• Journal of Bio-Environment Control
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• v.31 no.1
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• pp.43-51
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• 2022

This study was conducted to investigate the effect of ventilation at high temperature on the control of powdery mildew, silverleaf whitefly two-spotted spider mite occurred at Korean melon cultivation greenhouse, and on leaf rolling and flowering of the plant in summer season. 'Alchanggul' grafted onto 'Hidden Power' rootstock was planted on soil bed with the distance of 40 cm. Three ventilation temperatures of 45℃, 40℃, and 35℃ as set points were compared. Ventilation treatment was done by control of side window operation from 18th June to 13th July when silverleaf whitefly, mite, and powdery mildew were occurred in all greenhouses. The temperature inside greenhouse was increased up to the set temperature point on sunny days and maintained for about 9 hours with high relative humidity at 45℃ condition. The differences of day maximum air temperature and day minimum RH were the highest at 45℃ treatment. After 11 days of treatments, the damage by powdery mildew and two-spotted spider mite was almost recovered at 45℃ treatment but not at 40 and 35℃. The population of silverleaf whitefly and two-spotted spider mite were significantly decreased at 45℃ treatment at 14 days after treatment, while powdery mildew symptom was not significantly decreased. Leaf rolling was observed at high temperature but not severe at 45℃ treatment. After 26 days of treatments, female flowers did not bloom at all at 45℃ treatment, and the number of male flowers was 1.2 among 15 nodes of newly grown shoots. As the result, it indicates that ventilation at the high temperature of 45℃ for about 2 to 3 weeks can be an applicable method to control above mentioned pests and disease, and to recover the vegetative growth of Korean melon by reducing flowering of the plant.

• Korean journal of applied entomology
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• v.55 no.4
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• pp.489-494
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• 2016

Biological control of the fungus gnat Bradysia difformis by the predatory mite Hypoaspis aculeifer was examined in hydroponic systems of strawberries in Namwon and Hapcheon varieties of Jeollabuk-do and Gyeongsangbuk-do provinces, respectively, from 2012 to 2013. The damage to strawberries caused by B. difformis was examined in seedling stages and during cultivation periods. To achieve environment-friendly management of B. difformis, 60.6 individuals of H. aculeifer were released per square-meter three and four times during cultivations periods of the Namwon and Hapcheon strawberry varieties, respectively. H. aculeifer had better control efficiency against of B. difformis than that observed with conventional cultural practices. Wilt symptoms and damage of strawberries due to B. difformis were decreased by approximately 7.4-10.4%.

• Journal of Veterinary Clinics
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• v.12 no.1
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• pp.887-896
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• 1995

In order to determine the efficacy of $Bayvarol^{(R)}$ strips(Bayer AG) against the mite Varroa jacobsoni and the safety of $Bayvarol^{(R)}$ strips in honey bees, a series of trials was carried out under field condition in autumn and spring. The results obtained were as follows; 1. The average varroacidal rate of $Bayvarol^{(R)}$ strips was 92.7% in autumn and 93.7% in spring. However the average varroacidal rats of treated control group was 73.8 % in autumn and 75.1 % in spring, and that of untreated control group was 12.1 % in autumn and 16.1 % in spring. 3. The average number of dead bees in $Bayvarol^{(R)}$ group was 13.0 in recommended dosage(RD), 12.3 in 2 times of RD and 14.0 in 4 times of 70 in autumn, and 19.7 in RD,17.0 in 2 times of RD and 19.0 in 4 times of RD in spring. However the average number of dead bees in treated control groups was 38.3 in RD, 62.7 in 2 times of RD and 60.3 in 4 times of RD in autumn and 18.0 in RD, 43.3 in 2 times of RD and 102 in 4 times of RD in spring and that of untreated control of group was 12.7 in autumn and 19.3 in spring. 3. The varroacidal effects and the number of dead bees of all groups were higher in spring than in autumn. 4. It was revealed that $Bayvarol^{(R)}$ were highly saft and effective varroacides for honey bees.

