To better control populations of mosquitoes and break the transmission cycle of vector-borne diseases, it is crucial to understand the dispersal of adult mosquitoes. We performed a stable isotope mark-capture study, focusing on Culex quinquefasciatus and Aedes albopictus, to characterize dispersal distance and behavior. We enriched (i.e. marked) naturally occurring larval mosquitoes in container habitats with 13C-glucose or 15N-potassium nitrate at two different locations (~0.5km apart) in College Station, Texas in 2013. We used 32 CDC light trap, 32 gravid trap, and 16 BG Sentinel at different trap locations within a two-kilometer radius of the enriched larval habitats. Each location was trapped once per week and all mosquitoes collected were identified and numerated. Cx. quinquefasciatus and Ae. albopictus were pooled and tested for West Nile virus (WNV) by RT-PCR or tested by stable isotope analysis. In total, 720 trap nights were completed from July to August 2013 yielding a total of 32,140 Cx. quinquefasciatus and 7,722 Ae. albopictus. Overall, 69 marked female mosquitoes (n=2,758) and 24 marked male mosquitoes were captured throughout the study period. This study provides a greater understanding of the dispersal of two important mosquito vectors capable of transmitting diseases in urban environments. We also confirm the ability to use stable isotope enrichment as a means to study the biology of mosquitoes. At the same place and time, we executed a larvicide program targeting habitat containers along public streets and public creeks. The purpose of this study was to examine the efficacy of larvicide treatment on adult populations of Cx. quinquefasciatus and Ae. albopictus in a residential area. This study was conducted from June 3 to August 31, 2013 and yielded a total of 42,714 individuals distributed among 13 different species. Overall, we saw a significant reduction in Cx. quinquefasciatus adult population and no significant reduction in Ae. albopictus adult population, when comparing treated and untreated areas. This study suggests that the majority of container habitat producing these mosquito species were 'cryptic' (i.e. residential backyards) where we did not treat. However, we demonstrate that treating a subset of all container habitat with larvicide can still have a marked reduction in Cx. quinquefasciatus, the primary vector of WNV, suggesting that larvicide is an appropriate component of Integrative Mosquito Management.
- Hamer, Gabriel Associate Professor