• Korean journal of applied entomology
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• v.53 no.4
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• pp.435-440
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• 2014

The number of Bemisia tabaci adults attracted to horseweed, thistle, red bean, cucumber, and tomato plants, as measured by the number stuck to yellow sticky traps, was investigated in a polyvinyl greenhouse for growing tomatoes using organic methods. The number was highest on cucumber plants in the early days of B. tabaci infestation, but was highest on horseweed overall. Of the eight species of beans tested, B. tabaci adults were most attracted to Ultari-Gangnang; however, beans were not effective trap plants for B. tabaci. Measurement of olfactory behavioral response using a four-choice olfactometer showed that B. tabaci adults preferred horseweed to cucumber, eggplant, or tomato. The developmental period of B. tabaci eggs and larvae was shorter at high temperature. At $30^{\circ}C$, the developmental period of eggs and larvae on horseweed were reduced approximately 0.5 and 1 day, respectively, compared to those on cucumber or tomato.

• Weed & Turfgrass Science
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• v.4 no.3
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• pp.236-242
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• 2015

We surveyed the distribution of exotic weeds in the 141 crop fields of Jeju island. The exotic weeds were summarized as 66 taxa including 18 families, 50 genera, 64 species and 2 varieties. In winter crop fields there were 45 species of exotic seeds in 18 families, in summer crop fields 50 species in 16 families, and in perennial crop fields 39 species in 17 families. Total exotic weeds were classified to 39.4% of summer annuals, 36.4% of winter annuals, 7.6% of summer and winter annuals, and 16.7% of perennials. The ratio of summer annuals were high in the summer crop fields. Compositae was dominant family, followed by Gramineae, Malvaceae and Solanaceae. Malvaceae did not appear in perennial crop fields. Dominant exotic weeds in winter crop fields were Chenopodium album, Amaranthus viridis, Senecio vulgaris and Coronopus didymus, in summer crop fields, Chenopodium album, Amaranthus viridis, Senecio vulgaris and Sonchus oleraceus and in perennial crop fields, Conyza sumatrensis, Gnaphalium calviceps and Senecio vulgaris. The dominant exotic weeds in the crop fields of Jeju island were Chenopodium album, followed by Amaranthus viridis, Senecio vulgaris, and Conyza sumatrensis. This information could be useful for establishment of exotic weed control methods in Jeju island.

• Korean Journal of Environmental Biology
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• v.40 no.1
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• pp.1-10
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• 2022

Global warming has a major impact on the Earth's precipitation and temperature fluctuations, and significantly affects the habitats and biodiversity of many species. Although the number of alien plants newly introduced in South Korea has recently increased due to the increasing frequency of international exchanges and climate change, studies on how climate change affects the distribution of these alien plants are lacking. This study predicts changes in the distribution of suitable habitats according to RCPs climate change scenarios using the current distribution of the invasive alien plant Conyza sumatrensis and bioclimatic variables. C. sumatrensis has a limited distribution in the southern part of South Korea. Isothermality (bio03), the max temperature of the warmest month (bio05), and the mean temperature of the driest quarter (bio09) were found to influence the distribution of C. sumatrensis. In the future, the suitable habitat for C. sumatrensis is projected to increase under RCP 4.5 and RCP 8.5 climate change scenarios. Changes in the distribution of alien plants can have a significant impact on the survival of native plants and cause ecosystem disturbance. Therefore, studies on changing distribution of invasive species according to climate change scenarios can provide useful information required to plan conservation strategies and restoration plans for various ecosystems.

• Korean Journal of Plant Resources
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• v.16 no.1
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• pp.15-24
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• 2003

The study was performed to understand the actual vegetation by using the phytosociological method on the Ambrosia artemisiifolia var. elatior community group in Jeju Island. The flora was composed of 48 families, 156 genera, 200 species, 28 varieties, 2 forma or 230 taxa. The Ambrosia artemisiifolia var. elatior community group vegetation was classified into two communities and one association; Erigeron annuus - Conyza sumatrensis, Bromus tectorum - Bidens pilosa, Setaria viridis - Eleusine indica community and Lactuco indicae - Humuletum japonicae association. Ambrosia artemisiifolia var. elatior community group was wide from the coastal areas up to the elevation of 1500 meter on Young sil of Mt. Halla. The highest dominance of the Ambrosia artemisiifolia var. elatior is 345 meter which is located near Seoneheul-ri Jocheon-eup, on the other hand the lowest one is located 1020 meter near Young-sil of Mt. Halla.

• Weed & Turfgrass Science
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• v.5 no.2
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• pp.60-64
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• 2016

Investigation on weed flora in Lycium chinense upland fields was conducted to understand the current status of weed flora and establish the control measures. Investigation was conducted twice, May and June on 2015. From this investigation, 91 species of 30 families including 27 exotics were identified into 36 species of annuals, 28 species of biennials and 27 species of perennials. Dominance was the highest with Portulaca loeracea followed by Digitaria ciliaris, Stellaria media, Oxalis corniculata, Acalypha australis, Chenopodium album, Cyperus iria etc. in order. Chenopodium album was the highest in importance analysis and the followings were in order of Conyza canadensis, Conyza bonariensis, Senecio vulgaris, Amaranthus lividus, Sonchus asper etc.

