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 of (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.

Transient receptor potential (TRP) channels are a class of ion channel proteins that are closely related to thermosensation in insects. They are involved in detecting the ambient temperature and play vital roles in insect survival and reproduction. In this study, we identified and cloned two variants of the TRPA subfamily gene in Myzus persicae, MperTRPA1(A) and MperTRPA1(B), and analyzed their tissue expression by real-time quantitative PCR. Subsequently, these two variants of MperTRPA1 were expressed in the Xenopus oocyte system, and their functions were investigated using the two-electrode voltage clamp technique. The role of the MperTRPA1 gene in temperature adaptation of M. persicae was further determined by RNA interference and a behavioral choice assay to evaluate responses to temperature gradients. The results showed that the MperTRPA1 gene is widely expressed in tissues of M. persicae, with MperTRPA1(A) highly expressed in the mouthparts and MperTRPA1(B) mainly expressed in the antennae. The functional characterization results showed that both variants of MperTRPA1 could be activated and were not desensitized when the temperature increased from 20 to 45°C. The current value and thermal sensitivity (coefficient Q₁₀ value) of MperTRPA1(B) were significantly higher than those of MperTRPA1(A). When the MperTRPA1 gene was knocked down, the behavioral preference of M. persicae for the optimal temperature was reduced and tended to be at a higher temperature, showing a shift in the temperature adaptation range compared to both the wild type and dsGFP-treated M. persicae. In summary, our results elucidated the molecular mechanism of adaptive temperature perception in M. persicae mediated by the thermal sensor MperTRPA1.