Parasitoids of Anastrepha fraterculus (Wiedemann) and Ceratitis capitata (Wiedemann) infesting wild guava (Psidium guajava L.) and peach (Prunus persica (L.) Batsch) fruits in the southernmost extension of the Bolivian Yungas forest, in the Province of Tarija, were surveyed in Dec (early summer), Feb (mid summer) and Mar (late summer) 1999 and 2000. The abundance patterns and diversity of fruit fly larval-pupal parasitoid species were similar to previously published data for the southern and northern Yungas forests of Argentina. A total of 1,600 guavas and 800 peaches, weighing 57.713 kg and 24.544 kg, respectively, were collected yielding 13,080 tephritid puparia, 78.4% of which were A. fraterculus and 21.6% Ceratitis capitata (Wiedemann). We reared 712 larval-pupal parasitoids of the following species: Doryctobracon areolatus (Szépligeti), D. brasiliensis (Szépligeti), D. crawfordi (Viereck), Opius bellus Gahan, Utetes anastrephae (Viereck) (all Braconidae, Opiinae), Aganaspis pelleranoi (Brèthes) Odontosema anastrephae Borgmeier, and Lopheucoila anastrephae (Rohwer) (all Figitidae, Eucoilinae). Utetes anastrephae, O. anastrephae, and L. anastrephae are new fruit fly parasitoid reports for Bolivia, as well as O. anastrephae in the South American Yungas forest. A thorough sampling of other C. capitata and Anastrepha host plants, mostly native fruit species, will be necessary in the Yungas forest of Bolivia before further conclusions on abundance and composition of all fruit fly parasitoids can be reached.View this article in BioOne