Effects of land use on black fly assemblages (Diptera: Simuliidae) in submontane rivers (West Carpathians, Slovakia)

Abstract

The effects of land use on black fly assemblages were investigated in submontane rivers (the Ľubochnianka River, the Revuca River, upper Vah River catchment) in the Carpathians. We recorded 11 black fly species in the Ľubochnianka River and 10 species in the Revuca River. Land use differs between the catchments; the Ľubochnianka is a primarily forested catchment, and the Revuca is markedly deforested catchment. Fifteen environmental variables were analysed. Based on the results provided by CANOCO, phosphorus level and stream slope are the most important variables and have significant influences on the variability of black fly assemblages. In spring, Prosimulium rufipes occurred along the entire lengths of the streams. The black fly assemblage of the Revuca River differs from the assemblage of the Ľubochnianka River mainly by its higher abundances of Simulium variegatum and Simulium ornatum, by the presence of Simulium carthusiense, and by the absence of Prosimulium hirtipes.