Phylogeny and divergence estimates for the gasteruptiid wasps (Hymenoptera : Evanioidea) reveals a correlation with hosts

The Gasteruptiidae are an easily recognised family of wasps whose larvae are considered predator-inquilines in the nests of solitary bees and wasps. There has been minimal molecular research on the family and as a result little understanding of the evolutionary relationships within the group. We present the first molecular phylogeny focused on Gasteruptiidae, generated using three molecular fragments (mitochondrial C01 and nuclear markers EF1-α and 28s) and estimate the divergence times of Evanioidea based on three secondary calibration points. The analyses included 142 specimens of Gasteruptiidae and 5 outgroup taxa from Aulacidae and Evaniidae. The monophyly of the Gasteruptiidae and its subfamilies Gasteruptiinae (Gasteruption) and Hyptiogastrinae (Hyptiogaster and Pseudofoenus) are confirmed. Our results indicate that Evanioidea diverged during the late Jurassic at 151.3 (171.99-136.15) Ma with Evaniidae during the early Cretaceous at 137.33 (140.86-133.67) Ma, and Gasteruptiidae during the Palaeocene at 60.23 (83.78-40.02) Ma. The crown age of Hyptiogastrinae was estimated to be during the mid-Eocene 40.72 (60.9-22.57) Ma and for Gasteruption during the early Eocene at 47.46 (64.7-31.75) Ma, which corresponded to their host divergence ages. We anticipate that more extensive taxon sampling combined with the use of phylogenomic data will help resolve low support within the Gasteruption clade.