A closeup of an Aedes aegypti mosquito biting its host. Photo credit: Alex Wild, alexanderwild.com

The yellow fever mosquito,  Aedes aegypti, biting its prey. Photo credit: Alex Wild, alexanderwild.com

By Laurel Hamers

It’s a question asked by many a summer stargazer: How do mosquitoes home in on their human prey, turning a relaxing evening into an itchy disaster?

Meg Younger, an MBL Grass Fellow and a postdoctoral scientist at Rockefeller University, is trying to find out by looking at mosquitoes’ neural responses to different combinations of odors.

Behavioral studies have identified several cues that are mildly attractive to mosquitoes: carbon dioxide, heat, and lactic acid, a component of sweat. Presented alone, none of these cues is particularly powerful; when paired together, however, their effects multiply.

“What we don’t know yet is how these stimuli that are ignored or only mildly attractive are transformed into very attractive stimuli in the brain when presented simultaneously,” Younger says.

Younger is using electrophysiology and calcium imaging to monitor olfactory neurons, looking for differences in brain activity when mosquitoes are presented with certain stimuli alone or in different combinations.

She is carrying out her research in the yellow fever mosquito, Aedes aegypti, which is found in tropical and subtropical areas and is the also the major vector for dengue fever and chikungunya.

“The more we know about how mosquitoes process different stimuli to find humans, the more potential we have to come up with creative ways to stop them from biting people and spreading diseases,” Younger says.