The taxonomy of five South American species of Dargida Walker currently allocated in Leucania Ochsenheimer (four species) and in Lasionycta Aurivillius (one species) is revised. Leucania roseilinea (Köhler, 1947), Leucania phaeoneura Hampson, 1913, Leucania mocoides Dognin, 1897, Leucania alboradiata (Hampson, 1905) and Lasionycta radiata (Köhler, 1966), are here combined with the genus Dargida Walker for the first time (comb. nov.). Two new synonyms are proposed, Leucania roseilineoides Poole, 1989 is an objective junior synonym of Borolia roseilinea Köhler, 1947 (syn. nov.) (ICZN 51.4), and B. lilloana Köhler, 1947 is a subjective junior synonym of Leucania phaeoneura Hampson, 1913 (syn. nov.). Lectotype for Borolia lilloana is designated to ensure nomenclatural stability and recognizability of the taxon. All species are redescribed and discussed, and the habitus and male and female genitalia (when available) are given, as well as an updated geographical map.