ABSTRACT
As the Mediterranean fruit fly, Ceratitis capitata, began its dramatic spread across the tropics and subtropics in later years of the 19th century an interest in its biological control followed close behind. The establishment of parasitoids had a considerable effect on Hawaiian fruit flies. The economic returns on even the more substantial fly mortalities were not always obvious. Irradiation improves parasitism rates, presumably by compromising the flies’ immune system. With the availability of augmented-parasitoid suppression techniques, a new eradication tactic becomes possible: combined releases of sterile males and natural enemies. Tim Wong and his colleagues in Hawaii more than tripled parasitism and substantially reduced Mediterranean fruit fly populations by releasing approximately 20,000 Diachasmimorpha tryoni per square kilometer per week. Irradiation of larvae prior to exposure to parasitoids prevents fertile flies from being included in mass-releases. Lowering numbers of flies, either through release of newly discovered/appreciated species or the augmentation of old favorites, can help support fly-free zones.
