Taxonomic Study On Subfamily Iassinae From China

Iassinae belongs to Hemiptera,Auchenorrhyncha,Membracoidea and Cicadellidae,which is a larger subfamily of the leafhopper family.At present,there are more than 2200 species in 155 genera of 12 families in the world,and 89 species in 10 genera of 5 families in China.In this thesis,the history and current situations of taxonomic study of Iassinae was introduced,the species of Iassinae in China are systematically organized and described,identification of sexual dimorphism based on COI gene sequence,and analyzed the phylogenetic relationships among the families,genera and species of Iassinae by using the morphological characteristics and molecular data.The main results are as follows:1.Taxonomy100 species of 10 genera of 5 families of Iassinae are recorded in China,among them,including 10 new species and 1 new record species,and proposing 2 specific synonym(2 new species have been published).The keys to the genera and species of Iassinae in China was compiled.The color pictures of all new species,new recorded species and paired species and drawings of their external genitalia were attached.The categories of new classification units,new records and other classification status changes are as follows:New species: Batracomorphus bispinea sp.nov.;Batracomorphus cuspisa sp.nov.;Batracomorphus equitans sp.nov.;Batracomorphus irregularis sp.nov.;Batracomorphus quadriuncinatus sp.nov.;Batracomorphus spinosus sp.nov.;Siniassus gracilitus Yang & Dai,2022;Siniassus nigrimaculatus Yang & Dai,2022;Iassus longiforma sp.nov.;Krisna trifurcata sp.nov.。New recorded species: Coriojassus brunneus Evans,1972 rec.nov.New synonym: Batracomorphus notatus(Kuoh,1986)syn.nov.is a junior synonym of Batracomorphus pandarus Knight,1983;Krisna flavisterma Li & Zhang,2007 syn.nov.is a junior synonym of Krisna nigromarginata Cai & He,1998.2.DNA-based identification of sexual dimorphismIn this study,identification of sexual dimorphism with mitochondrial COI sequence information based on morphological classification.The external morphological characteristics of male and female insects were preliminarily identified,and then the similarity of COI sequences and P-distance between them were calculated to identification of sexual dimorphism.After identification of sexual dimorphism successfully,the specific characteristics that could be used for taxonomic identification were summarized.Among the 21 paired species,except Coriojassus brunneus Evans,1972 and Krisna viraktamathi Zhang,Zhang & Dai,2008,the COI gene sequence length was 614 bp and 647 bp,respectively and the COI gene sequences of the other 19 species were 650 bp.The COI gene sequences of male and female insects showed that the identity equal to or greater than 98.37%.The intraspecific and interspecific P-distances of COI gene sequences ranged from 0.000 to 0.011,and the interspecific P distances ranged from 0.105 to0.236.There was a significant difference in P-distance between the intraspecific and interspecific,and the calculated results could be used for identification of sexual dimorphism in this study,which included 21 species of 5 genera and the specific species as follows:Batracomorphus Lewis,1834(12 species): B.allionii(Turton,1802);B.cornutus Li & Li,2011;B.curvatus Knight,1983;B.extentus Cai & He,2001;B.laminocus Cai & He,2001;B.lateprocessus Li & Wang,2003;B.lineatus Cai & Shen,2010;B.matsumurai(Metcalf,1966);B.paradentatus(Li & Wang,1993);B.subfuscus(Li & Wang,1993);B.trifurcatus Li & Li,2011;B.lunatus Cai & He,2001Coriojassus Evans,1972(1 species): C.brunneus Evans,1972Gessius Distant,1908(2 species): G.rufidorsus Wang & Li,1997;G.strictus Wang & Li,1997Krisna Kirkaldy,1900(4 species): K.rufimarginata Cai & He,1998;K.expansiva Li & Li,2011;K.viraktamathi Zhang,Zhang & Dai,2008;K.quadrimaculosus Wang,Wu & Dai,2018Trocnadella Singh-Pruthi,1930(2 species): T.furculata Cai & Shen,1999;T.arisana Matsumura,19123.Phylogenetic analysisThe results of strict consensus tree of Chinese Iassinae based on morphological construction,ML tree and BI tree based on COI gene sequence were basically the same:(1)In the phylogenetic tree,Iassinae was a monophyletic group;(2)The establishment of new species was supported by phylogenetic trees;(3)Batracomorphini,Trocnadini and Krisnini were relatively stable among the five families of Iassinae.Among them,Krisnini was stable at the base of the tree,Batracomorphini was stable at the end of the tree.While Batracomorphini and Trocnadini were closely related.Except Hyalojassini,all the other families formed monophyletic stably,while the evolutionary tree based on molecular data showed that the family is not monophyletic group.