<i>Desaturase 11</i> responds to the pheromone biosynthesis activating neuropeptide signal to regulate the biosynthesis of sex pheromones and oviposition in <i>Helicoverpa armigera</i>

Abstract The sex pheromones of moths consist of multiple components that serve as chemical signals emitted by female individuals to attract male counterparts for mating purposes. Desaturases, which are key enzymes involved in creating unsaturated bonds on fatty acid chains, play a critical role in producing specific sex pheromone components. In this study, the Old World bollworm, Helicoverpa armigera Hübner (Lepidoptera: Noctuidae), was used as a model to identify a desaturase gene called Hades11 , which showed a high level of expression in the pheromone glands. RNA interference‐mediated knockdown of Hades11 led to a significant decrease in the production of the main sex pheromone components ( Z 11‐16:Ald and Z 9‐16:Ald). However, the ratio of sex pheromone components remained unchanged, indicating that Hades11 specifically affects sex pheromonal compound biosynthesis rather than their release ratio. Furthermore, inhibiting the expression of Hades11 also caused a notable reduction in the total number of eggs laid by female moths, without affecting the hatching rate. Importantly, it was found that the expression level of Hades11 may be indirectly regulated by pheromone biosynthesis activating neuropeptide (PBAN) and PBAN receptors in H. armigera .