolerance identified in barley, citrus, rice, and tomato and with ion transport under saline conditions in barley, citrus and rice. Physiologically salt tolerance is also complex, with halophytes and less tolerant plants showing a wide range of adaptations. Attempts to enhance tolerance have involved conventional breeding programmes, the use of in vitro selection, pooling physiological traits, interspecific hybridization, using halophytes as alternative crops, the use of marker-aided selection, and the use of transgenic plants. It is surprising that, in spite of the complexity of salt tolerance, there are commonly claims in the literature that the transfer of a single or a few genes can increase the tolerance of plants to saline conditions. Evaluation of such claims reveals that, of the 68 papers produced between 1993 and early 2003, only 19 report quantitative estimates of plant growth. Of these, four papers contain quantitative data on the response of transformants and wild-type of six species without and with salinity applied in an appropriate manner. About half of all the papers report data on experiments conducted under conditions where there is little or no transpiration: such experiments may provide insights into components of tolerance, but are not grounds for claims of enhanced tolerance at the whole plant level. Whether enhanced

Insight into Global Mosquito Biogeography from Country Species Records

DTIC Science & Technology

2007-01-01

biodiversity gradient was observed, with species richness increasing toward the equator. A linear log-log species (y)-area (x) relationship (SAR) was...and endemism is proposed to guide mosqUito biodiversity surveys. For species groups. we show that the number ofspecies ofAIWfJheles subgenus Anopheles...into global patterns of mosquito biodiversity and survey history. KEY WORDS mosquito, biogeography, country occurrence records. species richness, species

Estimating malaria transmission from humans to mosquitoes in a noisy landscape.

PubMed

Reiner, Robert C; Guerra, Carlos; Donnelly, Martin J; Bousema, Teun; Drakeley, Chris; Smith, David L

2015-10-06

A basic quantitative understanding of malaria transmission requires measuring the probability a mosquito becomes infected after feeding on a human. Parasite prevalence in mosquitoes is highly age-dependent, and the unknown age-structure of fluctuating mosquito populations impedes estimation. Here, we simulate mosquito infection dynamics, where mosquito recruitment is modelled seasonally with fractional Brownian noise, and we develop methods for estimating mosquito infection rates. We find that noise introduces bias, but the magnitude of the bias depends on the 'colour' of the noise. Some of these problems can be overcome by increasing the sampling frequency, but estimates of transmission rates (and estimated reductions in transmission) are most accurate and precise if they combine parity, oocyst rates and sporozoite rates. These studies provide a basis for evaluating the adequacy of various entomological sampling procedures for measuring malaria parasite transmission from humans to mosquitoes and for evaluating the direct transmission-blocking effects of a vaccine. © 2015 The Authors.

Estimating malaria transmission from humans to mosquitoes in a noisy landscape

PubMed Central

Reiner, Robert C.; Guerra, Carlos; Donnelly, Martin J.; Bousema, Teun; Drakeley, Chris; Smith, David L.

2015-01-01

A basic quantitative understanding of malaria transmission requires measuring the probability a mosquito becomes infected after feeding on a human. Parasite prevalence in mosquitoes is highly age-dependent, and the unknown age-structure of fluctuating mosquito populations impedes estimation. Here, we simulate mosquito infection dynamics, where mosquito recruitment is modelled seasonally with fractional Brownian noise, and we develop methods for estimating mosquito infection rates. We find that noise introduces bias, but the magnitude of the bias depends on the ‘colour' of the noise. Some of these problems can be overcome by increasing the sampling frequency, but estimates of transmission rates (and estimated reductions in transmission) are most accurate and precise if they combine parity, oocyst rates and sporozoite rates. These studies provide a basis for evaluating the adequacy of various entomological sampling procedures for measuring malaria parasite transmission from humans to mosquitoes and for evaluating the direct transmission-blocking effects of a vaccine. PMID:26400195

Use of Nicotiana tabacum L extract for anti-Aedes Aegypti mosquito paint

NASA Astrophysics Data System (ADS)

Sandralintang, Trisiana Chrysanthi; Fauzantoro, Ahmad; Hermansyah, Heri; Jufri, Mahdi; Gozan, Misri

2018-02-01

This study intended to formulate mosquito repellent paints based tobacco leaf extracts-free pyrethroid substance which is safe for users. The active substance which was added to the paint as a mosquito repellent was an extract of tobacco leaves. The result of Anti-mosquito paint formulation produced was according to the Indonesia National Standard (SNI). The results of anti-Aedes Aegypti mosquito paint effectiveness test showed that 5% concentration of tobacco extract could kill half of the mosquito population (LC50) for 2 hours, the concentration of tobacco extract between 3-5% killed half the mosquito population (LC50) during 4 hours, while 1-3% and 0-1% concentration of tobacco extract killed half the mosquito population (LC50) for 6 and 24 hours, respectively.

European Surveillance for West Nile Virus in Mosquito Populations

PubMed Central

Engler, Olivier; Savini, Giovanni; Papa, Anna; Figuerola, Jordi; Groschup, Martin H.; Kampen, Helge; Medlock, Jolyon; Vaux, Alexander; Wilson, Anthony J.; Werner, Doreen; Jöst, Hanna; Goffredo, Maria; Capelli, Gioia; Federici, Valentina; Tonolla, Mauro; Patocchi, Nicola; Flacio, Eleonora; Portmann, Jasmine; Rossi-Pedruzzi, Anya; Mourelatos, Spiros; Ruiz, Santiago; Vázquez, Ana; Calzolari, Mattia; Bonilauri, Paolo; Dottori, Michele; Schaffner, Francis; Mathis, Alexander; Johnson, Nicholas

2013-01-01

A wide range of arthropod-borne viruses threaten both human and animal health either through their presence in Europe or through risk of introduction. Prominent among these is West Nile virus (WNV), primarily an avian virus, which has caused multiple outbreaks associated with human and equine mortality. Endemic outbreaks of West Nile fever have been reported in Italy, Greece, France, Romania, Hungary, Russia and Spain, with further spread expected. Most outbreaks in Western Europe have been due to infection with WNV Lineage 1. In Eastern Europe WNV Lineage 2 has been responsible for human and bird mortality, particularly in Greece, which has experienced extensive outbreaks over three consecutive years. Italy has experienced co-circulation with both virus lineages. The ability to manage this threat in a cost-effective way is dependent on early detection. Targeted surveillance for pathogens within mosquito populations offers the ability to detect viruses prior to their emergence in livestock, equine species or human populations. In addition, it can establish a baseline of mosquito-borne virus activity and allow monitoring of change to this over time. Early detection offers the opportunity to raise disease awareness, initiate vector control and preventative vaccination, now available for horses, and encourage personal protection against mosquito bites. This would have major benefits through financial savings and reduction in equid morbidity/mortality. However, effective surveillance that predicts virus outbreaks is challenged by a range of factors including limited resources, variation in mosquito capture rates (too few or too many), difficulties in mosquito identification, often reliant on specialist entomologists, and the sensitive, rapid detection of viruses in mosquito pools. Surveillance for WNV and other arboviruses within mosquito populations varies between European countries in the extent and focus of the surveillance. This study reviews the current status of

Maintenance of residual activity of Bt toxin by using natural and synthetic dyes: a novel approach for sustainable mosquito vector control.

PubMed

Chandrashekhar, Patil; Rahul, Suryawanshi; Hemant, Borase; Chandrakant, Narkhede; Bipinchandra, Salunke; Satish, Patil

2015-01-01

Mosquito control protein from Bacillus thuringiensis gets inactivated with exposure to sunlight. To address this issue, the potential of synthetic and natural dye was investigated as sunlight protectants. Bt SV2 in absence of dyes when exposed to sunlight showed reduced effectiveness against the fourth instars of mosquito larvae. Whereas acriflavin, congo red and violacein were able to maintain 86.4%, 91.6% and 82.2% mosquito larvicidal efficacy of Bt SV2 against IVth instars larvae of Anopheles stephensi Meigen after exposure to sunlight. Similarly, beetroot dye, acriflavin, congo red and violacein maintained 98.4%, 97.1%, 90.8% and 70.7% larvicidal activities against Aedes aegypti Linnaeus after sunlight exposure. Prodigiosin was found to be the best photo-protectant by simultaneously protecting and enhancing Bt activity by 6.16% and 22.16% against A. stephensi and A. aegypti, respectively. Combination of dyes with Bt formulations can be a good strategy for mosquito control programmes in tropical and sub-tropical regions.

Surveillance of Mosquitoes (Diptera: Culicidae) in Southern Iowa, 2016.

PubMed

Kovach, Kristofer B; Smith, Ryan C

2018-05-19

The mosquito fauna of Iowa has been extensively investigated over several decades, providing a wealth of information regarding species distributions, relative abundance, temporal activity patterns, and identifying vectors of medical importance. However, these investigations have had unequal coverage, leaving the mosquito fauna in some parts of the state, including southern Iowa, largely uncharacterized. With the heightened public health threat of Zika virus in the summer of 2016, greater emphasis was placed on surveying for two potential Zika virus vectors: Aedes (Stegomyia) albopictus (Skuse) and Aedes (Stegomyia) aegypti (Linnaeus). Southern Iowa became an area of interest due to the range of Ae. Albopictus, potentially extending into this part of the state. Employing CO2-baited Centers for Disease Control and Prevention light traps and BG-Sentinel traps, our targeted trapping efforts in southern Iowa did not yield either Ae. albopictus or Ae. aegypti. However, the geographical expansion of our trapping efforts did lend valuable insights into the mosquito fauna of southern Iowa. Mosquito species such as Aedes atropalpus (Coquillett), Culex erraticus (Dyar and Knab), and several Psorophora species once presumed rare or uncommon in the state were found to be more prevalent in this ecologically diverse region, augmenting our understanding of mosquito distributions in the state. Moreover, these surveillance efforts established baseline data for continued monitoring of the potential introduction and spread of invasive mosquito species in Iowa as part of an integrated mosquito management program.

A Novel G-Protein-Coupled Receptors Gene from Upland Cotton Enhances Salt Stress Tolerance in Transgenic Arabidopsis

PubMed Central

Lu, Hejun; Kirungu, Joy Nyangasi; Wei, Yangyang; Dong, Qi; Wang, Xingxing; Cai, Xiaoyan; Zhou, Zhongli; Wang, Kunbo; Liu, Fang

2018-01-01

Plants have developed a number of survival strategies which are significant for enhancing their adaptation to various biotic and abiotic stress factors. At the transcriptome level, G-protein-coupled receptors (GPCRs) are of great significance, enabling the plants to detect a wide range of endogenous and exogenous signals which are employed by the plants in regulating various responses in development and adaptation. In this research work, we carried out genome-wide analysis of target of Myb1 (TOM1), a member of the GPCR gene family. The functional role of TOM1 in salt stress tolerance was studied using a transgenic Arabidopsis plants over-expressing the gene. By the use of the functional domain PF06454, we obtained 16 TOM genes members in Gossypium hirsutum, 9 in Gossypium arboreum, and 11 in Gossypium raimondii. The genes had varying physiochemical properties, and it is significant to note that all the grand average of hydropathy (GRAVY) values were less than one, indicating that all are hydrophobic in nature. In all the genes analysed here, both the exonic and intronic regions were found. The expression level of Gh_A07G0747 (GhTOM) was significantly high in the transgenic lines as compared to the wild type; a similar trend in expression was observed in all the salt-related genes tested in this study. The study in epidermal cells confirmed the localization of the protein coded by the gene TOM1 in the plasma membrane. Analysis of anti-oxidant enzymes showed higher concentrations of antioxidants in transgenic lines and relatively lower levels of oxidant substances such as H2O2. The low malondialdehyde (MDA) level in transgenic lines indicated that the transgenic lines had relatively low level of oxidative damage compared to the wild types. The results obtained indicate that Gh_A07G0747 (GhTOM) can be a putative target gene for enhancing salt stress tolerance in plants and could be exploited in the future for the development of salt stress-tolerant cotton cultivars

A Novel G-Protein-Coupled Receptors Gene from Upland Cotton Enhances Salt Stress Tolerance in Transgenic Arabidopsis.

PubMed

Lu, Pu; Magwanga, Richard Odongo; Lu, Hejun; Kirungu, Joy Nyangasi; Wei, Yangyang; Dong, Qi; Wang, Xingxing; Cai, Xiaoyan; Zhou, Zhongli; Wang, Kunbo; Liu, Fang

2018-04-12

Plants have developed a number of survival strategies which are significant for enhancing their adaptation to various biotic and abiotic stress factors. At the transcriptome level, G-protein-coupled receptors (GPCRs) are of great significance, enabling the plants to detect a wide range of endogenous and exogenous signals which are employed by the plants in regulating various responses in development and adaptation. In this research work, we carried out genome-wide analysis of target of Myb1 ( TOM1 ), a member of the GPCR gene family. The functional role of TOM1 in salt stress tolerance was studied using a transgenic Arabidopsis plants over-expressing the gene. By the use of the functional domain PF06454, we obtained 16 TOM genes members in Gossypium hirsutum , 9 in Gossypium arboreum , and 11 in Gossypium raimondii . The genes had varying physiochemical properties, and it is significant to note that all the grand average of hydropathy (GRAVY) values were less than one, indicating that all are hydrophobic in nature. In all the genes analysed here, both the exonic and intronic regions were found. The expression level of Gh_A07G0747 (GhTOM) was significantly high in the transgenic lines as compared to the wild type; a similar trend in expression was observed in all the salt-related genes tested in this study. The study in epidermal cells confirmed the localization of the protein coded by the gene TOM1 in the plasma membrane. Analysis of anti-oxidant enzymes showed higher concentrations of antioxidants in transgenic lines and relatively lower levels of oxidant substances such as H₂O₂. The low malondialdehyde (MDA) level in transgenic lines indicated that the transgenic lines had relatively low level of oxidative damage compared to the wild types. The results obtained indicate that Gh_A07G0747 (GhTOM) can be a putative target gene for enhancing salt stress tolerance in plants and could be exploited in the future for the development of salt stress-tolerant cotton

Niosomal carriers enhance oral bioavailability of carvedilol: effects of bile salt-enriched vesicles and carrier surface charge.

PubMed

Arzani, Gelareh; Haeri, Azadeh; Daeihamed, Marjan; Bakhtiari-Kaboutaraki, Hamid; Dadashzadeh, Simin

2015-01-01

Carvedilol (CRV) is an antihypertensive drug with both alpha and beta receptor blocking activity used to preclude angina and cardiac arrhythmias. To overcome the low, variable oral bioavailability of CRV, niosomal formulations were prepared and characterized: plain niosomes (without bile salts), bile salt-enriched niosomes (bilosomes containing various percentages of sodium cholate or sodium taurocholate), and charged niosomes (negative, containing dicetyl phosphate and positive, containing hexadecyl trimethyl ammonium bromide). All formulations were characterized in terms of encapsulation efficiency, size, zeta potential, release profile, stability, and morphology. Various formulations were administered orally to ten groups of Wistar rats (n=6 per group). The plasma levels of CRV were measured by a validated high-performance liquid chromatography (HPLC) method and pharmacokinetic properties of different formulations were characterized. Contribution of lymphatic transport to the oral bioavailability of niosomes was also investigated using a chylomicron flow-blocking approach. Of the bile salt-enriched vesicles examined, bilosomes containing 20% sodium cholate (F2) and 30% sodium taurocholate (F5) appeared to give the greatest enhancement of intestinal absorption. The relative bioavailability of F2 and F5 formulations to the suspension was estimated to be 1.84 and 1.64, respectively. With regard to charged niosomes, the peak plasma concentrations (Cmax) of CRV for positively (F7) and negatively charged formulations (F10) were approximately 2.3- and 1.7-fold higher than after a suspension. Bioavailability studies also revealed a significant increase in extent of drug absorption from charged vesicles. Tissue histology revealed no signs of inflammation or damage. The study proved that the type and concentration of bile salts as well as carrier surface charge had great influences on oral bioavailability of niosomes. Blocking the lymphatic absorption pathway

The Plasmodium bottleneck: malaria parasite losses in the mosquito vector

PubMed Central

Smith, Ryan C; Vega-Rodríguez, Joel; Jacobs-Lorena, Marcelo

2014-01-01

Nearly one million people are killed every year by the malaria parasite Plasmodium. Although the disease-causing forms of the parasite exist only in the human blood, mosquitoes of the genus Anopheles are the obligate vector for transmission. Here, we review the parasite life cycle in the vector and highlight the human and mosquito contributions that limit malaria parasite development in the mosquito host. We address parasite killing in its mosquito host and bottlenecks in parasite numbers that might guide intervention strategies to prevent transmission. PMID:25185005

Field evaluation of four widely used mosquito traps in Central Europe

PubMed Central

2014-01-01

Background To monitor adult mosquitoes several trapping devices are available. These are differently constructed and use various mechanisms for mosquito attraction, thus resulting in different trapping sensitivities and efficacies for the various species. Mosquito monitoring and surveillance programs in Europe use various types of mosquito traps, but only a few comparisons have been conducted so far. This study compared the performance of four commercial trapping devices, which are commonly used in Europe. Methods Four different traps, Biogents Sentinel trap (BG trap), Heavy Duty Encephalitis Vector Survey trap (EVS trap), Centres for Disease Control miniature light trap (CDC trap) and Mosquito Magnet Patriot Mosquito trap (MM trap) were compared in a 4 × 4 latin square study. In the years 2012 and 2013, more than seventy 24-hour trap comparisons were conducted at ten different locations in northern and southern Germany, representing urban, forest and floodplain biotopes. Results Per 24-hour trapping period, the BG trap caught the widest range of mosquito species, the highest number of individuals of the genus Culex as well as the highest number of individuals of the species Ochlerotatus cantans, Aedes cinereus/geminus, Oc. communis and Culex pipiens/torrentium. The CDC trap revealed best performance for Aedes vexans, whereas the MM trap was most efficient for mosquitoes of the genus Anopheles and the species Oc. geniculatus. The EVS trap did not catch more individuals of any genus or species compared to the other three trapping devices. The BG trap caught the highest number of individuals per trapping period in urban environments as well as in wet forest, while the CDC trap caught the highest number of individuals in the floodplain biotopes. Additionally, the BG trap was most efficient for the number of mosquito species in urban locations. Conclusion The BG trap showed a significantly better or similar performance compared to the CDC, EVS or MM trap with

Commensal Viruses of Mosquitoes: Host Restriction, Transmission, and Interaction with Arboviral Pathogens

PubMed Central

Hall, Roy A.; Bielefeldt-Ohmann, Helle; McLean, Breeanna J.; O’Brien, Caitlin A.; Colmant, Agathe M.G.; Piyasena, Thisun B.H.; Harrison, Jessica J.; Newton, Natalee D.; Barnard, Ross T.; Prow, Natalie A.; Deerain, Joshua M.; Mah, Marcus G.K.Y.; Hobson-Peters, Jody

2016-01-01

Recent advances in virus detection strategies and deep sequencing technologies have enabled the identification of a multitude of new viruses that persistently infect mosquitoes but do not infect vertebrates. These are usually referred to as insect-specific viruses (ISVs). These novel viruses have generated considerable interest in their modes of transmission, persistence in mosquito populations, the mechanisms that restrict their host range to mosquitoes, and their interactions with pathogens transmissible by the same mosquito. In this article, we discuss studies in our laboratory and others that demonstrate that many ISVs are efficiently transmitted directly from the female mosquito to their progeny via infected eggs, and, moreover, that persistent infection of mosquito cell cultures or whole mosquitoes with ISVs can restrict subsequent infection, replication, and transmission of some mosquito-borne viral pathogens. This suggests that some ISVs may act as natural regulators of arboviral transmission. We also discuss viral and host factors that may be responsible for their host restriction. PMID:28096646

Zika Virus Vector Competency of Mosquitoes, Gulf Coast, United States.

PubMed

Hart, Charles E; Roundy, Christopher M; Azar, Sasha R; Huang, Jing H; Yun, Ruimei; Reynolds, Erin; Leal, Grace; Nava, Martin R; Vela, Jeremy; Stark, Pamela M; Debboun, Mustapha; Rossi, Shannan; Vasilakis, Nikos; Thangamani, Saravanan; Weaver, Scott C

2017-03-01

Zika virus has recently spread throughout the Americas. Although Aedes aegypti mosquitoes are considered the primary vector, Culex quinquefasciatus and mosquitoes of other species may also be vectors. We tested Cx. quinquefasciatus and Ae. taeniorhynchus mosquitoes from the US Gulf Coast; both were refractory to infection and incapable of transmission.

The Collection of Mosquito Eggs for Classroom and Field Investigations

ERIC Educational Resources Information Center

Steinly, Bruce A.

2004-01-01

A method for the collection of Aedes mosquito eggs is described whereby collection of mosquito eggs is used to monitor the intensity of egg deposition in urban and rural areas. The data is used to increase public awareness of the effect of human habitation and cultural practices on mosquito abundance.

Reduction of mosquito biting-pressure: spatial repellents or mosquito traps? A field comparison of seven commercially available products in Israel

USDA-ARS?s Scientific Manuscript database

The personal protection capability of seven commercially available mosquito control devices (MCD) is compared under field conditions in Israel. Trials were performed in a high biting-pressure area inhabited by large populations of mosquito and biting midge species and using human volunteers for lan...

