Allyl-2,6-Dimethoxyphenol, A Female-Biased Compound, Is Robustly Attractive To Conspecific Males Of Bactrocera Dorsalis At Close Range

Insect cuticular hydrocarbons (CHCs) play important roles in mate recognition and chemical communication. To explore the cues regulating courtship and mating behaviour in the oriental fruit fly, Bactrocera dorsalis (Hendel) (Diptera: Tephritidae), CHCs were extracted from mature virgin female and male oriental fruit flies using n-hexane. Nine compounds - i.e., 4-allyl-2,6-dimethoxyphenol (designated 'compound 3') and eight ester compounds - had significantly greater abundance in female samples than in males. Of these nine compounds, six (1, 2, 4, 5, 6, and 8) elicited electrophysiological responses from the antennae of male flies. Compound 3 did not elicit a detectable male antennal response, but in Y-tube olfactometer bioassays, it exhibited robust attractiveness to conspecific males at close range. We speculate that compound 3 is a close-range sex pheromone in B. dorsalis. A mating competition experiment revealed that compound 3 significantly increased the competitiveness of males, which implied that compound 3 might be used in control programs of B. dorsalis.