• Journal of Microbiology and Biotechnology
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• v.18 no.2
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• pp.314-321
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• 2008

Acaricidal effects of materials derived from Diospyros kaki roots against Dermatophagoides farinae and D. pteronyssinus were assessed using impregnated fabric disk bioassay and compared with that of the commercial benzyl benzoate. The observed responses varied according to dosage and mite species. The $LD_{50}$ values of the chloroform extract of Diospyros kaki roots were 1.66 and $0.96{\mu}g/cm^2$ against D. farinae and D. pteronyssinus. The chloroform extract of Diospyros kaki roots was approximately 15.2 more toxic than benzyl benzoate against D. farinae, and 7.6 times more toxic against D. pteronyssinus. Purification of the biologically active constituent from D. kaki roots was done by using silica gel chromatography and high-performance liquid chromatography. The structure of the acaricidal component was analyzed by GC-MS, $^1H-NMR,\;^{13}C-NMR,\;^1H-^{13}C$ COSY-NMR, and DEPT-NMR spectra, and identified as plumbagin. The acaricidal activity of plumbagin and its derivatives (naphthazarin, dichlon, 2,3-dibromo-1,4-naphthoquinone, and 2-bromo-1,4-naphthoquinone) was examined. On the basis of $LD_{50}$ values, the most toxic compound against D. farinae was naphthazarin $(0.011{\mu}g/cm^2)$ followed by plumbagin $(0.019{\mu}g/cm^2),$ 2-bromo-1,4-naphthoquinone $(0.079{\mu}g/cm^2)$, dichlon $(0.422{\mu}g/cm^2)$, and benzyl benzoate $(9.14{\mu}g/cm^2)$. Additionally, the skin color of the dust mites was changed from colorless-transparent to dark brown-black by the treatment of plumbagin. Similar results have been exhibited in its derivatives (naphthazarin, dichlon, and 2-bromo-1,4-naphthoquinone). In contrast, little or no discoloration was observed for benzyl benzoate. From this point of view, plumbagin and its derivatives can be very useful for the potential control agents, lead compounds, and indicator of house dust mites.

• Korean journal of applied entomology
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• v.36 no.3
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• pp.237-242
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• 1997

Comparative studies on suppression possibility with three phytoseiid mite species (An.thly,seiu,sw omersleyi Schicha. A. ,fidIrrc~i.Gs arman and T\ulcornerphlorlrotiiu.s oc~c~idetitaliNs esbit) to the two-spotted spider mite (Te~trrrt~yc.Iir~l~l\ulcorner.i\c .(re Kwh) on kidney bean leaves in field and greenhouse were carried out. In the field experiments with the initial prey -predator ratio of 4 : 1. I0 : I and 20: I . A. ,firllrrcis suppressed successfully the prey populations at all three ratios 17 days after the initial infestation. A. wornc,r-;leyi \uppressed the prey population only at the ratio of 4 : 1, while T. oc~c~ideritcr1iw.s as unable to suppress the prey population at all tested ratios. In the greenhouse experiments with the initial prey-predator ratio of 10: 1, A. jil1ltrci.s could suppress the prey population continuously during the infestation period. A. ~~otnc~r,slceoyuil d suppress the prey population for 13 days after the initial infestation, while T. occie1mttrli.s could suppress the prey population for 8 - 23 days after the initial infestation.

• Korean Chemical Engineering Research
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• v.60 no.4
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• pp.557-563
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• 2022

In order to measure the allergen penetration of micropore fabrics, it is necessary to develop a convenient and appropriate experimental method for measuring a pore size of micropore fabrics. In this study, a simple and economical experimental apparatus was developed for the analysis of the pore size of micropore fabrics by measuring the weight reduction rate. In addition, the allergen blocking properties was evaluated by measuring the pore sizes of various fabrics. According to this study, the size of the pores of the microporous fabric could be obtained by measuring the weight reduction rates. In addition, higher weight reduction rate was obtained as the suction pressure passing through the particle permeation device decreased and the suction time was increased. It is expected that the developed experimental method and apparatus can be utilized as an experimental standard for quality control methods to verify the effectiveness of micropore fabrics used for house dust mite blocking bedding.

