The following two new species of biting midges of Culicoides Latreille are described and photographed: Culicoides carbonelli Spinelli Martínez from Uruguay, and C. dellapei Spinelli, Ronderos Díaz from Argentina. Culicoides crucifer Clastrier, 1968 and C. hoffmani Fox, 1946 are diagnosed and newly recorded from Argentina, and the studied specimens are photographed.
Keywords: Diptera, Biting midges, Argentina, Uruguay, aquatic insects.