INFLUENCE OF METHOPRENE ON THE AGE-RELATED MATING PROPENSITY OF MALES OF THE ORIENTAL FRUIT FLY AND THE MEDITERRANEAN FRUIT FLY (DIPTERA: TEPHRITIDAE)

The application of juvenile hormone (or chemical analogs, such as methoprene) to newly emerged adult male fruit flies (Diptera: Tephritidae) represents a promising method to improve the efficiency of the Sterile Insect Technique against economically important species. This procedure has been shown to accelerate male sexual maturity in species with a long pre-copulatory period, and could allow for release of sterile males at younger ages and a greater release rate of sterile males overall. Topical application of methoprene has been shown to enhance male mating competitiveness. The present study investigated the effect of methoprene on maturation speed in males of the oriental fruit fly, Bactrocera dorsalis (Hendel) (a 'slow' maturing species) and the Mediterranean fruit fly, Ceratitis capitata (Wiedemann) (a 'fast' maturing species). For both species, newly emerged males were treated with acetone containing methoprene (treated) or acetone alone (control). The mating propensity of males was then monitored in non-competitive environments with mature females. Contrary to other studies, we found no evidence that methoprene accelerated male sexual activity in either a wild-like or mass-reared strain of B. dorsalis or a mass-reared (genetic sexing strain) of C. capitata. Possible explanations for these results are discussed.