• Korean journal of applied entomology
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• v.35 no.2
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• pp.126-131
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• 1996

These experiments were conducted in the laboratory conditions to determine the prey consumption of a predaciousphytoseiid mite, Amblyseius womersleyi Schicha, and its ability to regulate the population of tea redspider mite, Tetranychus kanzawai Kishida. The functional response curve of the adult A. womersleyi to thedensity of eggs, larvae, and nymphs of T. kanzawai indicated Holling's Type 11: the consumption of prey bythe adult A. womersleyi increased with the prey density but the consumption rate decreased. The critical initialratio to suppress the prey population by the predator seemed to be 32:l @rey:predator) at 25"C, and 16:l at20$^{\circ}$C on kidney bean plant. The predator could not regulate any initial ratio of the prey population at 15$^{\circ}$C.^{\circ}$C.

• The Korean Journal of Soil Zoology
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• v.6 no.1_2
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• pp.17-20
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• 2001

The preference ratio of spider mites (Tetranychus urticae and T. kanrawai) on the chrysanthemum, Gypsophila paniculata, Carnation and Rose was high, but Lilium, Calla, Startis and Gladiolus was low. Field adaptability of Tetranychus kanzawai on the chrysanthemum variety was high in Yellowment variety but low in five other varieties. That of T. urticae line was high on 9818-1, 9819-5, 9820-6 chrysanthemum lines but low on other six lines . Preference ratio of T. urticae was 82.8% higher on upper than on lower surfaces in the field.

• Animal Systematics, Evolution and Diversity
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• v.13 no.1
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• pp.37-44
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• 1997

Two species of ascid mites, asca kosungensis n. sp. and asca odowdi n. sp. are described from Korea : The former was collected from soil and the latter from plant leaves.

• Korean journal of applied entomology
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• v.38 no.2
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• pp.151-155
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• 1999

Biological control of Tetranychus kanzawai by Phytoseiulus persimilis on the Angelica utilis was done in 'walk-in' plastic tunnels. The population of T. kanzawai nymphs and adults per 4 cm2 in damaged leaf decreased from 25 mites on July 22 after 25 predatory mites per m2 were released on July 23 to 0.4 mites on September 9 and then rose to 9.3 mites on October 16, 1997. Phytoseiulus persimilis could suppress T. kanzawai to low population level from August 13 to October 1.

• Journal of agriculture & life science
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• v.45 no.6
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• pp.151-162
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• 2011

Methanol and hexane extracts from 35 species in 27 families of herbal plants were evaluated for their acaricidal activities against two-spotted spider mite, Tetranychus urticae by leaf-dipping and spraying methods in laboratory, pot and field, respectively. Acaricidal activities were different depending on herbal plants. When T. urticae was released on leaves of Phaseolus vulgaris var. humilis that were dipped in the 1,000 ppm hexane extracts from fruits of Torreya nucifer and Daphan genkwa, seeds of Xanthium strumarium and Pharbitis nil at one minute they experienced 56.8, 47.8, 47.7, and 47.7% mortalities, respectively. Dipping time influenced acaricidal activity, that is, one minute dipping was more effective than 30 second dipping of Phaseolus vulgaris var. humilis leaves. However, extracts of X. strumarium and P. nil seeds had comparatively high activities. Concentration of hexane extract of X. strumarium and P. nil seeds revealing LC50 were 1,824 and 1,899 ppm, respectively. Extracts of both plants from hot and cold water were not effective representing <20% mortality at 1,000 ppm. However, hexane extracts of X. strumarium and P. nil seeds were effective against T. urticae on P. vulgaris var. humilis representing 76.3 and 71.3% mortalities in pot, respectively. Control effects of hexane extract of P. nil seed were 50.8 and 35.1% at 2,000 and 1,000 ppm against T. urticae on Chrysanthemum morifolium in greenhouse, respectively.

• Korean Journal of Environment and Ecology
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• v.26 no.3
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• pp.362-366
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• 2012

