• Korean journal of applied entomology
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• v.42 no.3
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• pp.233-240
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• 2003

The effect of density suppression of Amblyseius fallacis (Garman) against Panonychus citri (McGregor) on citrus tree introduced with some different ratio was investigated. When it was introduced with over 16:1 (Panonychus citri: A. fallacis) ratio, Panonychus citri was suppressed very effectively. And in case of introduced once or two times with 20: 1 ratio when the density of Panonychus citri was reached 0.5 and 1.0 per leaf, the density of A. fallacis was formed highly, but the suppression effect against Panonychus citri was not effective. Also, the density changes of P. citri and A. fallacis on the citrus tree released with 10: 1 ratio (P. citri: A. fallacis) when the density of P. citri was reached about 0.1 per leaf in plastic film house were investigated. In case of released twice at the interval of 10 days, the density of A. fallacis was high and P. citri was suppressed so effectively over two month. On the inside of canopy of the citrus tree planted in plastic film house, the air temperature was much lower than on the outside of canopy, while relative humidity was much higher.

• Journal of Environmental Science International
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• v.29 no.10
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• pp.997-1002
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• 2020

In this study, we investigated the effects of the eco-friendly chemical bio-sulfur, on the citrus melanose-causing pathogen, Diaporthe citri, and on the pest, Panonychus citri. In an open field experiment with a plot-scale application of the chemicals: Mancozeb, lime sulfur, lime sulfur + machine oil, and bio-sulfur, the control group showed 70.6% disease severity compared with 10.3% for the Mancozeb-treated group. Among the eco-friendly treatments, disease severity was the lowest for the group treated with lime sulfur + machine oil (32.2%) and was 53.9%, 58.8%, and 58.1% following treatment with lime sulfur, and bio-sulfur diluted 500 and 1000 times, respectively. The proportion of diseased fruit showed similar results, suggesting that bio-sulfur is an effective alternative to lime sulfur. Three days after treatment acaricidal effects on P. citri showed a 197.6% control survival rate whereas the machine oil, and bio-sulfur diluted 500 and 1000 times treatments showed rates of 2.9%, 5.8%, and 9.0%, respectively. After three days, the control value for bio-sulfur diluted 1000 times was 73.2% compared with the values for the machine oil (96.4%) and bio-sulfur diluted 500 times (94.6%) treatments. Therefore, we suggest that additional research is needed on the combined application of bio-sulfur and oils to enhance the additive control effect on citrus melanose and Panonychus citri.

• Parasites, Hosts and Diseases
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• v.52 no.1
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• pp.117-120
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• 2014

Several studies have reported that the citrus red mites Panonychus citri were an important allergen of citrus-cultivating farmers in Jeju Island. The aim of the present study was to purify and assess properties of a cysteine protease from the mites acting as a potentially pathogenic factor to citrus-cultivating farmers. A cysteine protease was purified using column chromatography of Mono Q anion exchanger and Superdex 200 HR gel filtration. It was estimated to be 46 kDa by gel filtration column chromatography and consisted of 2 polypeptides, at least. Cysteine protease inhibitors, such as trans poxy-succinyl-L-leucyl-amido (4-guanidino) butane (E-64) and iodoacetic acid (IAA) totally inhibited the enzyme activities, whereas serine or metalloprotease inhibitors did not affect the activities. In addition, the purified enzyme degraded human IgG, collagen, and fibronectin, but not egg albumin. From these results, the cysteine protease of the mites might be involved in the pathogenesis such as tissue destruction and penetration instead of nutrient digestion.

• Korean journal of applied entomology
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• v.45 no.2 s.143
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• pp.145-152
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• 2006

Predation of Neoseiulus fallacis was observed for biological control of Panonychus citri that is one of the major insect pests on citrus. The daily predation of development stages of P. citri by an adult female of N. fallacis were 20.1 eggs, 26.1 larvae, 18.2 protonymphs, and 7.4 deutonymphs at 25$^{\circ}C$, The daily predation of P. citri eggs by N, fallacis was observed under different temperatures. The predation was increased as the temperature rise. At this time, ratio of eggs production of l! fallacis after predation of P. citri eggs (number of eggs N. fallacis/number of eggs P. citri consumed by N. fallacis) was 0.09. The daily predation of P. citri eggs by N, fallacis was 21.1, 17.3, and 16.7 on the different arenas (diameter: 20, 40, and 60 mm), respectively. The predation was decreased as the arena of the leaf increase. The functional response of M fallacis to P. citri showed Holling's Type II response: the consumption of prey by N. fallacis increased as the density of prey increase but increasing rate was gradually reduced. As the result, it seemed that N. fallacis can be use for biological control of P. citri.

