Chalcidoidea (Hymenoptera) is extremely diverse with an estimated 500 000 species. We present the first phylogenetic analysis of the superfamily based on both morphological and molecular data. A web‐based, systematics workbench mx was used to score 945 character states illustrated by 648 figures for 233 morphological characters for a total of 66 645 observations for 300 taxa. The matrix covers 22 chalcidoid families recognized herein and includes 268 genera within 78 of 83 subfamilies. Morphological data were analysed alone and in combination with molecular data from ribosomal 18S (2105 bp) and 28S D2–D5 expansion regions (1812 bp). Analyses were analysed alone and in combined datasets using implied‐weights parsimony and likelihood. Proposed changes in higher classification resulting from the analyses include: (i) recognition of Eriaporidae, revised status; (ii) recognition of Cynipencyrtidae, revised status; (iii) recognition of Azotidae, revised status; (iv) inclusion of Sycophaginae in Agaonidae, revised status; (v) reclassification of Aphelinidae to include Aphelininae, Calesinae, Coccophaginae, Eretmocerinae and Eriaphytinae; (vi) inclusion of Cratominae and Panstenoninae within Pteromalinae (Pteromalidae), new synonymy; (vii) inclusion of Epichrysomallinae in Pteromalidae, revised status. At a higher level, Chalcidoidea was monophyletic, with Mymaridae the sister group of Rotoitidae plus the remaining Chalcidoidea. A eulophid lineage was recovered that included Aphelinidae, Azotidae, Eulophidae, Signiphoridae, Tetracampidae and Trichogrammatidae. Eucharitidae and Perilampidae were monophyletic if Eutrichosomatinae (Pteromalidae) was included, and Eupelmidae was monophyletic if Oodera (Pteromalidae: Cleonyminae) was included. Likelihood recovered a clade of Eupelmidae + (Tanaostigmatidae + (Cynipencyrtus + Encyrtidae). Support for other lineages and their impact on the classification of Chalcidoidea is discussed. Several life‐history traits are mapped onto the new phylogeny.

The family Pteromalidae (Hymenoptera: Chalcidoidea) is reviewed with the goal of providing nomenclatural changes and morphological diagnoses in preparation for a new molecular phylogeny and a book on world fauna that will contain keys to identification. Most subfamilies and some tribes of Pteromalidae are elevated to family level or transferred elsewhere in the superfamily. The resulting classification is a compromise, with the aim of preserving the validity and diagnosability of other, well-established families of Chalcidoidea. The following former subfamilies and tribes of Pteromalidae are elevated to family rank: Boucekiidae, Ceidae, Cerocephalidae, Chalcedectidae, Cleonymidae, Coelocybidae, Diparidae, Epichrysomallidae, Eunotidae, Herbertiidae, Hetreulophidae, Heydeniidae, Idioporidae, Lyciscidae, Macromesidae, Melanosomellidae, Moranilidae, Neodiparidae, Ooderidae, Pelecinellidae (senior synonym of Leptofoeninae), Pirenidae, Spalangiidae, and Systasidae. The following subfamilies are transferred from Pteromalidae: Chromeurytominae and Keiraninae to Megastigmidae, Elatoidinae to Neodiparidae, Nefoeninae to Pelecinellidae, and Erotolepsiinae to Spalangiidae. The subfamily Sycophaginae is transferred to Pteromalidae. The formerly incertae sedis tribe Lieparini is abolished and its single genus Liepara is transferred to Coelocybidae. The former tribe Tomocerodini is transferred to Moranilidae and elevated to subfamily status. The former synonym Tridyminae (Pirenidae) is treated as valid. The following former Pteromalidae are removed from the family and, due to phylogenetic uncertainty, placed as incertae sedis subfamilies or genera within Chalcidoidea: Austrosystasinae, Ditropinotellinae, Keryinae, Louriciinae, Micradelinae, Parasaphodinae, Rivasia, and Storeyinae. Within the remaining Pteromalidae, Miscogastrinae and Ormocerinae are confirmed as separate from Pteromalinae, the former tribe Trigonoderini is elevated to subfamily status, the former synonym Pachyneurinae is recognized as a distinct subfamily, and as the senior synonym of Austroterobiinae. The tribe Termolampini is synonymized under Pteromalini, and the tribe Uzkini is synonymized under Colotrechnini. Most former Otitesellinae, Sycoecinae, and Sycoryctinae are retained in the tribe Otitesellini, which is transferred to Pteromalinae, and all other genera of Pteromalinae are treated as Pteromalini. Eriaporidae is synonymized with Pirenidae, with Eriaporinae and Euryischiinae retained as subfamilies. Other nomenclatural acts performed here outside of Pteromalidae are as follows: Calesidae: elevation to family rank. Eulophidae: transfer of Boucekelimini and Platytetracampini to Opheliminae, and abolishment of the tribes Elasmini and Gyrolasomyiini. Baeomorphidae is recognized as the senior synonym of Rotoitidae. Khutelchalcididae is formally excluded from Chalcidoidea and placed as incertae sedis within Apocrita. Metapelmatidae and Neanastatidae are removed from Eupelmidae and treated as distinct families. Eopelma is removed from Eupelmidae and treated as an incertae sedis genus in Chalcidoidea. The following subfamilies and tribes are described as new: Cecidellinae (in Pirenidae), Enoggerinae (incertae sedis in Chalcidoidea), Erixestinae (in Pteromalidae), Eusandalinae (in Eupelmidae), Neapterolelapinae (incertae sedis in Chalcidoidea), Solenurinae (in Lyciscidae), Trisecodinae (in Systasidae), Diconocarini (in Pteromalidae: Miscogastrinae), and Trigonoderopsini (in Pteromalidae: Colotrechninae). A complete generic classification for discussed taxa is provided.

