Studies On The Molecular Phylogeny Of Syrphinae(Diptera: Syrphidae)

All the time, scholars hold different opinions for the taxonomic position of Syrphinae, which makes their status more chaotic, even influences the further study of Syrphinae. In recent years, many scholars have focused on the classification problems of Syrphinae using molecular methods, In China, Syrphinae research is still in the traditional classification method of identification stage, and study less to Syrphinae molecular system.In this experiment, the specimens of 5 groups 23 genera 39 species of Syrphinae and Mesembrius niveiceps(Syrphidae, Eristalinae) as out group were utilised for DNA extraction using DNeasy Blood & Tissue Kit(QIAGEN GmbH, Germany)..Mitochondrial COI and nuclear 28 s rRNA sequences were amplified by universal primers PCR, and comparison and analysis of the sequence information obtained from the sequencing of the company and its accuracy. MEGA5.02 software was used to analyze the bias, codon usage frequency and the frequency of use of the amino acid in the 28 s rRNA and COI genes of Syrphinae. Then, NJ, ML and MP methods are used to construct phylogenetic trees by MEGA5.02 software.The results were as follows:(1) Studies have found that mitochondrial COI and nuclear 28 S rRNA sequences have A and T base bias. Among Syrphinae. COI variant bases was relatively large, and 28 S rRNA gene was more conservative base. So 28 S rRNA gene hold more conservative in the evolution.(2) Among Syrphinae insects, the amino acid bias of COI and 28 S rRNA gene were Ile, Ser, Leu, Asn, Tyr and Ser.(3) By sequence analysis of COI and 28 S rRNA gene, the results showed that the two tests were unified in molecular system evolution of Syrphinae, and most of the experiments supported the traditional classification results.(4) The results of classification about Syrphinae in this paper was in congruence with present arrangements.(5) The monophyly genera were Pipiza, Chrysotoxum, Sphaerophorìa, Eupeodes and Syrphus. The polyphyletic groups were Melanostomini and Syrphini.(6) Close relationship between Chrysotoxini and Syrphini was in agreement with previous results of classification of Syrphinae.(7) This paper supported the separate classification for Melanostomini and Bacchini, each for a group.(8) Among Syrphinae insects, the close phylogenetic relations were between Allograpta and Meliscaeva, Didea and Dasysyrphus, Scaeva and Ischiodon, Epistrophe and Xanthogramma, respectivly.(9) Lamellidorsum was placed in a clade with Syrphinae, close to Syrphini but all other tribes of the subfamily, so this genera belong to Syrphini. Epistrophe lamellate was close to Syrphini, far from other tribes, so it belong to Syrphini, but the relationship with Epistrophe tiantaiensis should be resolved with more data.