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

Abstract

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.