Study On The Classification And DNA Barcode Of Megophthalminae From China

The leafhopper subfamily Megophthalminae belonging to the family Cicadellidae(Hemiptera: Cicadelloidea),and it is a smaller subfamily of Cicadellidae.The Megophthalminae now contains 4 tribes and has reported more than 720 species in 59 genera in the world,and including 59 species in 18 genera of 1 tribes from China.In this thesis,a comprehensive analysis on morphological classification and phylogeny of Megophthalminae from China were studied.The morphological classification,molecular research,biological habits,economic importance,classification characteristics and terminology of Megophthalminae were provided.The system of finishing and describing the list of Megophthalminae insects in China.The phylogenetic relationship among each genera and species based on the data combination with morphological and molecular was researched from China first time.The type specimens of the new species are deposited in the Institute of Entomology,Guizhou University,Guiyang,China(GUGC).The main results are as follows: 1.TaxonomyIn this thesis,63 species in 18 genera of 1 tribes of Megophthalminae from China were recorded,including two new species and two new record species.Description morphology and male genitalia characteristic of all new units,keys are given to genera and species taxa concerned.The new species and new record species from China are as follows:New species(2):Igerna mesialis sp.nov.Japanagallia turriformis sp.nov.New record species(2):Igerna shillongensis Meshram rec.nov.Igerna wilsoni Viraktamath rec.nov.2.PhylogenyIn order to study phylogenetic relationships,17 species in 11 genera of Megophthalminae from China were selected,outgroup is Idioscopus clypealis(Lethierry).Results based on 34 phylogenetic trees were as follows: 2.1 Phylogenetic Studies based on molecular dataA total of 45 genes partial sequences(COI,16 S rDNA,Cytb)were obtained,among them,19 sequences of COI gene,15 sequences of 16 S rDNA gene,11 sequences of Cytb gene,and 3 outgroup sequences,sum is 48.Mega 6.06(NJ,ML,MP)and MrBayes 3.2.1(BI)were used to construct phylogenetic tree based on a single gene sequence and combined genes sequences,20 phylogenetic trees were obtained.Research indicates M.guangxiensis was isolated from the majority of phylogenetic trees,and was located at the root of the tree.A.venosa was isolated and located in the lower part of the tree.Onukigallia and Sangeeta are sister group,located in the middle or lower part of the tree.There are only two species of Japanagallia clustered together,in other words,J.neohamata and Japanagallia sp1,located at the upper part or top of the tree.Two species of Dryodurgades,two species of Igrena are not aggregated into one.The phylogenetic tree based on the 16 S rDNA gene sequence was the most stable.2.2 Phylogenetic Studies based on morphological characteristicsA total of 36 characteristics including the external morphological features and male genitalia were selected.Using PAUP 4.0(MP,NJ)to construct phylogenetic tree,two phylogenetic trees were obtained.Research indicates A.venosa is located in the root of the tree,separated separately.D.nigropicta and I.tenuicaula are clustered into one,located above A.venosa.Two species of Onukigallia are clustered together,and then with S.sinuomacula formed sister group,located above D.nigropicta and I.tenuicaula.P.maculate and I.bifurcate are clustered into one,forming a sister group,located in the upper part of the tree.Two species of Dryodurgades are clustered together.J.neohamata and J.hamata are clustered into one.2.3 Phylogenetic Studies based on morphological characteristics and molecular data36 morphological characteristics and molecular data were selected.Using PAUP 4.0(MP,NJ)and MrBayes 3.2.1(BI)to construct phylogenetic tree,three phylogenetic trees were obtained.Research indicates most of the phylogenetic trees in M.guangxiensis were isolated separately,located at the roots of the tree.Onukigallia and Sangeeta are sister group.Two species of Dryodurgades and two species of Igrena are not aggregated into one.The phylogenetic tree obtained by combining morphological characteristics with 16 S rDNA gene sequence was the most stable.In summary,the results of most phylogenetic trees showed that M.guangxiensis was isolated separately,located at the roots of the tree.34 phylogenetic trees supported the relationship between Onukigallia and Sangeeta is sister group.In addition,in the case where the phylogenetic tree of single data is unstable,the stability of combined data is larger than that of single data.