Phylogeny of Rhynchium and Its Related Genera (Hymenoptera: Eumeninae) Based on Universal Single-Copy Orthologs and Ultraconserved Elements

SIMPLE SUMMARY: The eumenine wasps of the genus Rhynchium Spinola, 1806; Allorhynchium van der Vecht, 1963; Anterhynchium de Saussure, 1863; and Pararrhynchium de Saussure, 1855 are related and sometimes hard to tell apart from each other. In this study, we first reconstructed the phylogenetic relationships of these genera based on universal single-copy orthologs and ultraconserved elements extracted from 10 newly sequenced low-coverage whole genomes. The results showed that Allorhynchium and Lissodynerus are distinct from the other four taxa. The genus Rhynchium was recovered as monophyletic, whereas Anterhynchium was recovered as paraphyletic, with Anterhynchium (Dirhynchium) as a sister to Rhynchium and hence deserving a separate genus Dirhynchium; and within the genus Pararrhynchium, P. septemfasciatus feanus and P. venkataramani were separated, not clustered on a branch. It is suggested that the genus Lissodynerus should be restituted as a valid genus, not a synonym of the Pararrhynchium. The results are consistent with previous eumenine mitochondrial genome phylogenetic analyses. This paper confirms the feasibility of low-coverage whole genome eumenine wasp phylogenetics and provides a reference for subsequent research in Eumeninae. ABSTRACT: The subfamily Eumeninae is a large group of fierce predatory insects that prey mainly on the larvae of Lepidoptera pests. Because of the highly similar morphologies of the genus Rhynchium and its related genera in the subfamily, including Rhynchium Spinola, Allorhynchium van der Vecht, Anterhynchium de Saussure, Pararrhynchium de Saussure, it is essential to delineate their relationships. A previous phylogenetic analysis based on mitochondrial genomes suggested the inconsistent relationships of these genera under traditional classification based on morphological characters. In this study, we first used single-copy orthologs [USCO] and ultraconserved elements [UCE] extracted from 10 newly sequenced low-coverage whole genomes to resolve the phylogenetic relationships of the above genera. The newly sequenced genomes are 152.99 Mb to 211.49 Mb in size with high completeness (BUSCO complete: 91.5–95.6%) and G + C content (36.31–38.76%). Based on extracted 5811 USCOs and 2312 UCEs, the phylogenetic relationships of Rhynchium and its related genera were: ((Allorhynchium + Lissodynerus) + (Pararrhynchium + (Anterhynchium + (Dirhynchium + Rhynchium)))), which was consistent with the mitochondrial genome results. The results supported the genus Rhynchium as monophyletic, whereas Anterhynchium was recovered as paraphyletic, with Anterhynchium (Dirhynchium) as a sister to Rhynchium and hence deserving generic status; In addition, in the genus Pararrhynchium, P. septemfasciatus feanus and P. venkataramani were separated, not clustered on a branch, just as P. septemfasciatus feanus was not together with P. striatum based on mitochondrial genomes. Since Lissodynerus septemfasciatus, the type species of the genus Lissodynerus, was transferred to Pararrhynchium, it is considered that the genus Lissodynerus should be restituted as a valid genus, not a synonym of Pararrhynchium.