Attractiveness of MM-X Traps Baited with Human or Synthetic Odor to Mosquitoes (Diptera: Culicidae) in The Gambia

PubMed Central

QIU, YU TONG; SMALLEGANGE, RENATE C.; TER BRAAK, CAJO J. F.; SPITZEN, JEROEN; VAN LOON, JOOP J. A.; JAWARA, MUSA; MILLIGAN, PAUL; GALIMARD, AGNES M.; VAN BEEK, TERIS A.; KNOLS, BART G. J.; TAKKEN, WILLEM

2013-01-01

Chemical cues play an important role in the host-seeking behavior of blood-feeding mosquitoes (Diptera: Culicidae). A field study was carried out in The Gambia to investigate the effects of human odor or synthetic odor blends on the attraction of mosquitoes. MM-X traps baited with 16 odor blends to which carbon dioxide (CO2) was added were tested in four sets of experiments. In a second series of experiments, MM-X traps with 14 odor blends without CO2 were tested. A blend of ammonia and l-lactic acid with or without CO2 was used as control odor in series 1 and 2, respectively. Centers for Disease Control and Prevention (CDC) traps were placed in a traditional house and an experimental house to monitor mosquito densities during the experiments. The MM-X traps caught a total number of 196,756 mosquitoes, with the most abundant species belonging to the genera Mansonia (70.6%), Anopheles (17.5%), and Culex (11.5%). The most abundant mosquito species caught by the CDC traps (56,290 in total) belonged to the genera Mansonia (59.4%), Anopheles (16.0% An. gambiae s.l. Giles, and 11.3% An. ziemanni Grünberg), and Culex (11.6%). MM-X traps baited with synthetic blends were in many cases more attractive than MM-X traps baited with human odors. Addition of CO2 to synthetic odors substantially increased the catch of all mosquito species in the MM-X traps. A blend of ammonia + L-lactic acid + CO2 + 3-methylbutanoic acid was the most attractive odor for most mosquito species. The candidate odor blend shows the potential to enhance trap collections so that traps will provide better surveillance and possible control. PMID:18047195

Factors influencing stakeholders attitudes toward genetically modified aedes mosquito.

PubMed

Amin, Latifah; Hashim, Hasrizul

2015-06-01

Dengue fever is a debilitating and infectious disease that could be life-threatening. It is caused by the dengue virus which affects millions of people in the tropical area. Currently, there is no cure for the disease as there is no vaccine available. Thus, prevention of the vector population using conventional methods is by far the main strategy but has been found ineffective. A genetically modified (GM) mosquito is among the favoured alternatives to curb dengue fever in Malaysia. Past studies have shown that development and diffusion of gene technology products depends heavily upon public acceptance. The purpose of this study is to identify the relevant factors influencing stakeholders' attitudes toward the GM Aedes mosquito and to analyse the relationships between all the factors using the structural equation model. A survey was carried out on 509 respondents from various stakeholder groups in the Klang Valley region of Malaysia. Results of the survey have confirmed that public perception towards complex issues such as gene technology should be seen as a multi-faceted process. The perceived benefit-perceived risk balance is very important in determining the most predominant predictor of attitudes toward a GM mosquito. In this study the stakeholders perceived the benefit of the GM mosquito as outweighing its risk, translating perceived benefit as the most important direct predictor of attitudes toward the GM mosquito. Trust in key players has a direct influence on attitudes toward the GM mosquito while moral concern exhibited an indirect influence through perceived benefits. Other factors such as attitudes toward technology and nature were also indirect predictors of attitudes toward the GM mosquito while religiosity and engagement did not exhibited any significant roles. The research findings serve as a useful database to understand public acceptance and the social construct of public attitudes towards the GM mosquito to combat dengue.

Nature or nurture in mosquito resistance to malaria?

PubMed

Hurd, Hilary

2007-04-01

The genetic basis of mosquito resistance to malaria parasites is well established and currently receives a lot of attention. However this is not the sole determinant of the success or failure of an infection. In a recent article, Lambrechts and colleagues report the influence of the quality of the external environment of a mosquito on infection. They indicate that external variations could substantially reduce the importance of resistance genes in determining infection by malaria parasites. Furthermore, these variations could influence future plans to use malaria-resistant transgenic mosquitoes to control parasite transmission.

Biological Control of Mosquito Vectors: Past, Present, and Future.

PubMed

Benelli, Giovanni; Jeffries, Claire L; Walker, Thomas

2016-10-03

Mosquitoes represent the major arthropod vectors of human disease worldwide transmitting malaria, lymphatic filariasis, and arboviruses such as dengue virus and Zika virus. Unfortunately, no treatment (in the form of vaccines or drugs) is available for most of these diseases andvectorcontrolisstillthemainformofprevention. Thelimitationsoftraditionalinsecticide-based strategies, particularly the development of insecticide resistance, have resulted in significant efforts to develop alternative eco-friendly methods. Biocontrol strategies aim to be sustainable and target a range of different mosquito species to reduce the current reliance on insecticide-based mosquito control. In thisreview, weoutline non-insecticide basedstrategiesthat havebeenimplemented orare currently being tested. We also highlight the use of mosquito behavioural knowledge that can be exploited for control strategies.

Midgut of the non-hematophagous mosquito Toxorhynchites theobaldi (Diptera, Culicidae).

PubMed

Godoy, Raquel S M; Fernandes, Kenner M; Martins, Gustavo F

2015-10-30

In most mosquito species, the females require a blood-feeding for complete egg development. However, in Toxorhynchites mosquitoes, the eggs develop without blood-feeding, and both females and males exclusively feed on sugary diets. The midgut is a well-understood organ in blood-feeding mosquitoes, but little is known about it in non-blood-feeding ones. In the present study, the detailed morphology of the midgut of Toxorhynchites theobaldi were investigated using histochemical and ultrastructural methods. The midgut of female and male T. theobaldi adults consists of a long, slender anterior midgut (AMG), and a short, dilated posterior midgut (PMG). The AMG is subdivided into AMG1 (short, with folds) and AMG2 (long, without folds). Nerve branches and enteroendocrine cells are present in AMG and PMG, respectively. Compared with the PMG of blood-feeding female mosquitoes, the PMG of T. theobaldi is smaller; however, in both mosquitoes, PMG seems be the main region of food digestion and absorption, and protein secretion. The epithelial folds present in the AMG of T. theobaldi have not been reported in other mosquitoes; however, the midgut muscle organization and endocrine control of the digestion process are conserved in both T. theobaldi and blood-feeding mosquitoes.

Towards a Hybrid Agent-based Model for Mosquito Borne Disease.

PubMed

Mniszewski, S M; Manore, C A; Bryan, C; Del Valle, S Y; Roberts, D

2014-07-01

Agent-based models (ABM) are used to simulate the spread of infectious disease through a population. Detailed human movement, demography, realistic business location networks, and in-host disease progression are available in existing ABMs, such as the Epidemic Simulation System (EpiSimS). These capabilities make possible the exploration of pharmaceutical and non-pharmaceutical mitigation strategies used to inform the public health community. There is a similar need for the spread of mosquito borne pathogens due to the re-emergence of diseases such as chikungunya and dengue fever. A network-patch model for mosquito dynamics has been coupled with EpiSimS. Mosquitoes are represented as a "patch" or "cloud" associated with a location. Each patch has an ordinary differential equation (ODE) mosquito dynamics model and mosquito related parameters relevant to the location characteristics. Activities at each location can have different levels of potential exposure to mosquitoes based on whether they are inside, outside, or somewhere in-between. As a proof of concept, the hybrid network-patch model is used to simulate the spread of chikungunya through Washington, DC. Results are shown for a base case, followed by varying the probability of transmission, mosquito count, and activity exposure. We use visualization to understand the pattern of disease spread.

Crowdsourcing for large-scale mosquito (Diptera: Culicidae) sampling

USDA-ARS?s Scientific Manuscript database

Sampling a cosmopolitan mosquito (Diptera: Culicidae) species throughout its range is logistically challenging and extremely resource intensive. Mosquito control programmes and regional networks operate at the local level and often conduct sampling activities across much of North America. A method f...

Disrupting Mosquito Reproduction and Parasite Development for Malaria Control

PubMed Central

Gabrieli, Paolo; Buckee, Caroline O.; Catteruccia, Flaminia

2016-01-01

The control of mosquito populations with insecticide treated bed nets and indoor residual sprays remains the cornerstone of malaria reduction and elimination programs. In light of widespread insecticide resistance in mosquitoes, however, alternative strategies for reducing transmission by the mosquito vector are urgently needed, including the identification of safe compounds that affect vectorial capacity via mechanisms that differ from fast-acting insecticides. Here, we show that compounds targeting steroid hormone signaling disrupt multiple biological processes that are key to the ability of mosquitoes to transmit malaria. When an agonist of the steroid hormone 20-hydroxyecdysone (20E) is applied to Anopheles gambiae females, which are the dominant malaria mosquito vector in Sub Saharan Africa, it substantially shortens lifespan, prevents insemination and egg production, and significantly blocks Plasmodium falciparum development, three components that are crucial to malaria transmission. Modeling the impact of these effects on Anopheles population dynamics and Plasmodium transmission predicts that disrupting steroid hormone signaling using 20E agonists would affect malaria transmission to a similar extent as insecticides. Manipulating 20E pathways therefore provides a powerful new approach to tackle malaria transmission by the mosquito vector, particularly in areas affected by the spread of insecticide resistance. PMID:27977810

Potential impacts of climate change on the ecology of dengue and its mosquito vector the Asian tiger mosquito (Aedes albopictus)

NASA Astrophysics Data System (ADS)

Erickson, R. A.; Hayhoe, K.; Presley, S. M.; Allen, L. J. S.; Long, K. R.; Cox, S. B.

2012-09-01

Shifts in temperature and precipitation patterns caused by global climate change may have profound impacts on the ecology of certain infectious diseases. We examine the potential impacts of climate change on the transmission and maintenance dynamics of dengue, a resurging mosquito-vectored infectious disease. In particular, we project changes in dengue season length for three cities: Atlanta, GA; Chicago, IL and Lubbock, TX. These cities are located on the edges of the range of the Asian tiger mosquito within the United States of America and were chosen as test cases. We use a disease model that explicitly incorporates mosquito population dynamics and high-resolution climate projections. Based on projected changes under the Special Report on Emissions Scenarios (SRES) A1fi (higher) and B1 (lower) emission scenarios as simulated by four global climate models, we found that the projected warming shortened mosquito lifespan, which in turn decreased the potential dengue season. These results illustrate the difficulty in predicting how climate change may alter complex systems.

[Salt and cancer].

PubMed

Strnad, Marija

2010-05-01

' salt excretion through perspiration. Workers exposed to heat stress consumed as much as 13-38 g salt daily. As salt strongly enhances and promotes chemical gastric carcinogenesis and H. pylori infection in both humans and animals, there is an association between work, salt intake, and development of stomach cancer. Reducing salt intake, especially during pregnancy, also reduces the risk of developing breast cancer and many other diseases, as well as obesity. The risk of most cancers is reduced by losing weight. The geographical data and analyses currently available suggest that road salt (road salting in winter) may be associated with elevated mortality from cancer of the breast, lung, esophagus, throat, larynx, large intestine, rectum and bladder. There is no available literature on the health impacts of road salt. The cause and effect relationships cannot be established without further studies.

Harnessing mosquito-Wolbachia symbiosis for vector and disease control.

PubMed

Bourtzis, Kostas; Dobson, Stephen L; Xi, Zhiyong; Rasgon, Jason L; Calvitti, Maurizio; Moreira, Luciano A; Bossin, Hervé C; Moretti, Riccardo; Baton, Luke Anthony; Hughes, Grant L; Mavingui, Patrick; Gilles, Jeremie R L

2014-04-01

Mosquito species, members of the genera Aedes, Anopheles and Culex, are the major vectors of human pathogens including protozoa (Plasmodium sp.), filariae and of a variety of viruses (causing dengue, chikungunya, yellow fever, West Nile). There is lack of efficient methods and tools to treat many of the diseases caused by these major human pathogens, since no efficient vaccines or drugs are available; even in malaria where insecticide use and drug therapies have reduced incidence, 219 million cases still occurred in 2010. Therefore efforts are currently focused on the control of vector populations. Insecticides alone are insufficient to control mosquito populations since reduced susceptibility and even resistance is being observed more and more frequently. There is also increased concern about the toxic effects of insecticides on non-target (even beneficial) insect populations, on humans and the environment. During recent years, the role of symbionts in the biology, ecology and evolution of insect species has been well-documented and has led to suggestions that they could potentially be used as tools to control pests and therefore diseases. Wolbachia is perhaps the most renowned insect symbiont, mainly due to its ability to manipulate insect reproduction and to interfere with major human pathogens thus providing new avenues for pest control. We herein present recent achievements in the field of mosquito-Wolbachia symbiosis with an emphasis on Aedes albopictus. We also discuss how Wolbachia symbiosis can be harnessed for vector control as well as the potential to combine the sterile insect technique and Wolbachia-based approaches for the enhancement of population suppression programs. Copyright © 2013 International Atomic Energy Agency 2013. Published by Elsevier B.V. All rights reserved.

Adult Survivorship of the Dengue Mosquito Aedes aegypti Varies Seasonally in Central Vietnam

PubMed Central

Hugo, Leon E.; Jeffery, Jason A. L.; Trewin, Brendan J.; Wockner, Leesa F.; Thi Yen, Nguyen; Le, Nguyen Hoang; Nghia, Le Trung; Hine, Emma; Ryan, Peter A.; Kay, Brian H.

2014-01-01

The survival characteristics of the mosquito Aedes aegypti affect transmission rates of dengue because transmission requires infected mosquitoes to survive long enough for the virus to infect the salivary glands. Mosquito survival is assumed to be high in tropical, dengue endemic, countries like Vietnam. However, the survival rates of wild populations of mosquitoes are seldom measured due the difficulty of predicting mosquito age. Hon Mieu Island in central Vietnam is the site of a pilot release of Ae. aegypti infected with a strain of Wolbachia pipientis bacteria (wMelPop) that induces virus interference and mosquito life-shortening. We used the most accurate mosquito age grading approach, transcriptional profiling, to establish the survival patterns of the mosquito population from the population age structure. Furthermore, estimations were validated on mosquitoes released into a large semi-field environment consisting of an enclosed house, garden and yard to incorporate natural environmental variability. Mosquito survival was highest during the dry/cool (January-April) and dry/hot (May-August) seasons, when 92 and 64% of Hon Mieu mosquitoes had survived to an age that they were able to transmit dengue (12 d), respectively. This was reduced to 29% during the wet/cool season from September to December. The presence of Ae. aegypti older than 12 d during each season is likely to facilitate the observed continuity of dengue transmission in the region. We provide season specific Ae. aegypti survival models for improved dengue epidemiology and evaluation of mosquito control strategies that aim to reduce mosquito survival to break the dengue transmission cycle. PMID:24551251

Insect Repellents: Modulators of mosquito odorant receptor activity

USDA-ARS?s Scientific Manuscript database

Mosquitoes vector numerous pathogens that cause diseases including malaria, yellow fever, dengue fever and chikungunya. DEET, IR3535, Picaridin and 2-undecanone are insect repellents that are used to prevent interactions between humans and a broad array of disease vectors including mosquitoes. While...

The impact of salt replacers and flavor enhancer on the processing characteristics and consumer acceptance of restructured cooked hams.

PubMed

Pietrasik, Z; Gaudette, N J

2014-03-01

Two salt replacers (Ocean's Flavor - OF45, OF60) and one flavor enhancer [Fonterra™ 'Savoury Powder' (SP)] were evaluated for their ability to effectively reduce sodium, while maintaining the functional and sensory properties of restructured hams. Product functionality and safety were assessed using instrumental measures (yield, purge, pH, expressible moisture, proximate composition, sodium content, color, texture) and microbiological assessment. Sensory attributes were evaluated using consumer sensory panelists. All alternative formulations resulted in products with sodium contents below the Health Check(TM) Program guidelines, without detrimental effect on water binding and texture in treatments when NaCl was substituted with sea salt replacers (OF45, OF60). Sodium reduction had no effect on the shelf life of the cooked ham with up to 60 days of refrigerated storage. Consumer hedonics for flavor and aftertaste were lower for OF45 and OF60 compared to control, suggesting that these salt replacers may not be appropriate for inclusion in these products. Copyright © 2013 Elsevier Ltd. All rights reserved.

Ecological effects on arbovirus-mosquito cycles of transmission.

PubMed

Tabachnick, Walter J

2016-12-01

Mosquitoes transmit many viruses to a variety of hosts. Cycles of mosquito borne arbovirus transmission are the result of complex interactions between the mosquito, the arbovirus and the host that are influenced by genetic variations in a variety of traits in each that are all influenced by many environmental factors. R 0 , the basic reproduction number or mean number of individuals infected from a single infected individual, is a measure of mosquito borne arbovirus transmission. Understanding the causes for the distribution of R 0 in any transmission cycle is a daunting challenge due to the lack of information on the genetic and environmental variances that influence R 0 . Information about the major factors influencing R 0 for specific transmission cycles is essential to develop efficient and effective strategies to reduce transmission in different cycles and locations. Copyright © 2016 Elsevier B.V. All rights reserved.

Light manipulation of mosquito behaviour: acute and sustained photic suppression of biting activity in the Anopheles gambiae malaria mosquito.

PubMed

Sheppard, Aaron D; Rund, Samuel S C; George, Gary F; Clark, Erin; Acri, Dominic J; Duffield, Giles E

2017-06-16

Host-seeking behaviours in anopheline mosquitoes are time-of-day specific, with a greater propensity for nocturnal biting. We investigated how a short exposure to light presented during the night or late day can inhibit biting activity and modulate flight activity behaviour. Anopheles gambiae (s.s.), maintained on a 12:12 LD cycle, were exposed transiently to white light for 10-min at the onset of night and the proportion taking a blood meal in a human biting assay was recorded every 2 h over an 8-h duration. The pulse significantly reduced biting propensity in mosquitoes 2 h following administration, in some trials for 4 h, and with no differences detected after 6 h. Conversely, biting levels were significantly elevated when mosquitoes were exposed to a dark treatment during the late day, suggesting that light suppresses biting behaviour even during the late daytime. These data reveal a potent effect of a discrete light pulse on biting behaviour that is both immediate and sustained. We expanded this approach to develop a method to reduce biting propensity throughout the night by exposing mosquitoes to a series of 6- or 10-min pulses presented every 2 h. We reveal both an immediate suppressive effect of light during the exposure period and 2 h after the pulse. This response was found to be effective during most times of the night: however, differential responses that were time-of-day specific suggest an underlying circadian property of the mosquito physiology that results in an altered treatment efficacy. Finally, we examined the immediate and sustained effects of light on mosquito flight activity behaviour following exposure to a 30-min pulse, and observed activity suppression during early night, and elevated activity during the late night. As mosquitoes and malaria parasites are becoming increasingly resistant to insecticide and drug treatment respectively, there is a necessity for the development of innovative control strategies beyond insecticide

Application of mosquito repellent coils and associated self-reported health issues in Ghana.

PubMed

Hogarh, Jonathan N; Antwi-Agyei, Philip; Obiri-Danso, Kwasi

2016-02-04

The use of mosquito coils has gained widespread patronage in malaria-endemic countries, even though it is not a recommended preventive measure for avoiding mosquitoes. Mosquito coils contain insecticides, which are expected to vaporize slowly once the coil is lit, to provide protection against the mosquito. The mosquito coil base material contains a variety of compounds capable of burning slowly to gradually release the insecticide. The mosquito coil smoke, however, is potentially a source of indoor air pollution with implications for acute respiratory infections (ARI) and other illnesses. The present study investigated the application of mosquito coils and associated self-reported health issues in Ghana. A cross-sectional study was undertaken in which questionnaires were randomly administered to 480 households across four districts in Ghana. Respondents who exclusively applied mosquito coils were grouped as test cohort, while those who did not apply any mosquito repellency method constituted a control cohort. The test group that applied mosquito coils reported malaria incidence rate of 86.3 %. The control group that did not apply any mosquito repellency method reported an incidence rate of malaria at 72.4 %. Chi square analysis suggested that the observed difference was statistically significant (x (2) = 4.25; p = 0.04). The number of respondents who reported symptoms of cough from mosquito coil application (52.6 % incidence rate) was marginally greater than their counterparts who did not apply coils (46.1 % incidence rate). It was also found that respondents with shortage of breath, which was used as a proxy for ARI, were more likely to have applied mosquito coil. The application of mosquito coils did not necessarily reduce the incidence of malaria in the study communities. It however presented a potential respiratory risk factor, which should be further investigated by critically examining exposure to particulate matter emissions from burning coils.

Heart rate and blood pressure variabilities in salt-sensitive hypertension.

PubMed

Piccirillo, G; Bucca, C; Durante, M; Santagada, E; Munizzi, M R; Cacciafesta, M; Marigliano, V

1996-12-01

In salt-sensitive hypertension, a high sodium intake causes plasma catecholamines to rise and pulmonary baroreceptor plasticity to fall. In salt-sensitive and salt-resistant hypertensive subjects during low and high sodium intakes, we studied autonomic nervous system activity by power spectral analysis of heart rate and arterial pressure variabilities and baroreceptor sensitivity. In all subjects, high sodium intake significantly enhanced the low-frequency power of heart rate and arterial pressures at rest and after sympathetic stress. It also increased heart rate and arterial pressure variabilities. During high sodium intake, salt-sensitive hypertensive subjects had significantly higher low-frequency powers of systolic arterial pressure (7.5 mm Hg2, P < .05) and of heart rate at rest (59.2 +/- 2.4 normalized units [NU], P < .001) than salt-resistant subjects (6.6 +/- 0.3 mm Hg2, 55.0 +/- 3.2 NU) and normotensive control subjects (5.1 +/- 0.5 mm Hg2, 41.6 +/- 2.9 NU). In salt-sensitive subjects, low sodium intake significantly reduced low-frequency normalized units (P < .001) and the ratio of low- to high-power frequency (P < .001). High-sodium intake significantly increased baroreflex sensitivity in control subjects (from 10.0 +/- 0.7 to 17.5 +/- 0.7 ms/mm Hg, P < .001) and salt-resistant subjects (from 6.9 +/- 0.7 to 13.9 +/- 0.9, P < .05) but not in salt-sensitive subjects (7.4 +/- 0.3 to 7.9 +/- 0.4). In conclusion, a high sodium intake markedly enhances cardiac sympathetic activity in salt-sensitive and salt-resistant hypertension. In contrast, although reduced sodium intake lowers arterial pressure and sympathetic activity, it does so only in salt-sensitive subjects. Hence, in salt-resistant subjects, neither arterial pressure nor sympathetic activity depends on salt intake. During a high sodium intake in normotensive subjects and salt-resistant hypertensive subjects, increased sympathetic activity is probably compensated by enhanced baroreflex sensitivity.

