An Integrative Phylogenetic Analysis of the Genus Rhynchium Spinola (Hymenoptera: Vespidae: Eumeninae) from China Based on Morphology, Genomic Data and Geographical Distribution

TL;DR

This study clarifies the classification of the wasp genus Rhynchium in China using a combination of physical traits, genetic data, and geographic distribution.

Contribution

The study integrates morphology, genomic data, and geographic distribution to resolve taxonomic confusion in Rhynchium species in China.

Findings

Three Rhynchium species were verified in China, including a newly recorded species.

R. brunneum is widely distributed in China with diverse color patterns linked to geographic regions.

Genomic and morphological data confirmed distinct species boundaries and geographic ranges.

Abstract

By combining morphology with population genetic differentiation, phylogenetic relationship and geographical distribution, the taxonomic confusion of the genus Rhynchium Spinola in China was resolved. Three Chinese species, namely Rhynchium carnaticum, Rhynchium quinquecinctum, and Rhynchium brunneum, were verified, of which R. carnaticum is newly recorded and R. brunneum is widely distributed in China. Their morphologic features for classification are updated. The color patterns of the widely distributed species R. brunneum are diverse and were preliminarily analyzed in this study, which provides a useful reference for future explorations of the evolution of the family Vespidae.

The species of the genus Rhynchium Spinola are important natural insect control resources and widespread in the Old World. Due to the various color patterns of several species in China, it is difficulty to accurately classify and identify the genus. We combined their morphology with population genetic differentiation, phylogenetic relationship and geographical distribution to delimitate the species of Rhynchium from China. Within the genus, more than 600 pinned specimens were examined and a total of 37 whole genomes were analyzed, of which 35 were newly sequenced. Firstly, COI sequences, 13 PCGs and 2 rRNAs sequences of the mitochondrial genomes, USCO nucleotide matrix of 90% completeness (USCO90_fna), and USCO amino acid matrix of 90% completeness (USCO90_faa) were extracted from the whole-genome data. Then, genetic distances were calculated using the COI sequences, and ABGD species delimitation analysis identified three valid species. By integrating the four phylogenetic trees inferred from the four datasets and morphological analysis, the specimens of Rhynchium from China were recognized as R. carnaticum (newly recorded), R. quinquecinctum, and R. brunneum; the last is the most widely distributed in China, while the remaining two only occur in Hainan and Yunnan, respectively, markedly different from previous records. Finally, it is interesting that color patterns of the species R. brunneum seem to closely relate to the geographical distribution, embodying two different modes in the South and the North of China, as well as a transitional state in the middle. The roles of the color patterns are still not resolved and their underlying evolutionary mechanisms need further exploration.

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