D3418: Effects of the chemical repellents on the human odor-evoked responses of Aedes aegypti

The increasing levels of insecticide resistance in many mosquito species speak to the urgent need to develop effective alternatives to insecticides in order to control mosquito populations. Mosquitoes rely on their odorant receptors (ORs) on olfactory sensory neurons (OSN) in olfactory system to detect chemical odorants emitted by their preferred hosts, ultimately leading to the transmission of mosquito-borne diseases to humans. A better understanding of mosquito ORs involved in interacting with chemical repellents and/or human odorants will enable the development of more effective chemical repellents and of new tools for managing mosquito vectors. In the current study, we functionally characterized three potential human-odor-sensitive Aedes aegypti ORs, the responses of ORs to human odorants and chemical inhibitory terpenoid compounds, and the interference effects of chemical inhibitory terpenoids with human odorants. Our results demonstrated the disruptive potency of inhibitory terpenoids (α-terpinene and citronellal) to human-odor recognition at the molecular and neuronal level, which can ultimately impair mosquito host-seeking capacity to protect humans from mosquito biting behavior and mosquito-borne disease infections.