DNA barcoding for the Korean insects at NAAS: Its current advances and prospects

The first research purpose of NAAS on insects is in the control of agricultural insect pests and the industrial use of beneficial insects. Within this goal, the taxonomists at NAAS have the responsibility to identify insect specimens. While the requests for species identification of the pest and beneficial insects are received with the insect samples at different life stages, most species could be identified only in the adult stage. The identification of immature insects are time and effort-consuming because of the problems in rearing them to adult stage. Along with these problems, it is also a problem that the number of insect taxonomists is continuously decreasing in Korea. To address these issues, in 2007, we first tested for the possibility of species identification through molecular taxonomy using DNA barcodes. Then we undertook the DNA barcoding project in earnest with the two major goals: (i) To establish a DNA barcode library for 1,200 agricultural insect species; and (ii) to develop a nondestructive DNA extraction method and to retrieve the full-length barcode region (658bp) from old insect specimens. In the Department of Agricultural Biology, NAAS, from 2009 to present, the genomic DNA stocks extracted from agricultural insects of 5,185 individuals belonging to 1,468 species are preserved. Among them, DNA barcodes on 3,302 individuals of 1,200 species have been analyzed. Although DNA barcoding successfully identified more than 90% of tested specimens, there still remain some problems. Therefore, we are also trying to reveal their population structures caused from speciation pathway and geographical migration using multi gene loci. Using above techniques, NAAS are planning to construct DNA barcodes library on 2,000 agricultural insect species until 2017 as the second step of this project, and ultimately to establish DNA barcoding taxonomic system of 3,000 insect species by 2022. Each year, we have been establishing the "Insect Molecular Taxonomic Library," which includes the information on DNA stocks and DNA barcodes of the agricultural insects, at the "Insect Resources of Korea" website (http://www.genebank.go.kr/pb/main.jsp) for public service. By establishing this online database, we might facilitate a rapid and accurate identification of the agricultural insects in any life stage through the integration of morphological data and DNA barcodes.