Electroantennogram and Olfactory behavioral responses of Trabala vishnou gigantina (Lepidoptera: Lasiocampidae) to herbivore induced Hippophae rhamnoides leaf volatiles

The moth Trabala vishnou gigantina Yang, 1978 (Lepidoptera: Lasiocampidae), a leaf-eating pest, had a severe outbreak in the sea buckthorn, Hippophae rhamnoides L. (Elaeagnaceae) plantation in North China. This study aims to investigate the influence of volatiles emitted by T. vishnou gigantina -infested H. rhamnoides on the behavioral responses of T. vishnou gigantina , laying a basis for the development of plant-based elicitors. The chemical basis of herbivore insect host dynamics between these species were investigated, providing information for herbivore insect control methods. After identifying the compounds produced by the differences between healthy and infested plants, six critical volatile compounds were identified to explore their attractions to T. vishnou gigantina imagoes by using electroantennogram (EAG) and olfactory behavioral response experiments. The results showed that the EAG responses of T. vishnou gigantina imagoes did not only vary in these six different herbivore-infested volatiles, but also between different concentrations of the same volatile. The EAG responses to the herbivore-infested volatiles peaked at a stimulus concentration of 100 µg/µL, with Hexyl 2-methyl butyrate having the highest EAG response. The test results of olfactory behavioral responses had significant differences in the olfactory behavioral responses of female and male imagoes to the six herbivore-infested volatiles. Hexyl 2-methyl butyrate had the strongest attraction to female and male imagoes, followed by 2-ethylhexanol and longifolene. 2-ethylhexanol had a significant attraction to female imagoes, while there was no significant attraction to males.