• Korean Journal of Plant Resources
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• v.19 no.5
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• pp.598-601
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• 2006

In order to prevent chestnut from damaged by the chestnut gall wasp, Dryocosmus kuriphilus, a sprinkler system was installed on the chestnut orchard. Such a test was conducted at Sanchung-gun, Kyeongnam province, Korea in 2003 and 2004. Insecticide of carbaryl 50% WP, x1,500 was sprayed at every day and two-day intervals during the period of D. kuriphilus adult occurrence by sprinkler system. The chestnut gall wasps generally emerged for about 35 days from the middle June to the middle July, and peak emergence was 5 days of early July. Crown application of carbaryl by sprinkler system was found to be highly effective for control of the chestnut gall wasp. Gall formation rate of chestnut were 3.0 and 12.8% on average with crown insecticide spraying at every day and two-day intervals, while 82.9% when not treated. Control effectiveness of this insecticide spraying was 96.4% and 84.6%, respectively.

• Korean journal of applied entomology
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• v.26 no.3 s.72
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• pp.165-170
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• 1987

This experiment was carried out to evaluate the difference in the biochemical characteristic of the brown planthoppers of the insecticide risistant, susceptible strains and their hybrid progenies. Activity of the esterase isozyme separated by electrophoresis method was remarkably high in the resistant strain as compared with the susceptible strain. Esterase activity between the insecticide-treated strains and the non-insecticide strains was not degraded in the resistant strain and the $F_1$, but remarkably degraded in the susceptible strain. The increase of esterase activity was associated with the development of resistance, and that was inherited with a dominant gene.

• Journal of the Korean Chemical Society
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• v.10 no.2
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• pp.62-66
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• 1966

An insecticide was obtained from condensation of chloral hydrate with 2,4,5-trichloro phenol. The structure of the insecticide was found to be 5,6,8-trichloro 2,4-di-trichloro methyl benzo 1,3-dioxane. The best conditions of the condensation were as follows: 1) The sulfuric acid concentration; $97{\%}$. 2) The mole ratio of sulfuric acid to 2,4,5-trichloro phenol; 14.2. 3)The mole ratio of chloral hydrate to 2,4,5-trichloro phenol; 2.4. 4) The reaction time & reaction temperature;15hrs & $50-55^{\circ}C$.The insecticidal effects of T. D. B against the Citrus Red Mite and Green Peach Aphid were the same of Mydran.

• Korean Journal of Environmental Agriculture
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• v.29 no.2
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• pp.159-164
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• 2010

Imidacloprid is a systemic insecticide which has been used widely in various crops to control insects. In the present study, we demonstrated that pre-treatment of imidacloprid significantly induced tolerance to drought in plant. Relative water content, chlorophyll levels, and recovery rate upon rehydration after drought stress in tobacco plants pre-treated with imidacloprid were higher levels than the control plants. Induced drought tolerance by imidacloprid treatments in red pepper was also demonstrated by measurement of recovery rate and fresh weight upon drought stress. Taken together, our results suggest that imidacloprid, in addition to exerting direct insecticidal activity, may also protect plants by induced tolerance to drought in plant.

• The Korean Journal of Pesticide Science
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• v.6 no.2
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• pp.105-109
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• 2002

Synthetic method of a new benzoylphenylurea insecticide, DBI-3204 [1-(2,6-Difluorobenzoyl)-3-(3,5-bistrifluoromethyl-2-chlorophenyl) urea] was established for manufactural production; 2,6-Difluorobenzoylisocyanate was synthesized by the reaction of 2,6-difluorobenzamide with oxalylchloride in 95% yields, the reaction of 3,5-bis(trifluoromethyl)aniline with N-chlorosuccinimde gave 3,5-bis (trifluoromethyl)-2-chloroaniline in 92% yields, and DBI-3204 was got from 2,6-difluorobenzoylisocyanate and 3,5-bis(trifluoromethyl)-2-chloroaniline in 90% yields. All the process was simplified by using the same reaction solvent, carbontetrachloride.

