provided by Catalog of Hymenoptera in America North of Mexico
The North American fauna is very poorly known and probably a large number of taxa remain to be collected and described. Except in the Aphelopinae the sexes are strongly dimorphic and difficult to associate except by rearing. Males appear to be extremely rare or lacking in many species. Classification of the family is based entirely on characters of the females. ~These small wasps parasitize nymphs of Homoptera, principally species belonging to the Fulgoridae, Cercopidae, Membracidae and Cicadellidae. The wasp larvae develop endoparasitically in the host abdomen. In the later stages of development the parasite protrudes from the host abdomen as a cyst, formed from the moulted skins of the parasite in the Anteoninae, Dryininae and Gonatopodinae, but from the host tissues in the Aphelopinae. Pupation takes place in a cocoon spun on the host's food plant or in the soil.