Revalidation of the polymorphic genus Acephalonomia (Hymenoptera: Bethylidae) and description of a new species from Micronesia

The genus Acephalonomia Strejček, 1990 is revalidated and its single species, Acephalonomia cisidophaga Strejček, 1990, from Czech Republic and Slovakia is restituted in the original combination. The revalidation is based on distinct characters: antennae with eight flagellomeres and prestigmal abscissa of R1 vein dilated. The intraspecifi c polymorphism is also relevant for revalidation, although not exclusively so. We redescribe and illustrate the type species Acephalonomia cisidophaga and describe and illustrate a second new species with eight antennal fl agellomeres from the Mariana Islands, Acephalonomia micronesica sp. n., and provide a key to this genus.