Molecular biogeography of the wingless raspy crickets, genus <i>Apterolarnaca</i> (Orthoptera: Gryllacrididae)

The genus Apterolarnaca Gorochov, 2004 is a completely wingless group within the family Gryllacrididae Blanchard, 1845, with a relatively high species richness. Due to its low dispersal ability, it is an ideal model for investigations of historical biogeography. This study employed 3 species delimitation methods (Assembling Species by Automatic Partitioning, general mixed Yule-Coalescent model, and Bayesian implementation of the Poisson tree process model) based on the cytochrome c oxidase subunit I (COI) gene fragment to conduct molecular species delimitation within the genus Apterolarnaca. Integrating morphological characteristics, geographical distribution, and molecular species delimitation results, 3 new species of the genus are described: Apterolarnaca longa sp. nov., Apterolarnaca cerina sp. nov., and Apterolarnaca helvola sp. nov. Additionally, the female of Apterolarnaca longispina Pang et al., 2023 is described for the first time. Furthermore, this study presents the first phylogenetic analysis of the genus using Bayesian inference and maximum likelihood methods based on 1 nuclear gene fragment (18S rRNA) and 4 mitochondrial gene fragments (COI, Cytb, 12S rRNA, and 16S rRNA). The phylogenetic results strongly support the monophyly of the genus and recover 2 major clades. Molecular dating and biogeographic analyses suggest that Apterolarnaca likely originated during the Mid-Eocene in Southern Yunnan of China. During the period from the late Eocene to the Mid-Miocene, the uplift events of the Qinghai-Tibet Plateau and Himalayas, along with climatic changes, probably had substantial effects on lineage diversification of Apterolarnaca.