Abstract
Four compounds, tetradecyl acetate (14:OAc), (Z)-9-tetradecenyl acetate (Z9-14:OAc), (E)-11-tetradecenyl acetate (E11-14:OAc), and (Z)-11-tetradecenyl acetate (Z11-14:OAc), have been identified in extracts of female pheromone glands of the limabean pod borer, Etiella zinckenella. A mixture of these four components successfully attracted a number of conspecific males in both Hungary and Egypt. Unfortunately, the mixture attracted only a few males, and the attractiveness was not equivalent to that of virgin females in soybean fields in Japan. We therefore analyzed the pheromone gland extract from Japanese E. zinckenella females by using gas chromatography-mass spectrometry. In addition to the four compounds previously identified, we found a dodecenyl acetate. The mass spectrum pattern and retention indices of the acetate coincided well with those of authentic (E)-9-dodecenyl acetate (E9-12:OAc). The attractiveness of the five-component mixture containing E9-12:OAc to male moths was significantly increased and equivalent to that of virgin females in field trapping tests. The numbers of males attracted did not significantly decrease when 14:OAc and E11-14:OAc were removed from the mixture, whereas almost no males were attracted when Z9-14:OAc, Z11-14:OAc, or E9-12:OAc was deleted. The results suggest that Z9-14:OAc, Z11-14:OAc, and E9-12:OAc are essential components of the sex attractant pheromone of E. zinckenella in Japan.
