BackgroundMalaria control programmes across Africa and beyond are facing increasing insecticide resistance in the major anopheline vectors. In order to preserve or prolong the effectiveness of the main malaria vector interventions, up-to-date and easily accessible insecticide resistance data that are interpretable at operationally-relevant scales are critical. Herein we introduce and demonstrate the usefulness of an online mapping tool, IR Mapper.MethodsA systematic search of published, peer-reviewed literature was performed and Anopheles insecticide susceptibility and resistance mechanisms data were extracted and added to a database after a two-level verification process. IR Mapper ( http://www.irmapper.com) was developed using the ArcGIS for JavaScript Application Programming Interface and ArcGIS Online platform for exploration and projection of these data.ResultsLiterature searches yielded a total of 4,084 susceptibility data points for 1,505 populations, and 2,097 resistance mechanisms data points for 1,000 populations of Anopheles spp. tested via recommended WHO methods from 54 countries between 1954 and 2012. For the Afrotropical region, data were most abundant for populations of An. gambiae, and pyrethroids and DDT were more often used in susceptibility assays (51.1 and 26.8% of all reports, respectively) than carbamates and organophosphates. Between 2001 and 2012, there was a clear increase in prevalence and distribution of confirmed resistance of An. gambiae s.l. to pyrethroids (from 41 to 87% of the mosquito populations tested) and DDT (from 64 to 91%) throughout the Afrotropical region. Metabolic resistance mechanisms were detected in western and eastern African populations and the two kdr mutations (L1014S and L1014F) were widespread. For An. funestus s.l., relatively few populations were tested, although in 2010–2012 resistance was reported in 50% of 10 populations tested. Maps are provided to illustrate the use of IR Mapper and the distribution of insecticide resistance in malaria vectors in Africa.ConclusionsThe increasing pyrethroid and DDT resistance in Anopheles in the Afrotropical region is alarming. Urgent attention should be afforded to testing An. funestus populations especially for metabolic resistance mechanisms. IR Mapper is a useful tool for investigating temporal and spatial trends in Anopheles resistance to support the pragmatic use of insecticidal interventions.

Pesticides commonly contaminate the aquatic environments inhabited by mosquito juveniles. However, their role in shaping the mosquito microbiota is not well understood. We hypothesized that environmentally relevant concentrations of atrazine, permethrin and malathion will mediate a shift in the mosquito gut bacterial community structure due to their toxic effect on the aquatic bacterial communities, and reduce mosquito gut bacterial diversity by enriching pesticide-degrading bacterial communities over susceptible taxa. Illumina MiSeq sequencing of the V3-V4 hypervariable regions of the 16 S rRNA gene was used to characterize the microbial communities of larval and adult stages of the two mosquito species and the water samples from microcosms treated with each of the pesticides, separately. Bacterial community composition differed by sample type (larval stage vs. adult stage) and water sampling date (day 3 vs. day 7), but not by pesticide treatment. In larval stages, bacterial OTU richness was highest in samples exposed to malathion, intermediate in permethrin, and lowest in controls. Bacterial richness was significantly higher in larval stages compared to adult stages for all treatments. This study provides a primer for future studies evaluating mosquito microbial responses to exposures to chemical pesticides and the possible implications for mosquito ecology. One of the central goals of ecology is to understand patterns of species abundance and diversity in communities and ecosystems, and how these patterns are impacted by anthropogenic alterations 1-3. Pesticides are a common source of environmental disruption, and thousands of different pesticides are used around the world to improve crop production and human health. These pesticides often enter the aquatic habitats, including those that are not intended or legally registered for application to aquatic systems. Consequently, there is considerable research effort to understand and predict the impacts of anthropogenic chemical pesticides on non-target aquatic organisms 4-7. Atrazine, permethrin, and malathion are three of the most frequently used pesticides, and their residues are commonly detected in groundwaters of the United States 4,8,9. Although malathion is still used in agricultural pest control, it is no longer used in vector control in the United States. These three pesticides span a broad range of mode of action and uses. Atrazine, a triazine herbicide, is used globally to control broadleaf weeds by inhibiting electron transport in photosystem II 10. Groundwater atrazine concentration in the United States range between 0.0002 mg/L-0.05 mg/L with peaks of 1 mg/L reported whenever it rains heavily immediately after field applications 11,12. Recent monitoring data indicate that the value of 0.053 mg/L represents the 99 th percentile of atrazine concentrations in most ground waters of the United States, with a cutoff of 0.1 mg/L used to assess environmental relevance 13. Atrazine exerts adverse physiological effects on aquatic insects including mosquito la...

