Efeitos do desmatamento e da densidade populacional humana na abundância e diversidade de flebotomíneos (Diptera: Psychodidae) em um assentamento rural na Amazônia Central

Abstract

The sand fly are vectors of many parasites, including flagellates which cause leishmaniasis in tropical and subtropical regions. These insects can be found predominantly in forests, howevert, the impact of deforestation and subsequent colonization of these areas shown that the adaptation of some species in these environments.Under tthese premises, we realized a study of the sand flies fauna from Rio Pardo settlement, Presidente Figueiredo Municipality, Brazil. We observed the abundance and diversity of sand flies in four categories with differents degrees of deforestation and human population density: G1. High human population density and High deforestation; G2. Low human population density and high deforestation; G3. High human population density and low deforestation; G4. Low human population density and low deforestation. Material and Methods: in each category six collections were done in the following environments - forest, edge of forest, shrub, peridomicile and orchard with light traps (CDC); overnight in the months June, July, August 2009 and September, October, November 2010. A total of 3.073 specimens were collected, 1.163 females (37,8%) and 1.910 males (62,2%), and identified in 13 genera and 53 species. The most abundant genera were Nyssomyia and Psychodopygus. Some species captured five are incriminated as vectors of Leishmania: Nyssomyia antunesi (1.025 indivíduals), N. umbratilis (448), Trichophoromyia ubiquitalis (164), Psychodopygus amazonensis (82) e Bichromomyia flaviscutellata (76), found in forest and peridomicile. The largest abundances of species were observed in categories G1 and G3, both with high human population density; althought these differences were not statistically significant when compared with others; the Shannon-Wienner Indices shown the diversities in categories G2 and G3. Among these environments, the largest sandflies abundance was observed in the peridomicile and forest environments. Main conclusions: The results mayn suggest that even in area with high degree of deforestation and high human population, the abundance and diversity of sand flies still maintain in high numbers. Probably, human population densities produce favorable locations for maintenance life cycle of several species, providing potential site for breending, resting, reproduction and availability of sources meal.