ELECTROPHYSIOLOGICAL RESPONSES OF THE MALE ANTENNA TO COMPOUNDS FOUNDIN THE FEMALE SEX-PHEROMONE GLAND OF SPODOPTERA-EXIGUA, (HUBNER) (LEPIDOPTERA, NOCTUIDAE)

Four compounds, (Z)-9-tetradecenyl acetate (Z9-14: Ac), (Z,E)-9,12-tet radecadienyl acetate (Z9,E12-14: Ac), (Z)-9-tetradecen-1-ol (Z9-14: OH ) and (Z,E)-9,12-tetradecadien-1-ol (Z9,E12-14: OH) were found in sex pheromone extracts of female Spodoptera exigua from Japan. The ratio o f these compounds was 60:98: 100:83, respectively. Electroantennogram analysis of male moths to these four compounds suggests that receptor cells for these compounds are present in their antenna. Single sensill um recordings from male-specific trichodea (type-1 trichodea) showed t hat the sensitivity of type-B cells (Z9-14: OH receptor cells) to Z9,E 12-14: OH was not significantly different from the sensitivity to Z9-1 4: OH, whereas the threshold of type-A cells (Z9,E12-14: Ac receptor c ells) to Z9-14: Ac was 1,000 times higher than the sensitivity to Z9,E 12-14: Ac. Z9,E12-14: OH was suggested to have some activity as a sex pheromone component in the Japanese population of S. exigua.