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.昆虫性信息素是性通讯过程中的重要化学信号，传统观点认为其对幼虫无生物活性。然而已有研究发现，部分鳞翅目幼虫在取食环境中会被同种昆虫的性信息素显著吸引。本研究报道，早龄粘虫(*Mythimna separata*)幼虫的寄主取食选择可被性信息素组分(Z)-11-十六碳烯醛((Z)-11-hexadecenal, Z11-16:Ald)有效调控。进一步探究显示，两种嗅觉蛋白——粘虫普通气味结合蛋白2(general odorant binding protein 2, MsGOBP2)与嗅觉受体3(olfactory receptor 3, MsOR3)——是Z11-16:Ald介导的寄主取食选择调控的分子基础。沉默MsGOBP2或MsOR3均会导致幼虫对添加Z11-16:Ald的寄主的偏好性显著下降。粘虫幼虫对Z11-16:Ald标记寄主的偏好性，可能由MsGOBP2与MsOR3之间的相互作用所调控。本研究同时采用基于分子动力学(molecular dynamics)的方法探讨了MsGOBP2与Z11-16:Ald之间的相互作用。本研究深入解析了Z11-16:Ald介导的粘虫幼虫寄主取食选择调控机制，所有研究结果将有助于开发基于嗅觉途径的幼虫期害虫防控方法。