• Korean journal of applied entomology
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• v.28 no.1
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• pp.23-27
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• 1989

The green peach aphid(Myzus pericae Sulzer) was selected over 20 generations with cypermethrin and pirmicarb, respectively. The resulting resistant strains were tested to inverting-ate the development of insecticide resistance and cross-resistance to some insecticides in the laboratory. The development of insecticide resistance against green peach aphid at the 20th selected generation was greatly varied with the insecticides: 20.5 fold for cypermethrin and 3.2 fold for pirimicarb compared with the parent strain. The cypermethrin selected strain exhibited cross resistance to acephate and pirimicarb, and pirimicarb selected strain to acephate and cypermethrin, respectively. Demeton-S-methyl, however, has not been shown cross-resistance by the selected strains.

• Molecular & Cellular Toxicology
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• v.3 no.1
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• pp.11-18
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• 2007

Mechanisms of insecticide resistance found in insects may include three general categories. Modified behavioral mechanisms can let the insects avoid the exposure to toxic compounds. The second category is physiological mechanisms such as altered penetration, rapid excretion, lower rate transportation, or increased storage of insecticides by insects. The third category relies on biochemical mechanisms including the insensitivity of target sites to insecticides and enhanced detoxification rate by several detoxifying mechanisms. Insecticides metabolism usually results in the formation of more water-soluble and therefore more readily eliminated, and generally less toxic products to the host insects rather than the parent compounds. The representative detoxifying enzymes are general esterases and monooxygenases that catalyze the toxic compounds to be more water-soluble forms and then secondary metabolism is followed by conjugation reactions including those catalyzed by glutathione S-transferases (GSTs). However, a change in the resistant species is not easily determined and the levels of mRNAs do not necessarily predict the levels of the corresponding proteins in a cell. As genomics understands the expression of most of the genes in an organism after being stressed by toxic compounds, proteomics can determine the global protein changes in a cell. In this present review, it is suggested that the environmental proteomic application may be a good approach to understand the biochemical mechanisms of insecticide resistance in insects and to predict metabolomic changes leading to physiological changes of the resistant species.

• Journal of Plant Biology
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• v.25 no.3
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• pp.113-121
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• 1982

The effects of 6 biocides on the growth of Chlamydomonas reinhardii in pure culture were studied. For the batch culture assay of biocides, the growth rate in control tubes should be compared with in the test tubes and the effective concentration calculated on the basis of the percent decrease in growth rate at the different toxicant concentration. The concentrations at which 50% decrease in growth rate was observed are $40{\mu}g$/l for butachlor and $350{\mu}g$/l for alachlor in herbicide, $900{\mu}g$/l for phenazine-5-oxide and $3,400{\mu}g$/l for isoprothiolane in fungicide, and $3,330{\mu}g$/l for fenthion and $332,500{\mu}g$/l for trichlorfon in insecticide. The inhibitory effect on the growth of Chlamydomonas reinhardii by the treatment of various biocide concentrations was decreased in order of herbicide>fungicide>insecticide. Chlorophyll and carotenoid content per cell were increased, whereas chlorophyll a/b ratio was hardly affected by biocides. The effects of biocides on pigment content were also decreased in order of herbicide>fungicide>insecticide, which suggested the relationship between the effect of biocides on the pigment content and inhibition of growth rate.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.2
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• pp.197-202
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• 2005