• Korean journal of applied entomology
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• v.39 no.1
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• pp.13-19
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• 2000

This studies was carried out to investigate the natural enemies of citrus red mite, pononychus citri and seasonal occurrence of its major beneficial insects in Yuzu groves (Chonnam province) from 1996 to 1998. Natural enemies against citrus red mite were 9 species including Oligota kashmirica benifica, 0. yasumatsui, Stethorus punctillum, Chrysopa pallens, Propylea japonica, Orius sauteri, Scolothrips takahashii, Amblyseius womersleyi and one unidentified species of thrips (Family: Phlaeothripidae). Among them, Oligota kashmirica benzficu and Stethorus punctillum were found to be dominant species. 0 . kushmirica henifica had 4-5 generations from middle May to middle November with peak in early September. S. punctillum had 3 generations from late May to late October with peak of late June to middle July. Population dynamics between predator ( 0 . kushmiricu benifica and S. punctillum) and prey (Panonychus citri) were quite well synchronized until September but predator density was decreased abruptly after October.

• Korean journal of applied entomology
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• v.41 no.1
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• pp.55-60
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• 2002

Predation amount and density suppression ability of three species of phytoseiid mites (one native, Amblyseius womersleys Schica; two introduced species, Amblyseius fallacis Garman and Typhlodromus occidentalis Nesbit) on Panonychus citri McGregor were examined in laboratory condition (25$\pm$1$\^{C}$, RH 65$\pm$5%, 16L:8D). A. fallacis and T. occidentalis consumed 20.1 and 9.1 eggs of P. citri, respectively, whereas A. womersleyi consumed 1.1 eggs. When each larva, protonymph and deutonymph of P. citri were supplied as prey for 24 hours. A. womersleyi consumed 23.8, 16.5 and 9.0, and A. fallacis consumed 26.1, 18.2 and 7.4, respectively. However, T. occidentalis consumed only 7.8, 4.2 and 4.2. respectively Density suppression ability of A. womersleyi and A. fallacis against P. citri was very high at the release ratios of 20 : 1 (prey : predator). However, T. occidentalis did not regulate P. citri population effectively Developmental periods from egg to adult of A. womersleyi and A. fallacis was 6.1 and 5.9 days at 25$\^{C}$, respectively.

• Animal Systematics, Evolution and Diversity
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• v.2 no.2
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• pp.13-26
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• 1986

A Taxonomic investigation was carried out on the following seven spider mites (Family tetranychidae) by comparison of morphological characters, cuticular lobes and karyotypes. Materials used in this study were collected and reared at Jeonju, Jorea during October 1985-June 1986. Subfamily Bryobiinae ; Bryobia praetiosa Koch, 1836 ; Petrobia latens (Mller, 1776). Subfamily Tetranychinae ; Panonychus citri (McGregor , 1919) ; P.ulmi (Koch, 1836): T vienensis tranychus Zacher , 1920 ; T.urticae (Koch, 1836) ; T. kanzawai Kishida , 1927. Of them two species, P. latens and T. kanzawai , are newly recorded from Korea.

• Proceedings of the Korean Society of Applied Entomolohy Conference
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• 2002.05a
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• pp.164-164
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• 2002

• Korean journal of applied entomology
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• v.9 no.1
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• pp.33-35
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• 1970

The author collected 2 species of spider mites from persimmon and citrus trees in Taegu and Chun Chon during the summer of 1961 and 1969. Tenuipalpus japonicus collected from persimmon trees and Panonychus citri collected from citrus trees in and from trifoliate orange trees. In 1958 and 1961 Dr. E. S. Lee recorded four phytophagous species, i.e. Panonychus ulmi, Tetranychus pacificus, Tetranychus urticae and Bryobia praetiosa.

• Korean journal of applied entomology
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• v.40 no.2
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• pp.105-109
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• 2001

Dispersion pattern of the citrus red mite (CRM), Panonychus citri (McGregor) was determined to develop a monitoring method in the satsuma mandarin fields, Citrus unshiu L., in Jeju-do, during 1999 and 2000. CRM population was sampled by collecting leaves. Taylor's power law provided better description of mean-variance relationship for the dispersion indices compared to Iwao's patchiness regression. Slopes and intercepts of Taylor's power law from leaf samples did not differ among surveyed groves. Fixed-precision levels (D) of a sequential sampling plan were developed using Taylor's power law parameters generated from all motile stages of CRM in leaf sample. This sampling plan for leaf sample estimate was tested with resampling validation for sampling plan using 4 independent data sets. Resampling simulation analysis demonstrated that actual fixed-precision level values were better than desired D values of 0.20, 0.25 and 0.30. Required numbers for tree sampling at the density of more than 7 mites per tree were fewer than 18.