Phylogenomics and taxonomic revision of Stenarella Szépligeti (Hymenoptera, Ichneumonidae, Cryptinae)

The phylogeny of the Old World genus Stenarella Szépligeti is investigated using data from genomic ultraconserved elements. Thirteen species from the four biogeographic regions where the genus occurs were included in the analyses. The resulting trees corroborate the monophyly of Stenarella and show substantial biogeographic structure within the genus, with three major clades corresponding to species occurring in the Afrotropical, Palearctic and Oriental – Australasian regions.

The Afrotropical component of the genus is represented by fifteen species, while outside of the Afrotropics there seem to be only three species, each with very wide geographic distribution. The taxonomic limits of the genus are reviewed, and an updated diagnosis is provided. A total of eighteen species are recognized as valid, of which twelve are described as new: S. aurea sp. nov., S. bugalana sp. nov., S. delicata sp. nov., S. favilla sp. nov., S. fenestralis sp. nov., S. hopkinsi sp. nov., S. katanga sp. nov., S. natalina sp. nov., S. nigriscuta sp. nov., S. nigromaculata sp. nov., S. saaksjarvi sp. nov., and S. vannoorti sp. nov.

An updated identification key to the species of the genus is provided, as well as diagnoses, redescriptions, and new distribution records for the previously known species.