The effects of feeding Brassica vegetable market wastes on intake, body weight changes and pesticide/insecticide residues in products of goats were evaluated in two experiments. In the first experiment (Exp. 1) 16 goats (Bach Thao, 9 to 10 kg, 3 months old, 9 males and 7 females) were fed four diets with leaves either from cabbage (Brassica oleracea var. capitata), cauliflower (Brassica oleracea var. botrytis) or Chinese cabbage (Brassica campestris subsp. pekinensis) with 30% of Para grass. The control group was fed 100% Para grass. All diets contained soybean waste as a supplement and the experiment lasted for 136 days. In the second experiment (Exp. 2) 24 goats (Bach Thao, 12 to 14 kg, all males) were assigned to three treatments in a completely randomised block design based on initial body weight. The goats were fed cabbage waste supplemented with 200 g or 100 g DM (dry matter) of concentrate. Para grass with 100 g DM concentrate supplementation was used as a control group. The experiment lasted for 90 days and at the end of the study, 12 goats were slaughtered for pesticide/insecticide analysis. Due to low DM content (5.3 and 3.7%, respectively) feed intakes of cabbage and Chinese cabbage groups were lower than those of other groups in the experiment. The highest feed intake and body weight gain was obtained when the goats were fed cauliflower (529 g DM/day and 87.5 g/day, respectively). In Exp. 2 total intake of cabbage and concentrate was similar (484 g and 453 g DM/day) whether the goats were fed 100 or 200 g concentrate/day but lower than that of Para grass and concentrate probably due to the low DM content of the cabbage (5.9%). Crude protein intake (79 g to 86 g/day) and body weight gain (70 g to 88 g/day) was not significantly different between treatments. Adding concentrate consequently resulted in higher DM intake than in Exp. 1 but did not result in any higher growth rate. Three of the pesticide/insecticide residues tested were found in cabbage, Alpha-Cypermethrin, Bassa-Fenobucarb and Dimethoate with levels of 0.175, 0.074 and 0.028 mg/kg fresh cabbage respectively. Weight of livers from goats fed cabbage was about 90 g higher than from goats fed Para grass but no pesticide/herbicide residues were found in meat or liver.

• Korean journal of applied entomology
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• v.22 no.2 s.55
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• pp.98-105
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• 1983

The rapid increase in cases of insect resistance to insecticides indicates that the contribution of present chemical control practices inevitably leads to exhaustion of available insecticide resources against key insect species. Now the problem of insecticide resistance exists worldwide among insects and mites affecting field crops and animals including human beings, ranging from minimal or absent in some developing countries, where use of insecticides has been low, to extremely severe in many developed countries. Since the occurrence of insect resistance to insecticides was firstly recognized in 1908, the increase in recent decades has been almost linear and now the number of species of insects and acarines in which resistant strains have evolved have been increased to a total of 432. Of these, $261(60\%)$ are agricultural importance and $171(40\%)$ of medical/veterinary importance. The phenomenon of insecticide resistance is asserting itself as the greatest challenge to effective chemical control of many important insect pests. Resistance of insects to insecticides has a history of nearly 80 years, but its greatest increase and its strongest impact have occurred during the last 40 years following the discovery and extensive use of synthetic organic insecticides and acaricides. The impact of resistance should be considered not only in terms of greater cost of pest control due to increased dosages and number of applications but also in terms of the ecological disruption of pest-beneficial species density relationships, the loss of investment in the development of the insecticides concerned, and socio-economic disruption in agricultural communities. Despite its grave economic consequences, the phenomenon of insecticide resistance has received surprisingly little attention in Korea. Since the study of insecticides started firstly in 1963, many entomologists have been concerned with this study. According to their results, some of the rice pests and some of the mites on orchard trees, for example, have developed worrisome level of resistance in several areas of this peninsula. With many arthropods, considerable advances in the developed countries have been made in the study of the biochemical and physiological mechanisms of resistance. Progress involves the biochemical characteristics of specific defense mechanisms, their genetics, interactions, and their quantitative and qualitative contribution to resistance. But their studies arc still inadequately known and relatively little have been contributed in terms of unique schemes of population management in achieving satisfactory pest control. It is apparent that there is no easy solution to resistance as a general phenomenon. For future challenging to effective control of insect pests which are resistant to the insecticides concerned, new insecticide groups with distinctly novel mode of action are urgently needed. It is clear, however, that a great understanding of the factors which govern the intensity of selection of field population for resistance could lead to far more permanently successive use of chemicals within the framework of integrated pest management than heretofore practiced.