Behavioral and Electrophysiological Study on Eight Japanese Papilio Species with Five Hostplant Volatiles and Linalool

An electroantennogram (EAG) technique compared the antennal olfactory responses by both sexes of eight Japanese Papilio species with known host plants in laboratory experiments. Papilio species were collected from Honshû and Kyûshû (Japanese islands). The behavioral responses to volatile leaf substances from Citrus deliciosa, Zanthoxylum ailanthoides, Phellodendron amurense, Orixa japonica, and Foeniculum vulgare were examined in laboratory experiments. Individual EAG reactions were recorded. The results were very similar to the empirical field observations. The electrophysiological results of both sexes showed that the volatile substances released from non-preferred plants mainly elicited more significant EAG responses than the volatile substances from preferred host plants. Moreover, we performed behavioral experiments using eight female butterflies and their responses to five host plant species. An association between host plant selection behavior and taxonomical classification exists within the Papilio genus. The EAG responses were small when exposed to the plants with high scores in the behavioral experiments. Host plant preference patterns seem to be related to the volatile substances within the host plants. The butterflies responded to Linalool in both the behavioral and electrophysiological experiments.