The Mediterranean fruit fly (and other related species) are among the most destructive and costly agricultural pests in the Pacific Basin, the Caribbean Basin, and other tropical and sub-tropical areas around the world. Fruit flies pose an enormous threat to the agricultural economies of Florida, California, Texas, and other states: it is estimated that establishment of medfly alone in the U.S. would cause annual losses in excess of one billion dollars. Modern genetic techniques have pinpointed the medfly’s origin as sub-Saharan Africa. It has been well documented that a number of biological control agents attack medfly and related species in this native region, and the vast majority of these agents have never been studied. This project is currently surveying, collecting, rearing, and importing these biological control agents (Hymenopterous parasitoids) for subsequent release into medfly-invaded areas. These parasitoids (see photo) are being tested in quarantine facilities for their ability to successfully attack New World populations of medfly and a number of related species. They will eventually be released in field crops in Hawaii, Florida, Mexico, and Guatemala and their ability to establish viable populations and contribute to reductions of pest infestation levels will be determined.