Antennal olfactory sensitivity and its age-dependence in the hemimetabolous insect Metcalfa pruinosa

Metcalfa pruinosa is a highly polyphagous, invasive insect in Europe with the capability of transferring phytoplasma. In the present study, we aim to identify volatile organic compounds that may act as semiochemicals for M. pruinosa. Using a dynamic volatile collection system, volatile organic compounds were collected from Ailanthus altissima, Aristolochia clematitis and Tagetes patula. Compounds were identified using gas chromatography–mass spectrometry. We also tested the electrophysiological responses of M. pruinosa to the collected volatile organic compounds using gas chromatography-electroantennographic detection. In total, 77 volatile organic compounds were identified, and 29 compounds elicited an electroantennographic response. We analysed responses to volatile organic compounds extracted from Tagetes patula to compare antennal sensitivity between developmental stages and sexes. No differences were found in responders' number or response amplitude between males and females or adults and nymphs for any volatile. Based on the detected compounds, M. pruinosa adult females and males seem to have similar ecological needs in the host habitat. However, when we compared the response amplitudes among compounds, significant differences were found. These differences suggest that (E)-4,8-dimethyl-nonatriene, methyl salicylate, and piperitone could have an important role in M. pruinosa's behaviour. This is the first contribution to M. pruinosa olfaction profile providing a base for future semiochemical-based pest control tactics.