Energy-State Dependent Response of Anopheles gambiae to DEET-Protected, Simulated Blood-Hosts

Understanding how mosquito host-seeking behavior changes according to different energy levels in Anopheles gambiae (Diptera: Culicidae) when confronted with a known chemical barrier ( N , N -Diethyl-3-methylbenzamide; DEET) is of interest for vector control strategies. We used two identical straight-tube olfactometers to mimic domiciles containing a simulated blood host (human foot odor from a recently-used sock) wrapped in a DEET impregnated net (1 or 0.1 %) and a sugar source (honey) placed some distance away. The energy level of the mosquitoes was manipulated by depriving females of sugar for 6, 24 and 48 h, and we monitored their responses in the olfactometer. Energy level did not have a significant impact on behavior. However, significant differences in residence time at the sock and overall activity level of the mosquito were recorded wherein mosquitoes exposed to DEET responded less readily to the blood-host scent, almost never probing its source. We propose that DEET is perceived by the mosquito as such a strong risk that energy levels do not affect its behavioral outcome. This study, along with previous work showing DEET efficacy, suggests that DEET is an important asset in mosquito control campaigns.