Mosquitoes can learn to associate DEET with food, study finds

A research article released on May 28 in the Journal of Experimental Biology indicates that Aedes aegypti mosquitoes can learn to link the scent of DEET with the availability of a blood meal, leading to increased attraction. In the study, scientists trained laboratory-reared mosquitoes by exposing them to a bag of warm sheep's blood for 30 seconds, introducing DEET during the final ten seconds. After four training sessions, more than 60% of the mosquitoes attempted to access a blood bag that was out of reach when DEET was present. In a separate live experiment, around 60% of the trained mosquitoes favored a hand treated with DEET over an untreated one. These results imply that the effectiveness of repellents may decrease without regular reapplication, although experts still endorse DEET as the premier choice for protection.