Molecular and cellular basis of mosquito olfactory attraction to hay infusion for enhanced vector surveillance and control

The mosquito Aedes aegypti is a prolific disease vector that thrives in urban environments. Its explosive population dynamics are driven by the ability of female Ae. aegypti to seek out standing pools of water to lay their desiccation-resistant eggs. Of note, females are attracted to the scent of decomposing botanical matter in water, but only after mating and blood-feeding. In particular, gravid female Ae. aegypti are highly attracted to the scent of fermenting African Bermuda grass hay in water, which has been exploited for mosquito trapping strategies in the field that aim to lure this major disease vector to its death during the act of egg laying. We propose to apply integrative methods to define the molecular and cellular basis of Ae. aegypti olfactory attraction to hay infusion which will catalyze identification of olfactory circuitry mediating oviposition site search and novel oviposition attractants for this disease vector. To elucidate candidate chemoreceptors and associated neurons implicated in mosquito olfactory attraction to hay infusion, we will test the role of different chemoreceptor classes using loss-of-function genetics and olfactory sensory neuron populations by selectively disrupting neural activity using cell-type specific neuronal silencing. In parallel, we aim to reverse engineer attractive blends of oviposition attractants mimicking the scent of hay infusion by leveraging chemical analysis of infusion headspace combined with neural activity assays that compare olfactory sensitivity and response amplitudes of non-gravid and gravid mosquitoes to conserved volatile organic compounds found in this this natural lure. These aims will fundamentally improve our understanding of the chemosensory basis of Ae. aegypti oviposition site search behavior. From a translational perspective, this research will reveal new molecular targets in the Ae. aegypti olfactory system to modulate mosquito egg laying behavior and identify novel synthetic formulations of oviposition attractants for enhanced population surveillance and control of this globally important disease vector.