Riqueza de Drosophilidae (DIPTERA) da Reserva Ducke, na Amazônia Ocidental

Abstract

The genus Drosophila comprises more than 2000 species of flies just over 2 mm long, distributed in virtually every region of the world, with most species being ecologically restricted, living in a single type of environment. Forests seem to be the preferred habitat for drosophilids, with the highest concentration of species. This work aims to inventory the diversity of Drosophila species attracted to banana baits in an area of dryland primary forest in the Ducke Reserve, in the city of Manaus, Western Amazon region, surrounded by urban occupation. Samples were collected between December 5 and 15, 2005, in an area of 25 km', divided into 5 km trails (north-south direction), cut by perpendicular trails of the same size (east-west direction), every 1 km apart. On each of the north-south trails, 250-m transects were established at 1-km intervals at the midpoint of the transects. Collections were made within these transects, with traps containing banana bait. Six traps were distributed along each transect, 40 m apart and 1 m above ground level, totaling 180 traps in the 30 transects. Each trap remained in the field for 48 h. From the individuals from these samples, females were separated for later lineage formation (used in species identification) and for laboratory experiments. In 175 samples analyzed, 270 individuals were counted, identified in 20 species of drosophilids. Based on the collection methodology used and the samples identified so far, the completeness of the inventory reached about 66 %. The richness estimation analyses indicate a maximum of 32 Drosophila species for the Ducke Reserve, which, if confirmed, will show a lower richness than the Caxiuanã National Forest, Pará State, Eastern Amazon region, evaluated in previous work.