Schaus (1929: 49) described Boalda gyona in a monobasic genus known only from the holotype taken in Santa Catarina, Brazil. Biezanko et al. (1957) reported the species from Uruguay. A number of specimens of Boalda similar to gyona were collected recently in Paraguay, at least two of which match the anomalous Argentinian taxon Nephelistis pulcherrima Köhler (1947: 77-78). Herein the genus Boalda is reviewed, with one new species described from the Paraguayan samples, and with N. pulcherrima transferred Boalda. A singleton specimen from Parque Nacional Cerro Corá, Dpto. Amambay, Paraguay, is figured but not described as a distinct species because of a lack of additional specimens.
Keywords: Lepidoptera, Noctuidae.