• Journal of Applied Biological Chemistry
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• v.44 no.3
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• pp.105-112
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• 2001

Insect pests can be controlled through direct application of insecticides. Insect control by residual protectants is relatively inexpensive and has an advantage of destroying all stages of infestations. The efficacy of control is largely determined by the concentration of insecticides to which the pest species is exposed. A reduction in the period of control in the field afforded by a specific level of a protectant indicates that resistance has developed. An increase in the level of protectant is required to maintain control, and the efficacy of currently used insecticides has been severely reduced by insecticide resistance in pest species. Development of resistance to particular insecticide varies with species because insecticide resistance is often correlated with increased levels of certain enzymes, which are cytochrome P450-dependent monooxygenases, glutathione S-transferases and esterases. Some sections of insecticide molecules can be modified by one or more of these primary enzymes. A reduction in the sensitivity of the action site of a xenobiotic also constitutes a mechanism of resistance. Acetylcholinesterase is a major target site for insecticide action, as are axonal sodium ion channels and ${\gamma}$-aminobutyric acid receptors. Development of reduced sensitivity of these target sites to insecticides usually occurs. This review not only may contribute to a better understanding of insecticide resistance, but also illustrates the gaps still present for a full biochemical understanding of the resistance.

• Korean journal of applied entomology
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• v.31 no.3
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• pp.314-327
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• 1992

Insecticide resistance is a serious is a serious threat to IPM, resulting in various adverse effects not to mention the loss of yield in agriculture. One approach to counter the problem is the disruption of resistance mechanisms. This can be achieved by (1) compounds which show a negative correlation with resistance at the site of action, (2) specific metabolic inhibitors which serve as synergists, or (3) a certain combination of two insecticides producing a joint action. This approach, however, requires certain precautions for the side effects may cause an increase in toxicity to mammals. Owing to the recent advances in theoretical studies on resistance management employing computer simulation and mathematical models, a few principles to reduce the risk of development of resistance have been clarified. They are helpful in designing operational strategies with regard to, for instance, insecticide doses to be applied, mode of application, and choice and nature of the insecticide(s) to be used. For restoration of insecticide susceptibility of a resistant population, reintroduction of susceptible individuals to the resistant population is feasible when certain conditions are met. Natural enemies which developed resistance to insecticides can be an important component of IPM as has been shown in the pest management in apple orchards. After all, the implementation of a successful resistance management program depends upon cooperation between different sigments of the agricutural community. Although resistance is a preadaptive phenomenon, in some cases spontaneous loss of resistance does occur without contamination by susceptible individuals. The instability of resistance in these insects implies the possible existence of a switch machanism controlling the expression of resistance gene(s). Elucidation of such a mechanism may eventually provide us with a new technical approach with which we can combat the problem of insecticide resistance.

• The Korean Journal of Pesticide Science
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• v.20 no.4
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• pp.286-292
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• 2016

Malaria is mainly transmitted by Anopheles sinensis which is dominant species in malaria high-risk area, northern part of Gyeonggi province in Korea. Pyrethroid insecticide is used for malaria vector, An. sinensis in Korea and the previous investigation consistently reported insecticide resistance from the vector. This study investigated insecticide susceptible and resistant alleles from An. sinensis and the status of malaria vector control in malaria high-risk area. For the study, An. sinensis collected from Paju, Gimpo and Ganghwa were sequenced for kdr detection. In Paju, there was no homozygous susceptibility and all of tested samples had homozygous or heterozygous resistance. There were 6.7% for susceptible homozygosity and 93.3% for resistant homozygosity or heterozygosity in Gimpo. Furthermore, the percentages of homozygous susceptibility and homozygous or heterozygous resistance in Ganghwa were 5.7% and 94.3% respectively. The results showed that the frequency of the insecticide resistance from An. sinensis in malaria high-risk area were increased much more than the previous investigation. Hence, this study suggests that malaria vector control programs should have to be prepared for the management of pyrethroid insecticide resistance.

• 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.

• Korean journal of applied entomology
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• v.40 no.4
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• pp.327-335
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• 2001

In order to establish a whitefly control system using conventional groups of insecticide(carbamate, organophosphorus and pyrethroid insecticides), three alternative application methods were designed on the medium growth stage of cucumber. To discriminate the effectiveness of these sequences observed were the residual activity of insecticides, frequency of insecticide applications, residue of insecticides in cucumber leaves, development of insecticide resistance in whitefly, and yield of fruits. Spraying furathiocarb, a carbamate insecticide, was very effective in reducing the frequency of application for the control of white flies. The effectiveness of furathiocarb was enhanced by the potentiation process to carbofuran, the long residual activity, and the lower development rate of insecticide resistance. Methion, an organophosphorus insecticide, did not show resistance development after successive use but resulted in short residual activity. However, other organophosphates, profenofos and phenthoate, lost their activity by the resistance development. Decreasing activity was common to pyrethroids, deltamethrin and zetacypermethrin due to resistance. From these results it could be drawn a conclusion that furathiocarb, a carbamate insecticide, was the most desirable among conventional insecticide groups for the management of greenhouse whitefly population on the cucumber. To prevent an outbreak of the insect pest by various cause, it was recommended to choose acetamiprid, a nicotinoid, which showed very good control efficacy to the resistance insects to conventional insecticides.

