Gene Silencing of Olfactory Receptor Coreceptor by Systemic RNA Interference in Callosobruchus maculatus.

Abstract

Seed beetles are pernicious pests of leguminous seeds and are distributed globally. They cause great economic losses, particularly in developing countries. Of this genus, the cowpea weevil (Callosobruchus maculatus) is the most destructive and common species of this beetle. However, there are no effective and sustainable control strategies available for this species. Nevertheless, sustainable pest management strategies using sex pheromone compounds have been proposed, as C. maculatus uses species-specific sex pheromone signals for pre-mating isolation. Therefore, this study aimed to investigate the attractive capacity of male C. maculatus after RNA interference (RNAi)-based gene knockdown of olfactory receptor coreceptor (Cmac\Orco). The RNAi effect showed more than 90% reduction in transcripts, and a behavioral bioassay using a Y-tube olfactometer indicated that knocking down males impaired sexual attraction toward females, which would be a useful tool for further screening of target molecules for odorant chemical communication.