A pheromone from cuticular hydrocarbons regulates mating behavior in the hoverfly Eupeodes corollae

• Eupeodes corollae mating peaked at 5 days post-emergence, with the highest copulation/success rates, shortest male latency, and stable duration. • Two cuticular pheromones, ( Z )-9-tricosene and n -tricosane, evoked strong electrophysiological responses in both sexes of E. corollae . • ( Z )-9-tricosene acts as a dual attractant for both sexes of E. corollae and stimulates male courtship behavior. Mating behavior is crucial for most insects, as it is closely tied to reproduction and population growth and relies heavily on chemical communication via cuticular hydrocarbons (CHCs) between individuals. However, little is known about the mating behavior of Eupeodes corollae , a natural enemy insect, and how CHCs help it communicate. In this study, we performed a behavioral assay of the mating process of hoverfly E. corollae . The cuticular hydrocarbons of both male and female hoverflies were identified by gas chromatography-mass spectrometry (GC-MS). The electrophysiological activities of these compounds on the antennae of hoverflies were further determined by gas chromatography coupled with electroantennogram detection (GC-EAD) and electroantennogram (EAG). The effects of these compounds on the behavioral selection and mating of hoverflies were also determined. The results showed that the mating process of hoverflies was divided into five stages: orientation, approaching, wing fanning, mounting, and copulation. Fifth-aged individuals exhibited the highest copulation and mating success rates, the shortest male latency, and stable mating duration. The results of the determination of cuticular compounds showed that the CHCs of male and female hoverflies exhibited sexually monomorphic chemical profiles, and two compounds ( Z )-9-tricosene and n -tricosane could cause significant electrophysiological responses in both male and female hoverflies. Behavioral bioassay results showed that ( Z )-9-tricosene can significantly induce the attraction response of male and female E. corollae and can effectively regulate the courtship behavior of male E. corollae . This finding provides a new perspective for a deeper understanding of hoverflies' chemical communication mechanism and a valuable scientific basis and potential application prospect for developing a pheromone-based behavior strategy to control pests.