• Journal of Veterinary Science
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• v.21 no.4
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• pp.59.1-59.12
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• 2020

Background: Atopic dermatitis (AD) is a common chronic inflammatory skin disease. To understand AD, there have been many trials establishing AD animal models. Although various trials to establish AD animal models have been existed, even the mechanisms of AD in animal models are not enough clarified. Objectives: This study assessed AD characteristics induced in Nishiki-nezumi Cinnamon/Nagoya (Nc/Nga) mice following trinitrochlorobenzene (TNCB) treatment for different periods and house dust mite (HDM) treatment to compare each model's immunological patterns, especially with cytokine antibody array tool. Methods: In this study, we exposed Nc/Nga mice to TNCB or HDM extract to induce AD. Nc/Nga mice were divided into 4 groups: control, TNCB 2 weeks-treated, TNCB 8 weeks-treated, and HDM-treated groups. After AD induction, all mice were evaluated by serum immunoglobulin E (IgE) concentration and serum cytokine antibody assays, scoring of skin lesions, scoring of scratching frequency, and histological analysis. Results: The results showed significant differences between groups in serum IgE concentration, skin lesion scores, and scratching frequency. The analysis results for serum cytokine antibody arrays showed that in the TNCB 8 weeks- and HDM-treated groups, but not in the TNCB 2 weeks-treated group, expressions of genes related to the immune response were enriched. Among the histological results, the skin lesions in the HDM-treated group were most similar to those of AD. Conclusions: We confirmed that immunological pattern of AD mice was markedly different between HDM and TNCB treated groups. In addition, the immunological pattern was quietly different dependent on TNCB treated duration.

• Korean journal of applied entomology
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• v.45 no.2 s.143
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• pp.173-177
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• 2006

Biological control of Tetranychus urticae by Phytoseiulus persimilis was observed in eggp1ant greenhouse fur spring and autumn season culture. Tetranychus urticae was controlled to low density of less than 1 mite from June 24 after p. persimilis were released 3 times at rate of 10 per plant on June 1, 11, and 18, 2004 in spring season experiment. The population of Tetranychus urticae was also less than 1 mite per eggp1ant leaf from September 1 to October 22 after three times releases of 10 P. persimilis in autumn season experiment. In Phytoseiulus persimilis released plot, the percentage of leaves with T. urticae adults and nymphs were 8.6$\sim$13.3% and 5% or less in spring and autumn season experiment. The density of T urticae was from 1 to 2 on leaves with T urticae adults and nymphs.

• The Korean Journal of Pesticide Science
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• v.14 no.2
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• pp.170-174
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• 2010

The acaricidal activity of cyenopyrafen on the tea red spider mite, Tetranychus kanzawai was evaluated in laboratory and field studies. In the laboratory, cyenopyrafen was highly effective against egg, larva, protonymph and adult female of T. kanzawai. In surviving adult females of T. kanzawai exposed to cyenopyrafen, we observed significant reduction in reproduction and no egg hatch. Effectiveness of cyenopyrafen against adult female of T. kanzawai on bean leaves was lasted for 15 days at treatments of 125 and 83.3 ppm. In a field study, cyenopyrafen exhibited excellent activity to mixed developmental stages of T. kanzawai. Based on the results, cyenopyrafen could be used for the control of T. kanzawai and treatment of this acaricide at 83.3 ppm was recommended as the field rate.

• The Korean Journal of Pesticide Science
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• v.20 no.1
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• pp.66-71
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• 2016

Susceptibility of the predatory mite, Phytoseiulus persimilis to 8 insecticides was evaluated. In treatments with insecticides tested, 78-92% of adult female predators survived after 168 hrs after treatment. Adult female predators treated with insecticides tested produced 62.6-93.4% as many eggs as did control females and eclosion of eggs deposited by treated predators was not affected. Moreover, hatch percentage of P. persimilis eggs and survival of nymphs were not seriously affected by exposure to the insecticides tested. Immatures of P. persimilis survived on the leaf disc treated with insecticides tested and 98-100% of immature predators reached adulthood. Based on the results, insecticides tested are expected to be promising candidates for use in integrated pest management program with P. persimilis.