Oriental Fruit Fly Eradication by Male Annihilation

Abstract

During 1962–63 cane-fiber squares saturated with a solution of methyl eugenol-3% naled (by volume) and dropped from the air or suspended from trees eradicated a heavy infestation of oriental fruit flies, Dacus dorsalis Hendel, from the semi-isolated 33-square-mile Island of Rota, Mariana Islands. Most of the squares were dropped at 2-week intervals from an airplane flying over lines 1/5 mile apart. In inhabited areas permanent bait stations, re-treated monthly, were suspended from trees in lieu of aerial drops. Only 3.4 g of toxicant/acre were required for the entire operation. Male fly populations declined 99.6% within 1 generation. Virgin, sexually mature females were attracted and killed by the lure, but only after the male population was depressed 99%. Virgin females constituted 93% of flies caught in the 4th month; this response may have increased the efficiency of the method. Fly catches and fruit infestations ceased during the 6th month. The island has been free of oriental fruit flies for more than 24 months.