In order to better trap or evade malaria-carrying Aedes aegypti mosquitoes, it helps if we know more about the manner in which they track their victims. New research now indicates that it's a matter not just of smell, but also enhanced visual processing that's triggered by smell.

It's long been known that – among other things – mosquitoes are attracted to the odor of the carbon dioxide which we exhale. A team of Virginia Tech scientists, however, wondered if there was more to it than that. Led by Asst. Prof. Clément Vinauger, they built a sort of "flight simulator" for mosquitoes in order to find out.

A series of tethered female Aedes aegypti mosquitoes were placed in the device, which uses an immersive cylindrical array of flashing LEDs to simulate moving objects – in a real-life scenario, those objects could be people. Each insect, which had been fitted with a tiny 3D-printed helmet utilized to monitor their brain activity, was then subjected to a puff of CO2 (similar to what a person might exhale).

It was found that when this happened, not only did their brain's olfactory center register the odor, but that region also responded by activating neurons in the brain's visual processing center. This in turn allowed the insect to visually track the simulated moving objects much more accurately – the researchers were able to determine that this was the case by analyzing the manner in which the mosquitoes' wingbeat frequency, acceleration, and turning behavior changed in accordance to the moving LED light patterns.

"Analyzing how mosquitoes process information is crucial to figuring out how to create better baits and traps for mosquito control," says Vinauger. "My research aims at closing the key knowledge gaps in our understanding of the mechanisms that allow mosquitoes to be such efficient disease vectors and, more specifically, to identify and characterize factors that modulate their host-seeking behavior."

A paper on the research was recently published in the journal Current Biology.