Enhanced MFC power production and struvite recovery by the addition of sea salts to urine.

PubMed

Merino-Jimenez, Irene; Celorrio, Veronica; Fermin, David J; Greenman, John; Ieropoulos, Ioannis

2017-02-01

Urine is an excellent fuel for electricity generation in Microbial Fuel Cells (MFCs), especially with practical implementations in mind. Moreover, urine has a high content in nutrients which can be easily recovered. Struvite (MgNH 4 PO 4 ·6H 2 O) crystals naturally precipitate in urine, but this reaction can be enhanced by the introduction of additional magnesium. In this work, the effect of magnesium additives on the power output of the MFCs and on the catholyte generation is evaluated. Several magnesium sources including MgCl 2 , artificial sea water and a commercially available sea salts mixture for seawater preparation (SeaMix) were mixed with real fresh human urine in order to enhance struvite precipitation. The supernatant of each mixture was tested as a feedstock for the MFCs and it was evaluated in terms of power output and catholyte generation. The commercial SeaMix showed the best performance in terms of struvite precipitation, increasing the amount of struvite in the solid collected from 21% to 94%. Moreover, the SeaMix increased the maximum power performance of the MFCs by over 10% and it also changed the properties of the catholyte collected by increasing the pH, conductivity and the concentration of chloride ions. These results demonstrate that the addition of sea-salts to real urine is beneficial for both struvite recovery and electricity generation in MFCs. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Advances in insect physiology. Progress in mosquito research

USDA-ARS?s Scientific Manuscript database

This book review briefly summarizes the most interesting topics/chapters from the book: "Advances in Insect Physiology: Progress in mosquito Research". The book is an excellent overview of the recent advances in mosquito biology. This volume encompasses 13 chapters from 32 contributing authors who ...

Mosquito cytogenetics

PubMed Central

Kitzmiller, James B.

1963-01-01

Although an intensified interest in mosquito cytogenetics in the past decade has produced a number of contributions to knowledge on this subject, the available information is still superficial and limited to a few mosquito species only. The author of this review summarizes the research done in this field between 1953 and 1962. The following are some of the achievements and some of the gaps that remain to be filled. Karyotypes of several species of Anopheles, Aedes and Culex conform to the general pattern 2n=6, with heterosomes distinguishable only in Anopheles. At least three different karyotypes are present in Anopheles. Salivary gland chromosome maps are now available for several anopheline species, but are still lacking for Culex and Aedes. No precise correlation may yet be made between the frequency of chromosomal aberrations and the degree of insecticide-resistance. Sexual differences in the salivary X-chromosomes have been reported for several species of Anopheles. Chromosomal polymorphism is common in some anophelines, but rare in others. Chromosomal mutation has been induced by means of X-rays. In his conclusions, the author stresses that prospects are especially good for evolutionary and genetic studies involving chromosomal polymorphism. PMID:14058227

Mosquito repellent activity of volatile oils from selected aromatic plants.

PubMed

Lalthazuali; Mathew, Nisha

2017-02-01

Essential oils from fresh leaves of four aromatic plants viz., Ocimum sanctum, Mentha piperita, Eucalyptus globulus and Plectranthus amboinicus were extracted by hydrodistillation. The test solutions were prepared as 20% essential oil in ethanol and positive control as 20% DEET in ethanol. Essential oil blend was prepared as 5% concentration. Nulliparous, 3-5-day-old female adult Aedes aegypti mosquitoes were used for repellency screening as per ICMR protocol. The study showed that the repellency of 20% essential oil of O. sanctum, M. piperita and P. amboinicus were comparable with that of the standard DEET (20%) as no mosquito landing on the test was observed up to 6 h. The E. globulus oil exhibited mosquito repellency only upto 1½ h. Considerable mosquito landing and feeding was displayed in negative control. In the case of the oil blend, no landing of mosquitoes was seen up to 6 h as that of positive control. The results showed that the essential oil blend from O. sanctum, M. piperita, E. globulus and P. amboinicus could repel Ae. aegypti mosquitoes or prevent from feeding as in the case of DEET even at a lower concentration of 5%. This study demonstrates the potential of essential oils from O. sanctum, M. piperita, E. globulus and P. amboinicus and their blend as mosquito repellents against Ae. aegypti, the vector of dengue, chikungunya and yellow fever.

Fighting malaria with engineered symbiotic bacteria from vector mosquitoes.

PubMed

Wang, Sibao; Ghosh, Anil K; Bongio, Nicholas; Stebbings, Kevin A; Lampe, David J; Jacobs-Lorena, Marcelo

2012-07-31

The most vulnerable stages of Plasmodium development occur in the lumen of the mosquito midgut, a compartment shared with symbiotic bacteria. Here, we describe a strategy that uses symbiotic bacteria to deliver antimalaria effector molecules to the midgut lumen, thus rendering host mosquitoes refractory to malaria infection. The Escherichia coli hemolysin A secretion system was used to promote the secretion of a variety of anti-Plasmodium effector proteins by Pantoea agglomerans, a common mosquito symbiotic bacterium. These engineered P. agglomerans strains inhibited development of the human malaria parasite Plasmodium falciparum and rodent malaria parasite Plasmodium berghei by up to 98%. Significantly, the proportion of mosquitoes carrying parasites (prevalence) decreased by up to 84% for two of the effector molecules, scorpine, a potent antiplasmodial peptide and (EPIP)(4), four copies of Plasmodium enolase-plasminogen interaction peptide that prevents plasminogen binding to the ookinete surface. We demonstrate the use of an engineered symbiotic bacterium to interfere with the development of P. falciparum in the mosquito. These findings provide the foundation for the use of genetically modified symbiotic bacteria as a powerful tool to combat malaria.

Allatotropin: A pleiotropic neuropeptide that elicits mosquito immune responses

PubMed Central

Sánchez-Zavaleta, Minerva; Brito, Kevin; Herrera-Ortiz, Antonia; Ons, Sheila; Noriega, Fernando G.

2017-01-01

Allatotropins (AT) are neuropeptides with pleotropic functions on a variety of insect tissues. They affect processes such as juvenile hormone biosynthesis, cardiac rhythm, oviduct and hindgut contractions, nutrient absorption and circadian cycle. The present work provides experimental evidence that AT elicits immune responses in two important mosquito disease vectors, Anopheles albimanus and Aedes aegypti. Hemocytes and an immune-competent mosquito cell line responded to AT by showing strong morphological changes and increasing bacterial phagocytic activity. Phenoloxidase activity in hemolymph was also increased in Ae. aegypti mosquitoes treated with AT but not in An. albimanus, suggesting differences in the AT-dependent immune activation in the two species. In addition, two important insect immune markers, nitric oxide levels and expression of antimicrobial peptide genes, were increased in An. albimanus guts after AT treatment. AT conjugated to quantum dot nanocrystals (QDots) specifically labeled hemocytes in vivo in both mosquito species, implying molecular interactions between AT and hemocytes. The results of our studies suggest a new role for AT in the modulation of the immune response in mosquitoes. PMID:28426765

Allatotropin: A pleiotropic neuropeptide that elicits mosquito immune responses.

PubMed

Hernández-Martínez, Salvador; Sánchez-Zavaleta, Minerva; Brito, Kevin; Herrera-Ortiz, Antonia; Ons, Sheila; Noriega, Fernando G

2017-01-01

Allatotropins (AT) are neuropeptides with pleotropic functions on a variety of insect tissues. They affect processes such as juvenile hormone biosynthesis, cardiac rhythm, oviduct and hindgut contractions, nutrient absorption and circadian cycle. The present work provides experimental evidence that AT elicits immune responses in two important mosquito disease vectors, Anopheles albimanus and Aedes aegypti. Hemocytes and an immune-competent mosquito cell line responded to AT by showing strong morphological changes and increasing bacterial phagocytic activity. Phenoloxidase activity in hemolymph was also increased in Ae. aegypti mosquitoes treated with AT but not in An. albimanus, suggesting differences in the AT-dependent immune activation in the two species. In addition, two important insect immune markers, nitric oxide levels and expression of antimicrobial peptide genes, were increased in An. albimanus guts after AT treatment. AT conjugated to quantum dot nanocrystals (QDots) specifically labeled hemocytes in vivo in both mosquito species, implying molecular interactions between AT and hemocytes. The results of our studies suggest a new role for AT in the modulation of the immune response in mosquitoes.

The bacterium Wolbachia exploits host innate immunity to establish a symbiotic relationship with the dengue vector mosquito Aedes aegypti.

PubMed

Pan, Xiaoling; Pike, Andrew; Joshi, Deepak; Bian, Guowu; McFadden, Michael J; Lu, Peng; Liang, Xiao; Zhang, Fengrui; Raikhel, Alexander S; Xi, Zhiyong

2018-01-01

A host's immune system plays a central role in shaping the composition of the microbiota and, in return, resident microbes influence immune responses. Symbiotic associations of the maternally transmitted bacterium Wolbachia occur with a wide range of arthropods. It is, however, absent from the dengue and Zika vector mosquito Aedes aegypti in nature. When Wolbachia is artificially forced to form symbiosis with this new mosquito host, it boosts the basal immune response and enhances the mosquito's resistance to pathogens, including dengue, Zika virus and malaria parasites. The mechanisms involved in establishing a symbiotic relationship between Wolbachia and A. aegypti, and the long-term outcomes of this interaction, are not well understood. Here, we have demonstrated that both the immune deficiency (IMD) and Toll pathways are activated by the Wolbachia strain wAlbB upon its introduction into A. aegypti. Silencing the Toll and IMD pathways via RNA interference reduces the wAlbB load. Notably, wAlbB induces peptidoglycan recognition protein (PGRP)-LE expression in the carcass of A. aegypti, and its silencing results in a reduction of symbiont load. Using transgenic mosquitoes with stage-specific induction of the IMD and Toll pathways, we have shown that elevated wAlbB infection in these mosquitoes is maintained via maternal transmission. These results indicate that host innate immunity is utilized to establish and promote host-microbial symbiosis. Our results will facilitate a long-term projection of the stability of the Wolbachia-A. aegypti mosquito system that is being developed to control dengue and Zika virus transmission to humans.

Using infective mosquitoes to challenge monkeys with Plasmodium knowlesi in malaria vaccine studies.

PubMed

Murphy, Jittawadee R; Weiss, Walter R; Fryauff, David; Dowler, Megan; Savransky, Tatyana; Stoyanov, Cristina; Muratova, Olga; Lambert, Lynn; Orr-Gonzalez, Sachy; Zeleski, Katie Lynn; Hinderer, Jessica; Fay, Michael P; Joshi, Gyan; Gwadz, Robert W; Richie, Thomas L; Villasante, Eileen Franke; Richardson, Jason H; Duffy, Patrick E; Chen, Jingyang

2014-06-03

When rhesus monkeys (Macaca mulatta) are used to test malaria vaccines, animals are often challenged by the intravenous injection of sporozoites. However, natural exposure to malaria comes via mosquito bite, and antibodies can neutralize sporozoites as they traverse the skin. Thus, intravenous injection may not fairly assess humoral immunity from anti-sporozoite malaria vaccines. To better assess malaria vaccines in rhesus, a method to challenge large numbers of monkeys by mosquito bite was developed. Several species and strains of mosquitoes were tested for their ability to produce Plasmodium knowlesi sporozoites. Donor monkey parasitaemia effects on oocyst and sporozoite numbers and mosquito mortality were documented. Methylparaben added to mosquito feed was tested to improve mosquito survival. To determine the number of bites needed to infect a monkey, animals were exposed to various numbers of P. knowlesi-infected mosquitoes. Finally, P. knowlesi-infected mosquitoes were used to challenge 17 monkeys in a malaria vaccine trial, and the effect of number of infectious bites on monkey parasitaemia was documented. Anopheles dirus, Anopheles crascens, and Anopheles dirus X (a cross between the two species) produced large numbers of P. knowlesi sporozoites. Mosquito survival to day 14, when sporozoites fill the salivary glands, averaged only 32% when donor monkeys had a parasitaemia above 2%. However, when donor monkey parasitaemia was below 2%, mosquitoes survived twice as well and contained ample sporozoites in their salivary glands. Adding methylparaben to sugar solutions did not improve survival of infected mosquitoes. Plasmodium knowlesi was very infectious, with all monkeys developing blood stage infections if one or more infected mosquitoes successfully fed. There was also a dose-response, with monkeys that received higher numbers of infected mosquito bites developing malaria sooner. Anopheles dirus, An. crascens and a cross between these two species all were

Detection, monitoring, and evaluation of spatio-temporal change in mosquito populations

USDA-ARS?s Scientific Manuscript database

USDA-ARS scientists seek to implement a sampling and global information technology based system that can be used for mosquito detection and trap deployment, to estimate mosquito species composition and distribution in space and time, and for targeting and evaluation of mosquito controls. Knowledge ...

Perceived nuisance of mosquitoes on the Isle of Sheppey, Kent, UK.

PubMed

Hutchinson, Robert A; Lindsay, Steve W

2006-09-01

Little is known about the biting nuisance of mosquitoes in the UK, despite the high numbers found in some locations. A telephone questionnaire survey was used to determine the perceived nuisance of biting insects on the Isle of Sheppey, Kent, a place notorious for mosquitoes. Two hundred randomly selected individuals were interviewed and asked if they suffered from mosquito bites. If they answered yes, they were asked to describe where and when they were bitten, and what measures they took against mosquitoes. Forty-six percent of respondents completed the questionnaire. Of those, 50% reported being bitten by mosquitoes, mostly outside during the summer. Seventy percent said that most biting occurred during the evening and night. Of those respondents who protected themselves against biting (27), most used repellents (70%), with the remainder changing their behaviour to avoid mosquitoes, including closing or screening windows (33%), wearing thicker clothes (7%) and spraying insecticide (4%). One person slept under a bednet in summer (4%). This study provides evidence that on the Isle of Sheppey mosquitoes are considered a major nuisance by a sizeable proportion of the population. Since there is growing interest in the threat posed by new and emerging diseases in the UK, health authorities will need to make substantial efforts to inform and reassure the public about the threats posed by mosquitoes in areas where they are common.

Quantifying impact of mosquitoes on quality of life

USDA-ARS?s Scientific Manuscript database

New Jersey, like many eastern states, has a persistent problem of the Asian tiger mosquito. This and other mosquitoes reduce residents’ quality of life from discomfort and possible risk of disease. To guide a comprehensive area-wide pest management project to control Aedes albopictus in two counties...

Early warning of West Nile virus mosquito vector: climate and land use models successfully explain phenology and abundance of Culex pipiens mosquitoes in north-western Italy.

PubMed

Rosà, Roberto; Marini, Giovanni; Bolzoni, Luca; Neteler, Markus; Metz, Markus; Delucchi, Luca; Chadwick, Elizabeth A; Balbo, Luca; Mosca, Andrea; Giacobini, Mario; Bertolotti, Luigi; Rizzoli, Annapaola

2014-06-12

West Nile Virus (WNV) is an emerging global health threat. Transmission risk is strongly related to the abundance of mosquito vectors, typically Culex pipiens in Europe. Early-warning predictors of mosquito population dynamics would therefore help guide entomological surveillance and thereby facilitate early warnings of transmission risk. We analysed an 11-year time series (2001 to 2011) of Cx. pipiens mosquito captures from the Piedmont region of north-western Italy to determine the principal drivers of mosquito population dynamics. Linear mixed models were implemented to examine the relationship between Cx. pipiens population dynamics and environmental predictors including temperature, precipitation, Normalized Difference Water Index (NDWI) and the proximity of mosquito traps to urban areas and rice fields. Warm temperatures early in the year were associated with an earlier start to the mosquito season and increased season length, and later in the year, with decreased abundance. Early precipitation delayed the start and shortened the length of the mosquito season, but increased total abundance. Conversely, precipitation later in the year was associated with a longer season. Finally, higher NDWI early in the year was associated with an earlier start to the season and increased season length, but was not associated with abundance. Proximity to rice fields predicted higher total abundance when included in some models, but was not a significant predictor of phenology. Proximity to urban areas was not a significant predictor in any of our models. Predicted variations in start of the season and season length ranged from one to three weeks, across the measured range of variables. Predicted mosquito abundance was highly variable, with numbers in excess of 1000 per trap per year when late season temperatures were low (average 21°C) to only 150 when late season temperatures were high (average 30°C). Climate data collected early in the year, in conjunction with local land

Targeting male mosquito swarms to control malaria vector density

PubMed Central

Sawadogo, Simon Peguedwinde; Niang, Abdoulaye; Bilgo, Etienne; Millogo, Azize; Maïga, Hamidou; Dabire, Roch K.; Tripet, Frederic; Diabaté, Abdoulaye

2017-01-01

Malaria control programs are being jeopardized by the spread of insecticide resistance in mosquito vector populations. It has been estimated that the spread of resistance could lead to an additional 120000 deaths per year, and interfere with the prospects for sustained control or the feasibility of achieving malaria elimination. Another complication for the development of resistance management strategies is that, in addition to insecticide resistance, mosquito behavior evolves in a manner that diminishes the impact of LLINs and IRS. Mosquitoes may circumvent LLIN and IRS control through preferential feeding and resting outside human houses and/or being active earlier in the evening before people go to sleep. Recent developments in our understanding of mosquito swarming suggest that new tools targeting mosquito swarms can be designed to cut down the high reproductive rate of malaria vectors. Targeting swarms of major malaria vectors may provide an effective control method to counteract behavioral resistance developed by mosquitoes. Here, we evaluated the impact of systematic spraying of swarms of Anopheles gambiae s.l. using a mixed carbamate and pyrethroid aerosol. The impact of this intervention on vector density, female insemination rates and the age structure of males was measured. We showed that the resulting mass killing of swarming males and some mate-seeking females resulted in a dramatic 80% decrease in population size compared to a control population. A significant decrease in female insemination rate and a significant shift in the age structure of the male population towards younger males incapable of mating were observed. This paradigm-shift study therefore demonstrates that targeting primarily males rather than females, can have a drastic impact on mosquito population. PMID:28278212

Flying in tune: sexual recognition in mosquitoes.

PubMed

Gibson, Gabriella; Russell, Ian

2006-07-11

Mosquitoes hear with their antennae, which in most species are sexually dimorphic. Johnston, who discovered the mosquito auditory organ at the base of the antenna 150 years ago, speculated that audition was involved with mating behaviour. Indeed, male mosquitoes are attracted to female flight tones. The male auditory organ has been proposed to act as an acoustic filter for female flight tones, but female auditory behavior is unknown. We show, for the first time, interactive auditory behavior between males and females that leads to sexual recognition. Individual males and females both respond to pure tones by altering wing-beat frequency. Behavioral auditory tuning curves, based on minimum threshold sound levels that elicit a change in wing-beat frequency to pure tones, are sharper than the mechanical tuning of the antennae, with males being more sensitive than females. We flew opposite-sex pairs of tethered Toxorhynchites brevipalpis and found that each mosquito alters its wing-beat frequency in response to the flight tone of the other, so that within seconds their flight-tone frequencies are closely matched, if not completely synchronized. The flight tones of same-sex pairs may converge in frequency but eventually diverge dramatically.

Numerical modeling of mosquito population dynamics of Aedes aegypti.

PubMed

Yamashita, William M S; Das, Shyam S; Chapiro, Grigori

2018-04-16

The global incidences of dengue virus have increased the interest in studying and understanding the mosquito population dynamics. It is predominantly spread by Aedes aegypti in the tropical and sub-tropical countries in the world. Understanding these dynamics is important for public health in countries where climatic and environmental conditions are favorable for the propagation of these diseases. For this reason, a new model has been proposed to investigate the population dynamics of mosquitoes in a city. The present paper discusses the numerical modeling of population dynamics of Ae. aegypti mosquitoes in an urban neighborhood of a city using the finite volume method. The model describes how populations spread through the city assisted by the wind. This model allows incorporating external factors (wind and chemical insecticides) and topography data (streets, building blocks, parks, forests and beach). The proposed model has been successfully tested in examples involving two Brazilian cities (City center, Juiz de Fora and Copacabana Beach, Rio de Janeiro). Invasion phenomena of Ae. aegypti mosquitoes have been observed in each of the simulations. It was observed that, inside the blocks, the growth of the population for both winged and aquatic phase causes an infestation of Ae. aegypti in a short time. Within the blocks the mosquito population was concentrated and diffused slowly. In the streets, there was a long-distance spread, which was influenced by wind and diffusion with a low concentration of mosquito population. The model was also tested taking into account chemical insecticides spread in two different configurations. It has been observed that the insecticides have a significant effect on the mosquito population for both winged and aquatic phases when the chemical insecticides spread more uniformly along all the streets in a neighborhood of a city. The presented methodology can be employed to evaluate and to understand the epidemic risks in a specific

Direct PCR of indigenous and invasive mosquito species: a time- and cost-effective technique of mosquito barcoding.

PubMed

Werblow, A; Flechl, E; Klimpel, S; Zittra, C; Lebl, K; Kieser, K; Laciny, A; Silbermayr, K; Melaun, C; Fuehrer, H-P

2016-03-01

Millions of people die each year as a result of pathogens transmitted by mosquitoes. However, the morphological identification of mosquito species can be difficult even for experts. The identification of morphologically indistinguishable species, such as members of the Anopheles maculipennis complex (Diptera: Culicidae), and possible hybrids, such as Culex pipiens pipiens/Culex pipiens molestus (Diptera: Culicidae), presents a major problem. In addition, the detection and discrimination of newly introduced species can be challenging, particularly to researchers without previous experience. Because of their medical importance, the clear identification of all relevant mosquito species is essential. Using the direct polymerase chain reaction (PCR) method described here, DNA amplification without prior DNA extraction is possible and thus species identification after sequencing can be achieved. Different amounts of tissue (leg, head; larvae or adult) as well as different storage conditions (dry, ethanol, -20 and -80 °C) and storage times were successfully applied and showed positive results after amplification and gel electrophoresis. Overall, 28 different indigenous and non-indigenous mosquito species were analysed using a gene fragment of the COX1 gene for species differentiation and identification by sequencing this 658-bp fragment. Compared with standard PCR, this method is time- and cost-effective and could thus improve existing surveillance and control programmes. © 2015 The Authors. Medical and Veterinary Entomology published by John Wiley & Sons Ltd on behalf of Royal Entomological Society.

