• Korean journal of applied entomology
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• v.29 no.3
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• pp.170-175
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• 1990

These studies were conducted to examine the mechanism of acaricidal resistance in the twospotted spider mite (Tetranychus urticae Koch). The resistant strains were obtained by succssive selection of five acaricides including carbonphenothion and ethion of organophosphorus compound, dicofol of organochlorine compound, cyhexatin of compound and biphenthrin of synthetic pyrethroid. Esterase isozymes were separated by polyacrlyamide gel susceptible strains. The differences of the esterase isozymes of the resistant strains were Est. 1, Est. 3 in the carbonphenothion-selected strain, Est. 3 in the ethion- and the cyhexatin-selected strains, Est. 1, Est. 3, Est. 7 in the dicofol-selected strain, Est. 7 in the biphenthrin-selected strain as compared to the susceptible strain. With the difference of electrophoretic bands and their activities, esterases were related to the resistant mechanism of tested acaricides.

• Mycobiology
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• v.47 no.4
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• pp.408-414
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• 2019

Crinum asiaticum and Hymenocallis littoralis, commonly known as spider lilies are bulbous perennial and herbaceous plants that widely planted in Malaysia as ornamental. During 2015-2016, symptom of leaf blight was noticed on the hosts from several locations in Penang. The symptom appeared as irregular brown to reddish lesions surrounded by yellow halos. As the disease progressed, the infected leaves became blighted, dried, and fell off with the presence of black microsclerotia and pycnidia on the lesions parts. The present study was conducted to investigate the causal pathogen of leaf blight on C. asiaticum and H. littoralis. Based on morphological characteristics and DNA sequences of internal transcribed spacer (ITS) region and translation elongation factor 1-alpha (TEF1-α) gene, the causal pathogen was identified as Macrophomina phaseolina. Phylogenetic analysis of combined dataset of ITS and TEF1-α grouped the isolates studied with other isolates of M. phaseolina from GenBank. The grouping of the isolates was supported by 96% bootstrap value. Pathogenicity test proved the role of the fungus in causing leaf blight on both hosts.

• The Transactions of the Korean Institute of Power Electronics
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• v.17 no.2
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• pp.107-113
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• 2012

This paper proposes a PDS(Power Transfer Display separation) method for AC-PDP. The proposed PDS method can transfer power and perform an energy recovery by a power conversion circuit operates differently depending on the time. As a result, it uses less of components than conventional PDP power supply and sustain circuit use. Moreover, the manufacturing process can be streamlined. Therefore, the proposed method is suitable for low cost PDP module. To confirm the operation, validity and features of the proposed PDS method, experimental results from a prototype for 42-in diagonal PDP are presented.

• Applied Biological Chemistry
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• v.40 no.3
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• pp.249-253
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• 1997

The acaricidal and ovicidal activity against red spider mite (Tetranychus urticae) was examined for a series of S-aryl arenethiosulfonates and compared with sulfonate acaricide, ovex and senile. Substituted diphenyl disulfides were obtained from substituted thiophenols, chloronitrobenzene and aniline derivatives. The S-aryl arenesulfonothioates were synthesised from the oxidation of disulfides. Three kind of para substituted compounds were found to have good ovicidal effect but acaricidal activity against adult mite was negligible in all S-aryl arenethiosulfonates.

• The Korean Journal of Soil Zoology
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• v.10 no.1_2
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• pp.22-25
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• 2005

The fauna of spiders in streamsides were surveyed by pitfall trapping at three sites (Gichun-ri, Duckwoo-ri and Haechang-ri) in Paltan-myun in Hwasung areas, Gyeonggi-do. Total 83 spider species and 63 genera belonging to 20 families were identified from 3,128 spiders collected. Species richness and abundance are high in Linyphiidae and Lycosidae and these two groups comprised 60.7% of total collected spiders. Thirty-six species (43.4%) were Iveb builders and 47 species (56.6%) were hunters. This study was the first survey on streamside spiders form Korea and will be valuable in the management of biological resources and description of biodiversity, and augment for utilizing them as a biological control agent in agricultural landscape.

