Pitfall trap sampling and light trapping for Mutillidae were conducted in Cache County, Utah. Males of the nocturnal mutillid species Dilophotopsis concolor crassa (Cresson), Odontophotopsis erebus (Melander), and Odontophotopsis melicausa (Blake) were collected. The females of these species are unknown. Sphaeropthalma nanula Dalla Torre and two unknown female morphospecies of nocturnal mutillids also were collected at the study site. By comparison of species-specific genetic loci, the females were matched to the males collected from the same locality. The female of D. concolor crassa is S. nanula; the latter has priority and represents a new combination in Dilophotopsis. The female of D. concolor nanula is redescribed. The females of the remaining two species also are described and all three are compared to other known nocturnal females.