1Laboratory of Chemical Ecology, Kyoto University, Kyoto 606-8502, Japan.
2Hawaiian Evolutionary Biology Program, University of Hawaii, Hawaii 96822, USA.
alpha-Copaene, a potent attractant for male Mediterranean fruit flies, Ceratitis capitata, is found as a minor component in the essential oils ofvarious plant species, including its hosts such as orange, guava and mango. Despite the specific attraction of male flies and the wide distribution of the compound in host plants, the biological significance of alpha-aeneremains unknown. In a laboratory test, lek-like behavior of C. capitata was induced artificially using a plastic leaf model treated with (+)-alpha-copaene. It was also found that (+)-alpha-copaene affected virgin females rovoking 'pseudomale' courtship behavior in the short-range bioassay. Mating occurred exclusively on the artificial leaves treated with alpha-copaene, suggesting the compound potentially to serve as a chemical cue to facilitate orientation of the flies to the "rendez-vous" site.