DNA Barcoding Of Reduviidae(Insecta:Hemiptera)

DNA barcoding has gained more and more attention of scholars because of its rapid, objective and easy-to-operate advantages and became a routine method of classification and identification. Insect mitochondrial genome has been widely applied in the study|of phylogenetic, population structure and phylogeographic studies due to its stable gene content, uniparental inheritance, lack of extensive recombination and high evolve rate.In order to evaluate the effectiveness of barcodes in the identification of assassin bugs, we recovered812barcode records from specimens representing150species belonging to75genera in9subfamilies. Furthermore, we introduced the ITS2gene and mitochondrial genomics data to understand the species’status of three closely related species Peirates turpis Walker, Peirates fulvescens Lindberg and Peirates atromaculatus (Stal), due to the fact that DNA barcoding results opposed the current taxonomic status of these three species. On the other hand, we tested the utility of mitogenomic data in species identification. Conclusions were drawn as follows:(1)In this study, most species can be distinguished obviously, analysis of the COI gene revealed less than2%intra-specific divergence in nearly70%of the taxa examined, these results verified the utility of COI gene as DNA barcode in the discrimination of Reduviidae. These sequence divergences can be used as a reference to some extent, although we need to combine morphological and ecological data in different situations.(2) Our results indicated that DNA barcodes will aid the identification of Reduviidae, the discovery of taxonomic problems such as synonym and cryptic species that may exist.(3) ITS2data showed similar results with DNA barcoding analysis. The identification of Reduviidae based on COI and ITS2data showed effective and consistent performance. ITS2sequences were highly conserved within species, its lengths was species-specific. These advantages made ITS2a candidate barcode of Reduviidae.(4) Peirates mitochondrial genomes ranged in size from15702bp to16314bp, with length variations mainly in non-coding regions especially in control regions. The mitogenomes all harboured a typical set of37genes and an identical gene order to the mitogenome of D. yakuba. The nucleotide compositions were biased toward adenine and thymine. In addition, comparative studies of ribosomal RNAs showed high conservation at both primary sequence level and secondary structures level among these six mitogenomes. Among all tRNA genes, only trnSl did not exhibit the classic clover-leaf secondary structure, due to the deficiency of the dihydrouridine (DHU) arm.(5) P. atromaculatus, P. fulvescens and P. turpis should be treated as members of a single species inferred from COI, ITS2and mitochondrial genome data. (6) The utility of mitogenomic data in species identification has been testifie in this study, Furthermore, the generation of next-generation sequencing (NGS) technologies makes it possible to efficiently and cost-effectively obtain entire mt genome from large number of samples for resolving relationships at the level of species. Therefore, mitogenome sequences in future may be obtained for each species and become the standard for taxonomic sequencing, much like the COI barcodes today.