Insights from the first phylogenomic analysis of flat wasps (Hymenoptera, Bethylidae) reveal two new subfamilies

Abstract

Despite significant advances in alpha level taxonomy in the past few decades, the higher-level phylogeny of flat wasps (Hymenoptera, Bethylidae) remains poorly explored. Herein we provide the first phylogenomic assessment of the family based on data from ultraconserved elements for 96 species in 61 genera of the family, with material from 29 countries and all biogeographic regions. Dataset cutoffs including ultraconserved element loci recovered for 50 and 70% of terminals resulted in matrices with 1513 and 451 loci, which were analysed in both parsimony and maximum likelihood frameworks. We also provide the first analyses of divergence dating for the family based on the calibration of 12 nodes. All analyses recovered the Bethylidae as a monophyletic group and estimated the origin of the family at around 143 Ma. The results suggest that all extant subfamilies had already diversified by the Late Cretaceous. All topologies suggest that Glenosema and Chilepyris form a clade separate from other Scleroderminae; owing to the morphological distinctiveness of each genus, we propose that they are accommodated in two new subfamilies, Glenoseminae subf. nov. and Chilepyrinae subf. nov. The monotypic sclerodermine genus Galodoxa was consistently recovered within Epyrinae and is transferred to the latter subfamily.