Understanding the role of odorant receptors in larvae of Aedes mosquitoes

Mosquitoes rely largely on their sense of olfaction to detect host blood-meals. Considerable effort has focused on examining their odorant receptors (ORs) to develop effective repellents that disrupt these insects’ abilities to smell their hosts. Odorant receptors in mosquito larvae have been largely ignored, and hence, in this study, we examine the role of some larval ORs, with the goal of identifying which ORs detect specific odorants and whether those same ORs are used in the adults to detect the same odorants. Aedes aegypti larvae were first challenged with various classes of chemicals to measure their attraction to specific compounds. Then, by feeding larvae bacteria expressing dsRNAs targeting different OR gene transcripts, we examined which ORs detect the attractive odorants. The sex- and tissue-specific expression of the ORs was examined, to assess whether the OR was involved in differential growth rates of the larvae, and whether disruption of the OR’s function could impair the ability of the larvae to grow and reach maturity. By understanding the role of larval mosquito olfaction, we may ultimately design novel methods of reducing pest or disease vectoring mosquitoes at the larval stage, before they become blood-feeding adults.