To explore on the defense strategies against hervivory of five Viburnum species, morphological characteristics of the leaf, leaf domatia structure and the number, herbivores insects and mites on the leaves, collected from the trees growing in Wonju-si, Pyeungchang-gun, Taebaek-si, Taean-gun, Bonghwa-gun, Sancheung-gun and Jinju-si were investigated from May 2009 to October 2011. Domatia of V. carlesii reveals pocket type, these of V. burejaeticum, V. dilatatum and V. wrightii reveal tuft type, and that of V. odoratissimum var. awabuki reveals pouch type. Domatia number per leaf proves the highest figures, 24.0/leaf for V. burejaeticum, and the lowest, 4.9/leaf for V. carlesii. Leaf surface trichomes of four Viburnum species except for V. odoratissimum var. awabuki are mainly stellate and hispid on the leaf-blade and veins, and dense stellate trichomes on the upper leaf surface of V. carlesii, V. burejaeticum, and V. dilatatum are observed till late growing season. Extrafloral nectaries(EFN) on the terminal veins of five Viburnum species are observed. Pellucid dots on the lower leaf surface of V. dilatatum and V. wrightii might be a good defense strategies against herbivores. We observe many predatory mites eating nectar on large pellucid dots of V. dilatatum. Predatory mites number per leaf proved highly significant differences among tree species, and mean of mites number was highest values 8.1/leaf for V. burejaeticum, and the lowest 2.6/leaf for V. odoratissimum var. awabuki. These results indicate that temperate broadleave trees develop various defense strategies against herbivores for survival. The more studies on the defense strategies against herbivores of tree species might be needed for sustainable forest ecosystem.

• The Korean Journal of Pesticide Science
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• v.15 no.3
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• pp.317-322
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• 2011

A comparative experiment was conducted to investigate the persistence of chlorfenapyr residue and its biological activity to two spotted spider mite, Tetranychus urticae, after treatment of chlorfenapyr suspension concentrate (10% SC) on paprika plants at recommended (2000 times dilution) and double dosage. Biological half-lives of chlorpfenapyr were estimated as 8 and 5 days in leaves and fruits of paprika plants, respectively. While initial deposits of chlorfenapyr residues in leaves at recommended and double dosages were 22.22 and 37.75 ${\mu}g\;g^{-1}$ at the time of application, its residue decreased to 1.56 ${\mu}g\;g^{-1}$ and 3.62 ${\mu}g\;g^{-1}$ at 29 days after treatment, respectively. Residual biological activity of chlorfenapyr SC to T. urticae at recommended dosage lasted for 7 or 15 days on the basis of 24 or 48-hrs mortality test assayed with feeding on excised leaf chlorfenapyr-treated. The control efficacy to the mite showed a good agreement with the persistence of chlorfenapyr residues in leaves.

• Smart Media Journal
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• v.9 no.1
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• pp.16-22
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• 2020

In this study, a neural network method performing both Detection and Classification of diseases and insects in paprika is proposed with Multi-Tasking U-net. Paprika on farms does not have a wide variety of diseases in this study, only two classes such as powdery mildew and mite, which occur relatively frequently are made as the targets. Aiming to this, a U-net is used as a backbone network, and the last layers of the encoder and the decoder of the U-net are utilized for classification and segmentation, respectively. As the result, the encoder of the U-net is shared for both of detection and classification. The training data are composed of 680 normal leaves, 450 mite-damaged leaves, and 370 powdery mildews. The test data are 130 normal leaves, 100 mite-damaged leaves, and 90 powdery mildews. Its test results shows 89% of recognition accuracy.

• Korean journal of applied entomology
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• v.47 no.4
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• pp.429-433
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• 2008

On the leaf disc of fruit vegetables (cucumber, sweet pepper, tomato, egg plant, oriental melon), it has been evaluated that the capability of four predatory mites (Amblyseius swirskii Athias-Henriot, Neoseiulus barkeri (Hughes), N. cucumeris (Oudemans), N. californicus (McGregor)) to prey on the eggs of Bemisia tabaci (Gennadius) and to lay own eggs. The most aggressive mite was A. swirskii which had consumed about $9{\sim}12$ eggs in a day. The quantity of eggs consumed by N. barkeri, N. cucumeris and N. californicus was about $6{\sim}9,\;4{\sim}6$ and $1{\sim}4$, respectively. The most productive mite was also A. swirskii which had laid about $1.2{\sim}1.9$ eggs in a day. The others could not lay more than 0.5 eggs in a day.

• Korean journal of applied entomology
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• v.29 no.1
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• pp.20-24
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• 1990

Studies were carried out to investigate the overwintering densities of spider mites, hatching rate and time of P. ulmi eggs, and seasonal occurrences of spider mites (P. ulmi and T. urticae) in apple orchards of Kyungpook province from 1987 to 1989. Overwintering density of P. ulmi eggs was higher in Kunwi, Andong, Chilgok but lower in Kyungju. Overovintering densities of T. urticae were high in all the regions. With the hatching time and rate for P. ulmi eggs, the first hatching ate was April 14, and the last was May 3, and the average hatching rate was 89.3%. The density of P. ulmi was high from early May to middle July and T. urticae begin to increase rapidly from middle June and then was continuously high upto fruit harvesting time.