Dual treatment enhanced transfer of insect growth regulator from autodissemination station to mosquito oviposition sites

Asian tiger mosquito, Aedes albopictus (Skuse) (Diptera: Culicidae), is an urban species that colonizes cryptic small-volume larval habitats and visits multiple containers for skip oviposition. Larval habitats are often difficult to reach by traditional broadcast sprays of pesticides. We have developed an autodissemination station (ADS) that exploits gravid female oviposition behavior in the transfer of insect growth regulator (IGR) from the station to oviposition sites. The key components of successful IGR transfer are: 1) attraction of gravids to the station; 2) attachment of IGR to the insect; 3) persistence of IGR despite cleaning behaviors; and 4) release of IGR into the larval habitat. Our station design consists of a water reservoir that allows auto-refill by rain and attracts gravid mosquitoes; a transfer chamber that forces exiting mosquitoes through a dual contamination treatment (gel and powder) system; and IGR formulations that attach, persist and release well into subsequent oviposition sites. In room (31m³) trials with Ae.albopictus, 100% emergence inhibition was achieved. The evidence of transfer, mosquito footprints, was visualized with a florescent dye under UV light, and the amount of active ingredient transferred by individual mosquitoes was quantified by GC/MS and lab bioassay.