The Phylogeny Of Some Species Of The Arcypteridae (Orthoptera: Acridoidea) In China Based On Mitochondrial Gene Sequences

Grasshoppers are crucial phytophagous insects jeopardizing corps, bamboos woods and meadows. The Arcypteraidae (Orthoptera: Acridoidea) represents a great family within Acridoidea. It includes 223 species of 47 genera within 4 subfamilies. It has never been reported of the study on phytogeny of the Arcypteraidae based on mtDNA sequences.This dissertation project was designed with five separate, but related studies. The first chapter estimates phylogenetic relationships of Arcypteraidae including 13 species of 6 genera based on 16S rDNA fragment. The result supports that 16S rDNA is appropriate to analyse grasshoppers subfamilies and higher taxa, but unsuitable to analyse phylogenetic relationships between genera or species. The second chapter estimates phylogeny relationships of Arcypteraidae including 12 species of 6 genera based on 12S and 16S rDNA combined sequences. It is believed that the analysis based on 12S and 16S rDNA combined sequences is more effective and reliable than single rRNA gene. The third chapter also infers the phylogenetic relationships of Arcypteraidae including 11 species of 4 genera based on CO I gene fragment sequences. The result indicated that CO I gene was suitable to differentiate sibling species, but unsuitable to analyse relationships between genera of Arcypteraidae. Thefourth chapter combines 12S+16S+CO I gene sequences to infer the phylogenetic relationships of Arcypteraidae including 10 species of 4 genera. It is believed that the means based on combined molecular data of multi-genes can remarkably improve the effectiveness and reliability of mtDNA as molecular markers. It gives a conclusion in fifth chapter.Differences of mtDNA gene partial sequences and ammo acid sequences of CO I gene were analysed in the software MEGA2.1. The MP, NJ and ML phylogeny trees were reconstructed in the software PAUP4.0. Phylogeny trees indicate, 14 species of Arcypteraidae form two clusters : Ceracrinae and Arcypterinae, the former is more evolutional, and this is consistent with the morphology. The study results prove the validity that Ceracris kiangsu is modified Rammeacris kiangsu. Suspicion is given about the veracity that Ceracris fasciata fasciata and C. fasciata szemaoensis are two subspecies of same a specie. It is found that the phylogenetic relationship of Dnopherula sinensis and Chorthippus brunneus huabeiensis is close, just as two subspecies. The further study will be done about the phylogenetic relationships of the genus Chorthippus, species relationships of which are complicated.