Augmentative Releases of Diachasmimorpha tryoni (Hymenoptera: Braconidae) to Suppress a Mediterranean Fruit Fly (Diptera: Tephritidae) Population in Kula, Maui, Hawaii

Diachasmimorpha tryoni (Cameron), a larval parasitoid, was mass-reared in the laboratory and was used to suppress a wild Mediterranean fruit fly, Ceratitis capitata (Wiedemann), population in a nonisolated area (13 km(2)) of Kula, Maui, Hawaii. Weekly releases of D. tryoni, averaging 272,000 parasitoids per release, were made from March 10 to June 22, 1988. Trap catches of male C. capitata adults began to decline 8 weeks after the first release, and catches remained low throughout the summer months. However, in the control area of Keokea, adult catches began to increase in April and reached a peak in early July that was similar to that of previous years. The percentage of parasitism of C. capitata by D. tryoni was significantly higher for the six weekly collections of infested peaches in Kula than in the control area of Keokea: an average of 47.0% parasitism in Kula compared with 14.2% in Keokea. Of the total parasitoids, a significantly higher percentage of D. tryoni was recovered in fruit samples from Kula than in those from Keokea. Moreover, the number of C. capitata per fruit was significantly lower in the treated area than in the control area. (C) 1991 Academic Press, Inc.