RNAi‐mediated silencing of SlitPer disrupts sex pheromone communication behavior in Spodoptera litura

The 24-h circadian rhythm is considered crucial for insect sexual communication. However, its molecular mechanisms and signaling pathways, particularly the roles of the clock gene period (Per), remain largely unclear. The sex pheromone communication behavior of Spodoptera litura displays typical circadian rhythm characteristics. Thus, it represents an excellent model for functional analyses of the clock gene Per.In this study, we investigated the potential roles of SlitPer in regulating sex pheromone communication in S. litura using RNA interference, quantitative real-time polymerase chain reactions (qPCR), gas chromatography, and behavioral assays. The qPCR results showed that the expression levels of SlitPer and two desaturase genes (SlitDes5 and SlitDes11) in the siPer group differed significantly at most time points from those in the siNC group. Dynamic variation in the three major sex pheromone titers and calling behavior of S. litura females in the siPer group was disordered. In addition, the mating rates of siPer S. litura females decreased significantly by 33.33%. Oviposition by mated siPer females was substantially reduced by 84.84%.These findings provide a fundamental basis for elucidating the molecular mechanism by which Per regulates sex pheromone communication behavior in lepidopteran species. © 2023 Society of Chemical Industry.