• Korean journal of applied entomology
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• v.48 no.3
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• pp.327-333
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• 2009

Biological Characteristic of Obolodiplosis robiniae and insecticidal activity of some insecticides against larvae of O. robiniae were investigated. Egg was in oval shape, and its color was light orange and became red when close to hatch. Length of the major axis and the minor axis of egg was 0.4 mm and 0.1 mm, respectively. Larval color was milky and size was 2.6 mm. Pupa was deep brown and its size was about 3.2 mm. Wing and abdomen of adult was black and reddish, respectively. Size of female adult was about 3.3 mm, and larger than male adult. Number of eggs in the ovary was $192.3{\pm}50.7$. First emergence was from late April to late May, and second from late May to late June. Third emergence was from late June to late July. Newly emerged adult escaped from soil, and second and third emerged adult escaped directly from gall of Robinia pseudoacacia leaf. Egg parasitoid was identified as Platygaster robiniae and parasite rate was 51.6%. Among test insecticides, imidacloprid 10% WP and thiacoprid 10% FL showed very strong insecticidal activity against larvae of O. robiniae at 48h later after treatment.

• Journal of Applied Biological Chemistry
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• v.43 no.4
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• pp.222-229
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• 2000

In this paper we will assess the feasibility of some insect behavior-modifying chemicals for insect control, such as male orientation inhibitor, female calling interrupter and female attractant of cotton bollworm Helicoverpa armigera. These behavior-modifying chemicals have advantages of simple chemical structure, easy to synthesize and low price of products. The effects of sub-lethal insecticides on insect chemical communication system and the differences of pheromone communication systems between the resistant and susceptible strain of H. armigera will also be discussed.

• Journal of Applied Biological Chemistry
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• v.43 no.4
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• pp.185-191
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• 2000

Pest insect control is dependent on about 200 insecticides that work by relatively few mechanisms. The targets they disrupt are mostly involved in the nervous system, respiratory chain, growth and development, or the gut. The major nerve targets are: acetylcholinesterase for the organophosphates and methylcarbamates; the nicotinic acetylcholine receptor for the neonicotinoids; the $\gamma$-aminobutyric acid receptor for several chlorinated hydrocarbons and fipronil; the voltage-gated sodium channel for DDT and pyrethroids. Selection of resistant strains often confers cross-resistance to some or all other insecticides working at the same site. The toxicological properties of different compounds acting on the same target are increasingly considered together, summating the risk even though the compounds are of quite diverse chemical types. Continuing attention is also being given to secondary targets not involved in the primary mechanism of toxicity but instead in side effects that must be considered in the overall safety evaluation. Research on insecticide targets is important in learning to keep up with resistance and changing concepts and policies on safety. These relationships are illustrated by recent studies in the Environmental Chemistry and Toxicology Laboratory of the University of California at Berkeley.

• International Journal of Industrial Entomology and Biomaterials
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• v.14 no.2
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• pp.143-146
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• 2007

Concerns of entomopathogenic fungi as alternative pest control agents are increasing even though chemical pesticides have been used as the main control agents for pests and diseases in crop production. This study was conducted to test the influence of fungicides and insecticides on an isolate of Lecanicillium attenuatum that was reported to have the pathogenicity against cotton aphid, because fungicides and/or insecticides can apply with mycopesticides simultaneous, before and/or after. Fungicides fenbuconazole+thiram and propineb inhibited the spore germination and mycelial growth of L. attenuatum CS625; dimethomorph and procymidone did not affect spore germination or mycelial growth. The insecticide abamectin, deltamethrin, imidachropride, and spinosad had no detrimental effects on spore germination or mycelial growth. Therefore, these results demonstrated that careful selection of pesticides and fungicides can be applied to the integrated pest and disease control with microbial pesticide.

• Applied Biological Chemistry
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• v.31 no.1
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• pp.92-99
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• 1988

The responses of brain acetylcholinesterase and plasma cholinesterase activities were examined in chicken given oral doses of an organophosphorus insecticides. Acute oral $LD_{50}$ of terbufos was 1.82mg/kg, and terbufos sulfone was 2.85mg/kg, terbufos sulfoxide, terbufoso xon, terbufosoxon sulfone and terbufosoxon sulfoxide were about $0.30{\sim}0.79mg/kg$, respectively. Acute oral $LD_{50}$ of phorate was 1.02mg/kg, and phorate sulfone was 1.73mg/kg, phorate sulfoxide, phoratoxon, phoratoxon sulfoxide and phoratoxon sulfone were about $0.36{\sim}0.63mg/kg$, respectively. Dosages of 50% inhibition for brain AChE and plasma ChE activities in chicken at 60 mins after oral administration of organop hosphorus insecticides were $35.3{\pm}6.8%\;and\;17.4{\pm}3.6%$ of acute oral $LD_{50}$, respectively. Activities of brain AChE and plasma ChE in chicken at 60 mins after oral administratration of acute oral $LD_{50}$ of organophosphorus insecticides were inhibited by $83.7{\pm}3.9%\;and\;93.3{\pm}2.2%$, respectively.

