Mosquitoes exposed to DEET once are less repelled by it a few hours later | London School of Hygiene & Tropical Medicine | LSHTMPosted: May 1, 2013
In this new research, Dr Logan, Dr Nina Stanczyk and colleagues from the London School of Hygiene & Tropical Medicine uncovered a response in mosquitoes based on short-term changes, not genetic ones.
The authors tested changes in responses to DEET in Aedes aegypti mosquitoes, which are notorious for biting during the day and are capable of transmitting dengue fever and yellow fever viruses.
They found that a brief exposure to DEET was sufficient to make some mosquitoes less sensitive to the repellent. Three hours after the exposure, these mosquitoes were not deterred from seeking attractants like heat and human skin despite the presence of DEET.
The researchers found that this insensitivity to the smell could be correlated to a decrease in the sensitivity of odor receptors on the mosquito’s antennae following a previous exposure.
Dr Logan, medical entomologist and Chief Scientific Officer for the Arthropod Control Product Test Centre, said: “We think that the mosquitoes are habituating to the repellent, similar to a phenomenon seen with the human sense of smell also. However, the human olfactory system is very different from a mosquito’s so the mechanism involved in this case is likely to be very different.