Taxonomic Revision And And Phylogeny Of Tetranychidae In China(Acari:Tetranychoidea)

In this study,the morphogy,taxonomy,phylogenetic relationships among higher taxa and faunal features of Tetranychidae known from China were comprehensively studied.The research history and current situation of Tetranychidae taxonomics worldwide were reviewed with emphasizing on the highlights and main issues.The study mehtods was also well expounded with elaborating on classification basis and supporting material.The identified species inculding newly recorded taxa from China were described and illustrated in detail with notes on the classification status of specified taxa.The morphogenesis in ontogeny of the representative taxa were also conducted.Taxa described precisely with detail data of distribution and nabitatA totle of 28 genera and 158 species are identified,of which 49 species are based on the type specimens,two species are recognized as synonyms,one genus with one species is newly recorded from China,based on the mite collection including collected by the author in Institute of Entomology,Guizhou University(GZU)and those in other orgnizations outside the institution.The examined specimens(slides)including type specimens were from following the major collections:the Institute of Entomology,GZU(about 5000 slides),the Institute of Zoology,Chinese Academy of Sciences(about 2500 slides),the College of Plant Protetion,Fujian Agriculture and Forsetry University and Nanjing Agricultural University.The genera and species are described and illustrated in detail with the redesigning of generic concepts and species diagnosis.A species check list with the renewed data on distribution and habitate plants of 209 tetranychid species is also provided based on available information.The genus and the species new to China:Neotetranychus lek Flechtmann,2013,with first dscription of the male.New synonyms:O.hainanensis Ma,Yuan&Lin,1979 syn.nov.for Oligonychus biharensis(Hirst,1924);E.guangdongensis Ma&Yuan,1982 syn.nov.for Eutetranychus orientalis(Klein,1936)Morphogenetic parttern in representive speciesThe morphological genesis of six repesentive species in four genera were studied:concerning Oligonychus pratensis(Banks,1912);Oligonychus metasequoiae Kuang,1992);Eotetranychus kankitus Ehara,1955;Panonychus caglei Mellot,1968;Bryobia pritchardi Rimando,1962;Bryobia qinghaiensis Ma&Yuan,1981.B.pritchardi and B.qinghaiensis,repesent the first exploring on the ontogeny pattern of Bryobiinae.There are 28 setae(including 7 solenidia)in leg tarsus of B.pritchardi:the setae number of leg femur are 16?17,including 9?stable setae?(d,bv?,v?–v?,l?–l?,bv?₁–bv?₁,bl?₁)and present from lavea to adults;the rest of setae(l?₁–l?₁,l?₂–l?₂,v?₁–v?₁,v?₂–v?₂)may be present or absent but seem no principle to follow in ontogeny.The setae change rule of B.qinghaiensis are same as that of B.pritchardi,but there are slight difference in numbers and location of the missed setae between two species.The changes of dorsal aetae and ventral setae in O.pratensis and O.metasequoiae are onsistent with that proposed by Linquist;the change of leg setae showed significant difference among different species within the genus.These confirmed the value of the leg setae in the classification of spider mites.The ontogenetic changes in leg setae of E.kankitus and E.tiliarium are similar but different from that of Lindquist(1985).The ontogenetic changes of leg setae in P.citrus impalied that the setae number of leg IV genu may play an important role in identifying Panonychus species.Phylogenetic relationships among higher taxaThe phylogenetic relationship of 109 species of Tetranychinae of China was cladistically analyzed with maximum parsimony based on 96 external morphological characters,compared with the phylogenetic tree that Teranychinade of China inferred from three combined DNA fragments(COI,18S and 28S)using maximum liklihood method,which constructed by Jin et al.2019.The phylogenetic analysis shows that Olionychus,Schizotetranychus,Eotetranychus and Tetranychus are paraphyletic group;Mixonychus,Stigmaeopsis and Panonychus are monophyletic group.Eutetranychus,Eurytetranychoides and Eurytetranychus have a close relationship with each other,and Eurytetranychus is a paraphyletic group.Moreover,Aponychus is a sister group of Tenuipalpoides.Faunistic characteristicsThis study firstly provides a biogeographic analysis of the 209 species of 28genera of Tetranychidae from China,which based on statistic of every unitary patteern and accumulating patterns in fauna.According to the scheme of zoogeographic realm on world,the faunal features of Chinese Tetranychidae had dominant Orienental elements.The fauna had the closest relationship with the Palaearctic elements and a relative close relationship with the Nearctic regionin the six realms of the World Zoogeographic.According to system of zoogeography of China,the lineage intensity of the landscape,located in Huanan Region,with Huazhong Region is second,Huabei Region the third and then Dongbei Region,Xinan Region and Qingzang Region.The species identification of tetranychid mtes has been a key issue faced on taxonomic work and pest mite control due to their delicate and inperceptible structures,oversimplified description in ealy literature and intraspecies variation of morphological traits.By reviving the taxonomic work Chinese tetranychid mtes with examing specimen recently collected and collections of the organitions outside the institute,the present dissertation designed species diagnosis and detailed taxa description,clarified morphogenesis of representive species,parsed phylogenetic relayionships among higher taxa and fauanal features.The results has laid the theoretical groundwork for deepening the mite classification research and overcoming identification issue to meet the pragmatic needs against the spider mites.