• Korean journal of applied entomology
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• v.53 no.3
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• pp.287-293
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• 2014

Matsumuraeses phaseoli is one of the main pests that attack the flowers and pods of red bean (Vigna angularis) and mungbean (Vigna radiata) in Korea. To elucidate the developmental characteristics and over-wintering stage of M. phaseoli, several stages of the insect were observed through artificial rearing under outdoor conditions in Suwon ($37^{\circ}$16'N $126^{\circ}$59'E 35ASL), Korea. In colonies in which neonate larvae were reared at about 2-week intervals for more than a year, the developmental period from larva to adult emergence became longer from spring to summer, but shorter from summer to autumn; aestivation was not observed during the summer season. The colony in which rearing started on Oct 8, 2008 over-wintered as pupae and emerged in late April next year with a survival rate of 6%. However, the colony in which the rearing started on Oct 23, 2008 over-wintered as mature larvae, pupated in late April, and emerged in early and mid-May with a survival rate of 2%. When the fifth instar larvae were transferred outside from the laboratory ($25^{\circ}C$, 15L:9D) between November and February, no larvae could survive during the winter season. Some newly laid eggs and newly emerged adults could not hatch and could not survive, respectively, in outdoor conditions in November and December. These results suggest that neonate larvae of M. phaseoli that hatch in October can over-winter as late larvae or pupae in Suwon, Korea.

• Korean Journal of Environment and Ecology
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• v.33 no.1
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• pp.1-8
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• 2019

Pintail (Anas acuta) is the major wintering bird in South Korea and known as a major mediator of the highly pathogenic avian influenza (HPAI). Pintail migrates long distances between Russian Siberia and Korea. This species prefers a rice paddy area as their winter habitat. The purpose of this study is to provide the data necessary for the conservation and management of bird habitats in Korea by understanding the wintering home-range and habitat of pintail in Korea. We captured six pintails using a cannon-net in the winter of 2015 and attached the GPS-mobile phone based telemetry (WT-300) on them to study the wintering home-range and wintering habitat. We analyzed the tracking location data using ArcGIS 9.0 Animal Movement Extension and calculated Kernel Density Estimation (KDE) and Minimum Convex Polygon (MCP). The average home-range in the wintering ground analyzed by MCP was $677.3km^2$ (SD=130.2, n=6) while the maximum and minimum were $847.7km^2$ and $467.5km^2$, respectively. Extents of home-range analyzed by KDE were $194.7km^2$ (KDE 90%), $77.4km^2$ (KDE 70%), and $35.3km^2$ (KDE 50%). The pintails mostly used both sea and paddy field as habitat in the winter season and utilized paddy fields more during the nighttime and than the daytime. We concluded that the home-range and habitat of pintails in the winter could be used as the reference data for the preservation of species, management of habitats, and coping with a breakout of HPAI.

• Korean Journal of Environmental Biology
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• v.37 no.4
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• pp.483-492
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• 2019

During the breeding season, both adults and immature Eurasian Oystercatchers (Haematopus ostralegus osculans) were observed to feed on prey, such as gastropods (Umbonium thomasi) and bivalves, at the tide water line around Yubu island in Korea. To determine differences in the foraging efficiency between the adult and immature birds, we recorded the feeding behavior using digiscoping with a telescope and a smartphone. We compared the pace, the prey search rate, the proportion of prey search techniques, the feeding success rate, the handling time, and the heads-up rate between the adult and immature birds. There were significant differences in the proportion of prey search techniques when gastropods were consumed and in the prey search rate and heads-up rate when bivalves were consumed but there were no significant differences in feeding success rates. Therefore, although the immature birds on Yubu Island were inferior to adults during the breeding season and they lacked the proficiency to locate prey, their overall foraging efficiency was similar to adults. This was considered to be due to the continuous eating of bivalves during the wintering season, which requires a high level of foraging efficiency.

