Phylogenetic relationships and phylogeography of the genus Sinocyrtaspis Liu, 2000 (Orthoptera: Tettigoniidae: Meconematinae) reveal speciation processes related to climate change

Species of Sinocyrtaspis Liu inhabit moist montane environments in south China, and occur allopatrically in restricted regions without overlapping areas. This study presents the first phylogeny of Sinocyrtaspis based on one nuclear DNA sequence [partial ITS1-5.8S rDNA-ITS2 (ITS)] as well as two mitochondrial genes [cytochrome oxidase subunit I (COI) and cytochrome b (CYTB)] using Bayesian inference and maximum likelihood. In addition, reconstructing the ancestral geographical range on the basis of the combined genes and distribution information, MaxEnt modelling was used to predict potential distribution areas in the Last Glacial Maximum (LGM), the mid-Holocene, the present-day and in the year 2070, in order to understand speciation processes and responses to climate change in this genus. The phylogenetic analyses supported the monophyly of Sinocyrtaspis. The results of species delimitation confirmed seven Sinocyrtaspis species and that the speciation events mainly occurred in the late Miocene to early Pliocene when the climate became colder and drier. The conclusions of the phylogeographical analysis are as follows: (i) the centres of origin of Sinocyrtaspis were Hunan and north-east Guangxi; (ii) two dispersal routes became obvious with the final destinations of Jiangxi and Zhejiang, respectively; (iii) after the Miocene cooling period, the ancestor species partly remained in Guizhou and partly spread; (iv) as a response to climate change, species altered distribution areas by moving along altitude gradients in mountain regions, whereas the anthropogenic global warming trend has promoted some species moving to high-latitude areas or caused population differentiation.