Simuliidae (Diptera: Nematocera) na diagonal de áreas secas da América do Sul

Abstract

Simuliidae, popularly known as black flies, is a cosmopolitan group that has recognized importance, mainly due to the adults of some species are vectors of diseases such as onchocerciasis and mansonelliasis. There are currently 2135 valid species of Simuliidae (including 12 fossil) of which approximately 355 are found in the Neotropical region, with 90 recorded in Brazil. Understanding the distribution and species composition of species is one of the most important achievements for scientific studies, as well as provide assistance in defining conservation areas. The choice of Simuliidae as a target group of this study is due to several factors: I) is a group of aquatic insects with well developed taxonomy in the Neotropics; II) description and identification to the species level; III) medical importance -veterinary; IV) importance to ecological processes; V) it is a group of aquatic insetcs extremely important to lotic systems as filter feeders and also are considered as indicators of environmental quality and VI) lack of studies about the group in the state of Mato Grosso do Sul In this studythere are two chapters. The first one is about the distribution and diversity of Simuliidae in the State of Mato Grosso do Sul with a list of species of blackflies collected in 47 bodies of water in the two major watersheds: Paraná and Paraguay. In total 18 species were reported to the state, including two new records: Simulium dinellii (Joan) and Simulium virescens (Hamada, Silva & Pereira). The second chapter is a large-scale study on species of Simuliidae from the South America dry diagonal area. Our main focus was to analyze the pattern of species richness of Simuliidae with the principle of extreme deconstruction of common and rare species, to understand the role of environmental and spatial predictors from the models: i) common and rare species respond distinctly to spatial and environmental predictors and ii) if both species, common and rare, respond to the same sets of predictors "environmental and space." Although the environmental portion has not been high throughout the deconstruction (~ 10%), it remained relatively constant indicating that the role of the environment unbound space does not change along the gradient of common-rare. Our result is somewhat surprising, because the patterns of species richness are relatively rare poorly explained by environmental factors. Our study extends the Neotropics discussion of low predictive power of landscape variables in understanding the community structure of macroinvertebrates in streams.