Mosquitoes remember human smells, Virginia Tech researchers find

BLACKSBURG, Va. – The old adage that if your sweeter you may get more bug bites, may actually be backed up by scientific proof.

Scientist at Virginia Teach say that research shows that mosquitoes can rapidly learn and remember the smells of humans and that dopamine is a key mediator of this process. Mosquitoes use this information and incorporate it with other stimuli to develop preferences for a particular vertebrate host species, and, within that population, certain individuals.

The study did say though that whether sweet our sour, mosquito’s preference can shift either way.

Researchers also say that those who swat at mosquitoes or perform other defensive behaviors may be abandoned by mosquitoes, even if the smell of that certain human is attractive or engaging with the mosquitoes.

“Unfortunately, there is no way of knowing exactly what attracts a mosquito to a particular human — individuals are made up of unique molecular cocktails that include combinations of more than 400 chemicals,” said Lahondère.  “However, we now know that mosquitoes are able to learn odors emitted by their host and avoid those that were more defensive.”

Clément Vinauger, an assistant professor of biochemistry in the College of Agriculture and Life Sciences, and Chloé Lahondère, a research assistant professor in the Department of Biochemistry, demonstrated that mosquitoes exhibit a trait known as aversive learning by training female Aedes aegypti mosquitoes to associate odors (including human body odors) with unpleasant shocks and vibrations.

Twenty-four hours later, the same mosquitoes were assessed in a Y-maze olfactometer in which they had to fly upwind and choose between the once-preferred human body odor and a control odor. The mosquitoes avoided the human body odor, suggesting that they had been successfully trained, according to the Virginia Teach researchers. 

By taking a multidisciplinary approach and using cutting-edge techniques, the scientists were also able to identify that dopamine is a key mediator of aversive learning in mosquitoes.

“Understanding these mechanisms of mosquito learning and preferences may provide new tools for mosquito control,” said Vinauger. “For example, we could target mosquitoes’ ability to learn and either impair it or exploit it to our advantage.”

The research that is being done by Virginia Tech scientist is more important than seeing just what mosquitoes are attracted to.This research could help health experts and scientist figure out ways of stopping certain viruses and fevers that are spread through certain species of mosquitoes.

The Aedes aegypti mosquitoes, which Virginia Tech is studying, are known to carry and spread the Zika fever, dengue fever, chikungunya and the yellow fever virus.