Recently, with the development of genetic technology, interest in environmental DNA (eDNA) to study biodiversity according to molecular biological approaches is increasing. Environmental DNA has many advantages over traditional research methods for biological communities distributed in the environment but highly depends on the established base sequence database. This study conducted a comprehensive analysis of the habitat status and classification at the genus level, which is mainly used in eDNA (12S rRNA, 16S rRNA, 18S rRNA, COI, and CYTB), focusing on Korean registration taxon groups (phytoplankton, zooplankton, macroinvertebrates, and fish). As a result, phytoplankton and zooplankton showed the highest taxa proportion in 18S rRNA, and macroinvertebrates observed the highest ratio in the nucleotide sequence database in COI. In fish, all genes except 18S rRNA showed a high taxon ratio. Based on the Korean registration taxon group, the gene construction of the top 20 genera according to bio density observed that most of the phytoplankton were registered in 18S rRNA, and the most significant number of COI nucleotide sequences were established in macroinvertebrates. In addition, it was confirmed that there is a nucleotide sequence for the top 20 genera in 12S rRNA, 16S rRNA, and CYTB in fish. These results provided comprehensive information on the genes suitable for eDNA research for each taxon group.

DNA ‘barcoding’ has potential applications in insect pest monitoring and quarantine since large numbers of DNA sequences for insect species identification have been reported in recent years. However, the exact number of relevant COI sequences in public databases such as NCBI (http://www.ncbi.nlm.nih.gov/) is not readily available. The IMGD (Insect Mitochondrial Genome Database; http://www.imgd.org) contains 162,847 partially sequenced mitochondrial gene entries originated from 35,067 hexapod species and makes it possible to check whether DNA sequences have been previously reported or not for certain insect species. In this study, we applied the IMGD to establish baseline data for the forest pest insects in Korea, before constructing a DNA barcode system. Retrieving data from the IMGD, we recognized that DNA sequences were already available for 73 of 259 species known as forest pest insects in Korea. Most of the 73 species with DNA sequences are common pests worldwide but there maining 186 species are endemic to the Eastern Palearctic region. Based on these data, we are proceeding to construct a Korean Forest Insect Pest DNA barcode database.