Taxonomic Study On The Cerambycidae In Jilin Province

Longicorn beetles (Coleoptera: Cerambycidae), with more than 45000 known species, comprised one of the largest and most diverse groups of Coleoptera. The total number of longicorn beetles recorded from China has exceeded 3100 species up to 2005. Most longicorn beetles feed on plants. Several species of cerambycid beetles are known to damage living trees, and may seriously affect orchards and ornamental trees; others may damage coniferous or hardwood lumber, and a few taxa can damage row crops. The majority of species occur within uncultivated or forested habitats and are of great ecological importance within these natural ecosystems. Because of their close evolutionary linkage to their host plants, cerambycid beetles may be valuable bio-indicators of forest health and diversity.223 species representing 64 genera of 7 subfamilies of Cerambycidae in Jilin Province were identified and compiled in this study. The faunal composition and distribution characters were analysed. The 223 species are distributed in 7 subregions. 222 speices in Northeast China subregion, 111 speices in North China subregion, 108 speices in Mongolia Xinjiang subregion, 79 speices in Middle China subregion, 60 speices in South China subregion, 42 speices in Southwest China subregion, and 16 speices in Qinghai Xizang subregion. 84 species of 35 genera of Lamiinae account for 37.67%; 55 species of 26 genera of Cerambycinae account for 24.66%; 4 species of 4 genera of Prioninae account for 1.79%; 67 species of 32 genera of Lepturinae account for 30.04%; 6 species of 3 genera of Aseminae account for 2.69%; 1 species of 1 genera of Spondylidinae account for 0.45%; 6 species of 1 genera of Necydalinae account for 2.69%.Although the phylogenetic hypotheses of the subfamilial relationships of Cerambycidae were put forward by many scholars since Cerambycidae was found, the higher classification of the Cerambycidae has not been sufficiently elucidated so far. The phylogenetic relationships of 4 subfamilies broadly distributed in Jilin Province were reconstructed in this study. We also tested the traditional classification views on Cerambycidae through modern bio-technology. 36 species of 31 genera of 4 subfamilies in Cerambycidae were analysed in this study.1 BiochemistryIn this part, the EST isoenzyme of 11 species longicorn beetles of 9 genera of 3 subfamilies were analyzed by using the technique of vertical slab poly-acrylamidae gel electrophoresis, and clustering analysis of these species was researched based on their relative mobilities to test if EST isoenzyme analyses can be feasible to resolve the phylogenetic relationships of Cerambycidae at the subfamily level. The results are as follows:(1) The number of the isoenzyme bands of Lamiinae ranged from 9 to 13 and the number of the isoenzyme bands of Lepturinae ranged from 9 to 13. The enzyme activity of Lamiinae was stronger the other two subfamilies.(2) The 11 species of 3 subfamilies were grouped in 3 clades based on relative mobilities by clustering analysis. The results indicated that it was feasible to reconstruct the phylogenetic relationships of Cerambycidae using this method when the taxon was enough. However, the clustering analysis based on their relative mobilities cannot solve the phylogenetic relationships at the genera level.(3) The clustering analysis results of Cerambycidae based on their relative mobilities of the isoenzyme bands were consistent with the results inferred from morphological classification at subfamily level. Because the number of species in Cerambycidae is so large, it is necessary to solve the phylogenetic relationships combined with different methods.2 Molecular BiologyTotal genomic DNA was extracted from 36 species of 31 genera of 4 subfamilies in Cerambycidae. Amplification of the 2 fragment mitochondrial genes (COI 771bp; 16SrDNA 501bp) and 1 fragment ribosomal gene (28SrDNA 772bp) was performed using 3 pairs of universal primer. The base composition, base substitution and genetic distance of DNA sequences were analysed using Clustal v1.8, Bioedit v7.0.9 and MEGA 4.0 software. The phylogenetics relationships were reconstructed from the nuclear 28S ribosomal DNA and combined data using PAUP4.0 (maximum parsimony method, neighbor joining method), PHYML v2.4.4 (maximum likelihood method) and MrBayes 3.1.2 (Bayesian inference method). The results are as follows:(1) We submitted 104 new DNA sequences of 3 genes to GenBank, covering 36 species of 25 genera of Cerambycidae.(2) The family Cerambycidae is“AT”base-bias in the DNA sequences of mitochondrial genes, and transversion is higher than transition, but transition is higher than transversion in ribosomal gene sequences.(3) The phylogenetic trees were inferred from the nuclear 28S ribosomal DNA. The species of the 4 subfamilies were divided into 4 clades. The monophyly of the 4 subfamilies was resolved respectively.(4) The phylogenetics relationships inferred from combined gene sequences in our study were partically congruent with the results of previous investigations based on botany, geography, morphological and biology characteristics of Cerambycidae by Wang and Jiang (1991). Lamiinae and Cerambycinae are the older groups and Prioninae and Lepturinae are the younger groups.3 Fine structure of antennal sensillaThe average number of sensilla basiconica type 2 of Leptura arcuata Panzer and Leptura aethiops Poda on the antennae of the males was significant greater than that on the antennae of the females. The differences of the number of antennal sensilla between males and females were also found in other insects. The number and distribution of antennal sensilla of both species of the longicorn beetles in one genera were different.Because different scholars classified the sensilla into various types based on different standard and the descripition of the same type of the sensilla bear differences. So it is cautious to apply the characters of sensilla to identify specimen and solve the phylogenetics relationships of insects.We tested the traditional classification views on Cerambycidae through modern bio-technology. Modern bio-technology bear the characters of accuracy, impersonality and delicacy and play as a remedy for the traditional classification. DNA sequences have explicit genetic foundation. The amount of the DNA data was controlled by the size of gene. The merits of morphological data lie in that these data could be collected from fossil and specimen. And morphological data can be explained from individual growth. Some questions only can be solved by morphological characters, and the other questions only can be solved by molecular data. A large amounts of research demonstrated that the results of phylogenetics analyses based on molecular and morphological connected data were more convinced compared with the sole analyses.