Avaliação das liberações inoculativas do parasitóide exótico Diachasmimorpha longicaudata (Ashmead)(Hymenoptera: Braconidae) em pomar diversificado em Conceição do Almeida, BA

Abstract

The introduction of exotic species aiming at the biological control of established pests rises concern on its efficiency and also on its impact on native species. Pre-release evaluation of the parasitoid complex is important because the releases initiate a continuous and irreversible colonization process. Surveys of native fruit fly parasitoids were conducted in the region of the Recôncavo Baiano, in Conceição do Almeida, BA, Brazil. Surveys were undertaken before and after the release of the exotic braconid Diachasmimorpha longicaudata (Ashmead). Pre-release survey showed that the following species were present in the study area: Doryctobracon areolatus (Szépligeti), Utetes anastrephae (Viereck), Opius spp., Asobara anastrephae (Muesebeck) and Aganaspis pelleranoi (Brèthes). Following D. longicaudata releases, the same species were obtained. Despite of interspecific competition for oviposition sites, no biodiversity losses were observed. Notwithstanding, an alteration in the relative frequencies of native species was observed. The exotic parasitoid was recovered from infested fruits of carambola, guava and Spondia sp. 17 months after the releases ceased. Nevertheless, in 2004 and 2005, no individuals of D. longicaudata were recovered from infested fruit samples collected in the same locality of release.