Phylogenetic And Biogeography Of The Genus Diestramima In China

The genus Diestramima Storozhenko,1990 belongs to Orthoptera,Rhaphidophoroidea,Aemodogryllinae,Diestramimini.To date,the genus Diestramima includes approximately 41 species that belong to 3 subgenera,and 31 species of 3 subgenera have been recorded from China.All species of this genus has long protuberances on the seventh abdominal tergite,and the shape of the protuberances is significantly different among different species.The morphological classification system and the relationship between species are relatively clear.The species of genus Diestramima are apterous and cannot do long-distance migration,so they only distributed in the Oriental realm.Therefore,Diestramima is a suitable candidate group for studying the speciation and diversity patterns of Oriental realm in China and the corresponding geological changes.In this study,we reconstruct the phylogeny tree of 19 Diestramima species(including 2 new species)that belong to 3 subgenera based on maximum likelihood and Bayesian inference based on 3 mitochondrial molecular genes(COI,12S,16S)and 3 nuclear molecular genes(ACSL,CPL,WDL).We describe the taxonomic relationships among various species of Diestramima and the geographic distribution of this genus in China.We preliminarily explain the ancestral dispersal route and historical occurrence time.The following results have been preliminarily obtained:1.The interspecies morphological characteristics and molecular phylogeny relationships of all the samples have maintained extremely high consistency.The specialization of paraproct occupies a more dominant position in the morphological taxonomic research of the genus Diestramima.2.According to the shape of the 7th male abdomen apex and paraproct,combined with the molecular data of related samples.Two new species,Diestramima pingmengensis sp.nov.and Diestramima gulinjingensis sp.nov.,were described based on morphological and molecular data.3.The membership of each of these major clades were not strongly correlated with the distribution of their subgenera(Baculitettix,Diestramima and Excisotettix,Gorochov et al.,2019).Based on the results from the phylogenetic analyses,species in genus Diestramima that are morphologically similar and geographically area similar tend to be grouped together.This phenomenon may be related to their lack of wings and weak mobility.4.The ancestors of the genus Diestramima had already arrived in Guangxi and Yunnan provinces in China before the Miocene.The two temperature rises in the Palacocene and Miocene may have intensified the dispersal of the ancestors of the genus Diestramima in the Oriental realm.At the early Pliocene,they may have reached most of the areas where they are now.In addition,changes in humidity and changes in surface plant communities are also important factors affecting their divergence.5.The speciation events in Diestramima occurred mostly from Miocene.The temperature drop and the uplift of the Qinghai-Tibet Plateau were the main reasons for the divergence within the genus Diestramima.The low mountainous hilly region of Guangxi,Guizhou and Hunan is the area where the insects of this genus are most differentiated.The arrival of the Quaternary Ice Age has caused these species to undergo violent and complex evolution in inland China.