• The Korean Journal of Ecology
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• v.26 no.4
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• pp.209-214
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• 2003

In order to clarify the successional trend and its characteristics of plant community in abandoned field in Cheju Island, we investigated the seral changes of vegetation height, coverage, growth form, species richness, diversity and dominance index along with the time lapse, and then compared with those of mainland researches. And in order to seek the overall trend of vegetation changes, we used cluster, TWINSPAN and PCA ordination techniques. The succession was characterized by the lower species number, lower vegetation height, longer period of herb dominant and later invasion of tree species. These results may come from that ecological traits of Cheju Island itself, and ecosystem fragmented influences that block a seed (propagule) transport. Sere of the dominant species was shown as follows: Mazus japonicus(0.5∼1 years)→Conyza sumatrensis (2 years)→Artemisia princeps var. orientalis(4 years)→Artemisia princeps var. orientalis, indigofera pseudotinctoria(5 years)→Rosa multiflora, Miscanthus sinensis, etc.(8 years)→Miscanthus sinensis(12 years)→Boehmeria nivea, Pueraria thunbergiana etc.(15 years)→Mallotus japonicus(20 years)→Litsea japonica, Machilus thunbergii (20 years<). Abandoned fields were classified into three groups according to time lapse; earlier stage(0∼1 years), middle stage(2∼8 years) and later stage(8∼20 years).

• Korean journal of applied entomology
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• v.54 no.4
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• pp.311-316
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• 2015

This study was performed to ascertain the potential of egg plant for use as a trap plant to attract Bemisia tabaci adults compared to that of tomato. Choice tests were conducted to compare the preference of B. tabaci adults to horseweed, egg-plant, cucumber, and tomato. B. tabaci adults were found to be more sensitive to visual cues than to odor cues, and they preferred the egg-plant and cucumber to horseweed. The attraction rates of the egg-plant and cucumber to B. tabaci adults were 82.3% and 82.5% respectively, compared to that of tomato. Because egg-plants are easier to manage compared to cucumber, we excluded cucumber from subsequent experiment. The attraction rate of egg-plant to B. tabaci adults was >90% when the height of egg-plant was equal or more than that of the tomato plant.

• Korean Journal of Plant Resources
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• v.15 no.3
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• pp.227-236
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• 2002

The study was performed to understand the actual vegetation by using the phytosociological method on Hypochoeris radicata community group in Jeju-Island. 1. Tracheophyte belonged to the flora species is composed of 194 taxa which comprise 47 families,136 genera, 171 species, 22 varieties and 1 forma (Naturally plants 16 families, 47 genera, 67 taxa, including 64 species, 3 varieties). 2. According to the character species, the Hypochoeris radicata community group vegetation was classified into two communities; Erigeron annuus - Conyza sumatrensis, Setaria viridis var. pachystachs -Zoysia sinica community, distributed species. 3. This species is distributed from the shore to 1,700m the sea, on Jeju Island. 4. In terms of dominance and sociability of Hypochoeris radicata, the Seohong-dong, Seogwipo city site ranked highest site and the Seongsan-ri, Namjeju-gun site ranked lowest. 5. Catapodium rigidium which is belonged Gramineae was for the Hirst time found in JeJu.

• Korean journal of applied entomology
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• v.58 no.3
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• pp.203-207
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• 2019

Bemisia tabaci (Hemiptera: Aleyrodidae) is one of the major insect pests causing economic damages to over 900 different crops in the world. Especially, B. tabaci JpL (L. japonica) is known as a species living only in Japan and Korea so far, and mainly in Lonicera japonica and specific plant species. This study was conducted to investigate the occurrence and spread of B. tabaci JpL on Jeju Island in 2019. Of the total 25 areas surveyed, 1,003 individuals of B. tabaci JpL adults were collected from 24 L. japonica and one Conyza sumatrensis. All populations identified belonged to the JpL species. The result of this study showed that the population of B. tabaci JpL has increased at very high speeds to date compared to the previous reports in Korea.

• Korean Journal of Plant Resources
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• v.21 no.2
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• pp.162-170
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• 2008

The purpose of this study was to suggest the raw data on establishing the domestic wetland conservation plan. The results of this study were as follows. The vascular plants were summarized as 201 taxa in Ahnshim wetland; 57 families, 154 genera, 179 species and 22 varieties. The rare and endangered plant designated by Korea Forest Service was Hydorcharis dubia. In the wetland plants, the emerged plants were showed Typha angustata, Beckmannia syzigachne, Zizania latifolia, Phragmites communis, Persicaria thunbergii, Oenanthe javanica and Veronica undulata, and the submerged plants were Potamogeton crispus, Vallisneria asiatica, Hydrilla verticillata, Ceratophyllum demersum and Myriophyllum verticillatum. And the floating leaved plants were confirmed Potamogeton distinctus, Hydrocharis dubia, Nelumbo nucifera and Nymphoides peltata, and the floating plants were Salvinia natans, Spirodela polyrhiza and Lemna paucicostata. The naturalized plants were 33 taxa; Avena fatua, Dactylis glomerata, Rumex crispus, Rumex conglomeratus, Amaranthus retroflexus, Lepidium apetalum, Tlaspi arvense, Descurainia pinnata, Potentilla supina, Vicia villosa, Robinia pseruo-acacia, Amorpha fruticosa, Trifolium repens, Medicago sativa, Ailanthus altissima, Euphorbia supina, Oenothera lamarckiana, Quamoclit angulata, Ipomoea purpurea, Solanum nigrum, Veronica perisca, Helianthus tuberosus, Ambrosia artemisifolia var. elatior, Xanthium strumarium, Erigeron annuus, Erigeron canadensis, Conyza sumatrensis, Senecio vulgaris, Bidens frondosa, Tagetes minuta, Taraxacum officinale, Taraxacum laevigatum and Sonchus oleraceus.