FUNCTION OF CONTACT PHEROMONE IN THE MATING-BEHAVIOR OF THE CRYPTOMERIA BARK BORER, SEMANOTUS-JAPONICUS LACORDAIRE (COLEOPTERA, CERAMBYCIDAE)

Mating behavior of the male Cryptomeria bark borer, Semanotus japonicus LACORDAIRE, was elicited by the contact pheromone present on the body surface of the female. When the ether extract of the female body surface (female ether extract) was applied onto a glass rod (dummy), the male showed the mating behavior to the dummy. In contrast, when the ether extract of the male body surface male ether extract) was applied, the male did not exhibit the mating behavior toward the dummy. Chemical analysis of the female ether extract indicated that the sex pheromone fraction consisted of a mixture of n-, methyl-, dimethyl- and trimethylalkanes, and methyl- and dimethylalkene of 25 to 30 carbon number. A chemical analysis of the male ether extract evidenced the presence of both the sex pheromone fraction and of a hydrocarbon fraction that masks the sex pheromone activity. The chemically mediated mating and sex recognition system of the Cryptomeria bark borer is discussed.