Taxonomic description and phylogenetic placement of two new species of Spalangiopelta (Hymenoptera: Pteromalidae: Ceinae) from Eocene Baltic amber.

Marina Moser,John M Heraty,Roger A Burks,Lars Krogmann,Jonah M Ulmer,Thomas Van De Kamp

doi:10.7717/peerj.10939

Marina Moser, John M Heraty + Show 4 more

Open Access

https://doi.org/10.7717/peerj.10939

Copy DOI

Abstract

Spalangiopelta is a small genus of chalcid wasps that has received little attention despite the widespread distribution of its extant species. The fossil record of the genus is restricted to a single species from Miocene Dominican amber. We describe two new fossil species, Spalangiopelta darlingi sp. n. and Spalangiopelta semialba sp. n. from Baltic amber. The species can be placed within the extant genus Spalangiopelta based on the distinctly raised hind margin of the mesopleuron. 3D models reconstructed from µCT data were utilized to assist in the descriptions. Furthermore, we provide a key for the females of all currently known Spalangiopelta species. The phylogenetic placement of the fossils within the genus is analyzed using parsimony analysis based on morphological characters. Phylogenetic and functional relevance of two wing characters, admarginal setae and the hyaline break, are discussed. The newly described Baltic amber fossils significantly extend the minimum age of Spalangiopelta to the Upper Eocene.

Highlights

Ceinae is a small subfamily of Pteromalidae within the megadiverse Chalcidoidea
The fossil record of the genus is restricted to a single species from Miocene Dominican amber
The species can be placed within the extant genus Spalangiopelta based on the distinctly raised hind margin of the mesopleuron. 3D models reconstructed from μCT

Summary

Introduction

Ceinae is a small subfamily of Pteromalidae within the megadiverse Chalcidoidea. The subfamily contains three genera, two of which are monotypic (Mitroiu, 2016): BohpaDarling, 1991, which is known only from South Africa, and Cea Walker 1837, which is found throughout the Western Palearctic region. Ceinae is a small subfamily of Pteromalidae within the megadiverse Chalcidoidea. The subfamily contains three genera, two of which are monotypic (Mitroiu, 2016): Bohpa. Darling, 1991, which is known only from South Africa, and Cea Walker 1837, which is found throughout the Western Palearctic region. The genus Spalangiopelta Masi 1922 comprises 14 extant species, eight of which are known only from the Palearctic region, whereas the other six species are Nearctic or Neotropic (Darling, 1991; Mitroiu, 2016). Darling (1996) described Spalangiopelta georgei, a fossil from Dominican amber. How to cite this article Moser M, Burks RA, Ulmer JM, Heraty JM, van de Kamp T, Krogmann L. Taxonomic description and phylogenetic placement of two new species of Spalangiopelta (Hymenoptera: Pteromalidae: Ceinae) from Eocene Baltic amber.

Methods

Results

Discussion

Conclusion