The host-feeding choice of early-instar Mythimna separata larvae can be regulated by female-released sex pheromone

Insect<strong> </strong>sex pheromones are important chemical signals in sexual communication, they are traditionally thought to be inactive to larvae. However, it was found that some lepidopteran larvae can be significantly attracted by sex pheromones of the same species in a food context. Here we reported that the host-feeding choice of early-instar <em>Mythimna separata</em> larvae can be effectively regulated by the sex pheromone component (<em>Z</em>)-11-hexadecenal (<em>Z</em>11-16: Ald). Further exploration revealed that two olfactory proteins, <em>M. separata</em> general odorant binding protein 2 (MsGOBP2) and olfactory receptor 3 (MsOR3), were molecular basis of the host-feeding choice regulation mediated by <em>Z</em>11-16: Ald. Silencing either <em>MsGOBP2</em> or <em>MsOR3 </em>led to a sharply reduced preference for <em>Z</em>11-16: Ald-spiked hosts. It is possible that the <em>Z</em>11-16: Ald-based preference of the <em>M. separata</em> larvae for host is governed by the interplay between MsGOBP2 and MsOR3. In the present research, the interactions between MsGOBP2 and <em>Z</em>11-16: Ald were also discussed using molecular dynamics-based approaches. Our research explored insight into the <em>Z</em>11-16: Ald-mediated host-feeding choice regulation of <em>M. separata</em> larvae, all the results would aid in developing olfaction-based methods for controlling pests in larval stage.