• Journal of Ecology and Environment
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• v.32 no.3
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• pp.145-148
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• 2009

To understand whether experience of cold season in reproductive behaviors in the adults of Amaurobius ferox, the paired adults of a female and a male were exposed under 'cold-treated environment' and 'not cold-treated environment', respectively. I investigated effects of the cold treatment on the brood production of A. ferox. In not cold treatment in which male-female pairs were formed in October at a temperature of $20^{\circ}C$ (${\pm}2^{\circ}C$) and continuously kept under not cold-treated environment, only 3 of 50 pairs successfully reproduced (reproduction was defined as the emergence of spiderlings). In cold treatment where individuals were kept in cold conditions for 3 months prior to pair formation, 57 out of 60 couples succeeded in reproducing. Females which did not experience the low temperature displayed strong aggressiveness toward males. This behavioral inhibition might the primary barrier to copulation of A. ferox that decrease following a period of low temperature. The reproductive inhibition might help the females to allocate the maximum amount of energy in a given environment to reaching the adult stage and to delay reproduction in unfavorable wintering conditions.

• Journal of Environmental Science International
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• v.15 no.11
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• pp.1077-1086
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• 2006

This study aims at analyzing relationships between land use and habitat types of winter wildbirds to provide basic understanding of ecosystem for preservation and restoration of urban ecosystem in the future. The research area is Hanam City. Researches on land use types showed Hanam City had 79.1% of greenspace and openspace, but intensive urban development has been taking place in greenspace that is adjacent to urban districts. This has brought the problems of lack of greenspace in urban districts and damages to cultivated areas and grassland. A total of 61 and 8,642 populations of winter wildbird species were observed in research areas. Paradoxornis webbiann(16.91), Passer montanus(11.93), Pica pica(6.88) were dominant species. When they were divided according to habitat types, 20 species of interior species, 8 species of interior-edge generalist species, 12 species of edge species and 3 species of urban species were observed. When which land use type was mostly served as wildbirds habitats was examined, urban species(3 species and 290 populations) was a dominant species in urban districts while in greenspace and openspaece, water species(19species and 3,075 populations) including winter migratory birds was. Among greenspace and openspaece, edge species was dominant in forest while urban species was a dominant species in cultivated areas. This shows there is a need to improve diversity of wildbirds through restoration of cultivated areas in the central part of Hanam City.

• Journal of Preventive Medicine and Public Health
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• v.20 no.1 s.21
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• pp.137-146
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• 1987

The following facts have been identified as a result of epidemiological trend and characteristic of Japanese Encephalitis in Korea for the last 20 years. First: The Epidemiological period which was ten-year and three-year in the past has been disappeared following the start of immunization program at 1970. Second: The Incidence rate was much higher in the south and West areas than northeast area of Korea. City and Province with the highest incidence rate was Chungcheong Nam Province and Cholla Buk Province. Third: Regardless of scope of prevalence, the main season that 90 percent of total incidence occurrs in one month from mid-August through mid-September. Fourth: The number of case by age was that 80 percent of total patients is children aged $3{\sim}15$. Recently there is an increase in the number of patients who are elderly people. Fifth: The study on the ecological conditions of mosquito including wintering and effectiveness of immunization for Japanese Encephalitis and duration on antibody should be done. Sixth: There has been no case of Japanese Encephalitis for the last three years since 1984 mainly due to disinfecting to eradicate mosquitos, immunization for vulnerable group of people aged $3{\sim}15$, individual precaution not to be bitten by mosquito, improvement of environment sanitation. While there has been no case of Japanese Encephalitis during last three years, there is possibility that Japanese Encephalitis becomes prevalent again anytime since its virus has been isolated continuously from the natural reservoirs.

• Korean Journal of Microbiology
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• v.35 no.3
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• pp.185-191
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• 1999

This study was conducted to investigate the vibrio flora in an edible shellfish. sunset shelfish. Soletelliim olivacen. which were collected in the estuarine area. Dadaepo near Nakdong River in Korea lkoin January 1997 to November 1997. Including five pathogemc vibrios (Vibrio alginolyticus, Vibrio pamhaemol~~licz~s, Vibrio cholerae non-01. Vibrio vulnificus, and Vihrio jl~~vinlis), a lotal of eight species of vlbr~os (Vi61-io splendidrrs biovar I, Vibrio splendidus biovar 11, Vibrio snlrnonicida and Vibrio tr,~biasllii) were identified from the sunset shellfish by heir biochemical characters. The isolation of Vihrio pamhaemolyricns, which is known not to grow below $15^{\circ}C$, in winter season indicates that the sunset shelllish is one oT the natural owl.- wintering hosts for Vibrio parahuemolyticus.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.38 no.1
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• pp.39-54
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• 2005

