The Megaspilidae are a small hymenopteran family with 12 genera in two subfamilies, and some 450 known species, with a great many species still undescribed. It is a poorly known group as a whole, though most are believed to be parasitoids (especially of sternorrhynchan Hemiptera), and a few hyperparasitoids. Many are found in the soil, and of these, a number are wingless. The family is distinguished from the closely related Ceraphronidae by having a very large stigma in the wing, a relatively constricted metasomal petiole, and three grooves in the mesoscutum.