• Korean Journal of Environmental Agriculture
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• v.41 no.1
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• pp.55-64
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• 2022

BACKGROUND: This study was conducted to evaluate the residual characteristics and safety assessment of αcypermethrin and deltamethrin in minor crops, chives and spring onion cultivated in greenhouse. METHODS AND RESULTS: The insecticides α-cypermethrin 2% EC and deltamethrin 1% EC used in the experiment were diluted 1,000 times and then sprayed on chives and spring onion twice with 1-week intervals at 0, 7, 14, and 21 days before harvest. The residual insecticides were extracted from the minor crops using QuEchERS method and analyzed by GC-MS/MS. The average initial residues of α-cypermethrin and deltamethrin in chives after 21 days decreased from 2.74 to 0.82 mg/kg and 1.12 to 0.16 mg/kg, respectively. Similarly, in spring onion the residues after the same periods decreased from 0.26 to <0.01 mg/kg for α-cypermethrin and from 0.07 to <0.01 mg/kg for deltamethrin. CONCLUSION(S): The PHIs (pre-harvest intervals) for α-cypermethrin and deltamethrin in chives are recommended as 14 days before harvest with twice applications of the pesticides, whereas for α-cypermethrin in spring onion PHI of 7 days before harvest is recommended with 3 times of applications and PHI of 21 days for deltamethrin. The theoretical maximum daily intakes of cypermethrin and deltamethrin were 68.8% and 64.2%, respectively, indicating that residues of both compounds did not pose considerable health risks to consumers.

• Korean journal of applied entomology
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• v.46 no.3
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• pp.415-423
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• 2007

For the development of integrated pest management system by harmonizing biological and chemical control, some experiments were carried out to select low toxic pesticides and to evaluate residual toxicity to natural enemies. Leaf dipping method and body dipping method were set up for evaluating toxicity to minute pirate bug, Orius strigicollis adult. We had tested 52 kinds of pesticides (33 insecticides, 19 fungicides) commonly used to control greenhouse insects, mites, and disease pests to natural enemies at the recommended concentration. Fourteen insecticides by body dipping method, 12 insecticides by leaf dipping method and 19 fungicides were selected as low toxic pesticides to O. strigicollis adult. After insecticide spraying at recommending dose on the sweet pepper plant, we examined residual effect of insecticides by introducing natural enemies on different days. Safety interval for introduction of O. strigicollis adult was established according to residual toxicity of pesticides. Safety insecticides at one day after treatment were pyraclofos, methomyl, thiodicarb, esfenvalerate bifenthrin, alpha-cypermethrin, etofenprox, fenvalerate, imidacloprid, acetamiprid, abamectin, emamectin benzoate, spinosad, indoxacarb. However, residual toxicity of nee-nicotinoids last up to 21 days to O. strigicollis adults.

• The Korean Journal of Pesticide Science
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• v.18 no.1
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• pp.41-47
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• 2014

This study was performed to evaluate the exposure level of organophosphorus and pyrethroid pesticide to floriculture workers and florists. The urinary dialkylphosphates, metabolites of organophosphorus insecticides, including dimethylphosphate (DMP), diethylphosphate (DEP), dimethylthiophosphate (DMTP), diethylthiophosphate(DETP) and pyrethroids of metabolites, cis/trans DCCA, DBCA, and 3-PBA were analysed to evaluate the exposure of organophosphorus and pyrethroid pesticide to floriculture workers and florists. The concentration of DMP is highest in floriculture workers. but the concentration of DETP is highest in retail florist. The concentration of 3-PBA is highest in floriculture workers. The amount of organophosphorus and pyrethroid pesticide expusure is highest in flower workers, wholesale florist and retail florists are followed. The management for reducing pesticide exposure to floriculture workers and wholesale florist is required.

• 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.56 no.2
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• pp.153-164
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• 2017

Gene silencing using double-stranded RNA (dsRNA) has been widely used in functional genomics in biological organisms. Its principle stems from RNA interference (RNAi), a post-transcriptional control of gene expression. Suppression of specific gene expression using dsRNA may give significant lethal effect. Insect pest control exploits this molecular process to develop novel insecticides using specific dsRNAs. This review explains core principles of RNAi using dsRNA. Then it illustrates various examples to control insect pests using dsRNAs. It also discusses limitations to control insect pests using dsRNAs. Finally, it provides several breakthroughs to develop dsRNA insecticides.