The genus Ernassa Walker currently consists of five species: Ernassa justina (Stoll), E. sanguinolenta (Cramer), E. ignata Travassos, E. gabrielae Travassos, and E. cruenta (Rothschild). For about 40 years, the genus has been treated with these species. However, a large series of specimens and the study of the characters of the male genitalia, makes evident that the genus is more diverse. Eight new species are described: Ernassa inexplorata sp. nov., , E. rufula sp. nov., , E. persivalei sp. nov., , E. tarisca sp. nov., , E. skinnerorum sp. nov., , E. harveyi sp. nov., , E. markpacei sp. nov. and E. abscondita sp. nov. This work proposes that the species E. cruenta (Rothschild) does not have a common origin with the other species of the genus. At the moment it is treated as incertae sedis.