CHEMICALLY MEDIATED MATING SUCCESS IN MALE ORIENTAL FRUIT-FLIES (DIPTERA, TEPHRITIDAE)

Males of the oriental fruit fly, Bactrocera dorsalis (Hendel), are highly attracted to the chemical methyl eugenol. Despite wide use of this lure in detection and eradication programs, little attention has been given to explaining the underlying biological basis of this sex-specific attraction. Here, we report results of laboratory experiments that examined effects of methyl eugenol on mating behavior of male B. dorsalis. Treated males that fed on methyl eugenol mated more frequently than control males that had had no prior exposure to the lure. The effect of methyl eugenol was relatively long lasting; treated males whose feeding was restricted to 30 s had a mating advantage 35 d later. Enhanced mating success appeared to result from two factors: treated males displayed higher levels of wing-fanning than control males; also, for a given level of wing-fanning, treated males attracted more females per minute than did control males, indicating that signals produced by treated males were more attractive to females. Mechanisms and the possible adaptive function of female choice are discussed, and potential usefulness of prerelease exposure to lures is noted for sterile insect programs.