Acaenitinae is a subfamily of the parasitic wasp family Ichneumonidae. It is distributed on all continents except Antarctica, although only one specimen has ever been discovered in South America. Little is known of the Acaenitinae. The only reared species was a koinobiont endoparasitoid of a weevil. There are 24 genera. Hosts are believed to be Coleoptera larvae in wood. Female Acaenitinae have a large triangular projecting genital plate.