Molecular Phylogenetics and Mitochondrial Genomic Evolution in the Endemic Genus (Orthoptera: Eumastacoidea) in China.

BACKGROUND/OBJECTIVES: The genus Chang (Orthoptera: Eumastacoidea, 1937) is endemic to China, which is mainly distributed in low- and medium-altitude areas in central and eastern China. However, there are relatively few molecular data studies on the genus .

METHODS

In this study, three species of the genus were collected from Hubei and Henan, China, namely sp., Wang (1995) and Hsia and Liu (1989). Both sp. and were collected from the Shennongjia area of Hubei, but they exhibit some differences in morphological characteristics.

RESULTS

We obtained the mitochondrial genome structures of the three species, which were similar to those of the published mitochondrial genome structures of species within Eumastacoidea with 37 typical mitochondrial genes, including 13 PCGs, 22 tRNAs, and 2 ribosomal RNAs. The results of the maximum likelihood (ML) tree and the Bayesian inference (BI) tree showed that the families Eumastacidae, Chorotypidae and Episactinae in Eumastacoidea are a monophyletic group, and Thericleinae and Episactinae are sister clades. The time-calibrated phylogeny results indicated that the divergence time between Thericleinae and Episactinae was 95.58 Ma (56.71-128.02 Ma).

CONCLUSIONS

These phylogenetic tree results indicate that sp. and are the same species. And the time-calibrated phylogeny tree and the species distribution map of the genus indicate that the species of the genus spread from eastern to central China and diversified. These studies fill the gap in molecular data for the genus and the taxonomic status of Episactidae.