Behavioral insensitivity to DEET in Aedes aegypti is a genetically determined trait residing in changes in sensillum function.

N,N-Diethyl-m-toluamide (DEET) is one of the most effective and commonly used mosquito repellents. However, during laboratory trials a small proportion of mosquitoes are still attracted by human odors despite the presence of DEET. In this study behavioral assays identified Aedes aegypti females that were insensitive to DEET, and the selection of either sensitive or insensitive groups of females with males of unknown sensitivity over several generations resulted in two populations with different proportions of insensitive females. Crossing experiments showed the "insensitivity" trait to be dominant. Electroantennography showed a reduced response to DEET in the selected insensitive line compared with the selected sensitive line, and single sensillum recordings identified DEET-sensitive sensilla that were nonresponders in the insensitive line. This study suggests that behavioral insensitivity to DEET in A. aegypti is a genetically determined dominant trait and resides in changes in sensillum function.