none The results of this study contribute to the development of mass rearing procedures for Biosteres tryoni (Cameron) by providing a method for producing adequate number for releases, and by determining the potential for the use of this species in suppression programs against the Mediterranean fruit fly, Ceratitis capitata (Wiedenmann). Progeny production per cage of 200 females was 1,483.6 adult parasitoids per generation when oviposition exposure period was 6 hours per day. A yield of 94.4% of total progeny was obtained during a parasitoid age interval of 5 to 20 days. Progeny production and ratio of females declined significantly during the age interval of 21 to 30 days. Host larvae exposure periods of 4, 6, and 8 hours per day appeared to be optimum for parasitoid production even though parasitoids achieved their highest rate of reproduction per unit time after 2 hours exposure for oviposition.