• Korean Journal of Environment and Ecology
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• v.34 no.3
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• pp.198-206
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• 2020

The purpose of this study was to investigate the damage caused by rodents in the area around Seseokpyeongjeon in Jirisan National Park and identify suspected perpetrating species by analyzing rodent excrement found near the damaged trees. Damaged trees were surveyed regardless of species of trees in the exploration trail in the target site where visual observation was possible. Sequencing analysis of mitochondrial DNA Cyt-b was performed on rodent excrement around the damaged trees to identify the perpetrating species. A total of 52 trees were damaged by rodents, and they were all identified to be Korean Fir (Abies koreana) and were concentrated in places where Korean Fir formed communities with high density. A total of 40 Korean Fir over 1.5 meters high were surveyed, and only the affected branches, not the whole tree, were found to be withered in 39 of them. A total of 12 Korean Fir under 1.5 meters high were surveyed, and 7 of which were found to have been completely withered, indicating that relatively young trees were more vulnerable to withering. The genetic sequencing analysis of excrement confirmed that the species that perpetrated the Korean Fir was Craseomys regulus.

• Korean Journal of Clinical Laboratory Science
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• v.53 no.4
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• pp.317-325
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• 2021

In order to monitor the occurrence of chigger mites, collectors were installed at four places: rice field, field, waterway, and grass field. Totally, 207 chigger mites belonging to 7 species were collected. Starting with 2 mites in the 5 weeks of September, a maximum of 49 mites were collected during 3 weeks of November. Totally, 81, 52, 47 and 27 mites were collected from grass field, waterways, rice field, and field, respectively. Analysis of sampling and collecting chigger mites determined that the most encountered species was Neotrombicula kwangneun (73, 35.3%), followed by Leptotrombidium palpale (46, 22.2%), N. tamiyai (41, 19.8%) and N. asakawai (27, 13.0%). The grab results of 44 wild rodents revealed Apodemus agrarius (35, 79.5%), Crocidura spp. (5, 11.4%), Craseomys regulus (2, 4.5%), and A. peninsulae (2, 4.5%; which had not been detected previously). A total of 6,628 chigger mites were collected from rodents, and the chigger index was determined to be 150.6. Chigger index was found to be highest at 234.2 in October, followed by 223.3 in November, 75.6 in April, and 66.2 in May. PCR from all chigger mite samples tested negative for the Tsutsugamushi pathogen.