Potential mosquito repellent compounds of Ocimum species against 3N7H and 3Q8I of Anopheles gambiae.

PubMed

Gaddaguti, Venugopal; Venkateswara Rao, Talluri; Prasada Rao, Allu

2016-06-01

of mosquito) proteins may provide enhanced protection against mosquitoes bite. Based on the ADME properties, natural compounds of Ocimum species can be considered for design and development of safe mosquito repellents.

Mosquitoes and other aquatic insects in fallow field biotopes and rice paddy fields.

PubMed

Ohba, S Y; Matsuo, T; Takagi, M

2013-03-01

Fallow field biotopes that develop from abandoned rice fields are man-made wetlands that provide new habitats for various aquatic animals. Although consideration of such biotopes generally focuses on their positive aspects, this study evaluated the negative aspects of establishing fallow field biotopes with regard to mosquito breeding sites. To determine whether fallow field biotopes become breeding habitats for vector mosquitoes, we evaluated mosquito fauna in fallow field biotopes and adjacent rice fields. We found larvae of Anopheles lesteri, Anopheles sinensis and Culex tritaeniorhynchus (all: Diptera: Culicidae) in the biotopes. Although abundances of mosquito larvae in the biotopes and rice fields were statistically similar, mosquito abundances in rice fields increased dramatically in August when the water level reduced after the rainy season. The abundance and variety of the mosquitoes' natural predators were greater in biotopes than in rice fields because the former are a permanent and stable aquatic environment. A generalized linear mixed model showed a negative effect of predator diversity on mosquito larvae abundance in both habitats. Although fallow field biotopes become breeding habitats for vector mosquitoes, establishing biotopes from fallow fields in order to protect various aquatic animals, including mosquito insect predators, may help to control mosquito breeding. © 2012 The Royal Entomological Society.

Mosquito genomics. Highly evolvable malaria vectors: the genomes of 16 Anopheles mosquitoes.

PubMed

Neafsey, Daniel E; Waterhouse, Robert M; Abai, Mohammad R; Aganezov, Sergey S; Alekseyev, Max A; Allen, James E; Amon, James; Arcà, Bruno; Arensburger, Peter; Artemov, Gleb; Assour, Lauren A; Basseri, Hamidreza; Berlin, Aaron; Birren, Bruce W; Blandin, Stephanie A; Brockman, Andrew I; Burkot, Thomas R; Burt, Austin; Chan, Clara S; Chauve, Cedric; Chiu, Joanna C; Christensen, Mikkel; Costantini, Carlo; Davidson, Victoria L M; Deligianni, Elena; Dottorini, Tania; Dritsou, Vicky; Gabriel, Stacey B; Guelbeogo, Wamdaogo M; Hall, Andrew B; Han, Mira V; Hlaing, Thaung; Hughes, Daniel S T; Jenkins, Adam M; Jiang, Xiaofang; Jungreis, Irwin; Kakani, Evdoxia G; Kamali, Maryam; Kemppainen, Petri; Kennedy, Ryan C; Kirmitzoglou, Ioannis K; Koekemoer, Lizette L; Laban, Njoroge; Langridge, Nicholas; Lawniczak, Mara K N; Lirakis, Manolis; Lobo, Neil F; Lowy, Ernesto; MacCallum, Robert M; Mao, Chunhong; Maslen, Gareth; Mbogo, Charles; McCarthy, Jenny; Michel, Kristin; Mitchell, Sara N; Moore, Wendy; Murphy, Katherine A; Naumenko, Anastasia N; Nolan, Tony; Novoa, Eva M; O'Loughlin, Samantha; Oringanje, Chioma; Oshaghi, Mohammad A; Pakpour, Nazzy; Papathanos, Philippos A; Peery, Ashley N; Povelones, Michael; Prakash, Anil; Price, David P; Rajaraman, Ashok; Reimer, Lisa J; Rinker, David C; Rokas, Antonis; Russell, Tanya L; Sagnon, N'Fale; Sharakhova, Maria V; Shea, Terrance; Simão, Felipe A; Simard, Frederic; Slotman, Michel A; Somboon, Pradya; Stegniy, Vladimir; Struchiner, Claudio J; Thomas, Gregg W C; Tojo, Marta; Topalis, Pantelis; Tubio, José M C; Unger, Maria F; Vontas, John; Walton, Catherine; Wilding, Craig S; Willis, Judith H; Wu, Yi-Chieh; Yan, Guiyun; Zdobnov, Evgeny M; Zhou, Xiaofan; Catteruccia, Flaminia; Christophides, George K; Collins, Frank H; Cornman, Robert S; Crisanti, Andrea; Donnelly, Martin J; Emrich, Scott J; Fontaine, Michael C; Gelbart, William; Hahn, Matthew W; Hansen, Immo A; Howell, Paul I; Kafatos, Fotis C; Kellis, Manolis; Lawson, Daniel; Louis, Christos; Luckhart, Shirley; Muskavitch, Marc A T; Ribeiro, José M; Riehle, Michael A; Sharakhov, Igor V; Tu, Zhijian; Zwiebel, Laurence J; Besansky, Nora J

2015-01-02

Variation in vectorial capacity for human malaria among Anopheles mosquito species is determined by many factors, including behavior, immunity, and life history. To investigate the genomic basis of vectorial capacity and explore new avenues for vector control, we sequenced the genomes of 16 anopheline mosquito species from diverse locations spanning ~100 million years of evolution. Comparative analyses show faster rates of gene gain and loss, elevated gene shuffling on the X chromosome, and more intron losses, relative to Drosophila. Some determinants of vectorial capacity, such as chemosensory genes, do not show elevated turnover but instead diversify through protein-sequence changes. This dynamism of anopheline genes and genomes may contribute to their flexible capacity to take advantage of new ecological niches, including adapting to humans as primary hosts. Copyright © 2015, American Association for the Advancement of Science.

Higher Mosquito Production in Low-Income Neighborhoods of Baltimore and Washington, DC: Understanding Ecological Drivers and Mosquito-Borne Disease Risk in Temperate Cities

PubMed Central

LaDeau, Shannon L.; Leisnham, Paul T.; Biehler, Dawn; Bodner, Danielle

2013-01-01

Mosquito-vectored pathogens are responsible for devastating human diseases and are (re)emerging in many urban environments. Effective mosquito control in urban landscapes relies on improved understanding of the complex interactions between the ecological and social factors that define where mosquito populations can grow. We compared the density of mosquito habitat and pupae production across economically varying neighborhoods in two temperate U.S. cities (Baltimore, MD and Washington, DC). Seven species of mosquito larvae were recorded. The invasive Aedes albopictus was the only species found in all neighborhoods. Culex pipiens, a primary vector of West Nile virus (WNV), was most abundant in Baltimore, which also had more tire habitats. Both Culex and Aedes pupae were more likely to be sampled in neighborhoods categorized as being below median income level in each city and Aedes pupae density was also greater in container habitats found in these lower income neighborhoods. We infer that lower income residents may experience greater exposure to potential disease vectors and Baltimore residents specifically, were at greater risk of exposure to the predominant WNV vector. However, we also found that resident-reported mosquito nuisance was not correlated with our measured risk index, indicating a potentially important mismatch between motivation needed to engage participation in control efforts and the relative importance of control among neighborhoods. PMID:23583963

Biological Control of Mosquito Vectors: Past, Present, and Future

PubMed Central

Benelli, Giovanni; Jeffries, Claire L.; Walker, Thomas

2016-01-01

Mosquitoes represent the major arthropod vectors of human disease worldwide transmitting malaria, lymphatic filariasis, and arboviruses such as dengue virus and Zika virus. Unfortunately, no treatment (in the form of vaccines or drugs) is available for most of these diseases and vector control is still the main form of prevention. The limitations of traditional insecticide-based strategies, particularly the development of insecticide resistance, have resulted in significant efforts to develop alternative eco-friendly methods. Biocontrol strategies aim to be sustainable and target a range of different mosquito species to reduce the current reliance on insecticide-based mosquito control. In this review, we outline non-insecticide based strategies that have been implemented or are currently being tested. We also highlight the use of mosquito behavioural knowledge that can be exploited for control strategies. PMID:27706105

Mosquito and filth fly control in desert and temperate environments with a synergized pesticide mister and barrier treatment

USDA-ARS?s Scientific Manuscript database

U.S. military operations face significant negative impacts on mission readiness from disease-vector and nuisance filth flies, mosquitoes, and sand flies. Through the Deployed War Fighter Protection Program (DWFP) we previously developed small scale 9 ft by 3 ft pesticide-treated perimeters enhanced ...

The immune strategies of mosquito Aedes aegypti against microbial infection.

PubMed

Wang, Yan-Hong; Chang, Meng-Meng; Wang, Xue-Li; Zheng, Ai-Hua; Zou, Zhen

2018-06-01

Yellow fever mosquito Aedes aegypti transmits many devastating arthropod-borne viruses (arboviruses), such as dengue virus, yellow fever virus, Chikungunya virus, and Zika virus, which cause great concern to human health. Mosquito control is an effective method to block the spread of infectious diseases. Ae. aegypti uses its innate immune system to fight against arboviruses, parasites, and fungi. In this review, we briefly summarize the recent findings in the immune response of Ae. aegypti against arboviral and entomopathogenic infections. This review enriches our understanding of the mosquito immune system and provides evidence to support the development of novel mosquito control strategies. Copyright © 2017 Elsevier Ltd. All rights reserved.

Bile salt tolerance of Lactococcus lactis is enhanced by expression of bile salt hydrolase thereby producing less bile acid in the cells.

PubMed

Bi, Jie; Liu, Song; Du, Guocheng; Chen, Jian

2016-04-01

Changes of bile salt tolerance, morphology and amount of bile acid within cells were studied to evaluate the exact effects of bile salt hydrolase (BSH) on bile salt tolerance of microorganism. The effect of BSHs on the bile salt tolerance of Lactococcus lactis was examined by expressing two BSHs (BSH1 and BSH2). Growth of L. lactis expressing BSH1 or BSH2 was better under bile salt stress compared to wild-type L. lactis. As indicated by transmission electron microscopy, bile acids released by the action of BSH induced the formation of micelles around the membrane surface of cells subject to conjugated bile salt stress. A similar micelle containing bile acid was observed in the cytoplasm by liquid chromatography-mass spectrometry. BSH1 produced fewer bile acid micelles in the cytoplasm and achieved better cell growth of L. lactis compared to BSH2. Expression of BSH improved bile salt tolerance of L. lactis but excessive production by BSH of bile acid micelles in the cytoplasm inhibited cell growth.

The temporal spectrum of adult mosquito population fluctuations: conceptual and modeling implications.

PubMed

Jian, Yun; Silvestri, Sonia; Brown, Jeff; Hickman, Rick; Marani, Marco

2014-01-01

An improved understanding of mosquito population dynamics under natural environmental forcing requires adequate field observations spanning the full range of temporal scales over which mosquito abundance fluctuates in natural conditions. Here we analyze a 9-year daily time series of uninterrupted observations of adult mosquito abundance for multiple mosquito species in North Carolina to identify characteristic scales of temporal variability, the processes generating them, and the representativeness of observations at different sampling resolutions. We focus in particular on Aedes vexans and Culiseta melanura and, using a combination of spectral analysis and modeling, we find significant population fluctuations with characteristic periodicity between 2 days and several years. Population dynamical modelling suggests that the observed fast fluctuations scales (2 days-weeks) are importantly affected by a varying mosquito activity in response to rapid changes in meteorological conditions, a process neglected in most representations of mosquito population dynamics. We further suggest that the range of time scales over which adult mosquito population variability takes place can be divided into three main parts. At small time scales (indicatively 2 days-1 month) observed population fluctuations are mainly driven by behavioral responses to rapid changes in weather conditions. At intermediate scales (1 to several month) environmentally-forced fluctuations in generation times, mortality rates, and density dependence determine the population characteristic response times. At longer scales (annual to multi-annual) mosquito populations follow seasonal and inter-annual environmental changes. We conclude that observations of adult mosquito populations should be based on a sub-weekly sampling frequency and that predictive models of mosquito abundance must include behavioral dynamics to separate the effects of a varying mosquito activity from actual changes in the abundance of the

Biodiversity and ecosystem risks arising from using guppies to control mosquitoes

PubMed Central

Frauendorf, Therese C.; Marques, Piata S.; Mackenzie, Richard A.; Manna, Luisa R.; Mazzoni, Rosana; Phillip, Dawn A. T.; Warbanski, Misha L.; Zandonà, Eugenia

2016-01-01

Deploying mosquito predators such as the guppy (Poecilia reticulata) into bodies of water where mosquitoes breed is a common strategy for limiting the spread of disease-carrying mosquitoes. Here, we draw on studies from epidemiology, conservation, ecology and evolution to show that the evidence for the effectiveness of guppies in controlling mosquitoes is weak, that the chances of accidental guppy introduction into local ecosystems are large, and that guppies can easily establish populations and damage these aquatic ecosystems. We highlight several knowledge and implementation gaps, and urge that this approach is either abandoned in favour of more effective strategies or that it is used much more rigorously. Controlling mosquitoes does not need to come at the expense of freshwater biodiversity. PMID:28120806

Development of guidelines for the surveillance of invasive mosquitoes in Europe

PubMed Central

2013-01-01

Background The recent notifications of autochthonous cases of dengue and chikungunya in Europe prove that the region is vulnerable to these diseases in areas where known mosquito vectors (Aedes albopictus and Aedes aegypti) are present. Strengthening surveillance of these species as well as other invasive container-breeding aedine mosquito species such as Aedes atropalpus, Aedes japonicus, Aedes koreicus and Aedes triseriatus is therefore required. In order to support and harmonize surveillance activities in Europe, the European Centre for Disease Prevention and Control (ECDC) launched the production of ‘Guidelines for the surveillance of invasive mosquitoes in Europe’. This article describes these guidelines in the context of the key issues surrounding invasive mosquitoes surveillance in Europe. Methods Based on an open call for tender, ECDC granted a pan-European expert team to write the guidelines draft. It content is founded on published and grey literature, contractor’s expert knowledge, as well as appropriate field missions. Entomologists, public health experts and end users from 17 EU/EEA and neighbouring countries contributed to a reviewing and validation process. The final version of the guidelines was edited by ECDC (Additional file 1). Results The guidelines describe all procedures to be applied for the surveillance of invasive mosquito species. The first part addresses strategic issues and options to be taken by the stakeholders for the decision-making process, according to the aim and scope of surveillance, its organisation and management. As the strategy to be developed needs to be adapted to the local situation, three likely scenarios are proposed. The second part addresses all operational issues and suggests options for the activities to be implemented, i.e. key procedures for field surveillance of invasive mosquito species, methods of identification of these mosquitoes, key and optional procedures for field collection of population parameters

Variation in Wolbachia effects on Aedes mosquitoes as a determinant of invasiveness and vectorial capacity.

PubMed

King, Jessica G; Souto-Maior, Caetano; Sartori, Larissa M; Maciel-de-Freitas, Rafael; Gomes, M Gabriela M

2018-04-16

Wolbachia has been introduced into Aedes aegypti mosquitoes to control the spread of arboviruses, such as dengue, chikungunya and Zika. Studies showed that certain Wolbachia strains (such as wMel) reduce replication of dengue viruses in the laboratory, prompting the release of mosquitoes carrying the bacterium into the field, where vectorial capacity can be realistically assessed in relation to native non-carriers. Here we apply a new analysis to two published datasets, and show that wMel increases the mean and the variance in Ae. aegypti susceptibility to dengue infection when introgressed into Brazil and Vietnam genetic backgrounds. In the absence of other processes, higher mean susceptibility should lead to enhanced viral transmission. The increase in variance, however, widens the basis for selection imposed by unexplored natural forces, retaining the potential for reducing transmission overall.

Natural malaria infection reduces starvation resistance of nutritionally stressed mosquitoes.

PubMed

Lalubin, Fabrice; Delédevant, Aline; Glaizot, Olivier; Christe, Philippe

2014-07-01

In disease ecology, there is growing evidence that environmental quality interacts with parasite and host to determine host susceptibility to an infection. Most studies of malaria parasites have focused on the infection costs incurred by the hosts, and few have investigated the costs on mosquito vectors. The interplay between the environment, the vector and the parasite has therefore mostly been ignored and often relied on unnatural or allopatric Plasmodium/vector associations. Here, we investigated the effects of natural avian malaria infection on both fecundity and survival of field-caught female Culex pipiens mosquitoes, individually maintained in laboratory conditions. We manipulated environmental quality by providing mosquitoes with different concentrations of glucose-feeding solution prior to submitting them to a starvation challenge. We used molecular-based methods to assess mosquitoes' infection status. We found that mosquitoes infected with Plasmodium had lower starvation resistance than uninfected ones only under low nutritional conditions. The effect of nutritional stress varied with time, with the difference of starvation resistance between optimally and suboptimally fed mosquitoes increasing from spring to summer, as shown by a significant interaction between diet treatment and months of capture. Infected and uninfected mosquitoes had similar clutch size, indicating no effect of infection on fecundity. Overall, this study suggests that avian malaria vectors may suffer Plasmodium infection costs in their natural habitat, under certain environmental conditions. This may have major implications for disease transmission in the wild. © 2013 The Authors. Journal of Animal Ecology © 2013 British Ecological Society.

Aedes-Borne Virus-Mosquito Interactions: Mass Spectrometry Strategies and Findings.

PubMed

Pando-Robles, Victoria; Batista, Cesar V

2017-06-01

Aedes-borne viruses are responsible for high-impact neglected tropical diseases and unpredictable outbreaks such as the ongoing Zika epidemics. Aedes mosquitoes spread different arboviruses such as Dengue virus (DENV), Chikungunya virus (CHIKV), and Zika virus, among others, and are responsible for the continuous emergence and reemergence of these pathogens. These viruses have complex transmission cycles that include two hosts, namely the Aedes mosquito as a vector and susceptible vertebrate hosts. Human infection with arboviruses causes diseases that range from subclinical or mild to febrile diseases, encephalitis, and hemorrhagic fever. Infected mosquitoes do not show detectable signs of disease, even though the virus maintains a lifelong persistent infection. The infection of the Aedes mosquito by viruses involves a molecular crosstalk between cell and viral proteins. An understanding of how mosquito vectors and viruses interact is of fundamental interest, and it also offers novel perspectives for disease control. In recent years, mass spectrometry (MS)-based strategies in combination with bioinformatics have been successfully applied to identify and quantify global changes in cellular proteins, lipids, peptides, and metabolites in response to viral infection. Although the information about proteomics in the Aedes mosquito is limited, the information that has been reported can set up the basis for future studies. This review reflects how MS-based approaches have extended our understanding of Aedes mosquito biology and the development of DENV and CHIKV infection in the vector. Finally, this review discusses future challenges in the field.

Monitoring Malaria Vector Control Interventions: Effectiveness of Five Different Adult Mosquito Sampling Methods

PubMed Central

Onyango, Shirley A.; Kitron, Uriel; Mungai, Peter; Muchiri, Eric M.; Kokwaro, Elizabeth; King, Charles H.; Mutuku, Francis M.

2014-01-01

Long-term success of ongoing malaria control efforts based on mosquito bed nets (long-lasting insecticidal net) and indoor residual spraying is dependent on continuous monitoring of mosquito vectors, and thus on effective mosquito sampling tools. The objective of our study was to identify the most efficient mosquito sampling tool(s) for routine vector surveillance for malaria and lymphatic filariasis transmission in coastal Kenya. We evaluated relative efficacy of five collection methods—light traps associated with a person sleeping under a net, pyrethrum spray catches, Prokopack aspirator, clay pots, and urine-baited traps—in four villages representing three ecological settings along the south coast of Kenya. Of the five methods, light traps were the most efficient for collecting female Anopheles gambiae s.l. (Giles) (Diptera: Culicidae) and Anopheles funestus (Giles) (Diptera: Culicidae) mosquitoes, whereas the Prokopack aspirator was most efficient in collecting Culex quinquefasciatus (Say) (Diptera: Culicidae) and other culicines. With the low vector densities here, and across much of sub-Saharan Africa, wherever malaria interventions, long-lasting insecticidal nets, and/or indoor residual spraying are in place, the use of a single mosquito collection method will not be sufficient to achieve a representative sample of mosquito population structure. Light traps will remain a relevant tool for host-seeking mosquitoes, especially in the absence of human landing catches. For a fair representation of the indoor mosquito population, light traps will have to be supplemented with aspirator use, which has potential for routine monitoring of indoor resting mosquitoes, and can substitute the more labor-intensive and intrusive pyrethrum spray catches. There are still no sufficiently efficient mosquito collection methods for sampling outdoor mosquitoes, particularly those that are bloodfed. PMID:24180120

Modified mosquito landing boxes dispensing transfluthrin provide effective protection against Anopheles arabiensis mosquitoes under simulated outdoor conditions in a semi-field system.