Seasonal variation in species composition of fish in the Geum River estuary was determined using monthly samples collected with a bag net from February to December 2003. Of a total of seventy-three species collected, four groups of fishes were distinguished. Estuarine fishes such as Chelon haematocheilus and Synechogobius hasta were collected almost all the seasons and predominated in abundance during cold months. Coastal fish species such as Sardinella zunasi, Konosirus punctatus, Engraulis japonicus, Johnius grypotus and Thryssa kammalensis were dominated from late spring to autumn. Their adults entered into the estuary in spring and a large number of their juveniles were collected in summer and autumn till moving out to deeper waters for over-wintering. A few freshwater fishes were collected when the freshwater was discharged during the rainy season. Anguilla japonica elvers (diadromous fish) and Coilia nasus (amphidromous fish) were collected in spring during their upstream migration. The principal component analysis revealed that the seasonal variation in species composition of fishes was principally determined by water temperature and/or water temperature related factors.

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• v.2 no.4
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• pp.285-292
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• 2021

We investigated habitat use and home range of a rescued and released white-naped crane using GPS tracking technology in Cheorwon, South Korea, from October 2016 to March 2017. Four types of roosting sites were identified: frozen reservoirs, paddy fields, rivers, and wetlands. Upon arrival, the white-naped crane preferred wetlands in the Demilitarized Zone (DMZ). In late wintering season, it showed a tendency to change main roosting sites in the following order: rice paddies, rivers, and frozen reservoirs. Among 14 sleeping places, Civilian Control Zone (CCZ) with various type of available habitats was more preferred than the DMZ. Places outside of CCZ were rarely used due to anthropogenic disturbances during the night. The tracked white-naped crane widely chose daytime feeding sites while moving around all over rice paddies in the CCZ. Mean diurnal movement distance was 10.5 km with a maximum of 24.8 km. Its home range measured with Minimum Convex Polygon (MCP) and Kernel Density Estimation (KDE) was 172.30 km² with MCP, 159.60 km² with KDE 95%, 132.48 km² with KDE 90%, and 42.45 km² with KDE 50%. All estimated values of home ranges were higher in the early and later winter than those in the middle period.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.53 no.2
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• pp.196-202
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• 2008

To establish a cultivation system of Sedum sarmentosum using a rice nursery tray ($30{\times}60{\times}3\;cm$) in non-heating plastic film house, cuttings of two local strains (Wanju and Keumsan) were prepared and planted at different planting densities (40, 60 and 80 cuttings per tray) on September 7th, and subsequent growth and yield at pre- and post-winter season were investigated. When pre-wintering growth were measured at 60 days after planting, high planting density (80 cuttings/tray) decreased leaf length and lateral shoot number per plant compared to 40 cuttings/tray. When post-wintering growth were measured on April 20th, no significant growth differences as affected by planting density were observed in Keumsan strain, while decreased stem diameter, node number and leaf number were observed in Wanju strain planted at 80 cuttings/tray compared to 40 cuttings/tray. Fresh and dry weights were not significantly different as affected by planting density, but those were significantly increased in Wanju strain compared to Keumsan strain. When regrowth characteristics followed by the first harvest were measured on June 5th, significantly increased stem number was observed at 80 cuttings/tray compared to 40 cuttings/ tray. Fresh and dry weight were significantly increased in Keumsan strain planted at 80 cuttings/tray compared to 40 cuttings/tray, and dry weight were increased in Wanju strain compared to Keumsan strain. Wanju strain showed higher shoot yield, thicker stem, shorter node and larger leaf, and non-succulent stem under high planting density compared to Keumsan strain. Accordingly, the optimum density was 40 cuttings per tray, and Wanju strain was adequate for the cultivation system using a rice nursery tray.