• Korean journal of applied entomology
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• v.36 no.1
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• pp.30-36
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• 1997

Except for a cosmopolitan and major pest of apples, Tetranychus urticae Koch, Tetranychus mites in Korea such as T. viennensis Zaher, T. kanzawai Kishida, and T. truncams Ehara have been considered as quarantine pests by Canada and United States. Even though these mites are not feeders on apples, they are suspected to attach accidentally on apple h i t s in autumn as females enter the diapause. The characters used to identify Tetranychus mites have been confined to the shape of aedeagus in adult male. To develope a fast and accurate alternative identification protocol applied to hibernating female mites on apples, their mitochondrial DNA (mtDNA) were examined to find out any polymorphisms to discriminate each species from the other ones. Three pairs of primers for polymerase chain reaction (PCR) were used to amplify cytochrome oxidase subunit I (CO-I) coding region in mitochondrial DNA5 of four species of Tetranycus mites. The longest amplified product was estimated its size as about 680 bp. Digestion with restriction enzymes, AluI, Ddel, and Sau3A, showed length polymorphisms, which will he useful as diagnostic markers to identify Tetranychus mites. Schematic restriction maps in amplified region were shown for each species.

• Korean journal of applied entomology
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• v.33 no.1
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• pp.33-38
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• 1994

The expenment was conducted to study the foraging behavior of Amblyseius hngisp~nosus for eggs of Tetranychus urticoe. When preys were abundant, A. longispinosus repeated a series of foraging process (feeding, after-feeding movement, restmy, and searching) The time (Mean\ulcorner SD) spent for these components were 6 83+ 1.73. 3 OOi 1.66. 93.57+ 30 19. and -0.00 min., respectively. Afterfeeding movement was chractetired as a complex one-way circular moving path with a slow speed (0.09 mm/sec) and area-restricted Escaping movement was fast (0 31 mm/sec), more straight in direction, and edge-oriented walking. Positions of prey consumption of A. longispinosus were distributed in clump. KEY WORDS Foraging behavior, nlovlng path, Arnblyseius longispinosus, Tetranychus urtlcae.

• Journal of Life Science
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• v.13 no.2
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• pp.150-153
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• 2003

To determine the effect of newly developed insecticide on two spotted spider mite, Tetranychus Urticae, populations, ten leaf discs were sprayed with three different concentrations (0.5%, 1.0%, and 1.5%) of the tested insecticide solution, and with a water-sprayed control. The tested insecticide solution was toxic to adult female and immature of two spotted spider mite, but was relatively non-toxic to eggs. For equivalent concentrations, more adult females were killed than immature stages. There was no marked difference between the hatch of treated and untreated eggs, although a weak trend between the numbers of unhatched eggs and the insecticide concentration after 7 days is shown.

• Proceedings of the Zoological Society Korea Conference
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• 1997.10b
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• pp.112.2-112
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• 1997

No Abstract, See Full Text

• Korean journal of applied entomology
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• v.32 no.1
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• pp.61-67
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• 1993

Experiments were conducted to study the functional response of Amblyseius longispinosus Evans to egg densities (10-80) of Tetranychus urtica Koch under different egg distributions (clumped & uniform) and arena sizes (3, 9 & 16 $cm^2$). The searching success of A. longispinosus was affected by the spatial distribution and density of the prey but not by the arena size. there was a highly significant negative correlation (r=-0.85; p=0.0001) between predation amount and distances between preys. The predation response showed a type III functional response. The random predator equation satisfactorily described A. longispinosus predation. The search rate ranged from 0.1030 to 0.1504 under distribution of the prey while it ranged from 0.0546 to 0.276 under uniform distribution.

• Korean journal of applied entomology
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• v.32 no.2
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• pp.176-183
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• 1993

These sutdies were conducted to investigate the joint toxic action of mixtures of several acaricides including amitraz, bifenthrin, propargite, fenbutatin dxide and bxide dicofol to the field-collected strian of Tetranychus urticae. The synergistic action of acaricidal mixtures was greatly varied with the kind of acaricide combinations and their mixture ratios. The combinations of amitraz with each of the tested acaricides were synergized at the given mixture ratios. The higher synergistic action in the each combination was observed at 2 : 8 ratio of amitraz and bifenthrin, 8 : 2 ratio of amitraz and fenbutatin oxide, 4 : 6 ratio of amitraz and propargite and 6 : 4 ratio of amitraz and dicofol.

• 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.

• Korean journal of applied entomology
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• v.44 no.2
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• pp.161-164
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• 2005

Essential oils of three plants (caraway oil, hyssop oil and lime oil) were screened for repellency against Tetranychus urticae female adults in the lab condition. Among them, caraway oil (Carum carvi) showed $92.2\%$ repellency against female adults at 1,000 ppm concentration. Through the constituent analysis using GC and GC/MS, we confirmed that the two main constituents were carvone $(73.3\%)$ and limonene (26.7). Limonene showed 87.8 and $83.1\%$ repellency against adult females at 1,000 and 100 ppm concentrations, respectively.

• 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.

• Animal Systematics, Evolution and Diversity
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• v.3 no.2
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• pp.64-116
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• 1987

The purpose of the present paper is to record taxonomic notes on several Korean spider mites. The specimens on which this study is based were collected by the authors during the period from May, 1986 to June, 1987. The following species are the spider mites concerned in this paper. 1. Panonychus citri (McGregor), 2. Eotetranychus populi Koch, 3. Eotetranychus smithi Pritchard and Baker, 4. Shizotetranychus bambusae Reck, 5. Schizotetranychus celarius (Banks), 6. Shizotetranychus leguminosus Ehara, 7. Oligonychus orthis Rimando, 8. Tetranychus ranzawai Kishida, 9. Tetranychus phaselus Ehara, 10. Tetranychus trancatus Ehara , 11. Tetranychus vienensis Zacher, 12. Tetranychus urticae Koch . Among them, eight species with asterisk are newly recorded from Korea . In addition, empodiums of pretarsus were carefully observed and enzyme patterns by electrophoresis were compared on some species in order induce their systematic inter-relationship at either species or generic level.