A Systematic Study On The Genus Drepanura From China(Collembola,Entomobryidae)

Collembolans,are commonly known as springtails.As small to median size of arthropods,the number of individuals and species is very rich.It is widely distributed in various terrestrial ecosystems and one of the three soil animals(nematodes and mites).Collembola is characterised by its specialised abdominal appendages,tenaculum(furca-holding organ)and jumping organ(furcula).Drepanura is a medium-sized genus of the Entomohryinae(Collembola:Entomohryidae).To date,31 species have been reported in the world with only one from China.Current taxonomy lacks systematic researches on Drepanura with little on Chinese feuna.Therefore,systematic studies of Drepanure from China were carried out to enrich species diversity,to investigate its systematic status of Dtrepanura The main text is divided into four chapters.In the first chapter,the history of collembolan taxonomy,including external morphology especially chaetotaxy,summarizing the current taxonomy of Entomobryidae and Entomobryinae,introducing the characteristics and geographical distribution of the Drepanura,and the purpose of the study is proposed.In the second chapter concerns materials and methods of the study,containing species collection and preservation,specimen preparation,species identification and description,sampling,sequencing,assembling and data analyses etc.In the third chapter,eight species are described,including five new species from China:Drepanura cheni sp.nov.,Drepanura sunae sp.nov.,Drepanura pseudosexmaculata sp.nov.,Drepanura chifengensis sp.nov.,Drepanura dingae sp.noy.and a new species from Vietnam:Drepanura bifurcate sp.nov.,Drepanura mongolica Yosii,1949 and Drepanura sexmaculata Stach,1963.Their morphological characteristics,including body color,antennae,eyes,labrum,cephalic chaetotaxy,maxillary outer lobe,libial palp,labium,trochanteral organ,claws,ventral tube,furcula and body chaetotaxy.A key to the species of Drepanura from China is given.In addition,the phylogenetic reconstruction of the subfamily Entomobryinae by the maximum likelihood method and Bayesian method,both confirmed the monophyly of the Drepanura.However,its systemic status remains doubtful.The fourth chapter,comparison between Chinese(Palaearctic region)and Australia(Australian Region)Drepanura species.It is found that there are a large number of morphological differences and discontinuous distributions,and only the Palaearctic region of Asia can be inferred is monophyletic.