Mosquito taste responses to human and floral cues guide biting and feeding

Abstract

The taste system controls many insect behaviours, yet little is known about how tastants are encoded in mosquitoes or how they regulate critical behaviours. Here we examine how taste stimuli are encoded by Aedes albopictus mosquitoes—a highly invasive disease vector—and how these cues influence biting, feeding and egg laying. We find that neurons of the labellum, the major taste organ of the head, differentially encode a wide variety of human and other cues. We identify three functional classes of taste sensilla with an expansive coding capacity. In addition to excitatory responses, we identify prevalent inhibitory responses, which are predictive of biting behaviour. Certain bitter compounds suppress physiological and behavioural responses to sugar, suggesting their use as potent stop signals against appetitive cues. Complex cues, including human sweat, nectar and egg-laying site water, elicit distinct response profiles from the neuronal repertoire. We identify key tastants on human skin and in sweat that synergistically promote biting behaviours. Transcriptomic profiling identifies taste receptors that could be targeted to disrupt behaviours. Our study sheds light on key features of the taste system that suggest new ways of manipulating chemosensory function and controlling mosquito vectors. Taste neurons of the mosquito Aedes albopictus regulate biting, feeding and egg-laying behaviours by responding to taste cues in human sweat, nectar and egg-laying sites via excitation or inhibition.