Application of DNA Barcoding in Insect Taxonomy

DNA barcoding is a new technique in the field of taxonomy. This technique is based on a fragment of DNA sequence, such as the mitochondrial COⅠ gene, on which we can identify organisms by assessing its similarity to a set of reference taxa. The COⅠ gene is conservative enough to be amplified by the universal primers. Meanwhile, diversity in nucleotide sequences of the same gene region of COⅠ permits the discrimination of closely allied species. In recent years, DNA barcoding had been widely applied to the insect taxonomy, especially in species identification of different insects and biodiversity researches. DNA barcoding is generally considered as a reliable, cost-effective and easy tool in molecular identification, yet it has faced several taxonomic and molecular problems. Firstly, DNA barcoding should be used as a tool for species identification instead of species definition. Secondly, there are several issues in the DNA barcoding methodologies including gene locus selection, compatibility with traditional taxonomic system, and pseudogenes as well. This paper aims to review the DNA barcoding technique and its applications in insect taxonomy. Some problems and possible solutions in this technique will be analyzed as well.