Review of the Genus Mydas (Diptera: Mydidae): The xanthopterus Group of Southwestern United States and Mexico

The xanthopterus group of species of the genus Mydas is revised. The four species are M. luteipennis Loew (= M. simplex Loew, new synonymy); M. xanthopterus Loew (= M. lavatus Gerstaecker); M. evansi, new species; and M. fisheri, new species. The male and female terminalia of each species are illustrated. A lectotype is designated for M. xanthopterus. Illustrations also are provided for the male of M. subinterruptus Bellardi, a sympatric species which may be confused with M. luteipennis.