Trimedlure and the mating competitiveness of irradiated male Mediterraneanfruit flies (Diptera : Tephritidae)

Males of the Mediterranean fruit fly, Ceratitis capitata (Wiedemann), are a ttracted to trimedlure, a synthetic lure widely used in monitoring and erad ication programs. Previous work with wild males revealed that males exposed to trimedlure had a mating advantage over unexposed males under laboratory conditions. Here, I report the results of experiments that examine whether trimedlure increased the mating competitiveness of irradiated males from a long established laboratory colony (designated Maui-53 for location and ye ar [1953] founders were field-collected) relative to (unexposed) nonirradia ted males from a recently established laboratory colony (designated Maui-95 ). Maui-95 males achieved a disproportionately large number of matings when tested aginst unexposed Maui-53 males on feld-caged host plants. However, in tests conducted 1 d after exposure. Maui-53 males mated significantly mo re often than Maui-95 males. In tests conducted 3 and 7 d after exposure, M aui-53 males had the same mating success as Maui-95 males, Additional field studies revealed that both unexposed and exposed Maui-53 males spent more time pheromone-calling than Maui-95 males and consequently attracted greate r. numbers of females. Exposure to trimedlure resulted in a slight, but non significant, increase in the calling activity of Maui-53 males. Implication s of these results for control efforts of C. capitata are discussed.