PubMed

Andrés, Marta; Lorenz, Lena M; Mbeleya, Edgar; Moore, Sarah J

2015-06-24

Efforts to control malaria vectors have primarily focused on scaling-up of long-lasting insecticidal nets (LLINs) and indoor residual spraying. Although highly efficient against indoor-biting and indoor-resting vectors, these interventions have lower impact on outdoor-biting mosquitoes. Innovative vector control tools are required to prevent outdoor human-mosquito contacts. In this work, the potential of spatial repellents, delivered in an active system that requires minimal user compliance, to provide personal protection against exophagic mosquitoes active in the early evening was explored. A device previously used as an odour-baited lure and kill apparatus, the mosquito landing box (MLB), was modified to dispense the volatile synthetic pyrethroid, transfluthrin, as a spatial repellent. The MLB has an active odour-dispensing mechanism that uses a solar-powered fan and switches on at dusk to provide long duration dispensing of volatile compounds without the need for the user to remember to employ it. Two MLBs were located 5 m from a human volunteer to investigate the repellent effects of a transfluthrin 'bubble' created between the MLBs. Transfluthrin was emanated from polyester strips, hanging inside the MLB odour-dispensing unit. A fully randomized cross-over design was performed in a large, semi-field, screened cage to assess the effect of the repellent against laboratory-reared Anopheles arabiensis mosquitoes under ambient outdoor conditions. The knock-down capacity of the transfluthrin-treated strips was also evaluated at different time points up to 3 weeks after being impregnated to measure duration of efficacy. The protective transfluthrin bubble provided 68.9% protection against An. arabiensis bites under these simulated outdoor conditions. Volatile transfluthrin caused low mortality among mosquitoes in the semi-field system. Transfluthrin-treated strips continued to knock down mosquitoes in laboratory tests, 3 weeks after impregnation, although this effect

Biodiversity and ecosystem risks arising from using guppies to control mosquitoes

Treesearch

Rana W. El-Sabaawi; Therese C. Frauendorf; Piata S. Marques; Richard A. Mackenzie; Luisa R. Manna; Rosana Mazzoni; Dawn A. T. Phillip; Misha L. Warbanski; Eugenia Zandon

2016-01-01

Deploying mosquito predators such as the guppy (Poecilia reticulata) into bodies of water where mosquitoes breed is a common strategy for limiting the spread of disease-carrying mosquitoes. Here, we draw on studies from epidemiology, conservation, ecology and evolution to show that the evidence for the effectiveness of guppies in controlling...

Toxicity of a plant based mosquito repellent/killer.

PubMed

Singh, Bhoopendra; Singh, Prakash Raj; Mohanty, Manoj Kumar

2012-12-01

The mission to make humans less attractive to mosquitoes has fuelled decades of scientific research on mosquito behaviour and control. The search for the perfect topical insect repellent/killer continues. This analysis was conducted to review and explore the scientific information on toxicity produced by the ingredients/contents of a herbal product. In this process of systemic review the following methodology was applied. By doing a MEDLINE search with key words of selected plants, plant based insect repellents/killers pertinent articles published in journals and authentic books were reviewed. The World Wide Web and the Extension Toxicity Network database (IPCS-ITOX) were also searched for toxicology data and other pertinent information. Repellents do not all share a single mode of action and surprisingly little is known about how repellents act on their target insects. Moreover, different mosquito species may react differently to the same repellent. After analysis of available data and information on the ingredient, of the product in relation to medicinal uses, acute and chronic toxicity of the selected medicinal plants, it can be concluded that the ingredients included in the herbal product can be used as active agents against mosquitoes. If the product which contains the powder of the above said plants is applied with care and safety, it is suitable fo use as a mosquito repellent/killer.

Toxicity of a plant based mosquito repellent/killer

PubMed Central

Singh, Prakash Raj; Mohanty, Manoj Kumar

2012-01-01

The mission to make humans less attractive to mosquitoes has fuelled decades of scientific research on mosquito behaviour and control. The search for the perfect topical insect repellent/killer continues. This analysis was conducted to review and explore the scientific information on toxicity produced by the ingredients/contents of a herbal product. In this process of systemic review the following methodology was applied. By doing a MEDLINE search with key words of selected plants, plant based insect repellents/killers pertinent articles published in journals and authentic books were reviewed. The World Wide Web and the Extension Toxicity Network database (IPCS-ITOX) were also searched for toxicology data and other pertinent information. Repellents do not all share a single mode of action and surprisingly little is known about how repellents act on their target insects. Moreover, different mosquito species may react differently to the same repellent. After analysis of available data and information on the ingredient, of the product in relation to medicinal uses, acute and chronic toxicity of the selected medicinal plants, it can be concluded that the ingredients included in the herbal product can be used as active agents against mosquitoes. If the product which contains the powder of the above said plants is applied with care and safety, it is suitable fo use as a mosquito repellent/killer. PMID:23554562

West Nile Virus in Mosquitoes of Iranian Wetlands.

PubMed

Bagheri, Masoomeh; Terenius, Olle; Oshaghi, Mohammad Ali; Motazakker, Morteza; Asgari, Sassan; Dabiri, Farrokh; Vatandoost, Hassan; Mohammadi Bavani, Mulood; Chavshin, Ali Reza

2015-12-01

The West Nile virus (WNV) transmission cycle includes a wide range of migratory wetland birds as reservoirs, mosquitoes as biological vectors, and equines and humans as dead-end hosts. Despite the presence of potential vector species, there is no information about the existence of WNV in mosquito vectors in Iran. The Iranian West Azerbaijan Province is located in the northwestern part of Iran and has borders with Turkey, Iraq, Armenia, and the Republic of Azerbaijan. The current study was conducted to identify the wetland mosquitoes of the West Azerbaijan Province and their infection with WNV. In this study, 2143 specimens were collected, comprising 1541 adults and 602 larvae. Six species belonging to four genera were collected and identified: Anopheles maculipennis sensu lato (s.l.), Culex (Cx.) hortensis, Cx. pipiens s.l., Cx. theileri, Culiseta longiareolata, and Aedes (Ae.) (Ochlerotatus) caspius. In total, 45 pools of mosquitoes were examined. Two of the adult pools collected from the same location showed the presence of WNV in Ae. (Och.) caspius, from Sangar, Makoo County, as confirmed by PCR and sequencing. Due to the discovery of WNV in the mosquito population of the region, and the presence of wetlands and significant populations of migratory birds, the health sector should carefully monitor the factors involved in the cycle of this disease.

Mosquitoes and Mosquito-Borne Arboviruses in the Qinghai-Tibet Plateau—Focused on the Qinghai Area, China

PubMed Central

Li, Wen-Juan; Wang, Jing-Lin; Li, Ming-Hua; Fu, Shi-Hong; Wang, Huan-Yu; Wang, Zhi-Yu; Jiang, Shuang-Ying; Wang, Xue-Wen; Guo, Peng; Zhao, Sheng-Cang; Shi, Yan; Lu, Nan-Nan; Nasci, Roger S.; Tang, Qing; Liang, Guo-Dong

2010-01-01

An investigation was conducted to identify the distribution of mosquitoes and mosquito-borne arboviruses in the Qinghai-Tibet Plateau, China from July to August in 2007. A total of 8,147 mosquitoes representing six species from three genera (Aedes, Culex, and Anopheles) were collected in three locations (Geermu city, altitude of 2,780 m; Xining city, 2,200 m; Minhe county, 1,700 m). Six virus isolates were obtained including Tahyna virus (TAHV), Liaoning virus, and Culex pipiens pallens Densovirus. A serosurvey showed immunoglobulin G antibodies by immunofluorescence assay (IFA) against TAHV in residents of all three locations. The IFA-positive human samples were confirmed by 90% plaque-reduction neutralization tests (PRNT90) against TAHV with titers ranging from 1:20 to 1:10,240. In addition, TAHV seropositive cows, sheep, and swine were found in these locations. This investigation represents the first isolation of TAHV from Ae. (Och.) detritus and the first evidence of TAHV infection in residents and livestock in the Qinghai-Tibet Plateau. PMID:20348523

Variation in Aedes aegypti Mosquito Competence for Zika Virus Transmission.

PubMed

Roundy, Christopher M; Azar, Sasha R; Rossi, Shannan L; Huang, Jing H; Leal, Grace; Yun, Ruimei; Fernandez-Salas, Ildefonso; Vitek, Christopher J; Paploski, Igor A D; Kitron, Uriel; Ribeiro, Guilherme S; Hanley, Kathryn A; Weaver, Scott C; Vasilakis, Nikos

2017-04-01

To test whether Zika virus has adapted for more efficient transmission by Aedes aegypti mosquitoes, leading to recent urban outbreaks, we fed mosquitoes from Brazil, the Dominican Republic, and the United States artificial blood meals containing 1 of 3 Zika virus strains (Senegal, Cambodia, Mexico) and monitored infection, dissemination, and virus in saliva. Contrary to our hypothesis, Cambodia and Mexica strains were less infectious than the Senegal strain. Only mosquitoes from the Dominican Republic transmitted the Cambodia and Mexica strains. However, blood meals from viremic mice were more infectious than artificial blood meals of comparable doses; the Cambodia strain was not transmitted by mosquitoes from Brazil after artificial blood meals, whereas 61% transmission occurred after a murine blood meal (saliva titers up to 4 log 10 infectious units/collection). Although regional origins of vector populations and virus strain influence transmission efficiency, Ae. aegypti mosquitoes appear to be competent vectors of Zika virus in several regions of the Americas.

Variation in Aedes aegypti Mosquito Competence for Zika Virus Transmission

PubMed Central

Roundy, Christopher M.; Azar, Sasha R.; Rossi, Shannan L.; Huang, Jing H.; Leal, Grace; Yun, Ruimei; Fernandez-Salas, Ildefonso; Vitek, Christopher J.; Paploski, Igor A.D.; Kitron, Uriel; Ribeiro, Guilherme S.; Hanley, Kathryn A.

2017-01-01

To test whether Zika virus has adapted for more efficient transmission by Aedes aegypti mosquitoes, leading to recent urban outbreaks, we fed mosquitoes from Brazil, the Dominican Republic, and the United States artificial blood meals containing 1 of 3 Zika virus strains (Senegal, Cambodia, Mexico) and monitored infection, dissemination, and virus in saliva. Contrary to our hypothesis, Cambodia and Mexica strains were less infectious than the Senegal strain. Only mosquitoes from the Dominican Republic transmitted the Cambodia and Mexica strains. However, blood meals from viremic mice were more infectious than artificial blood meals of comparable doses; the Cambodia strain was not transmitted by mosquitoes from Brazil after artificial blood meals, whereas 61% transmission occurred after a murine blood meal (saliva titers up to 4 log10 infectious units/collection). Although regional origins of vector populations and virus strain influence transmission efficiency, Ae. aegypti mosquitoes appear to be competent vectors of Zika virus in several regions of the Americas. PMID:28287375

Mosquito vectors and the spread of cancer: an overlooked connection?

PubMed

Benelli, Giovanni; Lo Iacono, Annalisa; Canale, Angelo; Mehlhorn, Heinz

2016-06-01

Mosquitoes (Diptera: Culicidae) represent a key threat for millions of humans and animals worldwide, vectoring important pathogens and parasites, including malaria, dengue, filariasis, and Zika virus. Besides mosquito-borne diseases, cancers figure among the leading causes of mortality worldwide. It is expected that annual cancer cases will rise from 14 million in 2012 to 22 million within the next two decades. Notably, there are few contrasting evidences of the relationship between cancer and mosquito-borne diseases, with special reference to malaria. However, analogies at the cellular level for the two diseases were reported. Recently, a significant association of malaria incidence with all cancer mortality in 50 USA states was highlighted and may be explained by the ability of Plasmodium to induce suppression of the immune system. However, it was hypothesized that Anopheles vectors may transmit obscure viruses linked with cancer development. The possible activation of cancer pathways by mosquito feeding events is not rare. For instance, the hamster reticulum cell sarcoma can be transmitted through the bites of Aedes aegypti by a transfer of tumor cells. Furthermore, mosquito bites may influence human metabolic pathways following different mechanisms, leading to other viral infections and/or oncogenesis. Hypersensitivity to mosquito bites is routed by a unique pathogenic mechanism linking Epstein-Barr virus infection, allergy, and oncogenesis. During dengue virus infection, high viral titers, macrophage infiltration, and tumor necrosis factor alpha production in the local tissues are the three key important events that lead to hemorrhage. Overall, basic epidemiological knowledge on the relationships occurring between mosquito vector activity and the spread of cancer is urgently needed, as well as detailed information about the ability of Culicidae to transfer viruses or tumor cells among hosts over time. Current evidences on nanodrugs with multipotency against

Evaluation of various models of propane-powered mosquito traps.

PubMed

Kline, Daniel L

2002-06-01

Large cage and field studies were conducted to determine the efficacy of various models of propane-powered mosquito traps. These traps utilized counterflow technology in conjunction with catalytic combustion to produce attractants (carbon dioxide, water vapor, and heat) and a thermoelectric generator that converted excess heat into electricity for stand-alone operation. The cage studies showed that large numbers of Aedes aegypti and Ochlerotatus taeniorhynchus were captured and that each progressive model resulted in increased trapping efficiency. In several field studies against natural populations of mosquitoes two different propane traps were compared against two other trap systems, the professional (PRO) and counterflow geometry (CFG) traps. In these studies the propane traps consistently caught more mosquitoes than the PRO trap and significantly fewer mosquitoes than the CFG traps. The difference in collection size between the CFG and propane traps was due mostly to Anopheles crucians. In spring 1997 the CFG trap captured 3.6X more An. crucians than the Portable Propane (PP) model and in spring 1998 it captured 6.3X more An. crucians than the Mosquito Magnet Beta-1 (MMB-1) trap. Both the PP and MMB-1 captured slightly more Culex spp. than the CFG trap.

Microbial Pre-exposure and Vectorial Competence of Anopheles Mosquitoes

PubMed Central

Dieme, Constentin; Rotureau, Brice; Mitri, Christian

2017-01-01

Anopheles female mosquitoes can transmit Plasmodium, the malaria parasite. During their aquatic life, wild Anopheles mosquito larvae are exposed to a huge diversity of microbes present in their breeding sites. Later, adult females often take successive blood meals that might also carry different micro-organisms, including parasites, bacteria, and viruses. Therefore, prior to Plasmodium ingestion, the mosquito biology could be modulated at different life stages by a suite of microbes present in larval breeding sites, as well as in the adult environment. In this article, we highlight several naturally relevant scenarios of Anopheles microbial pre-exposure that we assume might impact mosquito vectorial competence for the malaria parasite: (i) larval microbial exposures; (ii) protist co-infections; (iii) virus co-infections; and (iv) pathogenic bacteria co-infections. In addition, significant behavioral changes in African Anopheles vectors have been associated with increasing insecticide resistance. We discuss how these ethological modifications may also increase the repertoire of microbes to which mosquitoes could be exposed, and that might also influence their vectorial competence. Studying Plasmodium–Anopheles interactions in natural microbial environments would efficiently contribute to refining the transmission risks. PMID:29376030

Transmission of Rift Valley fever virus from European-breed lambs to Culex pipiens mosquitoes.

PubMed

Vloet, Rianka P M; Vogels, Chantal B F; Koenraadt, Constantianus J M; Pijlman, Gorben P; Eiden, Martin; Gonzales, Jose L; van Keulen, Lucien J M; Wichgers Schreur, Paul J; Kortekaas, Jeroen

2017-12-01

Rift Valley fever virus (RVFV) is a mosquito-borne bunyavirus of the genus Phlebovirus that is highly pathogenic to ruminants and humans. The disease is currently confined to Africa and the Arabian Peninsula, but globalization and climate change may facilitate introductions of the virus into currently unaffected areas via infected animals or mosquitoes. The consequences of such an introduction will depend on environmental factors, the availability of susceptible ruminants and the capacity of local mosquitoes to transmit the virus. We have previously demonstrated that lambs native to the Netherlands are highly susceptible to RVFV and we here report the vector competence of Culex (Cx.) pipiens, the most abundant and widespread mosquito species in the country. Vector competence was first determined after artificial blood feeding of laboratory-reared mosquitoes using the attenuated Clone 13 strain. Subsequently, experiments with wild-type RVFV and mosquitoes hatched from field-collected eggs were performed. Finally, the transmission of RVFV from viremic lambs to mosquitoes was studied. Artificial feeding experiments using Clone 13 demonstrated that indigenous, laboratory-reared Cx. pipiens mosquitoes are susceptible to RVFV and that the virus can be transmitted via their saliva. Experiments with wild-type RVFV and mosquitoes hatched from field-collected eggs confirmed the vector competence of Cx. pipiens mosquitoes from the Netherlands. To subsequently investigate transmission of the virus under more natural conditions, mosquitoes were allowed to feed on RVFV-infected lambs during the viremic period. We found that RVFV is efficiently transmitted from lambs to mosquitoes, although transmission was restricted to peak viremia. Interestingly, in the mosquito-exposed skin samples, replication of RVFV was detected in previously unrecognized target cells. We here report the vector competence of Cx. pipiens mosquitoes from the Netherlands for RVFV. Both laboratory

Driven to extinction? The ethics of eradicating mosquitoes with gene-drive technologies.

PubMed

Pugh, Jonathan

2016-09-01

Mosquito-borne diseases represent a significant global disease burden, and recent outbreaks of such diseases have led to calls to reduce mosquito populations. Furthermore, advances in 'gene-drive' technology have raised the prospect of eradicating certain species of mosquito via genetic modification. This technology has attracted a great deal of media attention, and the idea of using gene-drive technology to eradicate mosquitoes has been met with criticism in the public domain. In this paper, I shall dispel two moral objections that have been raised in the public domain against the use of gene-drive technologies to eradicate mosquitoes. The first objection invokes the concept of the 'sanctity of life' in order to claim that we should not drive an animal to extinction. In response, I follow Peter Singer in raising doubts about general appeals to the sanctity of life, and argue that neither individual mosquitoes nor mosquitoes species considered holistically are appropriately described as bearing a significant degree of moral status. The second objection claims that seeking to eradicate mosquitoes amounts to displaying unacceptable degrees of hubris. Although I argue that this objection also fails, I conclude by claiming that it raises the important point that we need to acquire more empirical data about, inter alia, the likely effects of mosquito eradication on the ecosystem, and the likelihood of gene-drive technology successfully eradicating the intended mosquito species, in order to adequately inform our moral analysis of gene-drive technologies in this context. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Bacterial microbiota assemblage in Aedes albopictus mosquitoes and its impacts on larval development.

PubMed

Wang, Xiaoming; Liu, Tong; Wu, Yang; Zhong, Daibin; Zhou, Guofa; Su, Xinghua; Xu, Jiabao; Sotero, Charity F; Sadruddin, Adnan A; Wu, Kun; Chen, Xiao-Guang; Yan, Guiyun

2018-05-30

Interactions between bacterial microbiota and mosquitoes play an important role in mosquitoes' capacity to transmit pathogens. However, microbiota assemblages within mosquitoes and the impact of microbiota in environments on mosquito development and survival remain unclear. This study examined microbiota assemblages and the effects of aquatic environment microbiota on the larval development of the Aedes albopictus mosquito, an important dengue virus vector. Life table studies have found that reducing bacterial load in natural aquatic habitats through water filtering and treatment with antibiotics significantly reduced the larva-to-adult emergence rate. This finding was consistent in two types of larval habitats examined-discarded tires and flowerpots, suggesting that bacteria play a crucial role in larval development. Pyrosequencing of the bacterial 16S rRNA gene was used to determine the diversity of bacterial communities in larval habitats and the resulting numbers of mosquitoes under both laboratory and field conditions. The microbiota profiling identified common shared bacteria among samples from different years; further studies are needed to determine whether these bacteria represent a core microbiota. The highest microbiota diversity was found in aquatic habitats, followed by mosquito larvae, and the lowest in adult mosquitoes. Mosquito larvae ingested their bacterial microbiota and nutrients from aquatic habitats of high microbiota diversity. Taken together, the results support the observation that Ae. albopictus larvae are able to utilize diverse bacteria from aquatic habitats and that live bacteria from aquatic habitats play an important role in larval mosquito development and survival. These findings provide new insights into bacteria's role in mosquito larval ecology. © 2018 John Wiley & Sons Ltd.

Dynamics of West Nile virus evolution in mosquito vectors.

PubMed

Grubaugh, Nathan D; Ebel, Gregory D

2016-12-01

West Nile virus remains the most common cause of arboviral encephalitis in North America. Since it was introduced, it has undergone adaptive genetic change as it spread throughout the continent. The WNV transmission cycle is relatively tractable in the laboratory. Thus the virus serves as a convenient model system for studying the population biology of mosquito-borne flaviviruses as they undergo transmission to and from mosquitoes and vertebrates. This review summarizes the current knowledge regarding the population dynamics of this virus within mosquito vectors. Copyright © 2016 Elsevier B.V. All rights reserved.

Combined effect of salt and drought on boron toxicity in Puccinellia tenuiflora.

PubMed

Liu, Chunguang; Dai, Zheng; Xia, Jingye; Chang, Can; Sun, Hongwen

2018-08-15

Boron toxicity is a worldwide problem, usually accompanied by salt (NaCl) and drought. The combined stresses may induce complex toxicity to the plant. The aim of the present study was to investigate how the combined stresses of salt and drought affect B toxicity in plants. Puccinellia tenuiflora seedlings were planted in vermiculite. A three (B) × three (salt) × three (drought) factorial experiment (for a total of 27 treatments) was conducted. After a 30-day cultivation, plants were harvested to determine dry weight and the concentrations of B, Na + , K + , Ca 2+ , and Mg 2+ . Plant growth was inhibited by B toxicity, which was alleviated by salt and drought. B stress enhanced B uptake and transport of the plant, which was inhibited by salt and drought. B stress had a little effect on K + and Na + concentration and caused Ca 2+ and Mg 2+ accumulation in the plant. Salt addition increased Na + concentration and inhibited Ca 2+ and Mg 2+ accumulation. Drought addition inhibited Na + accumulation and enhanced Ca 2+ and Mg 2+ accumulation. The combined stresses of salt and drought had a greater alleviation on the inhibition of dry weight caused by B than individual salt and drought. Besides, the combined stresses of salt and drought also enhanced B uptake and inhibited B transport. The results indicate that salt, drought, and the combined stresses of salt and drought all can alleviate B toxicity in P. tenuiflora, the main mechanism of which is the restriction of B and Na + uptake caused by salt and drought. The combined stresses of salt and drought have a greater effect on B toxicity than individual salt and drought. Copyright © 2018 Elsevier Inc. All rights reserved.

