Riqueza e distribuição das espécies da guilda de drosofilídeos frugívoros (Diptera), em resposta às variações ambientais pela estratificação da floresta e topografia

Abstract

Among the factors that may influence the distribution of the species are the climate, the topography and the strata of the vegetation. Diptera that make up the Drosophilidae family are insects closely adapted to the physical conditions of their environment, and responses to environmental conditions are reflected in community structure, population size and local species composition. The variation effect of the climatic elements and topography in microscale on the richness, composition and distribution of abundance of frugivorous Drosophilidae was tested, in an area of dense ombrophilous of “terra firme” forest. The collections were conducted in April / 2016, September / 2016 and September-October / 2017 in the Amazonian Biodiversity Research Program (PPBio) in the Amapá National Forest (0 ° 40 "N, 51 ° 10" W; 50 °, 52 ° 30 ° W). The insects were collected using traps with fermented banana bait in 100g portions. There were 2.028 insects belonging to the family Drosophilidae, with 674 males distributed in 19 species. The species were distributed selectively between the vertical strata of vegetation and topographic profiles, with greater richness found in the understorey and lower topographic levels of the forest. The environmental heterogeneity was demonstrated by the variations of canopy opening, temperature and relative humidity of the air. Independently of the expedition, the species, except D. sturtevanti, demonstrated constancy in the occupation of the strata. The different microclimatic conditions between the forest strata and topographic profiles were determinant for the community structure of drosophilids. However, observed differences between expeditions indicate that other factors may also interfere with the behavior of these organisms causing variations in community.