Olfactory responses of sex pheromone receptors in Spodoptera litura (Lepidoptera: Noctuidae) to inter- and intra-specific sex pheromone

Spodoptera litura is an important crop pest while sex pheromone trapping has been used as a tool for S. litura population monitoring. The objective of this study was to detect olfactory responses of sex pheromone receptors in S. litura to inter- and intra- specific sex pheromone. We identified three pheromone odorant receptors (ORs) --- SlituOR13, SlituOR6 and SlituOR16 . SlituOR6 had the strongest response to the minor sex pheromone component E 11-14:Ac of S. litura , and weak responses to the inter-specific sex pheromone components 16:Ac and Z 9-14:Ac. SlituOR13 had a strong response to the minor sex pheromone component E 11-14:Ac of S. litura , and a weak response to the minor component Z 9-14:Ac. SlituOR16 responded strongly to the sex pheromone component Z 9-14:OH of S. exigua , had some responses to the intra-specific sex pheromone component Z 9-14:Ac, Z 9 E 11-14:Ac and Z 9 E 12-14:Ac of S. litura , and the inter-specific sex pheromone component Z 7-12:Ac of Agrotis ipsilon , but a weak response to the minor component E 11-14:Ac of S. litura . Field data from sex pheromone trapping supported that Z 9-14:OH and Z 7-12:Ac inhibited the olfactory response of male S. litura to sex pheromones.