Consumption of Methyl Eugenol by Male Bactrocera dorsalis (Diptera: Tephritidae): Low Incidence of Repeat Feeding

The tendency of male Bactrocera dorsalis (Hendel) to re-visit a methyl eugenol source following initial exposure was examined. The first field test investigated the effect of duration of exposure on subsequent capture probability. “Treated” males were allowed to feed on methyl eugenol for 30 s or had access to methyl eugenol for 1 h, 4 h, or 24 h immediately prior to release. Capture probabilities (1%-4%) did not differ significantly among the different treatments but were significantly below that (22%) recorded for “control” (unexposed) males. In a second field test, treated males were released 7 d, 21 d, or 35 d after an initial exposure (2 h) to methyl eugenol. Capture probabilities (11%-18%) did not differ significantly among the different treatments but were significantly below that (34%) recorded for control males. Laboratory tests yielded similar results as both the incidence and duration of re-feeding on methyl eugenol were uniformly low for males held 7 d, 21 d, or 35 d after their initial exposure. By exposing sterile males to the lure prior to release, it may be possible to combine programs of male annihilation and sterile insect release. The present findings also suggest that the effectiveness of male annihilation efforts may be reduced in areas where wild males have consumed sufficient amounts of methyl eugenol from natural sources.