Functional Characterization and Small Molecule Drug Screening of Sex Pheromone Receptors in <i>Ectropis obliqua</i>

<i>Ectropis obliqua</i> (Lepidoptera: Geometridae) is a major pest of tea plants in China. Sex pheromone traps are effective for monitoring and controlling its population. However, the specific mechanisms of sex pheromone recognition in this pest remain unclear. Fifty-seven candidate odorant receptors were identified using antennal transcriptome analysis, including two potential pheromone receptors (EoblOR17 and EoblOR45). Expression profiles indicated that EoblOR17 and EoblOR45 were highly expressed in the males. Among them, EoblOR17 was identified in response to the primary pheromone components of <i>E. obliqua</i>, Z3,epo6,Z9-18:H and Z3,Z6,Z9-18:H. The in vivo function of EoblOR17 was confirmed using RNA interference (RNAi) analysis. A small molecule (T7392) targeting EoblOR17 significantly reduced the mating rate of <i>E. obliqua</i>. Our findings provide a better understanding of the mechanisms of sex pheromone recognition in <i>E. obliqua</i> and provide a class of potential compounds to control this pest.