• Korean journal of applied entomology
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• v.48 no.2
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• pp.123-158
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• 2009

An attempt was made to stimulate future research by providing exemplary information, which would integrate published knowledge to solve specific pest problem caused by resistance. This review was directed to find a way for delaying resistance development with consideration of chemical(s) nature, of mixture, rotation, or mosaics, and of insecticide(s) compatible with the biological agents in integrated pest management (IPM). The application frequency, related to the resistance development, was influenced by insecticide activity from potentiation, residual period, and the vulnerability to resistance development of chemical, with secondary pest. Chemical affected feeding, locomotion, flight, mating, and predator avoidance. Insecticides with negative cross-resistance by the difference of target sites and mode of action would be adapted to mixture, rotation and mosaic. Mixtures for delaying resistance depend on each component killing very high percentage of the insects, considering allele dominance, cross-resistance, and immigration and fitness disadvantage. Potential disadvantages associated with mixtures include disruption of biological control, resistance in secondary pests, selecting very resistant population, and extending cross-resistance range. The rotation would use insecticides in high and low doses, or with different metabolic mechanisms. Mosaic apply insecticides to the different sectors of a grid for highly mobile insects, spray unrelated insecticides to sedentary aphids in different areas, or mix plots of insecticide-treated and untreated rows. On the evolution of pest resistance, selectivity and resistance of parasitoids and predator decreased the number of generations in which pesticide treatment is required and they could be complementary to refuges from pesticides To enhance the viability of parasitoids, the terms on the insecticides selectivity and factors affecting to the selectivity in field were examined. For establishment of resistant parasitoid, migration, survivorship, refuge, alternative pesticides were considered. To use parasitoids under the pressure of pesticides, resistant or tolerant parasitoids were tested, collected, and/or selected. A parasitoid parasitized more successfully in the susceptible host than the resistant. Factors affecting to selective toxicity of predator are mixing mineral oil, application method, insecticide contaminated prey, trait of individual insecticide, sub-lethal doses, and the developmental stage of predators. To improve the predator/prey ratio in field, application time, method, and formulation of pesticide, reducing dose rate, using mulches and weeds, multicropping and managing of surroundings are suggested. Plant resistance, predator activity, selective insect growth regulator, and alternative prey positively contributed to the increase of the ratio. Using selective insecticides or insecticide resistant predator controlled its phytophagous prey mites, kept them below an economic level, increased yield, and reduced the spray number and fruits damaged.

• 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.

• Korean journal of applied entomology
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• v.60 no.2
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• pp.167-173
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• 2021

Sweet potato whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is an insect pest with sucking mouth part and globally attacks diverse crops and vegetables. Since first reported in 1998, it is now widely spread in many regions in Korea. Due to insecticide resistance, it is necessary for optimal control of the whiteflies to select effective insecticides with precise insecticide resistance monitoring. In this study, B. tabaci individuals were collected from 12 regions in 7 provinces of Korea from June to September in 2020. Using these field populations, insecticide resistance levels were monitored using a residual contact bioassay along with molecular markers. Bioassay results revealed that B. tabaci possessed high levels of resistance to five insecticides exhibiting different modes of action: dinotefuran, spinosad, emamectin benzoate, chlorfenapyr, and bifenthrin. In addition, quantitative sequencing in target sites of organophosphate and pyrethroid insecticides revealed that point mutations reached to saturated or near-saturated levels across the country. This suggests that insecticide resistance management is required for effective control of B. tabaci populations in Korea.

• Korean journal of applied entomology
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• v.29 no.3
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• pp.194-200
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• 1990

The diamondback moth (Plutella xylostella L.) was selected over 24 generations with fenvalerate. The resulting resistant strain was tested to study development of insecticide resistance and cross resistance to some insecticides in the laboratory. Insecticide resistance of diamondback moth at the 24th generation devleoped 66.2 fold compared to the parent strain for fenvalerate. The fenvalerate selected strain exhibited 145 fold, a high level of cross resistance to deltamethrin, and also showed 17.4-45.0 fold cross resistance to alphamethrin, cypermethrin, fenvalerate, permethrin, and tetramethrin in the pyrethroid insecticides. The fenvalerate selected strain showed 2.5-4.3 fold, low cross resistance to diazinon, dichlorvos, EPN, BPMC, cabaryl, and methomyl. However, it did not show cross resistance to acephate, fenitrothion, phenthoate, and carbofuran.

• Journal of the Korean Society of Tobacco Science
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• v.19 no.2
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• pp.107-116
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• 1997

Karyotype of apterous green peach aphid (Myzus persicae SuIBer) populations occurring in tobacco fields and their resistance to insecticides were investigated. All of the 16 clones collected from tobacco fields had same chromosome number of 2n=12. Among them, 5 clones had the normal karyotype, regardless of color morph, but chromosomal translnations between #1 and #3 autosomal chromosomes were noted in the other 11 clones. All of the aphid clones were highly resistant tolambda cyhalothrin, a pyrethroid pesticide, having over 20 times higher concentrations of LD90 than recommended concentration (10ppm) for the aphid. However, their resistance to acephate, demeton 5-methyl and pirimicarh varied depending on the clones, among which green-colored clones were generally more resistant to the pesticides than red-colored ones. No association was found between the insecticide resistance and the karyotype of the aphid in this experiment.