The Phylogenetics Of The Moth Pyraustinae And Spilomelinae Based On Larval Morphology And Mtdna COâ…  Gene

This thesis draws attention to taxonomic study by focusing on somegenera in Pyraustinae and Spilomelinae of Crambidae in China. It comprises threeparts:the general introduction, the morphology of mature larvae, and the molecularphylogeny based on COâ…  mitochondrial gene.In the general part, the study history on the morphology of mature larvae fromPyraustinae and Spilomelinae has been briefly introduced. And the research progressof molecular phylogeny in the field of insects has been reviewed.In the morphology part, the head, mouthparts (labrum, labium, mandible,maxillae), thoracic leg, crochets and chaetotary of mature larvae from8species in8genera of Pyraustinae and21species in13genera of Spilomelinae have beendescribed and illustrated. The identifying features of each species have beensummarized and keys to species of each subfamily has been provided. In addition,thehost-plants for each species have been given.By studying COâ…  mitochondrial gene, the thesis explores the phylogeneticrelationships of two subfamily (Pyraustinae and Spilomelinae) and two outgroupspecies (Pseudocera trissosticha and Unadophanes trissomita). The fragments ofthe COâ…  of4species from4genera of the Pyraustinae and12species from11genera of the Spilomelinae both from China were amplified and sequenced. TheCOâ…  homologous sequences of24specie were obtained from the GenBank. Thestudy was to analyze the base composition of sequences, ratio of transition andtransversion, and genetic distance. Phylogenies were estimated using Maximumarsimony, Neighbour joining and Bayesian inference. The results are as follows:1. The result of sequence analysis showed the sequence of COâ…  gene fromboth Pyraustinae and Spilomelinae was635bp in length. The average content of T, C,A and G was38.7%,14.8%,31.0%and15.5%respective. In addtion, A+T contentis69.7%and G+C content is30.3%.2. The average ratio of Tansition(Ts) to Transversion(Tv) is0.58. The Tansitionusually occurs between T and C and Transversion mainlly occurs between T and A.Base substitutions in CO I DataSet were unsaturated at this level, so the Phylogenetic signals were strong.3. The MP tree, NJ tree and BI tree shows that10representative species ofPyraustinae form a monophyletic group and the molecular relationship among partialgenera (except Udea) is (Uresiphita polygonalis+(Ostrinia furnacalis+Pyraustacontigualis (Anania coronata+Eurrhypara hortulata)+(Aponia minnithalis+Crocidophora evenoralis))). The interspecfic relationships of genera Cnaphalocrocis,Glyphodes and Palpita from Spilomelinae were with high bootstrap value but theintergeneric relationships remian to further study.4. According to the phylogenetic analysis of Pyraustinae and Spilomelinae usingCO I gene, the results indicated that COâ…  is an efficient molecular marker forinterpreting the interspecific relationship both in two subfamilies and theintergeneric relationship in Pyraustinae. However, CO I is not an appropriateindication of interpreting the intergeneric relationships in Spilomelinae and thephylogenic relationship between Pyraustinae and Spilomelinae.