Chalcidoidea (Hymenoptera) are extremely diverse with more than 23,000 species described and over 500,000 species estimated to exist. This is the first comprehensive phylogenetic analysis of the superfamily based on a molecular analysis of 18S and 28S ribosomal gene regions for 19 families, 72 subfamilies, 343 genera and 649 species. The 56 outgroups are comprised of Ceraphronoidea and most proctotrupomorph families, including Mymarommatidae. Data alignment and the impact of ambiguous regions are explored using a secondary structure analysis and automated (MAFFT) alignments of the core and pairing regions and regions of ambiguous alignment. Both likelihood and parsimony approaches are used to analyze the data. Overall there is no impact of alignment method, and few but substantial differences between likelihood and parsimony approaches. Monophyly of Chalcidoidea and a sister group relationship between Mymaridae and the remaining Chalcidoidea is strongly supported in all analyses. Either Mymarommatoidea or Diaprioidea are the sister group of Chalcidoidea depending on the analysis. Likelihood analyses place Rotoitidae as the sister group of the remaining Chalcidoidea after Mymaridae, whereas parsimony nests them within Chalcidoidea. Some traditional family groups are supported as monophyletic (Agaonidae, Eucharitidae, Encyrtidae, Eulophidae, Leucospidae, Mymaridae, Ormyridae, Signiphoridae, Tanaostigmatidae and Trichogrammatidae). Several other families are paraphyletic (Perilampidae) or polyphyletic (Aphelinidae, Chalcididae, Eupelmidae, Eurytomidae, Pteromalidae, Tetracampidae and Torymidae). Evolutionary scenarios discussed for Chalcidoidea include the evolution of phytophagy, egg parasitism, sternorrhynchan parasitism, hypermetamorphic development and heteronomy.

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 Torymidaes.s. (stat. rev.). Within Torymidaes.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 ofGlyphomerus,Thaumatorymus,Zaglyptonotus) are assigned to tribes within our new classification. Five genera are restored from synonymy—AmeromicrusandDidactyliocerusfrom underTorymoides(stat. rev.),IridophagaandIridophagoidesfrom underPodagrionella(stat. rev.) andNannocerusfrom underTorymus(stat. rev.)—and three genera are synonymized—AllotorymusunderTorymussyn. nov.,DitropinotusunderEridontomerussyn. nov.andPseuderimerusunderErimerussyn. 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 Torymidaes.s. is ectoparasitism on gall‐forming Cynipidae. The life strategy and putative hosts of the common ancestor of Megastigmidae remain uncertain.

Chalcidoidea are mostly parasitoid wasps that include as many as 500 000 estimated species. Capturing phylogenetic signal from such a massive radiation can be daunting. Chalcidoidea is an excellent example of a hyperdiverse group that has remained recalcitrant to phylogenetic resolution. We combined 1007 exons obtained with Anchored Hybrid Enrichment with 1048 ultra‐conserved elements (UCEs) for 433 taxa including all extant families, >95% of all subfamilies, and 356 genera chosen to represent the vast diversity of the superfamily. Going back and forth between the molecular results and our collective knowledge of morphology and biology, we detected bias in the analyses that was driven by the saturation of nucleotide data. Our final results are based on a concatenated analysis of the least saturated exons and UCE datasets (2054 loci, 284 106 sites). Our analyses support an expected sister relationship with Mymarommatoidea. Seven previously recognized families were not monophyletic, so support for a new classification is discussed. Natural history in some cases would appear to be more informative than morphology, as illustrated by the elucidation of a clade of plant gall associates and a clade of taxa with planidial first‐instar larvae. The phylogeny suggests a transition from smaller soft‐bodied wasps to larger and more heavily sclerotized wasps, with egg parasitism as potentially ancestral for the entire superfamily. Deep divergences in Chalcidoidea coincide with an increase in insect families in the fossil record, and an early shift to phytophagy corresponds with the beginning of the “Angiosperm Terrestrial Revolution”. Our dating analyses suggest a middle Jurassic origin of 174 Ma (167.3–180.5 Ma) and a crown age of 162.2 Ma (153.9–169.8 Ma) for Chalcidoidea. During the Cretaceous, Chalcidoidea may have undergone a rapid radiation in southern Gondwana with subsequent dispersals to the Northern Hemisphere. This scenario is discussed with regard to knowledge about the host taxa of chalcid wasps, their fossil record and Earth's palaeogeographic history.

Two new genera, Striastigmus, gen. nov., and Vitreostigmus, gen. nov., as well as three new species, S. bicoloratus, sp. nov., V. maculatus, sp. nov., and V. kangarooislandi, sp. nov., are described from Australia. A key to species of Vitreostigmus is provided as well as new information on the biology of genus Bortesia. Potential hosts of the newly described genera are discussed.