Mosquito bacterial communities are essential in mosquito biology, and knowing the factors shaping these bacterial communities is critical to their application in mosquito-borne disease control. This study investigated how the larval environment influences the bacterial communities of larval stages of two container-dwelling mosquito species, Aedes triseriatus, and Aedes japonicus. Larval and water samples were collected from tree holes and used tires at two study sites, and their bacteria characterized through MiSeq sequencing of the 16S rRNA gene. Bacterial richness was highest in Ae. japonicus, intermediate in Ae. triseriatus, and lowest in water samples. Dysgonomonas was the dominant bacterial taxa in Ae. triseriatus larvae; the unclassified Comamonadaceae was dominant in water samples from waste tires, while Mycobacterium and Carnobacterium, dominated Ae. japonicus. The two mosquito species harbored distinct bacterial communities that were different from those of the water samples. The bacterial communities also clustered by habitat type (used tires vs. tree holes) and study site. These findings demonstrate that host species, and the larval sampling environment are important determinants of a significant component of bacterial community composition and diversity in mosquito larvae and that the mosquito body may select for microbes that are generally rare in the larval environment.

Background The bacterial communities associated with mosquito eggs are an essential component of the mosquito microbiota, yet there are few studies characterizing and comparing the microbiota of mosquito eggs to other host tissues. Methods We sampled gravid female Culex pipiens L. and Culex restuans Theobald from the field, allowed them to oviposit in the laboratory, and characterized the bacterial communities associated with their egg rafts and midguts for comparison through MiSeq sequencing of the 16S rRNA gene. Results Bacterial richness was higher in egg rafts than in midguts for both species, and higher in Cx pipiens than Cx. restuans. The midgut samples of Cx. pipiens and Cx. restuans were dominated by Providencia. Culex pipiens and Cx. restuans egg rafts samples were dominated by Ralstonia and Novosphingobium, respectively. NMDS ordination based on Bray-Curtis distance matrix revealed that egg-raft samples, or midgut tissues harbored similar bacterial communities regardless of the mosquito species. Within each mosquito species, there was a distinct clustering of bacterial communities between egg raft and midgut tissues. Conclusion These findings expand the list of described bacterial communities associated with Cx. pipiens and Cx. restuans and the additional characterization of the egg raft bacterial communities facilitates comparative analysis of mosquito host tissues, providing a basis for future studies seeking to understand any functional role of the bacterial communities in mosquito biology.

13Background: The bacterial communities associated with mosquito eggs are an essential 14 component of the mosquito microbiota, yet there are few studies characterizing and comparing 15 the microbiota of mosquito eggs to other host tissues. 16 Methods:We sampled gravid female Culex pipiens and Culex restuans from the field, allowed 17 them to oviposit in the laboratory, and characterized the microbiota associated with their egg 18 rafts and midguts for comparison through MiSeq sequencing of the 16S rRNA gene. 19Results: Bacterial richness was higher in egg rafts than in midguts for both species, and higher 20 in Cx pipiens L. than Cx. restuans. The midgut samples of Cx. pipiens and Cx. restuans were 21 dominated by Providencia. Culex pipiens L. and Cx. restuans egg rafts samples were dominated 22by Ralstonia and Novosphingobium, respectively. NMDS ordination based on Bray-Curtis 23 distance matrix revealed that egg raft samples, or midgut tissues harbored similar bacterial 24 communities regardless of the mosquito species. Within each mosquito species, there were 25 distinct clustering of bacterial communities between egg raft and midgut tissues. 26Conclusion: These findings expand the list of described bacterial communities associated with 27Cx. pipiens L. and Cx. restuans and the additional characterization of the egg raft bacterial 28 communities facilitates comparative analysis of mosquito host tissues, providing a basis for 29 future studies seeking to understand any functional role of microbiota in mosquito biology. 30Keywords: Mosquito egg raft, mosquito midgut, Culex pipiens L., Culex restuans, bacterial 31 communities 32 33 [19,20]. To what extent the bacterial communities on the egg surface drive the hatching effect 51 relative to the microbes in the water column remains unclear. 52Previous studies characterizing and comparing the bacterial communities of mosquito 53 eggs with those of their other host tissues (e.g., midguts) have been conducted with well-known 54Afro-tropical or Asian vectors, including Anopheles or Aedes species, but not important North 55American vector species such as Culex pipiens L. or Culex restuans [5][6][7]. Culex pipiens L. is an