Sex peptide receptor mediates the post-mating switch in Helicoverpa armigera (Lepidoptera: Noctuidae) female reproductive behavior.

Background In Drosophila, the sex peptide receptor (SPR) in females to detect male sex peptide (SP) and trigger changes in female behavior including mating rejection and oviposition. In moths, the SPR had been identified and investigated the limited function by using RNAi. However, the detailed function of SPR after a normal mating in moths, especially the role in female sexual receptivity, remains to be elucidated. Results In this study, we use Helicoverpa armigera, an economically important pest worldwide, as a case study to verify the function of SPR in vivo by CRISPR/Cas9 gene editing system. Analyzing the post-mating behaviors in mutant females, we investigated that HarmSPR could mediate the long-term sexual receptivity (remating, sex pheromone production and calling behavior) switch in female, but not affect the short-term sexual receptivity and the duration time of remating. The oviposition of mated HarmSPR-/- females was significantly decreased by ~70% comparing to WT mated females and there were more eggs staying in the ovary of mutant females. SPR also showed effect on female longevity, which is that the mated HarmSPR-/- females showed longer longevity than mated WT females. Conclusion The results detailedly demonstrated the functional role of SPR in female post-mating behaviors and we could propose a pest control strategy in which developing a antagonist of SPR to reduce the oviposition of female. This article is protected by copyright. All rights reserved.