A new species belonging to the previously monotypic steganine genus Mayagueza Wheeler, 1960 (Diptera: Drosophilidae) is described. The new species, Mayagueza lopesi sp. nov., was collected in the Brazilian Cerrado. This is the first record of this genus for South America, and the description of the new species, based on male and female adult specimens, includes photographs and detailed illustrations of male and female terminalia.