Flower-feeding affects mating performance in male oriental fruit flies Bactrocera dorsalis

1. Males of the oriental fruit fly Bactrocera dorsalis are attracted to and feed on flowers of the golden shower blossom Cassia fistula. Flowers of th is plant contain methyl eugenol, the metabolites of which apparently functi on in the synthesis of male sex pheromone. 2. The goal of the study reported here was to determine whether feeding on C. fistula flowers enhanced male mating success. Mating frequencies of unfe d (control) and fed (treated) males were compared in trials conducted 0 (sa me day), 2, 7, or 21 days after treated males were exposed to the flowers. Trials were performed using flowers from three trees of C. fistula to inves tigate whether the effects of floral feeding were similar among different p lants. 3. For all three trees, treated males accounted for a disproportionately la rge number of matings in trials performed 0, 2, and 7 days after floral fee ding by the treated males. For two of the trees, treated males also had a m ating advantage 21 days after flower-feeding. 4. Additional tests were conducted to compare female attraction to perch si tes of control and treated males. When at a lek, males exhibit rigorous win g-fanning behaviour, presumably to increase dispersal of the sex pheromone. Floral feeding had no significant effect on the level of wing-fanning. Sig nificantly more female sightings were recorded for perches of treated than control males, however, suggesting that the treated males produced a pherom one more attractive to females than did control males.