Gustatory reception of chemicals affecting feeding in aedine mosquitoes

USDA-ARS?s Scientific Manuscript database

Mosquitoes vector dangerous human diseases during blood feeding. Gustatory (taste) receptor neurons in the mosquito provide important chemical information including the nature and suitability of a potential host. Here we discuss the behavior, neurophysiology and molecular mechanisms associated wit...

Reciprocal Trophic Interactions and Transmission of Blood Parasites between Mosquitoes and Frogs

PubMed Central

Ferguson, Laura V.; Smith, Todd G.

2012-01-01

The relationship between mosquitoes and their amphibian hosts is a unique, reciprocal trophic interaction. Instead of a one-way, predator-prey relationship, there is a cyclical dance of avoidance and attraction. This has prompted spatial and temporal synchrony between organisms, reflected in emergence time of mosquitoes in the spring and choice of habitat for oviposition. Frog-feeding mosquitoes also possess different sensory apparatuses than do their mammal-feeding counterparts. The reciprocal nature of this relationship is exploited by various blood parasites that use mechanical, salivary or trophic transmission to pass from mosquitoes to frogs. It is important to investigate the involvement of mosquitoes, frogs and parasites in this interaction in order to understand the consequences of anthropogenic actions, such as implementing biocontrol efforts against mosquitoes, and to determine potential causes of the global decline of amphibian species. PMID:26466534

Enhanced water transport and salt rejection through hydrophobic zeolite pores.

PubMed

Humplik, Thomas; Lee, Jongho; O'Hern, Sean; Laoui, Tahar; Karnik, Rohit; Wang, Evelyn N

2017-12-15

The potential of improvements to reverse osmosis (RO) desalination by incorporating porous nanostructured materials such as zeolites into the selective layer in the membrane has spurred substantial research efforts over the past decade. However, because of the lack of methods to probe transport across these materials, it is still unclear which pore size or internal surface chemistry is optimal for maximizing permeability and salt rejection. We developed a platform to measure the transport of water and salt across a single layer of zeolite crystals, elucidating the effects of internal wettability on water and salt transport through the ≈5.5 Å pores of MFI zeolites. MFI zeolites with a more hydrophobic (i.e., less attractive) internal surface chemistry facilitated an approximately order of magnitude increase in water permeability compared to more hydrophilic MFI zeolites, while simultaneously fully rejecting both potassium and chlorine ions. However, our results also demonstrated approximately two orders of magnitude lower permeability compared to molecular simulations. This decreased performance suggests that additional transport resistances (such as surface barriers, pore collapse or blockages due to contamination) may be limiting the performance of experimental nanostructured membranes. Nevertheless, the inclusion of hydrophobic sub-nanometer pores into the active layer of RO membranes should improve both the water permeability and salt rejection of future RO membranes (Fasano et al 2016 Nat. Commun. 7 12762).

Enhanced water transport and salt rejection through hydrophobic zeolite pores

NASA Astrophysics Data System (ADS)

Humplik, Thomas; Lee, Jongho; O'Hern, Sean; Laoui, Tahar; Karnik, Rohit; Wang, Evelyn N.

2017-12-01

The potential of improvements to reverse osmosis (RO) desalination by incorporating porous nanostructured materials such as zeolites into the selective layer in the membrane has spurred substantial research efforts over the past decade. However, because of the lack of methods to probe transport across these materials, it is still unclear which pore size or internal surface chemistry is optimal for maximizing permeability and salt rejection. We developed a platform to measure the transport of water and salt across a single layer of zeolite crystals, elucidating the effects of internal wettability on water and salt transport through the ≈5.5 Å pores of MFI zeolites. MFI zeolites with a more hydrophobic (i.e., less attractive) internal surface chemistry facilitated an approximately order of magnitude increase in water permeability compared to more hydrophilic MFI zeolites, while simultaneously fully rejecting both potassium and chlorine ions. However, our results also demonstrated approximately two orders of magnitude lower permeability compared to molecular simulations. This decreased performance suggests that additional transport resistances (such as surface barriers, pore collapse or blockages due to contamination) may be limiting the performance of experimental nanostructured membranes. Nevertheless, the inclusion of hydrophobic sub-nanometer pores into the active layer of RO membranes should improve both the water permeability and salt rejection of future RO membranes (Fasano et al 2016 Nat. Commun. 7 12762).

A deep insight into the sialotranscriptome of the mosquito, Psorophora albipes

PubMed Central

2013-01-01

Background Psorophora mosquitoes are exclusively found in the Americas and have been associated with transmission of encephalitis and West Nile fever viruses, among other arboviruses. Mosquito salivary glands represent the final route of differentiation and transmission of many parasites. They also secrete molecules with powerful pharmacologic actions that modulate host hemostasis, inflammation, and immune response. Here, we employed next generation sequencing and proteome approaches to investigate for the first time the salivary composition of a mosquito member of the Psorophora genus. We additionally discuss the evolutionary position of this mosquito genus into the Culicidae family by comparing the identity of its secreted salivary compounds to other mosquito salivary proteins identified so far. Results Illumina sequencing resulted in 13,535,229 sequence reads, which were assembled into 3,247 contigs. All families were classified according to their in silico-predicted function/ activity. Annotation of these sequences allowed classification of their products into 83 salivary protein families, twenty (24.39%) of which were confirmed by our subsequent proteome analysis. Two protein families were deorphanized from Aedes and one from Ochlerotatus, while four protein families were described as novel to Psorophora genus because they had no match with any other known mosquito salivary sequence. Several protein families described as exclusive to Culicines were present in Psorophora mosquitoes, while we did not identify any member of the protein families already known as unique to Anophelines. Also, the Psorophora salivary proteins had better identity to homologs in Aedes (69.23%), followed by Ochlerotatus (8.15%), Culex (6.52%), and Anopheles (4.66%), respectively. Conclusions This is the first sialome (from the Greek sialo = saliva) catalog of salivary proteins from a Psorophora mosquito, which may be useful for better understanding the lifecycle of this mosquito and

Survey of the Mosquitoes (Diptera: Culicidae) of Mayotte

PubMed Central

Le Goff, Gilbert; Goodman, Steven M.; Elguero, Eric; Robert, Vincent

2014-01-01

A transversal survey of immature mosquitoes was conducted on Mayotte Island (France) in the Comoros Archipelago, western Indian Ocean, with the aim to inventory the Culicidae and to document inter-species relationships in different habitats. In total 420 habitats were sampled for larvae and/or pupae mosquitoes, resulting in more than 6,000 specimens. Forty species belonging to 15 genera were collected, with eight taxa integrated for the first time to the Mayotte mosquito list. The most frequently recorded species were Stegomyia aegypti, St. albopicta, Anopheles gambiae and Eretmapodites subsimplicipes, the first three species being known vectors of viruses and parasites transmitted to humans. Mean species richness in habitats ranged from 1.00 to 3.29, with notable differences between habitats. For example, water-filled axils of banana leaves, tree-holes and crab-holes had low species richness, while cut bamboo, water pools, abandoned tires and marsh and swamp water had notably higher species richness. Twenty-seven mosquito species belonging to 12 genera were routinely collected (in ≥20% of at least one type of larval habitat) suggesting that multiple species play a role in the biocenosis of these aquatic habitats. Multispecies association was observed in 52% of the habitats. The co-occurrence of up to six species belonging to five genera was recorded in a single habitat. The mosquitoes of Mayotte show notable biogeographical affinities to those of Madagascar, as compared to the African continent. These two potential source areas are nearly equidistant from Mayotte, which in turn indicates biased dispersal from east to west. Our findings suggest that with relatively short-term intensive sampling in different habitats, it is possible to approach exhaustive species inventories based on collection of larvae. Mayotte, with its modest elevation range and land surface, has a notable species richness of mosquitoes with 45 well-documented species belonging to 15 genera

Methionine: a new biopesticide for use in mosquito management

USDA-ARS?s Scientific Manuscript database

Mosquito larvicides are an effective means of source reduction, controlling the population size so that the number of adult females that are present to bite and potentially spread pathogenic organisms is decreased. Currently utilized mosquito larvicides include insect growth regulators, organophosph...

Differential expression of salt-responsive genes to salinity stress in salt-tolerant and salt-sensitive rice (Oryza sativa L.) at seedling stage.

PubMed

Singh, Vijayata; Singh, Ajit Pal; Bhadoria, Jyoti; Giri, Jitender; Singh, Jogendra; T V, Vineeth; Sharma, P C

2018-05-08

The understanding of physio-biochemical and molecular attributes along with morphological traits contributing to the salinity tolerance is important for developing salt-tolerant rice (Oryza sativa L.) varieties. To explore these facts, rice genotypes CSR10 and MI48 with contrasting salt tolerance were characterized under salt stress (control, 75 and 150 mM NaCl) conditions. CSR10 expressed higher rate of physio-biochemical parameters, maintained lower Na/K ratio in shoots, and restricted Na translocation from roots to shoots than MI48. The higher expression of genes related to the osmotic module (DREB2A and LEA3) and ionic module (HKT2;1 and SOS1) in roots of CSR10 suppresses the stress, enhances electrolyte leakage, promotes the higher compatible solute accumulation, and maintains cellular ionic homeostasis leading to better salt stress tolerance than MI48. This study further adds on the importance of these genes in salt tolerance by comparing their behaviour in contrasting rice genotypes and utilizing specific marker to identify salinity-tolerant accessions/donors among germplasm; overexpression of these genes which accelerate the selection procedure precisely has been shown.

EPA Registers the Wolbachia ZAP Strain in Live Male Asian Tiger Mosquitoes

EPA Pesticide Factsheets

EPA registered a new mosquito biopesticide – ZAP Males® - that can reduce local populations of the type of mosquito (Aedes albopictus, or Asian Tiger Mosquitoes) that can spread numerous diseases of significant human health concern, including the Zika viru

Nature, Nurture and Evolution of Intra-Species Variation in Mosquito Arbovirus Transmission Competence

PubMed Central

Tabachnick, Walter J.

2013-01-01

Mosquitoes vary in their competence or ability to transmit arthropod-borne viruses (arboviruses). Many arboviruses cause disease in humans and animals. Identifying the environmental and genetic causes of variation in mosquito competence for arboviruses is one of the great challenges in public health. Progress identifying genetic (nature) and environmental (nurture) factors influencing mosquito competence for arboviruses is reviewed. There is great complexity in the various traits that comprise mosquito competence. The complex interactions between environmental and genetic factors controlling these traits and the factors shaping variation in Nature are largely unknown. The norms of reaction of specific genes influencing competence, their distributions in natural populations and the effects of genetic polymorphism on phenotypic variation need to be determined. Mechanisms influencing competence are not likely due to natural selection because of the direct effects of the arbovirus on mosquito fitness. More likely the traits for mosquito competence for arboviruses are the effects of adaptations for other functions of these competence mechanisms. Determining these other functions is essential to understand the evolution and distributions of competence for arboviruses. This information is needed to assess risk from mosquito-borne disease, predict new mosquito-arbovirus systems, and provide novel strategies to mitigate mosquito-borne arbovirus transmission. PMID:23343982

Nature, nurture and evolution of intra-species variation in mosquito arbovirus transmission competence.

PubMed

Tabachnick, Walter J

2013-01-11

Mosquitoes vary in their competence or ability to transmit arthropod-borne viruses (arboviruses). Many arboviruses cause disease in humans and animals. Identifying the environmental and genetic causes of variation in mosquito competence for arboviruses is one of the great challenges in public health. Progress identifying genetic (nature) and environmental (nurture) factors influencing mosquito competence for arboviruses is reviewed. There is great complexity in the various traits that comprise mosquito competence. The complex interactions between environmental and genetic factors controlling these traits and the factors shaping variation in Nature are largely unknown. The norms of reaction of specific genes influencing competence, their distributions in natural populations and the effects of genetic polymorphism on phenotypic variation need to be determined. Mechanisms influencing competence are not likely due to natural selection because of the direct effects of the arbovirus on mosquito fitness. More likely the traits for mosquito competence for arboviruses are the effects of adaptations for other functions of these competence mechanisms. Determining these other functions is essential to understand the evolution and distributions of competence for arboviruses. This information is needed to assess risk from mosquito-borne disease, predict new mosquito-arbovirus systems, and provide novel strategies to mitigate mosquito-borne arbovirus transmission.

Combining Synthetic Human Odours and Low-Cost Electrocuting Grids to Attract and Kill Outdoor-Biting Mosquitoes: Field and Semi-Field Evaluation of an Improved Mosquito Landing Box

PubMed Central

Matowo, Nancy S.; Koekemoer, Lizette L.; Moore, Sarah J.; Mmbando, Arnold S.; Mapua, Salum A.; Coetzee, Maureen; Okumu, Fredros O.

2016-01-01

Background On-going malaria transmission is increasingly mediated by outdoor-biting vectors, especially where indoor insecticidal interventions such as long-lasting insecticide treated nets (LLINs) are widespread. Often, the vectors are also physiologically resistant to insecticides, presenting major obstacles for elimination. We tested a combination of electrocuting grids with synthetic odours as an alternative killing mechanism against outdoor-biting mosquitoes. Methods An odour-baited device, the Mosquito Landing Box (MLB), was improved by fitting it with low-cost electrocuting grids to instantly kill mosquitoes attracted to the odour lure, and automated photo switch to activate attractant-dispensing and mosquito-killing systems between dusk and dawn. MLBs fitted with one, two or three electrocuting grids were compared outdoors in a malaria endemic village in Tanzania, where vectors had lost susceptibility to pyrethroids. MLBs with three grids were also tested in a large semi-field cage (9.6×9.6×4.5m), to assess effects on biting-densities of laboratory-reared Anopheles arabiensis on volunteers sitting near MLBs. Results Significantly more mosquitoes were killed when MLBs had two or three grids, than one grid in wet and dry seasons (P<0.05). The MLBs were highly efficient against Mansonia species and malaria vector, An. arabiensis. Of all mosquitoes, 99% were non-blood fed, suggesting host-seeking status. In the semi-field, the MLBs reduced mean number of malaria mosquitoes attempting to bite humans fourfold. Conclusion The improved odour-baited MLBs effectively kill outdoor-biting malaria vector mosquitoes that are behaviourally and physiologically resistant to insecticidal interventions e.g. LLINs. The MLBs reduce human-biting vector densities even when used close to humans, and are insecticide-free, hence potentially antiresistance. The devices could either be used as surveillance tools or complementary mosquito control interventions to accelerate malaria

Assessment on the ownership and use of mosquito nets in Mozambique

PubMed Central

Arroz, Jorge Alexandre Harrison; Chirrute, Francisco; Mendis, Chandana; e, Marta Honesta Chande; Kollhoff, Veronique

2016-01-01

ABSTRACT OBJECTIVE To assess the ownership and use of mosquito nets in 2014, in Mozambique. METHODS This observational and cross-sectional study assessed, in February and March 2015, 69 districts (nine of 11 provinces of Mozambique) that have benefited from the mass distribution of mosquito nets. The Lot Quality Assurance Sampling methodology was used. Each locality was denominated supervision area. The Lot Quality Assurance Sampling opts for a minimum of 19 households (in this case, we decided for a minimum of 100 households per district) from each supervision area to assess an indicator (in this case, two indicators were assessed: ownership and use of mosquito nets). Two questions guided the research: a) received a mosquito net; b) used a mosquito net the night before. RESULTS A total of 6,725 households were assessed. Eighty three percent of them had received mosquito nets in the campaign. Of the 6,232 respondents, 82.0% said they used mosquito nets the night before. The districts of the provinces with low coverage of ownership and use were Tete (69.5% and 60.0%, respectively), Zambezia (79.0% and 60.0%, respectively), and Gaza (81.6% and 70.7%, respectively). The largest coverage of ownership and use were observed in the districts of Nampula (96.7% and 93.8%, respectively) and Niassa (86.0% and 85.4% respectively). CONCLUSIONS In the districts assessed, the progression of ownership and use of mosquito nets is satisfactory. Nampula and Niassa are the only provinces where ownership and use are at desired levels. PMID:28099655

A natural agonist of mosquito TRPA1 from the medicinal plant Cinnamosma fragrans that is toxic, antifeedant, and repellent to the yellow fever mosquito Aedes aegypti.

PubMed

Inocente, Edna Alfaro; Shaya, Marguerite; Acosta, Nuris; Rakotondraibe, L Harinantenaina; Piermarini, Peter M

2018-02-01

Plants produce various secondary metabolites that offer a potential source of novel insecticides and repellents for the control of mosquito vectors. Plants of the genus Cinnamosma are endemic to, and widely-distributed throughout, the island of Madagascar. The barks of these species are commonly used in traditional medicines for treating a wide range of maladies. The therapeutic nature of the bark is thought to be associated with its enrichment of pungent drimane sesquiterpenes, which elicit antifeedant and toxic effects in some insects. Here we test the hypothesis that a bark extract of Cinnamosma fragrans (CINEX) and its major drimane sesquiterpenes are insecticidal, antifeedant, and repellent to Aedes aegypti, the principal mosquito vector of chikungunya, dengue, yellow fever, and Zika viruses. We demonstrate that CINEX is 1) toxic to larval and adult female mosquitoes, and 2) antifeedant and repellent to adult female mosquitoes. Moreover, we show that cinnamodial (CDIAL), a sesquiterpene dialdehyde isolated from CINEX, duplicates these bioactivities and exhibits similar toxic potency against pyrethroid-susceptible and -resistant strains of Ae. aegypti. Importantly, we show that CDIAL is an agonist of heterologously-expressed mosquito Transient Receptor Potential A1 (TRPA1) channels, and the antifeedant activity of CDIAL is dampened in a TRPA1-deficient strain of Ae. aegypti (TRPA1-/-). Intriguingly, TRPA1-/- mosquitoes do not exhibit toxic resistance to CDIAL. The data indicate that modulation of TRPA1 is required for the sensory detection and avoidance of CDIAL by mosquitoes, but not for inducing the molecule's toxicity. Our study suggests that CDIAL may serve as a novel chemical platform for the development of natural product-based insecticides and repellents for controlling mosquito vectors.

Culicinae (Diptera: culicidae) mosquitoes in chabahar county, sistan and baluchistan province, southeastern iran.

PubMed

Moosa-Kazemi, Sh; Vatandoost, H; Nikookar, H; Fathian, M

2009-01-01

Mosquito-borne diseases are a major public health threat in Iran. The objective of this study was to determine the fauna of culicinae mosquitoes for future mosquito control programs. THREE GENERA AND ELEVEN SPECIES OF THE SUBFAMILY CULICINAE (DIPTERA: Culicidae) were collected by dipping technique and identified in Chabahar County, Sistan and Baluchistan Province, southeastern Iran, during January, February, and March 2007. THE COLLECTED SPECIES INCLUDED: Aedes vexans (new occurrence record for the province), Culex arbieeni, Cx. bitaeniorhynchus, Cx. deserticola, Cx. hortensis, Cx. perexiguus, Cx. pipiens, Cx. pseudovishnui, Cx. pusillus, Cx. quinquefasciatus, Cx. sinaiticus, Cx. theileri, Cx. tritaeniorhynchus, Culiseta longiareolata, Ochlerotatus caballus, Oc. caspius, and Uranotaenia unguiculata. Our observations indicate that, in South of Iran hot and wet climatic conditions support the persistence of culicinae mosquitoes. As our study, regular monitoring of culicinae mosquitoes in this area could be the most useful for mosquito control and mosquito-borne disease prevention.

