抄録
Chemical components that attract males in the laboratory were extracted from the female elytra of the white-spotted longicorn beetle, Anoplophora malasiaca (Thomson) (Coleoptera: Cerambycidae), and found to be comprised of several sesquiterpene hydrocarbons. Males located females that had fed on the bark of the host plant Citrus unshiu more frequently than those fed on an artificial diet in the laboratory. Male attraction was also confirmed in the corresponding sesquiterpene fractions of the host plant. The sesquiterpene fractions of female elytra and C. unshiu leaves showed quite similar GC profiles. In the field, the beetles were found on C. unshiu trees baited with intact females or males as frequently as those baited with the leaf extracts containing the sesquiterpenes at different purification levels. The beetles were found on those baited trees significantly more frequently than on unbaited control trees. Males, as well as females attracted both sexes, and the male elytra also contained the sesquiterpenes that were identical with those in female and C. unshiu. This indicated that active components in the elytra are acquired from C. unshiu by feeding, contact and/or adsorption. These sesquiterpenes may serve for intraspecific communication in A. malasiaca. The major sesquiterpenes from the C. unshiu leaves were isolated and elucidated by NMR analyses of four sesquiterpene hydrocarbons, β-elemene, β-caryophyllene, α-humulene, and α-farnesene.
