Phylogeny of the subfamilies of Ichneumonidae (Hymenoptera)

Abstract

A combined morphological and molecular phylogenetic analysis was performed to evaluate the subfamily relationships of the parasitoid wasp family Ichneumonidae (Hymenoptera). Data were obtained by coding 135 morphological and 6 biological characters for 131 exemplar species of ichneumonids and 3 species of Braconidae (the latter as outgroups). The species of ichneumonids represent all of the 42 currently recognized subfamilies. In addition, molecular sequence data (cytochrome oxidase I “DNA barcoding” region, the D2 region of 28S rDNA and part of the F2 copy of elongation factor 1-alpha) were obtained from specimens of the same species that were coded for morphology (1309 base pairs total). The data were analyzed using parsimony and Bayesian analyses. The parsimony analysis using all data recovered previously recognized informal subfamily groupings (Pimpliformes, Ophioniformes, Ichneumoniformes), although the relationships of these three groups to each other differed from previous studies and some of the subfamily relationships within these groupings had not previously been suggested. Specifically, Ophioniformes was the sister group to (Ichneumoniformes + Pimplformes), and Labeninae was placed near Ichneumoniformes, not as sister group to all Ichneumonidae except Xoridinae. The parsimony analysis using only morphological characters was poorly resolved and did not recover any of the three informal subfamily groupings and very few of the relationships were similar to the total-evidence parsimony analysis. The molecular-only parsimony analysis and both Bayesian analyses (total-evidence and molecular-only) recovered Pimpliformes, a restricted Ichneumoniformes grouping and many of the subfamily groupings recovered in the total-evidence parsimony analysis. A comparison and discussion of the results obtained by each phylogenetic method and different data sets is provided. It is concluded that the molecular characters produced results that were relatively consistent with traditional, non-phylogenetic concepts of relationships between the ichneumonid subfamilies, whereas the morphological characters did not (at least not by themselves). The inclusion of both molecular and morphological characters using parsimony produced a topology that was the closest to the traditional subfamily relationships. The method of analysis did not greatly affect the overall topology for the molecular-only analyses, but there were differences between Bayesian and parsimony results for the total-evidence analyses (especially near the root of the tree). The Bayesian results did not seem to be altered very much by the inclusion of morphological characters, unlike in the parsimony analysis. In summary, the following groups were supported in multiple analyses regardless of the characters used or method of tree-building: Pimpliformes, higher Ophioniformes, higher Pimpliformes, (Claseinae + Pedunculinae), (Banchinae + Stilbopinae), Campopleginae, Cremastinae, Diplazontinae, Ichneumoninae (including Alomya), Labeninae, Ophioninae, Poemeniinae, Rhyssinae, and Tersilochinae sensu stricto. Conversely, Ctenopelmatinae and Tryphoninae were never recovered without inclusion of other taxa. Based on the hypothesis of relationships obtained by the total-evidence parsimony analysis, the following formal taxonomic changes are proposed: Alomyinae Förster (= Alomya Panzer and Megalomya Uchida) is once again synonymized with Ichneumoninae and is now considered a tribe (Alomyinirev. stat.); and Notostilbops Townes is transferred from Stilbopinae to Banchinae, tribe Atrophini.

Endogenization from diverse viral ancestors is common and widespread in parasitoid wasps

“…The hyperdiversity of species within the Ichneumonidae has made their evolutionary relationships historically difficult to resolve. However, recent studies Klopfstein et al 2019;Bennett et al 2019) have confirmed results from a single gene phylogeny to show that Campopleginae and Banchinae are not closely related to each other. Two previous studies have described the IVSPERs in a single member of each of these subfamilies, and from extensive overlap of the catalogue of IVSPER genes, concluded that these EVEs came from similar, if not identical virus ancestors (Béliveau et al 2015;Volkoff et al 2010) .…”

The Unconventional Viruses of Ichneumonid Parasitoid Wasps

“…Subsequently, another event of virus integration occurred in the Venturia lineage of the campoplegine subfamily: an alphanudivirus was captured, giving rise to the virus-like particles described in the species Venturia canescens . Schematic phylogenic tree drawn based on Bennett et al, 2019 [ 1 ].…”

“…The ichneumonid wasps (Hymenoptera: Ichneumonidae) form a very large and diverse group of insects [ 1 ] that share a life cycle involving parasitism. Around 25,000 ichneumonid species have been described to date [ 2 ], but their actual numbers are estimated to be about four times this high [ 3 ].…”

Hybrizon Fallén (Hymenoptera, Ichneumonidae, Hybrizontinae) in China

“…Quicke et al (2009) and Broad et al (2018) placed Hybrizon as derived subfamily within the ophioniformes-group of the Ichneumonidae. In the most recent overview (Bennett et al 2019) Hybrizontinae are also included in the ophioniformes and grouped with part of the Ctenopelmatinae if all morphological and molecular data are combined. When only the molecular data are used Hybrizontinae cluster with Tersilochinae, Cremastinae, part of Mesochorinae and Sisyrostolinae.…”

“…Only Neorhacodinae show a similar fusion of veins SR and M (= vein 3-SR+M) of the fore wing (as a result no vein r-m is present) and have also antenna with 13 segments, but Neorhacodinae lack the enlarged hind basitarsus of Hybrizontinae. Neorhacodinae are not considered to be closely related, but are grouped also in the ophioniformes (Bennett et al 2019). Hybrizon is known from the Holarctic region and the NE part of the Oriental region (van Achterberg et al 2013).…”