Diversity of biting midges of the genus Culicoides Latreille (Diptera: Ceratopogonidae) in the area of the Yacyretá Dam Lake between Argentina and Paraguay.

The Culicoides communities have been analyzed between 1993/1998 in the area influenced by the Yacyret Dam Lake (Paran River, Argentina-Paraguay). Adults of Culicoides were collected monthly by using CDC light traps exposed for 24 h in 9 sampling sites located at both margins of the river; 21 species were recorded. Highest values of species richness were recorded during 1993/1994, being Quiteria and Corpus the sites with the higest number of species (10 and 11, respectively). The species diversity was elevated in Quiteria, Zaim n, Candelaria, Santa Tecla, Capit n Meza and Corpus (Shannon's diversity index 1.0-1.9) while Corate , Ituzaing and Aguapey showed less richness and diversity. The more abundant species were C. insignis, C. venezuelensis, C. leopoldoi, C. limai, C. flinti, C. debilipalpis, C. paraensis and C. guttatus. C. insignis, potential vector of bluetongue virus (BTV) to domestic and wild rumiants in the Neotropical region, is the predominant species in the area and was the only species widely distributed. C. paraensis, a proven vector of Oropouche virus to humans, is a common and abundant species. C. pusillus and C. lahillei, potential vectors of BTV and a filarial parasite, respectively, were occasionally collected. The taxonomic structure of communities was constant during the study period. The occasional species were not characteristic to one particular site and their presence could be related to non-intrinsic conditions.