Calliphoridae (Diptera) do noroeste da América do Sul: diversidade, distribuição e código de barras genético

Abstract

The blow fly fauna of Northwest South America was studied based in three main approaches: 1. Local diversity of assemblages; 2. geographical distribution of their species; and 3. efficacy of short DNA sequences (Mini barcode) to identify their species. In order to study the patterns of species richness, abundance and dominance of local assemblages, three scenarios were chosen: the Amazonian interfluvial region; an altitudinal gradient in the Andean belt and the Páramo ecosystem. By the other hand, the geographical information of 13.474 specimens belonging to 28 species, deposited in eleven entomological collection of Brazil, Colombia, Ecuador and Venezuela was retrieved. Based on this data, it was possible to make a preliminary regionalization into six natural divisions: Amazon, Andes, Caribbean, Orinoquia, Pacific and Tepuyan region. It was also possible to identify preliminary patterns of geographical distribution and classify the blow fly species according to the biographic origin as follow: Tropical (25 spp); Temperate (4 spp) and Introduced (4spp). According to the altitudinal distribution, 17 species come from lowlands; 27 of montane and 8 of high elevations. Finally according to the level of synanthropy: 14 species were asynanthropic; 13 hemisynanthropic and 14 eusynanthropic. We recovered short mitochondrial DNA sequences (Mini barcodes of 317bp) from 143 specimens of thirty Neotropical species. This molecular marker allow the species identification of Calliphora, Chrysomya, Cochliomyia, Compsomyiops, Sarconesia, and Hemilucilia. However, it was not suitable for the correct identification of Lucilia species. In addition, we recovered genetic information from old preserved specimens deposited in museums for up to 57 year. The global diversity patterns together with the local assemblages assessed demostrated that the existence of an altitudinal gradient affects the composition of the blow fly fauna in the region. Being the most diverse assemblages, those located at intermediate elevations and the less diverse the perennial páramo ecosystem. The noticeable sensibility of blow flies to anthropized environments, the relative low number of species and their ubiquity, together with their relatively stable taxonomy, makes this group of flies as an ideal indicator of the level of human influence in environments of Northwest South America.