Taxonomic Study Of The Genus Trouessartia Canestrini,1899 (Analgoidea:Trouessartiidae) From China

The feather mite genus Trouessartia Canestrini,1899(Analgoidea: Trouessartiidae)is one of the largest feather mite genera among the 11 genera currently recognized in the family.This genus is host specific and distributed worldwide.Until now,128 species from the genus Trouessartia belonging to 11 species groups has been reported.Although there has been extensive literature on the this genus,we still have limited understanding because of the simple morphological description,doubtful species determination and species groups definition.Yet research on this genus in China lags behind the others.In order to better understand the biodiversity of the genus in China and clarify the taxonomic status of some doubtful species,in this study,we explored feather mites mainly from birds of Southwestern and Northeast China.The morphology of the collected specimens were identified and described.Moreover,we amplified COI genes of some species to further confirm the morphological results using three species delimitation methods.Finally,the phylogenetic tree was constructed for species clustering analyse and explored the relability of DNA barcoding in species identification of the genus Trouessartia.Here are the main results:(1)Morphological classificationIn this study,we arranged and recorded 27 morphospecies,including 10 new species,4 new record species.Two misidentifications was determined,a new groups rubecula was established.The key to 27 species of the Trouessartia was constructed.A total of 35 morphological pictures of male and female mites including 27 morphospecies were taken with their detailed characters were decipted.a.New species including Trouessartia certhiola sp.nov.,Trouessartia bonvaloti sp.nov.,Trouessartia alba sp.nov.,Trouessartia fulvetta sp.nov.,Trouessartia chrysotis sp.nov.,Trouessartia semitorques sp.nov.,Trouessartia burkii sp.nov.,Trouessartia cyanomelana sp.nov.,Trouessartia leucophaei sp.nov.and Trouessartia proreguli sp.nov.were described.b.New record species such as Trouessartia pygocera(Sundevall,1837),Trouessartia incisa Gaud,1957,Trouessartia swidwiensis Jablonska,1968,Trouessartia amadoni Gaud & Till,1961 were found in this study.c.It was clarified that the samples in research of Huiqun Chang(2019)was misidentified as Trouessartia jedliczkai Jablonska,1968,and the samples in research of Ning Mu(2016)was misidentified as Trouessartia bulligera Gaud,1968.Consequently,those two misidentification was described as new species of Trouessartia alba sp.nov.and Trouessartia bulligera Gaud,1968 respectively in this resarch.d.A new group rubecula was established by the presence of a nonsclerotized,membranous zone around setae h1 in the female,and conical terminal lamellae in male.Three species including:Trouessartia burkii sp.nov.,Trouessartia swidwiensis Jablonska,1968 and Trouessartia rubecula Jablonska,1968 were classified into this new group.(2)Studies on part species of the genus Trouessartia by DNA barcodingIn this study,we amplified 62 sequences belonging to 13 morphospecies of the genus Trouessartia,otherwise,10 sequences obtained from Gen Bank were employed as supplementary ingroup and 4 sequences belonging to genus Calcealges,were used as outgroup.a.Among the the 13 morphospecies of the genus Trouessartia,intraspecific COI genetic divergence(K2P)ranged from 0.00% to 7.36%,with average of 1.50%;interspecific COI genetic divergence(K2P)ranged from 8.10% to 17.13%,with average of 13.99%,the results provided a reference for the further study of this group.b.The species were well clustered based on the Maximum Likelihood tree of COI,the same species were almost completely clustered and showed high support rate except Trouessartia incisa.The clustering results of the phylogenetic tree on other samples constructed by the ML were consistent with the morphological inditificiation results.c.Three species delimitation methods presented different results(ABGD: 15;b PTP: 14;GMYC: 15).Aftering comparing the morphological characteristics,we deduced that the intraspecific variation may result from the changes of external environment during the host-shift speciation.We still adoped the 13 species as the finally results.In this study,we found that the traditional classification is reliable,meanwhile,the biodiversity of feather mites is rich in China.DNA barcoding based on COI gene was used for the species identification of the genus Trouessartia.Therefore,we recommend that a combination of these two methods,the molecular and morphological indificiation should be used.