Heritable variation in the sensitivity of Anopheles gambiae to DEET

DEET (N,N-diethyl-3-methylbenzamide) is the most effective personal insect repellent currently in widespread use, and as such is essential in combating the spread of mosquito born disease both domestically and abroad.  Despite its ubiquitous use and integral role in integrated vector management programs, the potential for the evolution of insensitivity to DEET in mosquito populations is not fully understood, and the mode of action of DEET is still debated.  We demonstrate that insensitivity to DEET can be selected for in Anopheles coluzzi and Aedes aegypti populations, similarly to what has been demonstrated by others.  We also demonstrate that insensitivity to DEET is host specific in Anopheles coluzzi and Aedes aegypti.  DEET insensitivity selected for on one human volunteer does not translate to DEET insensitivity on another human volunteer.  This suggests that DEET in some way acts in synergy with host-specific odorants that vary due to diet, microbiome, and/or other factors.  Based on these findings, it is unlikely that insensitivity to DEET can be selected for in wild mosquito populations.