Salt Lake City, Utah

NASA Technical Reports Server (NTRS)

2002-01-01

Salt Lake City, Utah, will host the 2002 Winter Olympic Games. The city is located on the southeastern shore of the Great Salt Lake and sits to the west of the Wasatch Mountains, which rise more than 3,500 meters (10,000 feet) above sea level. The city was first settled in 1847 by pioneers seeking relief from religious persecution. Today Salt Lake City, the capital of Utah, is home to more than 170,000 residents. This true-color image of Salt Lake City was acquired by the Enhanced Thematic Mapper Plus (ETM+), flying aboard Landsat 7, on May 26, 2000. The southeastern tip of the Great Salt Lake is visible in the upper left of the image. The furrowed green and brown landscape running north-south is a portion of the Wasatch Mountains, some of which are snow-capped (white pixels). The greyish pixels in the center of the image show the developed areas of the city. A number of water reservoirs can be seen east of the mountain range. Salt Lake City International Airport is visible on the northwestern edge of the city. About 20 miles south of the airport is the Bingham Canyon Copper Mine (tan pixels), the world's largest open pit excavation. See also this MODIS image of Utah. Image courtesy NASA Landsat7 Science Team and USGS Eros Data Center

Multiple Resistances and Complex Mechanisms of Anopheles sinensis Mosquito: A Major Obstacle to Mosquito-Borne Diseases Control and Elimination in China

PubMed Central

Fang, Qiang; Hartsel, Joshua; Zhou, Guofa; Shi, Linna; Fang, Fujin; Zhu, Changliang; Yan, Guiyun

2014-01-01

Malaria, dengue fever, and filariasis are three of the most common mosquito-borne diseases worldwide. Malaria and lymphatic filariasis can occur as concomitant human infections while also sharing common mosquito vectors. The overall prevalence and health significance of malaria and filariasis have made them top priorities for global elimination and control programmes. Pyrethroid resistance in anopheline mosquito vectors represents a highly significant problem to malaria control worldwide. Several methods have been proposed to mitigate insecticide resistance, including rotational use of insecticides with different modes of action. Anopheles sinensis, an important malaria and filariasis vector in Southeast Asia, represents an interesting mosquito species for examining the consequences of long-term insecticide rotation use on resistance. We examined insecticide resistance in two An. Sinensis populations from central and southern China against pyrethroids, organochlorines, organophosphates, and carbamates, which are the major classes of insecticides recommended for indoor residual spray. We found that the mosquito populations were highly resistant to the four classes of insecticides. High frequency of kdr mutation was revealed in the central population, whereas no kdr mutation was detected in the southern population. The frequency of G119S mutation in the ace-1 gene was moderate in both populations. The classification and regression trees (CART) statistical analysis found that metabolic detoxification was the most important resistance mechanism, whereas target site insensitivity of L1014 kdr mutation played a less important role. Our results indicate that metabolic detoxification was the dominant mechanism of resistance compared to target site insensitivity, and suggests that long-term rotational use of various insecticides has led An. sinensis to evolve a high insecticide resistance. This study highlights the complex network of mechanisms conferring multiple

Uncovering the Repertoire of Endogenous Flaviviral Elements in Aedes Mosquito Genomes

PubMed Central

Suzuki, Yasutsugu; Frangeul, Lionel; Dickson, Laura B.; Blanc, Hervé; Verdier, Yann; Vinh, Joelle

2017-01-01

ABSTRACT Endogenous viral elements derived from nonretroviral RNA viruses have been described in various animal genomes. Whether they have a biological function, such as host immune protection against related viruses, is a field of intense study. Here, we investigated the repertoire of endogenous flaviviral elements (EFVEs) in Aedes mosquitoes, the vectors of arboviruses such as dengue and chikungunya viruses. Previous studies identified three EFVEs from Aedes albopictus cell lines and one from Aedes aegypti cell lines. However, an in-depth characterization of EFVEs in wild-type mosquito populations and individual mosquitoes in vivo has not been performed. We detected the full-length DNA sequence of the previously described EFVEs and their respective transcripts in several A. albopictus and A. aegypti populations from geographically distinct areas. However, EFVE-derived proteins were not detected by mass spectrometry. Using deep sequencing, we detected the production of PIWI-interacting RNA-like small RNAs, in an antisense orientation, targeting the EFVEs and their flanking regions in vivo. The EFVEs were integrated in repetitive regions of the mosquito genomes, and their flanking sequences varied among mosquito populations. We bioinformatically predicted several new EFVEs from a Vietnamese A. albopictus population and observed variation in the occurrence of those elements among mosquitoes. Phylogenetic analysis of an A. aegypti EFVE suggested that it integrated prior to the global expansion of the species and subsequently diverged among and within populations. The findings of this study together reveal the substantial structural and nucleotide diversity of flaviviral integrations in Aedes genomes. Unraveling this diversity will help to elucidate the potential biological function of these EFVEs. IMPORTANCE Endogenous viral elements (EVEs) are whole or partial viral sequences integrated in host genomes. Interestingly, some EVEs have important functions for host

Uncovering the Repertoire of Endogenous Flaviviral Elements in Aedes Mosquito Genomes.

PubMed

Suzuki, Yasutsugu; Frangeul, Lionel; Dickson, Laura B; Blanc, Hervé; Verdier, Yann; Vinh, Joelle; Lambrechts, Louis; Saleh, Maria-Carla

2017-08-01

Endogenous viral elements derived from nonretroviral RNA viruses have been described in various animal genomes. Whether they have a biological function, such as host immune protection against related viruses, is a field of intense study. Here, we investigated the repertoire of endogenous flaviviral elements (EFVEs) in Aedes mosquitoes, the vectors of arboviruses such as dengue and chikungunya viruses. Previous studies identified three EFVEs from Aedes albopictus cell lines and one from Aedes aegypti cell lines. However, an in-depth characterization of EFVEs in wild-type mosquito populations and individual mosquitoes in vivo has not been performed. We detected the full-length DNA sequence of the previously described EFVEs and their respective transcripts in several A. albopictus and A. aegypti populations from geographically distinct areas. However, EFVE-derived proteins were not detected by mass spectrometry. Using deep sequencing, we detected the production of PIWI-interacting RNA-like small RNAs, in an antisense orientation, targeting the EFVEs and their flanking regions in vivo The EFVEs were integrated in repetitive regions of the mosquito genomes, and their flanking sequences varied among mosquito populations. We bioinformatically predicted several new EFVEs from a Vietnamese A. albopictus population and observed variation in the occurrence of those elements among mosquitoes. Phylogenetic analysis of an A. aegypti EFVE suggested that it integrated prior to the global expansion of the species and subsequently diverged among and within populations. The findings of this study together reveal the substantial structural and nucleotide diversity of flaviviral integrations in Aedes genomes. Unraveling this diversity will help to elucidate the potential biological function of these EFVEs. IMPORTANCE Endogenous viral elements (EVEs) are whole or partial viral sequences integrated in host genomes. Interestingly, some EVEs have important functions for host fitness and

Vector Competence of New Zealand Mosquitoes for Selected Arboviruses

PubMed Central

Kramer, Laura D.; Chin, Pam; Cane, Rachel P.; Kauffman, Elizabeth B.; Mackereth, Graham

2011-01-01

New Zealand (NZ) historically has been free of arboviral activity with the exception of Whataroa virus (Togaviridae: Alphavirus), which is established in bird populations and is transmitted by local mosquitoes. This naive situation is threatened by global warming, invasive mosquitoes, and tourism. To determine the threat of selected medically important arboviruses to NZ, vector competence assays were conducted using field collected endemic and introduced mosquito species. Four alphaviruses (Togaviridae): Barmah Forest virus, Chikungunya virus, Ross River virus, and Sindbis virus, and five flaviviruses (Flaviviridae): Dengue virus 2, Japanese encephalitis virus, Murray Valley encephalitis virus, West Nile virus, and Yellow fever virus were evaluated. Results indicate some NZ mosquito species are highly competent vectors of selected arboviruses, particularly alphaviruses, and may pose a threat were one of these arboviruses introduced at a time when the vector was prevalent and the climatic conditions favorable for virus transmission. PMID:21734146

Reconsolidated Salt as a Geotechnical Barrier

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

Hansen, Francis D.; Gadbury, Casey

Salt as a geologic medium has several attributes favorable to long-term isolation of waste placed in mined openings. Salt formations are largely impermeable and induced fractures heal as stress returns to equilibrium. Permanent isolation also depends upon the ability to construct geotechnical barriers that achieve nearly the same high-performance characteristics attributed to the native salt formation. Salt repository seal concepts often include elements of reconstituted granular salt. As a specific case in point, the Waste Isolation Pilot Plant recently received regulatory approval to change the disposal panel closure design from an engineered barrier constructed of a salt-based concrete to onemore » that employs simple run-of-mine salt and temporary bulkheads for isolation from ventilation. The Waste Isolation Pilot Plant is a radioactive waste disposal repository for defense-related transuranic elements mined from the Permian evaporite salt beds in southeast New Mexico. Its approved shaft seal design incorporates barrier components comprising salt-based concrete, bentonite, and substantial depths of crushed salt compacted to enhance reconsolidation. This paper will focus on crushed salt behavior when applied as drift closures to isolate disposal rooms during operations. Scientific aspects of salt reconsolidation have been studied extensively. The technical basis for geotechnical barrier performance has been strengthened by recent experimental findings and analogue comparisons. The panel closure change was accompanied by recognition that granular salt will return to a physical state similar to the halite surrounding it. Use of run-of-mine salt ensures physical and chemical compatibility with the repository environment and simplifies ongoing disposal operations. Our current knowledge and expected outcome of research can be assimilated with lessons learned to put forward designs and operational concepts for the next generation of salt repositories. Mined salt

Quantitative analysis of harmonic convergence in mosquito auditory interactions

PubMed Central

Aldersley, Andrew; Champneys, Alan; Robert, Daniel

2016-01-01

This article analyses the hearing and behaviour of mosquitoes in the context of inter-individual acoustic interactions. The acoustic interactions of tethered live pairs of Aedes aegypti mosquitoes, from same and opposite sex mosquitoes of the species, are recorded on independent and unique audio channels, together with the response of tethered individual mosquitoes to playbacks of pre-recorded flight tones of lone or paired individuals. A time-dependent representation of each mosquito's non-stationary wing beat frequency signature is constructed, based on Hilbert spectral analysis. A range of algorithmic tools is developed to automatically analyse these data, and used to perform a robust quantitative identification of the ‘harmonic convergence’ phenomenon. The results suggest that harmonic convergence is an active phenomenon, which does not occur by chance. It occurs for live pairs, as well as for lone individuals responding to playback recordings, whether from the same or opposite sex. Male–female behaviour is dominated by frequency convergence at a wider range of harmonic combinations than previously reported, and requires participation from both partners in the duet. New evidence is found to show that male–male interactions are more varied than strict frequency avoidance. Rather, they can be divided into two groups: convergent pairs, typified by tightly bound wing beat frequencies, and divergent pairs, that remain widely spaced in the frequency domain. Overall, the results reveal that mosquito acoustic interaction is a delicate and intricate time-dependent active process that involves both individuals, takes place at many different frequencies, and which merits further enquiry. PMID:27053654

Physiological Mechanism of Enhancing Salt Stress Tolerance of Perennial Ryegrass by 24-Epibrassinolide

PubMed Central

Wu, Wenli; Zhang, Qiang; Ervin, Erik. H.; Yang, Zhiping; Zhang, Xunzhong

2017-01-01

Brassinosteroids (BR) regulate plant tolerance to salt stress but the mechanisms underlying are not fully understood. This study was to investigate physiological mechanisms of 24-epibrassinolide (EBR)'s impact on salt stress tolerance in perennial ryegrass (Lolium perenne L.) The grass seedlings were treated with EBR at 0, 10, and 100 nM, and subjected to salt stress (250 mM NaCl). The grass irrigated with regular water without EBR served as the control. Salt stress increased leaf electrolyte leakage (EL), malondialdehyde (MDA), and reduced photosynthetic rate (Pn). Exogenous EBR reduced EL and MDA, increased Pn, chlorophyll content, and stomatal conductance (gs). The EBR applications also alleviated decline of superoxide dismutase (SOD) and catalase (CAT) and ascorbate peroxidase (APX) activity when compared to salt treatment alone. Salt stress increased leaf abscisic acid (ABA) and gibberellin A4 (GA4) content but reduced indole-3-acetic acid (IAA), zeatin riboside (ZR), isopentenyl adenosine (iPA), and salicylic acid (SA). Exogenous EBR at 10 nm and 100 nM increased ABA, and iPA content under salt stress. The EBR treatment at 100 nM also increased leaf IAA, ZR, JA, and SA. In addition, EBR treatments increased leaf proline and ions (K+, Mg2+, and Ca2+) content, and reduced Na+/K+ in leaf tissues. The results of this study suggest that EBR treatment may improve salt stress tolerance by increasing the level of selected hormones and antioxidant enzyme (SOD and CAT) activity, promoting accumulation of proline and ions (K+, Ca2+, and Mg2+) in perennial ryegrass. PMID:28674542

Broad Surveys of DNA Viral Diversity Obtained through Viral Metagenomics of Mosquitoes

PubMed Central

Ng, Terry Fei Fan; Willner, Dana L.; Lim, Yan Wei; Schmieder, Robert; Chau, Betty; Nilsson, Christina; Anthony, Simon; Ruan, Yijun; Rohwer, Forest; Breitbart, Mya

2011-01-01

Viruses are the most abundant and diverse genetic entities on Earth; however, broad surveys of viral diversity are hindered by the lack of a universal assay for viruses and the inability to sample a sufficient number of individual hosts. This study utilized vector-enabled metagenomics (VEM) to provide a snapshot of the diversity of DNA viruses present in three mosquito samples from San Diego, California. The majority of the sequences were novel, suggesting that the viral community in mosquitoes, as well as the animal and plant hosts they feed on, is highly diverse and largely uncharacterized. Each mosquito sample contained a distinct viral community. The mosquito viromes contained sequences related to a broad range of animal, plant, insect and bacterial viruses. Animal viruses identified included anelloviruses, circoviruses, herpesviruses, poxviruses, and papillomaviruses, which mosquitoes may have obtained from vertebrate hosts during blood feeding. Notably, sequences related to human papillomaviruses were identified in one of the mosquito samples. Sequences similar to plant viruses were identified in all mosquito viromes, which were potentially acquired through feeding on plant nectar. Numerous bacteriophages and insect viruses were also detected, including a novel densovirus likely infecting Culex erythrothorax. Through sampling insect vectors, VEM enables broad survey of viral diversity and has significantly increased our knowledge of the DNA viruses present in mosquitoes. PMID:21674005

Enhanced bioreduction synthesis of ethyl (R)-4-chloro-3-hydroybutanoate by alkalic salt pretreatment.

PubMed

Chong, Ganggang; Di, Junhua; Ma, Cuiluan; Wang, Dajing; Wang, Chu; Wang, Lingling; Zhang, Pengqi; Zhu, Jun; He, Yucai

2018-08-01

In this study, biomass-hydrolysate was used for enhancing the bioreduction of ethyl 4-chloro-3-oxobutanoate (COBE). Firstly, dilute alkalic salt pretreatment was attempted to pretreat bamboo shoot shell (BSS). It was found that enzymatic in situ hydrolysis of 20-50 g/L BSS pretreated with dilute alkalic salts (0.4% Na 2 CO 3 , 0.032% Na 2 S) at 7.5% sulfidity by autoclaving at 110 °C for 40 min gave sugar yields at 59.9%-73.5%. Moreover, linear relationships were corrected on solid recovery-total delignification-sugar yield. In BSS-hydrolysates, xylose and glucose could promote the reductase activity of recombinant E. coli CCZU-A13. Compared with glucose, hydrolysate could increase the reductase activity by 1.35-folds. Furthermore, the cyclohexane-hydrolysate (10:90, v/v) biphasic media containing ethylene diamine tetraacetic acid (EDTA, 40 mM) and l-glutamine (150 mM) was built for the effective biosynthesis of ethyl (R)-4-chloro-3-hydroxybutanoate [(R)-CHBE] (94.6% yield) from 500 mM COBE. In conclusion, this strategy has high potential for the effective biosynthesis of (R)-CHBE (>99% e.e.). Copyright © 2018 Elsevier Ltd. All rights reserved.

Test of a mosquito eggshell isolation method and subsampling procedure.

PubMed

Turner, P A; Streever, W J

1997-03-01

Production of Aedes vigilax, the common salt-marsh mosquito, can be assessed by determining eggshell densities found in soil. In this study, 14 field-collected eggshell samples were used to test a subsampling technique and compare eggshell counts obtained with a flotation method to those obtained by direct examination of sediment (DES). Relative precision of the subsampling technique was assessed by determining the minimum number of subsamples required to estimate the true mean and confidence interval of a sample at a predetermined confidence level. A regression line was fitted to cube-root transformed eggshell counts obtained from flotation and DES and found to be significant (P < 0.001, r2 = 0.97). The flotation method allowed processing of samples in about one-third of the time required by DES, but recovered an average of 44% of the eggshells present. Eggshells obtained with the flotation method can be used to predict those from DES using the following equation: DES count = [1.386 x (flotation count)0.33 - 0.01]3.

Willingness to Pay for Mosquito Control in Key West, Florida and Tucson, Arizona.

PubMed

Dickinson, Katherine L; Hayden, Mary H; Haenchen, Steven; Monaghan, Andrew J; Walker, Kathleen R; Ernst, Kacey C

2016-04-01

Mosquito-borne illnesses like West Nile virus (WNV) and dengue are growing threats to the United States. Proactive mosquito control is one strategy to reduce the risk of disease transmission. In 2012, we measured the public's willingness to pay (WTP) for increased mosquito control in two cities: Key West, FL, where there have been recent dengue outbreaks, and Tucson, AZ, where dengue vectors are established and WNV has been circulating for over a decade. Nearly three quarters of respondents in both cities (74% in Tucson and 73% in Key West) would be willing to pay $25 or more annually toward an increase in publicly funded mosquito control efforts. WTP was positively associated with income (both cities), education (Key West), and perceived mosquito abundance (Tucson). Concerns about environmental impacts of mosquito control were associated with lower WTP in Key West. Expanded mosquito control efforts should incorporate public opinion as they respond to evolving disease risks. © The American Society of Tropical Medicine and Hygiene.

Culicinae (Diptera: Culicidae) Mosquitoes in Chabahar County, Sistan and Baluchistan Province, Southeastern Iran

PubMed Central

Moosa-Kazemi, SH; Vatandoost, H; Nikookar, H; Fathian, M

2009-01-01

Background Mosquito-borne diseases are a major public health threat in Iran. The objective of this study was to determine the fauna of culicinae mosquitoes for future mosquito control programs. Methods: Three genera and eleven species of the subfamily Culicinae (Diptera: Culicidae) were collected by dipping technique and identified in Chabahar County, Sistan and Baluchistan Province, southeastern Iran, during January, February, and March 2007. Results: The collected species included: Aedes vexans (new occurrence record for the province), Culex arbieeni, Cx. bitaeniorhynchus, Cx. deserticola, Cx. hortensis, Cx. perexiguus, Cx. pipiens, Cx. pseudovishnui, Cx. pusillus, Cx. quinquefasciatus, Cx. sinaiticus, Cx. theileri, Cx. tritaeniorhynchus, Culiseta longiareolata, Ochlerotatus caballus, Oc. caspius, and Uranotaenia unguiculata. Conclusion: Our observations indicate that, in South of Iran hot and wet climatic conditions support the persistence of culicinae mosquitoes. As our study, regular monitoring of culicinae mosquitoes in this area could be the most useful for mosquito control and mosquito-borne disease prevention. PMID:22808369

Competence of Aedes aegypti, Ae. albopictus, and Culex quinquefasciatus Mosquitoes as Zika Virus Vectors, China.

PubMed

Liu, Zhuanzhuan; Zhou, Tengfei; Lai, Zetian; Zhang, Zhenhong; Jia, Zhirong; Zhou, Guofa; Williams, Tricia; Xu, Jiabao; Gu, Jinbao; Zhou, Xiaohong; Lin, Lifeng; Yan, Guiyun; Chen, Xiao-Guang

2017-07-01

In China, the prevention and control of Zika virus disease has been a public health threat since the first imported case was reported in February 2016. To determine the vector competence of potential vector mosquito species, we experimentally infected Aedes aegypti, Ae. albopictus, and Culex quinquefasciatus mosquitoes and determined infection rates, dissemination rates, and transmission rates. We found the highest vector competence for the imported Zika virus in Ae. aegypti mosquitoes, some susceptibility of Ae. albopictus mosquitoes, but no transmission ability for Cx. quinquefasciatus mosquitoes. Considering that, in China, Ae. albopictus mosquitoes are widely distributed but Ae. aegypti mosquito distribution is limited, Ae. albopictus mosquitoes are a potential primary vector for Zika virus and should be targeted in vector control strategies.

Competence of Aedes aegypti, Ae. albopictus, and Culex quinquefasciatus Mosquitoes as Zika Virus Vectors, China

PubMed Central

Liu, Zhuanzhuan; Zhou, Tengfei; Lai, Zetian; Zhang, Zhenhong; Jia, Zhirong; Zhou, Guofa; Williams, Tricia; Xu, Jiabao; Gu, Jinbao; Zhou, Xiaohong; Lin, Lifeng; Yan, Guiyun

2017-01-01

In China, the prevention and control of Zika virus disease has been a public health threat since the first imported case was reported in February 2016. To determine the vector competence of potential vector mosquito species, we experimentally infected Aedes aegypti, Ae. albopictus, and Culex quinquefasciatus mosquitoes and determined infection rates, dissemination rates, and transmission rates. We found the highest vector competence for the imported Zika virus in Ae. aegypti mosquitoes, some susceptibility of Ae. albopictus mosquitoes, but no transmission ability for Cx. quinquefasciatus mosquitoes. Considering that, in China, Ae. albopictus mosquitoes are widely distributed but Ae. aegypti mosquito distribution is limited, Ae. albopictus mosquitoes are a potential primary vector for Zika virus and should be targeted in vector control strategies. PMID:28430562

Spin-injection optical pumping of molten cesium salt and its NMR diagnosis

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

Ishikawa, Kiyoshi

2015-07-15

Nuclear spin polarization of cesium ions in the salt was enhanced during optical pumping of cesium vapor at high magnetic field. Significant motional narrowing and frequency shift of NMR signals were observed by intense laser heating of the salt. When the hyperpolarized salt was cooled by blocking the heating laser, the signal width and frequency changed during cooling and presented the phase transition from liquid to solid. Hence, we find that the signal enhancement is mostly due to the molten salt and nuclear spin polarization is injected into the salt efficiently in the liquid phase. We also show that opticalmore » pumping similarly induces line narrowing in the solid phase. The use of powdered salt provided an increase in effective surface area and signal amplitude without glass wool in the glass cells.« less

Salt and nitric oxide synthase inhibition-induced hypertension: kidney dysfunction and brain anti-oxidant capacity.

PubMed

Oktar, Süleyman; Ilhan, Selçuk; Meydan, Sedat; Aydin, Mehmet; Yönden, Zafer; Gökçe, Ahmet

2010-01-01

The specific aim of this study was to examine the effects of salt-loading on kidney function and brain antioxidant capacity. Wistar rats were divided into four groups: Control rats were given normal drinking water and no drug treatment for 2 weeks. LNNA group: rats were given normal drinking water and the nitric oxide (NO) inhibitor NG-nitro-L-arginine (L-NNA), 3 mg/kg/day. LNNA + Salt group: rats were given drinking water containing salt 2% and 3 mg/kg L-NNA. Salt group: rats were given drinking water containing salt 2% and no drug treatment. Basal blood pressure and the levels of serum BUN, creatinine, uric acid, cortisol, electrolyte, serum antioxidant capacity, and oxidative stress were measured. NO, superoxide dismutase (SOD), and catalase (CAT) levels were measured in the hypothalamus, brainstem, and cerebellum. Salt overload increased the blood pressure of the LNNA + Salt group. Salt-loading enhanced BUN, creatinine, sodium retention. High salt produced an increase in uric acid levels and a decrease in cortisol levels in serum. Additionally, the oxidative stress index in serum increased in the LNNA + Salt group. Salt-loading enhanced brain NO levels, but not SOD and CAT activity. L-NNA increased brain SOD activity, but not CAT and NO levels. In conclusion, salt-loading causes hypertension, kidney dysfunction, and enhances oxidative stress in salt-sensitive rats.

