Aerial Ultra-Low–volume Assessment of Anvil 10+10® Against Anopheles Quadrimaculatus

Abstract

Against caged field-collected adults of Anopheles quadrimaculatus, optimized aerial applications of ANVIL 10+10 at 18.4 ml (1.63 g active ingredient)/0.4 ha produced a mean mortality of 92% at 1, 12, and 24 h after treatment. These trials were conducted with 7 stacked passes applied 1,067 m upwind of the target site when wind velocity was 18-21 km/h at an application altitude of 46 m and 5-10 km/h at groundlevel. When the wind velocity aloft was greater than might be operationally acceptable (27 km/h), reduced efficacy (64% mortality) was observed in the bioassay site (1,524 m downwind from 11 stacked passes) in an unreplicated application. Droplets from the 2 tail-mounted Beecomist 360-A-12-V rotary atomizers (fitted with wire sleeve cages of size 40 mesh) collected on spinning Teflon-coated slides in the target area averaged a volume mean diameter (VMD) of 29 microm and a droplet density of 39 droplets/cm2 in 18- to 21-km/h winds. With 27-km/h winds aloft and a greater application offset, the VMD and droplet density dropped to 23 microm and 18 droplets/cm2, respectively. Coupled with unreplicated results from a nonoptimized application, these tests provide further documentation of the efficacy of ANVIL 10+10 for wide-area adult mosquito control and for optimization technology.