Technical Abstract: The West Indian fruit fly, Anastrepha obliqua (Macquart), infests numerous fruit species, particularly Anacardiaceae and most importantly mango (Mangifera indica L.). Widespread in the Neotropics, it was first reported in Hispaniola nearly 70 years ago. Continental populations are attacked by the opiine braconid parasitoids Utetes anastrephae (Viereck) and Doryctobracon areolatus (Szépligeti). Largely sympatric, the two species co-exist through microhabitat specializations based on different ovipositor lengths and asymmetries in larval competitive abilities during multiparasitism. U. anastrephae, but not D. areolatus, is apparently native to the Dominican Republic. Since the two parasitoids share an evolutionary history over a substantial portion of their distributions it was proposed that 1) D. areolatus would find the Dominican environment suitable, as does U. anastrephae; and 2) that there would be no negative interactions when the two species were reunited and overall parasitism would increase. Immediately following releases, D. areolatus averaged 9% of adult insects recovered and two years after releases were concluded constituted a mean of 13%. By then the parasitoid had spread at least up to 50 km from release sites. There was no evidence of competitive exclusion of U. anastrephae by D. areolatus. Another opiine biological control candidate, Diachasmimorpha longicaudata (Ashmead), could be considered for release and establishment. Parasitoids alone are unlikely to provide economic levels of control, but can serve as components of an integrated pest management program established to maintain “fly-free” or “low prevalence” fruit export zones.