Nine species of the genus Dasymutilla Ashmead have been recorded from South America. One additional species, D. campogrande Manley Pitts was erroneously recorded from Mexico but is from Brazil, and another species, D. colorado Cambra, Williams Quintero was recently discovered in Colombia. Four of these nine Dasymutilla belong to a new genus, Quwitilla Williams, Bartholomay Cambra, gen. nov., which includes: Q. peruviana (Suárez), comb. nov. (and its newly recognized female D. homochroma Suárez, syn. nov.; Q. bellatrix (Manley Pitts), comb. nov. (based on female only); and Q. blattoserica (Kohl) comb. nov. (type species, already known from both sexes). Two others are actually synonyms of previously recognized Traumatomutilla André species: Dasymutilla brazilia Manley Pitts, syn. nov. is a junior synonym of T. oculifera (Smith), and D. campogrande, syn. nov. is a junior synonym of T. inermis (Klug). One species is transferred out of Dasymutilla: Xystromutilla aequatorialis (André), comb. nov. Finally, updates and comments are provided on the distribution of D. araneoides (Smith), D. colorado, D. paradoxa (Gerstaecker), and D. pulchra (Smith), the only four South American species remaining in the genus Dasymutilla.
Keywords: Hymenoptera, Sphaeropthalminae, velvet ants, new synonymy, South America, Neotropics.