The flea subgenus Neornipsyllus Smit, 1976, is revised and diagnostic criteria provided for it and the two other subgenera of Dasypsyllus Baker, 1905. A new species, Dasypsyllus (Neornipsyllus) lewisi, is described from a male (female unknown) collected from Thomasomys sp. (Rodentia: Muridae) in Piura Department, Peru. The male of Dasypsyllus (N.) araucanus (Jordan and Rothschild, 1920) is described for the first time and the species is first documented in Neuquén and Río Negro Provinces, Argentina. New country records are noted for Dasypsyllus (N.) comatus Jordan, 1933, from Diego Ramírez Archipelago, Chile and Dasypsyllus (N.) cteniopus (Jordan and Rothschild 1920) from Neuquén and Río Negro Provinces, Argentina. Dasypsyllus (N.) aemulus Jordan, 1933, is considered a junior synonym of Dasypsyllus (N.) stejnegeri (Jordan, 1929). A key to the Nearctic and Neotropical species of Dasypsyllus is provided. Dasypsyllus currently contains eleven valid taxa (two of subgenus Avesopsylla I. Fox and Anduze, 1947, three of subgenus Dasypsyllus, and six of subgenus Neornipsyllus).