D3365: The impact of sugar diets on the humidity sensation of mosquitoes

Mosquito-borne diseases have caused more than one million deaths each year and there is an urgent need for the feasible and effective ways to prevent disease transmission. Humidity detection (hygrosensation) is important to mosquito fitness, especially in host-seeking and egg-laying. In the present study, we examined how sugar diets impact the humidity sensation in Aedes aegypti and Culex pipiens. We used the two-choice assay with high (100%) and low (75%) relative humidity (RH) to record the avidity and behavioral preference index (PI) after mosquitoes were treated with sucrose and artificial sugar (sorbitol and arabinose) at different concentrations (10% and 30%). We demonstrated that the effect of sugar diets on hygrosensation is species-specific. Compared to the control group (10% sucrose + water), the avidity of Aedes aegypti was significant lower under all but the sorbitol treatment (10% sorbitol + water). On the contrary, the avidity of Culex pipiens was merely significantly lower in two treatments (30% sucrose only and 10% sorbitol + water treatment). Aedes aegypti under 30% sucrose only, 10% arabinose + water, and 10% sorbitol only treatments showed significantly lower PI, but Culex pipiens PI had no significant difference under any sugar treatment. This work confirms that specific sugar treatments could be applied to mosquito control, potentially dampening their humidity sensation for reproduction and host-seeking, thus preventing the mosquito-borne disease transmission.