• The Korean Journal of Ecology
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• v.21 no.1
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• pp.15-26
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• 1998

This study was conducted to analyze arthropod community patterns in smallrice fields managed by different cultural methods [Conventional and Low Input Sustainable Agriculture(LISA)] in Suwon in 1995 and 1996. A half of nitrogen fertilizers and a quarter of pesticides were applied in the LISA field compared to in the conventional field. Total 15 orders and 43 families of arthropods were collected in two years. No differences were found in arthropod abundance and arthropod species composition between two differently practiced fields. The arthropod community was analyzed using guild categories. The arthropods were found in the order of 'pest(phytophag)>natural enemy>non-pest' in their densities. The pest species were mainly Homoptera and dominated by Delphacidae (Nilaparvata lugens Stal and Sogatella furcifera Horvath). They constituted > 80% of pest abundance. The spider was the most dominant group in the natural enemy and constituted > 90% of natural enemy abundance. Hunting spiders constituted > 60% of spider abundance and were dominated by Pirata subpiraticus Bos. et Str.(Lycosidae). Pachygnatha clerki Sundevall(Tetragnathidae), Gnathonarium dentatum Weider and Ummeliata angulituberis Oi(Erigonidae) were the dominant species in webbing spiders.

• Korean journal of applied entomology
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• v.37 no.2
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• pp.207-212
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• 1998

Tea field-collected populations of the tea red spider mite (Tetranychus kazawai Kishida) from five different locations in the southern region of Korea were assessed for resistance to seven acaricides using leaf spray method. There were considerable differences in susceptibility depending on the tested acaricides and the location from which the population was collected. The populations showing high resistance ratio of more than 20 with respect to certain acaricide were as follows: the Sungjun and Cheju populations to azocyclotin, tebufenpyrad, fenpyroximate, pyridaben, propargite, and fenpropathrin; the Haenam population to propargite and fenpyroximate; the Bosung population to propargite; the Youngam population to pyridaben. Therefore, the use of other alternative acaricides against the Sungjun and Cheju populations is needed. However, careful selection of the appropriate acaricide against the Haenam, Bosung and Youngam populations of the tea red spider mite might be maintained in effective control.

• The Korean Journal of Mycology
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• v.26 no.1 s.84
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• pp.78-85
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• 1998

During the screening of biological control agents for insect pests in the greenhouse, 70 dead insect-related fungi were isolated and tested insecticidal effect of their culture filtrates was tested. From this studies, CNAB-63 isolate showed strong control effects against the cotton aphids and the two-spotted spider mite as 65.19% and 77.55%, respectively. The insecticidal active compound of CNAB-63 isolate was purified from culture filtrate by silica gel chromotography, thin layer chromatography and HPLC. Purified active compound (CNAB) showed control effects against the two-spotted spider mite with 63.45% at $100\;{\mu}g/ml$ concentration. However, it did not exhibit antimicrobial activity against fungi and bacteria.

• Journal of Species Research
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• v.10 no.1
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• pp.86-98
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• 2021

The genus Pholcus Walckenaer, 1805 is the largest genus among the cellar spider family Pholcidae C.L. Koch, 1850, including 339 species. To date, 33 species in the genus are known to be distributed in Korea, being placed into three species-groups(crypticolens-group, phalangioides-group, and phungiformes-group). About 91% of these species are endemic to Korea. In this study, four new species of the genus Pholcus were discovered in Korea, viz, Pholcus chuncheonensis Lee, Choi and Kim sp. nov., Pholcus pajuensis Lee, Choi and Kim sp. nov., Pholcus pocheonensis Lee, Choi and Kim sp. nov., and Pholcus unaksanensis Lee, Choi and Kim sp. nov. These new species are classified as members of the phungiformes-group, having morphological characteristics such as male chelicerae with a frontal apophysis, palpal tibia with a prolateroventral tubercle, and genital bulb without appendix or having pseudo-appendix, but can be distinguished from congeners by characteristics of the male palp and female genitalia. Detailed descriptions and a key to new species are provided with accompanying photographs.

• Animal Systematics, Evolution and Diversity
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• v.39 no.4
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• pp.272-283
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• 2023

The spider fauna of rice fields, marshes, and reclaimed lands was intensively explored in 2015-2022. During the seasonal survey, six Tibellus spiders were collected; two of them, Tibellus fengi Efimik, 1999 and Tibellus japonicus Efimik, 1999, were new to Korean spider fauna and four of them were identified as new species, Tibellus deokjeok sp. nov., Tibellus gimcheon sp. nov., Tibellus sihwa sp. nov., and Tibellus yeongdong sp. nov.. Four new species are similar to each other and known species in the shape of the genital organ and body appearance in both sexes, but can be distinguished from the other Tibellus members by the shape of embolus, conductor, retrolateral tibial apophysis, and ventral tibial apophysis in male and median septum, receptaculum, spermatheca, and copulatory duct in female. The present study taxonomically describes these six Tibellus spiders with diagnoses, measurements, and morphological photos with a key to the Korean Tibellus species.