Phylogenomics of bees

Apoid wasps and bees (Apoidea) are an ecologically and morphologically diverse group of aculeate Hymenoptera (ants, bees and wasps). During the last decades, significant progress has been made in illuminating the phylogenetic relationships of the major Apoidea lineages. However, some uncertainties have remained. In this study, we present results from re-investigating the phylogeny of Apoidea by including genome skimming data of key taxa that were missing in previous investigations: a representative of Entomosericini (tribe of the former Pemphredoninae) and a representative of Eremiaspheciinae (subfamily of the former ‘Crabronidae’). We additionally skimmed the genomes of two Heterogyna species (Heterogynaidae). Our results from applying concatenation and coalescence-based phylogenetic approaches confirm the previously suggested sister group relationship of Ammoplanidae and bees. They also corroborate most taxonomic changes published in 2018 granting eight lineages of the former family ‘Crabronidae’ family status. However, some of our analyses indicate that the families Pemphredonidae and Psenidae could be para- or polyphyletic. After carefully assessing topological discordance and data quality, the exact placements of Heterogyna and of the genera Eremiasphecium and Entomosericus in the apoid wasp phylogeny remain ambiguous. However, our analyses indicate that inclusion of Entomosericus and Eremiasphecium in any of the currently accepted apoid wasp families cannot be well justified, and we consequently suggest raising Entomosericinae and Eremiaspheciini to family rank, respectively, to acknowledge this situation in the apoid classification: Entomosericidae Dalla Torre, 1897 (stat. n.) and Eremiaspheciidae Menke, 1967 (stat. n.).