Simultaneous analysis of 16S, 28S, COI and morphology in the Hymenoptera: Apocrita - evolutionary transitions among parasitic wasps

Simultaneous analysis of morphological and molecular characters from the 16 S rDNA, 28S rDNA and cytochrome oxidase 1 genes was employed to resolve phy logenetic relationships among the apocritan (Insecta: Hymenoptera: Apocrita ) wasps. Parsimony analyses, employing a broad range of models, consistentl y recovered the Proctotrupomorpha as a natural group, the Megalyridae and T rigonalidae as sister groups, a clade comprising the Monomachidae, Diapriid ae, and Maamingidae, the Vanhorniidae and Proctotrupidae as sister groups, the Proctotrupoidea as polyphyletic, and the Evaniomorpha as a grade (but i ncluding the Ichneumonoidea, Aculeata, and Stephanidae). The Proctotrupomor pha, containing virtually all of the wholly endoparasitic lineages, was con sistently recovered as an apical clade, with the remaining groups forming a paraphyletic grade below them. Although the relative placement of the grou ps forming this basal grade varied among analyses, the most commonly recove red arrangement is consistent with the ancestral biology being ectoparasiti sm of coleopteran, wood-boring larvae. Furthermore, the recovery of the ect oparasitic-containing proctotrupomorphs (Chalcidoidea and, in some analyses , Ceraphronoidea) as apical lineages argues that these biologies are revers als. (C) 2001 The Linnean Society of London.