
NIFTI PI Jeff Riffell recently published a paper in Current Biology: “Visual-Olfactory Integration in the Human Disease Vector Mosquito Aedes aegypti“. The paper focuses on mosquito’s integration of various sensory cues to find and track their hosts.
As mosquitoes buzz around searching for their next target, they receive a multitude of signals from the environment. These signals include scents, sights, and environmental heats, which the mosquito must processes in order to locate the most viable target. The Riffell lab worked to determine the interaction between two of the previously unconnected senses, sight and smell.
To track the wing movements during flight, researchers placed mosquitoes in an enclosed space with an optical sensor. Researchers then mimicked human breath and movement with triggered puffs of CO2 infused air and a moving bar. The mosquitoes moved to both the air and the motion, but more dramatically to the motion after receiving a CO2 puff. This experiment was repeated with mosquitoes whose central nervous system cells glowed when firing. Neural data showed both the puff of CO2 and the motion triggered the cells. Stimulus order changed the scale of the reaction, as only bar motion after the CO2 puff caused an increase in cell firing. As Dr. Riffell states, “Smell triggers vision, but vision does not trigger the sense of smell.”

Dr. Riffell hopes scientists can gain a better understanding of how mosquitos feed, and develop new methods of bite prevention. Identifying how mosquitoes track their hosts may lead to the ideal prevention strategy.
Multiple news organizations have featured the research, including Everyday Health, the Seattle Times, and the UW news.