GLOBE Observer Mosquito Habitat Mapper: Geoscience and Public Health Connections

NASA Astrophysics Data System (ADS)

Low, R.; Boger, R. A.

2017-12-01

The global health crisis posed by vector-borne diseases is so great in scope that it is clearly insurmountable without the active help of tens-or hundreds- of thousands of individuals, working to identify and eradicate risk in communities around the world. Mobile devices equipped with data collection capabilities and visualization opportunities are lowering the barrier for participation in data collection efforts. The GLOBE Observer Mosquito Habitat Mapper (MHM) provides citizen scientists with an easy to use mobile platform to identify and locate mosquito breeding sites in their community. The app also supports the identification of vector taxa in the larvae development phase via a built-in key, which provides important information for scientists and public health officials tracking the rate of range expansion of invasive vector species and associated health threats. GO Mosquito is actively working with other citizen scientist programs across the world to ensure interoperability of data through standardization of metadata fields specific to vector monitoring, and through the development of APIs that allow for data exchange and shared data display through a UN-sponsored proof of concept project, Global Mosquito Alert. Avenues of application for mosquito vector data-both directly, by public health entities, and by modelers who employ remotely sensed environmental data to project mosquito population dynamics and epidemic disease will be featured.

Plasmodium vivax Sporozoite Production in Anopheles albimanus Mosquitoes for Vaccine Clinical Trials

PubMed Central

Solarte, Yezid; Manzano, María R.; Rocha, Leonardo; Hurtado, Hugo; James, Mark A.; Arévalo-Herrera, Myriam; Herrera, Sócrates

2011-01-01

Vaccine development for Plasmodium vivax malaria is underway. A model to assess the protective efficacy of vaccine candidates in humans is urgently needed. Given the lack of continuous P. vivax cultures, we developed a system to infect Anopheles albimanus mosquitoes using blood from P. vivax-infected patients and determined parameters for challenge of malaria-naive volunteers by mosquito bite. Absence of co-infections in parasitized blood was confirmed by tests consistent with blood bank screening. A total of 119 experiments were conducted using batches of 900–4,500 mosquitoes fed by an artificial membrane feeding method. Optimal conditions for mosquito probing and infection were determined. Presence of oocyst and sporozoites were assessed on Days 7–8 and 14–15, respectively, and conditions to choose batches of infected mosquitoes for sporozoite challenge were established. Procedures to infect volunteers took a 2-hour period including verification of inoculum dose. Anopheles albimanus mosquitoes represent a valuable resource for P. vivax sporozoite challenge of volunteers. PMID:21292875

Converting Mosquito Surveillance to Arbovirus Surveillance with Honey-Baited Nucleic Acid Preservation Cards.

PubMed

Flies, Emily J; Toi, Cheryl; Weinstein, Philip; Doggett, Stephen L; Williams, Craig R

2015-07-01

Spatially and temporally accurate information about infectious mosquito distribution allows for pre-emptive public health interventions that can reduce the burden of mosquito-borne infections on human populations. However, the labile nature of arboviruses, the low prevalence of infection in mosquitoes, the expensive labor costs for mosquito identification and sorting, and the specialized equipment required for arbovirus testing can obstruct arbovirus surveillance efforts. The recently developed techniques of testing mosquito expectorate using honey-baited nucleic acid preservation cards or sugar bait stations allows a sensitive method of testing for infectious, rather than infected, mosquito vectors. Here we report the results from the first large-scale incorporation of honey-baited cards into an existing mosquito surveillance program. During 4 months of the peak virus season (January-April, 2014) for a total of 577 trap nights, we set CO2-baited encephalitis vector survey (EVS) light traps at 88 locations in South Australia. The collection container for the EVS trap was modified to allow for the placement of a honey-baited nucleic acid preservation card (FTA™ card) inside. After collection, mosquitoes were maintained in a humid environment and allowed access to the cards for 1 week. Cards were then analyzed for common endemic Australian arboviruses using a nested RT-PCR. Eighteen virus detections, including 11 Ross River virus, four Barmah Forest virus, and three Stratford virus (not previously reported from South Australia) were obtained. Our findings suggest that adding FTA cards to an existing mosquito surveillance program is a rapid and efficient way of detecting infectious mosquitoes with high spatial resolution.

Resistance Level of Mosquito Species (Diptera: Culicidae) from Shandong Province, China.

PubMed

Liu, Hong-Mei; Yang, Pei-Pei; Cheng, Peng; Wang, Hai-Fang; Liu, Li-Juan; Huang, Xiaodan; Zhao, Yu-Qiang; Wang, Huai-Wei; Zhang, Chong-Xing; Gong, Mao-Qing

2015-01-01

This study describes the aquatic habitats, species composition, and the insecticide resistance level of the mosquito Culex pipiens pallens in Shandong Province, China. A cross-sectional survey of mosquito larval habitats was conducted from May to November 2014 to determine the species composition and larval abundance. Larvae were collected using the standard dipping technique, and a total of four habitat types were sampled. The fourth instar larvae of Cx. pipiens pallens collected in each habitat type were tested for resistance to five insecticides according to a WHO bioassay. A total of 7,281 mosquito larvae were collected, of which 399 (5.48%) were categorized as Anopheles mosquito larvae (An. sinensis), 6636 (91.14%) as culicine larvae (Cx. pipiens pallens, Cx. tritaeniorhynchus, Cx. halifaxii, and Cx. bitaeniorhynchus), 213 (2.93%) as Armigeres larvae, and 33 (0.45%) as Aedes larvae (Aedes albopictus). In addition, a total of 1,149 mosquito pupae were collected. Culex larvae were distributed in all habitats investigated. Tukeys HSD analysis showed that roadside drainages were the most productive habitat type for Culex larvae. Armigeres species were found only in drains, Aedes only in water tanks, and Anopheles in water that was comparatively clear and rich in emergent plants. Bioassay showed that the maximum resistance level of Cx. pipiens pallens was to deltamethrin, while it was lowest to plifenate. The productivity of various mosquitoes in different habitat types is very heterogeneous. It is particularly important to modify human activity and the environment to achieve effective mosquito vector control. For effective larval control, the type of habitat should be considered, and the most productive habitat type should be given priority in mosquito abatement programs.

Satellite Microwave Remote Sensing for Environmental Modeling of Mosquito Population Dynamics

PubMed Central

Chuang, Ting-Wu; Henebry, Geoffrey M.; Kimball, John S.; VanRoekel-Patton, Denise L.; Hildreth, Michael B.; Wimberly, Michael C.

2012-01-01

Environmental variability has important influences on mosquito life cycles and understanding the spatial and temporal patterns of mosquito populations is critical for mosquito control and vector-borne disease prevention. Meteorological data used for model-based predictions of mosquito abundance and life cycle dynamics are typically acquired from ground-based weather stations; however, data availability and completeness are often limited by sparse networks and resource availability. In contrast, environmental measurements from satellite remote sensing are more spatially continuous and can be retrieved automatically. This study compared environmental measurements from the NASA Advanced Microwave Scanning Radiometer on EOS (AMSR-E) and in situ weather station data to examine their ability to predict the abundance of two important mosquito species (Aedes vexans and Culex tarsalis) in Sioux Falls, South Dakota, USA from 2005 to 2010. The AMSR-E land parameters included daily surface water inundation fraction, surface air temperature, soil moisture, and microwave vegetation opacity. The AMSR-E derived models had better fits and higher forecasting accuracy than models based on weather station data despite the relatively coarse (25-km) spatial resolution of the satellite data. In the AMSR-E models, air temperature and surface water fraction were the best predictors of Aedes vexans, whereas air temperature and vegetation opacity were the best predictors of Cx. tarsalis abundance. The models were used to extrapolate spatial, seasonal, and interannual patterns of climatic suitability for mosquitoes across eastern South Dakota. Our findings demonstrate that environmental metrics derived from satellite passive microwave radiometry are suitable for predicting mosquito population dynamics and can potentially improve the effectiveness of mosquito-borne disease early warning systems. PMID:23049143

Replacement of salt by a novel potassium- and magnesium-enriched salt alternative improves the cardiovascular effects of ramipril.

PubMed Central

Mervaala, E. M.; Paakkari, I.; Laakso, J.; Nevala, R.; Teräväinen, T. M.; Fyhrquist, F.; Vapaatalo, H.; Karppanen, H.

1994-01-01

1. The influence of salt (sodium chloride; NaCl) (an additional 6% in the diet) and that of a novel sodium-reduced, potassium-, magnesium-, and L-lysine-enriched salt alternative on the cardiovascular effects of ramipril was studied in stroke-prone spontaneously hypertensive rats in a 6-week study. The intake of sodium chloride was adjusted to the same level by adding the salt alternative at a 1.75 times higher amount than regular salt. 2. Salt produced a marked rise in blood pressure and induced cardiac hypertrophy and significant mortality, while the salt alternative neither increased blood pressure nor caused any mortality and produced less cardiac hypertrophy than salt. 3. Ramipril treatment at a daily dose of 3 mg kg-1 normalized blood pressure and prevented the development of cardiac hypertrophy of rats on control diet. These effects of ramipril were blocked by the addition of salt but were only slightly attenuated by the addition of the salt alternative. The mortality in the salt group was prevented by ramipril. 4. Responses of mesenteric arterial rings in vitro were examined at the end of the study. Salt, but not the salt alternative, increased vascular contractile responses to noradrenaline. Ramipril treatment improved the arterial relaxation responses to acetylcholine and to sodium nitroprusside. The vascular relaxation enhancing effect of ramipril was blocked by salt but only slightly attenuated by the salt alternative. 5. Ramipril treatment did not significantly increase plasma renin activity in the presence or in the absence of salt supplementation. The salt alternative did not cause hyperkalaemia, either alone or in combination with ramipril treatment.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8032605

West Nile virus in Tunisia, 2014: First isolation from mosquitoes.

PubMed

Wasfi, F; Dachraoui, K; Cherni, S; Bosworth, A; Barhoumi, W; Dowall, S; Chelbi, I; Derbali, M; Zoghlami, Z; Beier, J C; Zhioua, E

2016-07-01

Several outbreaks of human West Nile virus (WNV) infections were reported in Tunisia during the last two decades. Serological studies on humans as well as on equine showed intensive circulation of WNV in Tunisia. However, no virus screening of mosquitoes for WNV has been performed in Tunisia. In the present study, we collected mosquito samples from Central Tunisia to be examined for the presence of flaviviruses. A total of 102 Culex pipiens mosquitoes were collected in September 2014 from Central Tunisia. Mosquitoes were pooled according to the collection site, date and sex with a maximum of 5 specimens per pool and tested for the presence of flaviviruses by conventional reverse transcription heminested PCR and by a specific West Nile virus real time reverse transcription PCR. Of a total of 21 pools tested, 7 were positive for WNV and no other flavivirus could be evidenced in mosquito pools. In addition, WNV was isolated on Vero cells. Phylogenetic analysis showed that recent Tunisian WNV strains belong to lineage 1 WNV and are closely related to the Tunisian strain 1997 (PAH 001). This is the first detection and isolation of WNV from mosquitoes in Tunisia. Some areas of Tunisia are at high risk for human WNV infections. WNV is likely to cause future sporadic and foreseeable outbreaks. Therefore, it is of major epidemiological importance to set up an entomological surveillance as an early alert system. Timely detection of WNV should prompt vector control to prevent future outbreaks. In addition, education of people to protect themselves from mosquito bites is of major epidemiological importance as preventive measure against WNV infection. Copyright © 2016 Elsevier B.V. All rights reserved.

Identification of Wolbachia Strains in Mosquito Disease Vectors

PubMed Central

Osei-Poku, Jewelna; Han, Calvin; Mbogo, Charles M.; Jiggins, Francis M.

2012-01-01

Wolbachia bacteria are common endosymbionts of insects, and some strains are known to protect their hosts against RNA viruses and other parasites. This has led to the suggestion that releasing Wolbachia-infected mosquitoes could prevent the transmission of arboviruses and other human parasites. We have identified Wolbachia in Kenyan populations of the yellow fever vector Aedes bromeliae and its relative Aedes metallicus, and in Mansonia uniformis and Mansonia africana, which are vectors of lymphatic filariasis. These Wolbachia strains cluster together on the bacterial phylogeny, and belong to bacterial clades that have recombined with other unrelated strains. These new Wolbachia strains may be affecting disease transmission rates of infected mosquito species, and could be transferred into other mosquito vectors as part of control programs. PMID:23185484

New and improved mosquito repellents based on structural similarity

USDA-ARS?s Scientific Manuscript database

N,N-diethyl-3-methylbenzamide (DEET) is the most effective and best studied mosquito repellent currently on the market in the U.S.; however, this repellent is not a highly efficacious, repellent of long duration that prevents bites from all medically important mosquito species, especially those that...

A highly stable blood meal alternative for rearing Aedes and Anopheles mosquitoes.

PubMed

Baughman, Ted; Peterson, Chelsea; Ortega, Corrie; Preston, Sarah R; Paton, Christopher; Williams, Jessica; Guy, Amy; Omodei, Gavin; Johnson, Brian; Williams, Helen; O'Neill, Scott L; Ritchie, Scott A; Dobson, Stephen L; Madan, Damian

2017-12-01

We investigated alternatives to whole blood for blood feeding of mosquitoes with a focus on improved stability and compatibility with mass rearing programs. In contrast to whole blood, an artificial blood diet of ATP-supplemented plasma was effective in maintaining mosquito populations and was compatible with storage for extended periods refrigerated, frozen, and as a lyophilized powder. The plasma ATP diet supported rearing of both Anopheles and Aedes mosquitoes. It was also effective in rearing Wolbachia-infected Aedes mosquitoes, suggesting compatibility with vector control efforts.

Evaluation of textile substrates for dispensing synthetic attractants for malaria mosquitoes.

PubMed

Mweresa, Collins K; Mukabana, Wolfgang R; Omusula, Philemon; Otieno, Bruno; Gheysens, Tom; Takken, Willem; van Loon, Joop J A

2014-08-16

The full-scale impact of odour-baited technology on the surveillance, sampling and control of vectors of infectious diseases is partly limited by the lack of methods for the efficient and sustainable dispensing of attractants. In this study we investigated whether locally-available and commonly used textiles are efficient substrates for the release of synthetic odorant blends attracting malaria mosquitoes. The relative efficacy of (a) polyester, (b) cotton, (c) cellulose + polyacrylate, and (d) nylon textiles as substrates for dispensing a synthetic odour blend (Ifakara blend 1(IB1)) that attracts malaria mosquitoes was evaluated in western Kenya. The study was conducted through completely randomized Latin square experimental designs under semi-field and field conditions. Traps charged with IB1-impregnated polyester, cotton and cellulose + polyacrylate materials caught significantly more female Anopheles gambiae sensu stricto (semi-field conditions) and An. gambiae sensu lato (field conditions) mosquitoes than IB1-treated nylon (P = 0.001). The IB1-impregnated cellulose + polyacrylate material was the most attractive to female An. funestus mosquitoes compared to all other dispensing textile substrates (P < 0.001). The responses of female An. funestus mosquitoes to IB1-treated cotton and polyester were equal (P = 0.45). Significantly more female Culex mosquitoes were attracted to IB1-treated cotton than to the other treatments (P < 0.001). Whereas IB1-impregnated cotton and cellulose + polyacrylate material attracted equal numbers of female Mansonia mosquitoes (P = 0.44), the catches due to these two substrates were significantly higher than those associated with the other substrates (P < 0.001). The number and species of mosquitoes attracted to a synthetic odour blend is influenced by the type of odour-dispensing material used. Thus, surveillance and intervention programmes for malaria and other mosquito vectors using

Salt-induced epithelial-to-mesenchymal transition in Dahl salt-sensitive rats is dependent on elevated blood pressure.

PubMed

Wang, Y; Mu, J J; Liu, F Q; Ren, K Y; Xiao, H Y; Yang, Z; Yuan, Z Y

2014-02-01

Dietary salt intake has been linked to hypertension and cardiovascular disease. Accumulating evidence has indicated that salt-sensitive individuals on high salt intake are more likely to develop renal fibrosis. Epithelial-to-mesenchymal transition (EMT) participates in the development and progression of renal fibrosis in humans and animals. The objective of this study was to investigate the impact of a high-salt diet on EMT in Dahl salt-sensitive (SS) rats. Twenty-four male SS and consomic SS-13(BN) rats were randomized to a normal diet or a high-salt diet. After 4 weeks, systolic blood pressure (SBP) and albuminuria were analyzed, and renal fibrosis was histopathologically evaluated. Tubular EMT was evaluated using immunohistochemistry and real-time PCR with E-cadherin and alpha smooth muscle actin (α-SMA). After 4 weeks, SBP and albuminuria were significantly increased in the SS high-salt group compared with the normal diet group. Dietary salt intake induced renal fibrosis and tubular EMT as identified by reduced expression of E-cadherin and enhanced expression of α-SMA in SS rats. Both blood pressure and renal interstitial fibrosis were negatively correlated with E-cadherin but positively correlated with α-SMA. Salt intake induced tubular EMT and renal injury in SS rats, and this relationship might depend on the increase in blood pressure.

Salt-Sensitive Hypertension: Perspectives on Intrarenal Mechanisms

PubMed Central

Majid, Dewan S.A.; Prieto, Minolfa C.; Navar, L Gabriel

2015-01-01

Salt sensitive hypertension is characterized by increases in blood pressure in response to increases in dietary salt intake and is associated with an enhanced risk of cardiovascular and renal morbidity. Although researchers have sought for decades to understand how salt sensitivity develops in humans, the mechanisms responsible for the increases in blood pressure in response to high salt intake are complex and only partially understood. Until now, scientists have been unable to explain why some individuals are salt sensitive and others are salt resistant. Although a central role for the kidneys in the development of salt sensitivity and hypertension has been generally accepted, it is also recognized that hypertension is of multifactorial origin and a variety of factors can induce, or prevent, blood pressure responsiveness to the manipulation of salt intake. Excess salt intake in susceptible persons may also induce inappropriate central and sympathetic nervous system responses and increase the production of intrarenal angiotensin II, catecholamines and other factors such as oxidative stress and inflammatory cytokines. One key factor is the concomitant inappropriate or paradoxical activation of the intrarenal renin-angiotensin system, by high salt intake. This is reflected by the increases in urinary angiotensinogen during high salt intake in salt sensitive models. A complex interaction between neuroendocrine factors and the kidney may underlie the propensity for some individuals to retain salt and develop salt-dependent hypertension. In this review, we focus mainly on the renal contributions that provide the mechanistic link between chronic salt intake and the development of hypertension. PMID:26028244

Efficacy of Commercial Mosquito Traps in Capturing Phlebotomine Sand Flies in Egypt

USDA-ARS?s Scientific Manuscript database

Adult mosquito traps of four types that are marketed for homeowner use in residential settings were compared with a standard CDC light trap for efficacy in collecting phlebotomine sand flies. We evaluated the Mosquito MagnetTM Pro (MMP), the SentinelTM 360 mosquito trap (S360), the BG-SentinelTM mo...

Quality and consumer acceptability of salt and phosphate enhanced goat loin from goats fed varying levels of pine bark.

PubMed

Leick, C M; Broadway, P R; Solaiman, S; Behrends, J M

2012-03-01

Goat loins (n=22) were evaluated to test effects of 0, 15, and 30% dietary pine bark (PB) and salt, water, and phosphate enhancement on shelf-life, shear force (WBSF) and consumer acceptability. No interactions existed between PB and enhancement. Dietary PB did not affect objective color, but enhancement increased a* and b* values (P<0.05). Thiobarbituric acid reactive substances (TBARS) increased from d 1 to d 5 of storage (P<0.0001), but were not affected by PB or enhancement. The WBSF for 30% PB was less than that of 0% PB (P=0.0199), and enhancement decreased WBSF (P=0.0010). Texture, flavor, and overall acceptability were greater (P<0.05) for 15 and 30% PB compared to 0% PB. Enhanced loin samples had greater appearance, aroma, texture, flavor, and overall acceptability scores (P<0.05). Results indicated that enhancement improved tenderness and consumer acceptability of goat loin, and PB had minimal impact on goat loin quality. Copyright © 2011 Elsevier Ltd. All rights reserved.

The serine protease homolog CLIPA14 modulates the intensity of the immune response in the mosquito Anopheles gambiae

PubMed Central

Nakhleh, Johnny; Christophides, George K.; Osta, Mike A.

2017-01-01

Clip domain serine protease homologs (SPHs) are positive and negative regulators of Anopheles gambiae immune responses mediated by the complement-like protein TEP1 against Plasmodium malaria parasites and other microbial infections. We have previously reported that the SPH CLIPA2 is a negative regulator of the TEP1-mediated response by showing that CLIPA2 knockdown (kd) enhances mosquito resistance to infections with fungi, bacteria, and Plasmodium parasites. Here, we identify another SPH, CLIPA14, as a novel regulator of mosquito immunity. We found that CLIPA14 is a hemolymph protein that is rapidly cleaved following a systemic infection. CLIPA14 kd mosquitoes elicited a potent melanization response against Plasmodium berghei ookinetes and exhibited significantly increased resistance to Plasmodium infections as well as to systemic and oral bacterial infections. The activity of the enzyme phenoloxidase, which initiates melanin biosynthesis, dramatically increased in the hemolymph of CLIPA14 kd mosquitoes in response to systemic bacterial infections. Ookinete melanization and hemolymph phenoloxidase activity were further increased after cosilencing CLIPA14 and CLIPA2, suggesting that these two SPHs act in concert to control the melanization response. Interestingly, CLIPA14 RNAi phenotypes and its infection-induced cleavage were abolished in a TEP1 loss-of-function background. Our results suggest that a complex network of SPHs functions downstream of TEP1 to regulate the melanization reaction. PMID:28928218