The Hymenopteran superfamily Proctotrupoidea is a somewhat confusing assemblage of taxa, with new families being added (or removed) with surprising frequency, and very little to unify them all into a single natural group. It seems quite likely that the superfamily, as presently understood, is polyphyletic, consisting of at least two groups of otherwise unrelated wasps that have been lumped together because of superficial similarities and historical artifacts of classification. At least the following "clusters" of families do appear to be good groups: Austroniidae, Diapriidae, Maamingidae and Monomachidae in one group, and Heloridae, Pelecinidae, Peradeniidae, Proctotrupidae, and Vanhorniidae in another. The affinities of Proctorenyxidae and Roproniidae (which are closely related to one another) are still uncertain.
Only two of these families (Diapriidae and Proctotrupidae) have a substantial number of species - together they contain over 2000 species. The others are all tiny, often relictual groups. See links for individual families for details of life history and diversity.