Torymidae (Hymenoptera, Chalcidoidea) revised: molecular phylogeny, circumscription and reclassification of the family with discussion of its biogeography and evolution of life-history traits

Abstract

A phylogeny of the Torymidae (Chalcidoidea) is estimated using 4734 nucleotides from five genes. Twelve outgroups and 235 ingroup taxa are used, representing about 70% of the recognized genera. Our analyses do not recover Torymidae as monophyletic and we recognize instead two families: Megastigmidae (stat. rev.) and Torymidae s.s. (stat. rev.). Within Torymidae s.s., we recognize six subfamilies and six tribes, including Chalcimerinae, Glyphomerinae and Microdontomerinae (subf. nov.), and two new tribes: Boucekinini and Propalachiini (trib. nov.). Seven unclassified genera (i.e. Cryptopristus, Echthrodape, Exopristoides, Exopristus, part of Glyphomerus, Thaumatorymus, Zaglyptonotus) are assigned to tribes within our new classification. Five genera are restored from synonymy—Ameromicrus and Didactyliocerus from under Torymoides (stat. rev.), Iridophaga and Iridophagoides from under Podagrionella (stat. rev.) and Nannocerus from under Torymus (stat. rev.)—and three genera are synonymized—Allotorymus under Torymussyn. nov., Ditropinotus under Eridontomerussyn. nov. and Pseuderimerus under Erimerussyn. nov. A Palaearctic or Eurasian origin for Torymidae is proposed. The ancestral area of Megastigmidae is indicated as the Australian region. The most probable ancestral life strategy for Torymidae s.s. is ectoparasitism on gall-forming Cynipidae. The life strategy and putative hosts of the common ancestor of Megastigmidae remain uncertain.