The genus Crostis Casey (Coleoptera: Curculionidae: Baridinae) in North America.

The originally monobasic genus Crostis Casey, 1922 (type species Crostis subexplanata Casey, 1922 from Brazil) is redefined based on two named and approximately 15 unnamed species occurring between the southern United States and northern Argentina. Three oblong-ovate northern species here grouped informally as the Crostis boreas species group are described: Crostis boreas Prena Anderson new species from Arkansas and Texas in the U.S.A. and Quertaro and Tamaulipas in Mexico, Crostis boreodes Prena Anderson new species from Guanajuato and Michoacn in Mexico, and Crostis caperata Prena Anderson new species from Chiapas in Mexico. The South American Baridius thoracicus Kirsch, 1875 is transferred from Lamprobaris Champion, 1908 to Crostis, as Crostis thoracica (Kirsch) new combination.