Research On The Relationship Between Fanjing Mountain Leafhopper Species Diversity And Its Host Plant

Leafhopper is a generic term for insects(Hemiptera : Cicadellidae).At present,Domestic research on leafhoppers mainly focuses on classification and pest control.Fanjing Mountain is a collection of geographical components of various floras and is rich in plant species.It is significantly different from habitats in other regions.such as,Climate,landform,elevation.the animals and plants are significantly affected by geographical environment and altitude.(1)In this paper,the Shannon-Werner diversity index(H),uniformity index(P),and dominance index(S)were used to study the biodiversity and species uniformity of the leafhoppers in different habitats and different altitudes of Fanjing Mountain.(2)Using literature,field surveys and other research methods to determine the geographical distribution of harvested species,and analyze their attribution characteristics in the world and China's animal geographic division.(3)Selecting the most representative and suitable relationship of the leafhopper(insect)host plants in the study area,using molecular biology,comparative morphology and other research methods to analyze the representative species and their interaction with host plants,to Provide scientific basis and reveal the ecological evolution process and biodiversity conservation for Fanjing mountain.Below are key research findings:(1)A total of 4348 leafhoppers specimens were collected,belonging to 15 families and 128 genera.The species richness index of Typhlocybinae is the highest,and 37 are specimens of No.2207.The habitat types of Salka,Evacanthus and Abrus are diverse,and vegetation types are positively correlated with species richness.The similarity index of leafhoppers is low in different habitats,and the climate,elevation and vegetation of habitats are the main reasons for the differences in leafhopper communities.The dominant genus of the mixed forest area of the mountain ridge and the evergreen deciduous broad-leaved forest is Salka;the dominant genus of the evergreen broad-leaved forest belt is Atkinsoniella;subalpine coniferous forest and shrub The dominant species of the meadow belt belongs to the genus of the genus Coalitus.With the elevation and the change of the vegetation belt,the species of locusts distributed in different forest belts also change.The evergreen broad-leaved forest has a single species of leafhoppers,and there are many populations in the mountainous farming area,subalpine coniferous forest and shrub meadow belt,and the species richness is high.The similarity of the leafhopper species between adjacent forest belts is greater than the similarity between adjacent forest belts.The similarity of the leafhopper species between adjacent forest belts at high altitude is greater than the similarity between adjacent forest belts at low altitudes.(2)The Fanjing Mountain leafhopper species have five fauna types in the world's animal geography division,which are roughly distributed in the Gubei,Dongyang,Australia,and Africa.The main types are Dongyang,Gubei-Dongyang.the GubeiDongyang-African,Gubei-Dongyang-Australia are few,and all species are distributed in the Eastern Ocean.The proportion of the Oriental Ocean is 57.14%,and the GubeiDongyang Ocean World accounts for 39.82%.There are 24 fauna types in the Chinese animal geography division.The Central China area has the largest proportion,accounting for 22.94%;the North of Central and the South of Central regions in China are 19.91% and 16.01% respectively.Mengxin District and Dongbei District account for a small proportion.It can be seen that the world's animal geography zoning has a dominant advantage in the Oriental Ocean species.The Chinese animal geography zone is dominated by the Central of region in China,which is consistent with the geographical location of Fanjing Mountain.(3)The mitochondrial genome of the host leafhoppers consists of 13 protein-coding genes,2 rRNA genes,and 22 tRNA genes.It is a complete mitochondrial genome stem-loop structure.The mitochondrial genome sequence of Chlorotettix nigromaculatus is 15012 bp in length.The total length of the protein-coding gene is 10947 bp,the AT content is 76.31%,and the GC content is 23.69%.Nad4 L and Nad2 genes use ATT as a start codon,other protein-coding genes use ATA and ATG as start codons;except Cox2 uses incomplete T as a stop codon,and other protein-coding genes use TAA and TAG as stop codons.The mitochondrial genome sequence of Evacanthus acuminatus was 14794 bp in length,and the total length of the protein-coding gene was 10019 bp,the AT content was 53%,and the GC content was 14%.The start codon of Nad3 is ATA,the start codon of ATP8 is TTG,and other protein coding genes are common ATT and ATG.Cox2-3 uses incomplete T as a stop codon,and other genes use TAA,TAG as a stop codon.The order of the genes of the host leafhoppers is consistent with the order of other mitochondrial genes in the subfamily leafhoppers.(4)There are many kinds of volatile chemicals emitted by plants,and the volatile matter composition of specific species is an important signal and basis for leafhoppers to avoid non-host plants and to determine host plants.Through the analysis of the chemical constituents of the volatiles of host plants,it was found that olefins,aldehydes,alcohols,esters and other major categories,among which olefins are the most widely distributed,mainly terpenes.Studies on parasitic leafhoppers have found that the host plants of the leafhopper have common substances: benzaldehyde,isobutanol and 3-methylbutanal.Studying the effects of chemical constituents of host plant volatiles on the growth,development and behavior of the leafhopper species help to clarify the host seeking mechanism and provide a scientific basis for the integrated management of pests.(5)Based on the relationship between the mitochondrial DNA COI gene sequence leafhopper and host plants:(1)the genus Decursus nirvana excelsa and the genus Shaddai typicus are parasitic on the Urticaceae Pilea Pumila.The average genetic distance between different species of parasitic leafhoppers was 0.856.Different leafhoppers parasitic on the same host plant are closely related,its genetic evolution is similar,and these kinds of phylogenetic trees are clustered together.The two leafhoppers share a common habitat and are long-term parasitic on the same host plant,with little genetic difference and similar genetic structure.In addition,the nutrients of host plants can cause certain changes in the genetic structure of parasitic insects.Having Survived in the same geographical environment,the sequence structure and genetic evolution of the leafhoppers are similar with the same host plants.(2)Chlorotettix nigromaculatus and Psammotettix sp.are hosted in different plants,with different habitats and distinct genetic differentiation.Shaddai typicus is a single group,and the genetic differentiation of non-parasitic leafhoppers is obvious.The geographical environment of host plants is related to the genetic evolution of parasitic leafhoppers.The genetic distance and similarity are different from Empoascini sp.and non-parasitic leafhoppers.Host plants in the parasitic process have certain effects on the growth and genetic structure of the leafhoppers.Different feeding habits have certain effects on the species differentiation of the leafhoppers,and further affect the genetic differences between the leafhoppers,leading to gene structure differentiation.Different habitats will affect the nutritional composition of host plants.such as altitude,climate and other environmental factors.