Divergence estimates and early evolutionary history of Figitidae (Hymenoptera: Cynipoidea)

Abstract

We examine the phylogenetic relationships of Figitidae and discuss host use within this group in light of our own and previously published divergence time data. Our results suggest Figitidae, as currently defined, is not monophyletic. Furthermore, Mikeiinae and Pycnostigminae are sister‐groups, nested adjacent to Thrasorinae, Plectocynipinae and Euceroptrinae. The recovery of Pycnostigminae as sister‐group to Mikeiinae suggests two major patterns of evolution: (i) early Figitidae lineages demonstrate a Gondawanan origin (Plectocynipinae: Neotropical; Mikeiinae and Thrasorinae: Australia; Pycnostigminae: Africa); and (ii) based on host records for Mikeiinae, Thrasorinae and Plectocynipinae, Pycnostigminae are predicted to be parasitic on gall‐inducing Hymenoptera. The phylogenetic position of Parnips (Parnipinae) was unstable, and various analyses were conducted to determine the impact of this uncertainty on both the recovery of other clades and inferred divergence times; when Parnips was excluded from the total evidence analysis, Cynipidae was found to be sister‐group to [Euceroptrinae + (Plectocynipinae (Thrasorinae + (Mikeiinae + Pycnostigminae)))], with low support. Divergence dating analyses using BEAST indicate the stem‐group node of Figitidae to be c. 126 Ma; the dipteran parasitoids (Eucoilinae and Figitinae), were estimated to have a median age of 80 and 88 Ma, respectively; the neuropteran parasitoids (Anacharitinae), were estimated to have a median age of 97 Ma; sternorrhynchan hyperparasitoids (Charipinae), were estimated to have a median age of 110 Ma; the Hymenoptera‐parasitic subfamilies (Euceroptinae, Plectocynipinae, Trasorinae, Mikeiinae, Pycnostigminae, and Parnipinae), ranged in median ages from 48 to 108 Ma. Rapid radiation of Eucoilinae subclades appears chronologically synchronized with the origin of their hosts, Schizophora (Diptera). Overall, the exclusion of Parnips from the BEAST analysis did not result in significant changes to divergence estimates. Finally, though sparsely represented in the analysis, our data suggest Cynipidae have a median age of 54 Ma, which is somewhat older than the age of Quercus spp (30–50 Ma), their most common host.

Trissolcus japonicus (Ashmead) (Hymenoptera, Scelionidae) emerges in North America

“…Images of T. japonicus collected in Beltsville, MD, are presented in Figures 1-5. To confirm morphological identifications, genomic DNA was extracted from the legs of 4 females, and one whole female specimen, using techniques summarized in Buffington et al (2012). The 'barcode' region of cytochrome oxidase I (COI) and the internal transcribed spacer region 2 (ITS2) regions were amplified and sequenced in the Scheffer Laboratory (USDA/ARS, Systematic Entomology Laboratory) and compared with sequences obtained from populations of previously identified Asian Trissolcus from Asian field surveys (Bon et al, unpublished).…”

Afrotropical Cynipoidea (Hymenoptera)

“…A preliminary analysis of the phylogeny of Figitidae demonstrated that the family was monophyletic (Ronquist 1999). Subsequent analyses, employing more thorough taxon and character sampling, found the family monophyletic (Buffington et al 2007) and paraphyletic (Buffington et al 2012), the latter study having recovered Cynipidae as sister-group to the figitid subfamilies Thrasorinae + (Pycnostigminae + Mikeiinae). Further phylogenetic interpretation of cynipoids is beyond the scope of this study, however, it should be pointed out that cynipids are very rare in the Afrotropical region, and the gall-associated figitid subfamilies Thrasorinae, Parnipinae, Mikeiinae and Plectocynipinae have not been recorded to date.…”

“…Afrotropical figitids are primarily endoparasitoids of Muscomorpha Diptera, attacking the early instar stages of their hosts and emerging from the host puparium (Buffington et al 2012). The two exceptions to this pattern are the Anacharitinae and Charipinae, of which the former are Chrysopidae parasitoids (Neuroptera), and the latter are hyperparasitoids of braconids and chalcidoids in plant lice (Sternorrhyncha) (Buffington et al 2012). Hosts are unknown for the Emargininae and Pycnostigminae, as well as numerous species of Eucoilinae.…”

“…Afrotropical anachritines are primary parasitoids of aphid-hunting Neuroptera larvae (Buffington et al 2012). …”

“…Some headway has been made with a recent biological study of the cynipid Rhoophilus loewi Mayr, 1881 (van Noort et al 2006) and the discovery of two true indigenous gall formers, Phanacis neserorum Melika and Prinsloo (2007), and Qwaqwaia scolopiae Liljeblad, Nieves-Aldrey & Melika (2011), the latter meriting the description of a new genus and establishment of a new tribe (Liljeblad et al 2011). However, the majority of the species and generic level diversity within the Afrotropical cynipoids can be found within the eucoiline Figitidae, a monophyletic group that are primary koinobiont endoparasitoids of muscomorphan Diptera (Ronquist 1999, Fontal-Cazalla et al 2002, Buffington et al 2007, 2012). …”