Insects are the most speciose group of animals, but the phylogenetic relationships of many major lineages remain unresolved. We inferred the phylogeny of insects from 1478 protein-coding genes. Phylogenomic analyses of nucleotide and amino acid sequences, with site-specific nucleotide or domain-specific amino acid substitution models, produced statistically robust and congruent results resolving previously controversial phylogenetic relations hips. We dated the origin of insects to the Early Ordovician [~479 million years ago (Ma)], of insect flight to the Early Devonian (~406 Ma), of major extant lineages to the Mississippian (~345 Ma), and the major diversification of holometabolous insects to the Early Cretaceous. Our phylogenomic study provides a comprehensive reliable scaffold for future comparative analyses of evolutionary innovations among insects.

Hymenoptera (sawflies, wasps, ants, and bees) are one of four mega-diverse insect orders, comprising more than 153,000 described and possibly up to one million undescribed extant species [1, 2]. As parasitoids, predators, and pollinators, Hymenoptera play a fundamental role in virtually all terrestrial ecosystems and are of substantial economic importance [1, 3]. To understand the diversification and key evolutionary transitions of Hymenoptera, most notably from phytophagy to parasitoidism and predation (and vice versa) and from solitary to eusocial life, we inferred the phylogeny and divergence times of all major lineages of Hymenoptera by analyzing 3,256 protein-coding genes in 173 insect species. Our analyses suggest that extant Hymenoptera started to diversify around 281 million years ago (mya). The primarily ectophytophagous sawflies are found to be monophyletic. The species-rich lineages of parasitoid wasps constitute a monophyletic group as well. The little-known, species-poor Trigonaloidea are identified as the sister group of the stinging wasps (Aculeata). Finally, we located the evolutionary root of bees within the apoid wasp family "Crabronidae." Our results reveal that the extant sawfly diversity is largely the result of a previously unrecognized major radiation of phytophagous Hymenoptera that did not lead to wood-dwelling and parasitoidism. They also confirm that all primarily parasitoid wasps are descendants of a single endophytic parasitoid ancestor that lived around 247 mya. Our findings provide the basis for a natural classification of Hymenoptera and allow for future comparative analyses of Hymenoptera, including their genomes, morphology, venoms, and parasitoid and eusocial life styles.

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 Willi Hennig Society 2013. Without question, Chalcidoidea is one of the most megadiverse groups of insects. Their morphological diversity is staggering (Fig. 1). They range in size from such veritable giants as females of Leptofoenus (Pteromalidae), which exceed 20 mm, to the minute and morphologically bizarre male of Dicopomorpha echmepterygis (Mymaridae), the smallest known specimen of which is 0.13 mm long. Males of D. echmepterygis have lost eyes, ocelli, mouthparts, antennal flagellum, wings, tarsi except for a highly modified arolium, and virtually any other feature that places them as parasitic wasps (Fig. 1a). Other bizarrities include male fig wasps, which can be reduced to turtle-like fighting machines that bear no resemblance to their corresponding females and are hardly recognizable as chalcidoids, or the grotesquely enlarged scutellum (Fig. 1h) of Galearia latreillei (Eucharitidae) and the dart-shaped ovipositor sheaths (Fig. 1j) of Cameronella (Pteromalidae). Convergent morphology is also rampant, and enlarged...

A comprehensive data set of hymenopteran mesosomal anatomy is presented and analysed. Eighty-nine taxa, including three outgroups, were scored for 273 characters. Analyses were carried out under different weighting conditions (equal and implied weights). Topologies retrieved for the non-apocritan Hymenoptera were highly congruent with previously published results. Apocrita were always retrieved as monophyletic, as were most superfamilies. Relationships amongst apocritan superfamilies were mostly weakly corroborated. Stephanoidea were almost always the sister group to the remaining Apocrita. Evaniomorpha were usually retrieved, Ceraphronoidea being the sister group to Megalyroidea, and Evanioidea to Trigonaloidea. Aculeata did not always come out as monophyletic, and of the aculeate superfamilies, only Apoidea was retrieved. Ichneumonoidea were always monophyletic and often the sister group of Aculeata. Maamingidae and Mymarommatoidea were usually sister groups; together, they often form the sister group of Chalcidoidea. A large clade comprising Cynipoidea, Platygastroidea, and Proctotrupoidea was usually retrieved, the two former superfamilies being nested within Proctotrupoidea. Cynipoidea were usually closely related to some of the Diapriidae. Platygastroidea were usually the sister group of a clade comprising Heloridae, Pelecinidae, Proctotrupidae, and Vanhorniidae. The mesosomal region proved to be a very substantial source of phylogenetically relevant information. The results of the present analyses indicate that a reclassification, especially of Proctotrupoidea, is required, but this should be carried out after thorough analyses of more comprehensive combined data sets.

The first comprehensive analysis of higher-level phylogeny of the order Hymenoptera is presented. The analysis includes representatives of all extant superfamilies, scored for 392 morphological characters, and sequence data for four loci (18S, 28S, COI and EF-1a). Including three outgroup taxa, 111 terminals were analyzed. Relationships within symphytans (sawflies) and Apocrita are mostly resolved. Well supported relationships include: Xyeloidea is monophyletic, Cephoidea is the sister group of Siricoidea + [Xiphydrioidea + (Orussoidea + Apocrita)]; Anaxyelidae is included in the Siricoidea, and together they are the sister group of Xiphydrioidea + (Orussoidea + Apocrita); Orussoidea is the sister group of Apocrita, Apocrita is monophyletic; Evanioidea is monophyletic; Aculeata is the sister group of Evanioidea; Proctotrupomorpha is monophyletic; Ichneumonoidea is the sister group of Proctotrupomorpha; Platygastroidea is sister group to Cynipoidea, and together they are sister group to the remaining Proctotrupomorpha; Proctotrupoidea s. str. is monophyletic; Mymarommatoidea is the sister group of Chalcidoidea; Mymarommatoidea + Chalcidoidea + Diaprioidea is monophyletic. Weakly supported relationships include: Stephanoidea is the sister group of the remaining Apocrita; Diaprioidea is monophyletic; Ceraphronoidea is the sister group of Megalyroidea, which together form the sister group of [Trigonaloidea (Aculeata + Evanioidea)].