• Korean journal of applied entomology
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• v.48 no.1
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• pp.87-94
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• 2009

KNI3126 which is the eco-friendly material made by plant extracts - neem and matrine - have been evaluated for efficacies against 6 main pests and toxicity on natural enemies. Insecticidal efficacies of KNI3126 against plant hopper were above 95% at 5 days after treatment (DAT), whereas pesticidal effects against the cotton aphid were above 95% at 3 DAT and slightly decreased at 5 DAT. Insecticidal efficacy against the palm thrips resulted in lower control value as 68.1% than that of chemical insecticides. KNI3126 showed more than 95% control value against diamond back moth, suggesting that it could suppress the population of pest hard to control as eco-friendly material. Mortalities against two-spotted spider mite were about 80% at 1 DAT and over 90% at 5 DAT, respectively. For evaluation of the toxicity on natural enemies, effect against predatory natural enemy was classified as moderate selective toxicity based on the criterion of International Organization of Bio-Control (IOBC), whereas against parasitic natural enemies was found to be relatively safe. Repellent effect was weak against plant hopper, but strong against two-spotted spider mite. In the toxicity test for safety, KNI3126 was classified as the lowest level at acute oral, acute dermal and fish toxicity test and did not induce the irritancy at skin irritation test and eye irritation test.

• Journal of Conservation Science
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• v.10 no.1 s.13
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• pp.21-30
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• 2001

The antibacterial and insecticidal properties of ethanol extracts and volatile components extracted from Eugenia caryophyllata, Boswellia carterii, Agastache rugosa, Aristolochia contorta, and Aquilaria agallocha were evaluated. The ethanol extract and volatile component of E. caryophyllata showed strong antimicrobial effect against all strains (Mucor hiemalis, Aspergillus niger, Penicillium funiculosum, Trichoderma viride) and the volatile component of B. carterii showed antimicrobial effect against all strains except T. viride. The ethanol extract of E. caryophyllata and A. contorta showed $100\%\;and\;32\%$ mortality against Reticulitemes spertus kyushuensis Morimoto for 48 hours and 72 hours, respectively. In the case of volatile component, E. aryophyllata showed $100\%\;and\;20\%$ mortality against R. spertus and Lyctus linearis GOZE, respectively. The main constitute, eugenol $(92\%)$ among nine components from volatile component of E. aryophyllata were identified as antibacterial active substance.

• The Korean Journal of Pesticide Science
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• v.3 no.2
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• pp.69-73
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• 1999

The insecticidal activities and residues of chlorfenapyr [4-bromo-2-(4-chlorophenyl)-1-ethoxymethyl-5-trifluorornethyl pyrrole-3-carbonitrile] against Thrips palmi was evaluated under laboratory and vinyl house conditions. Effectiveness of chlorfenapyr against T. palmi on red pepper leaves was lasted for 9 days at a concentration of 50 ppm but there was no significant differences between emulsifiable concentration and wettable granule under laboratory conditions. In vinyl house, high toxicity was investigated at 6 hours after application of chlorfenapyr in a concentration of 50 and 100 ppm and insecticidal effect was maintained for 11days after 2 times weekly application in cucumber. Control effect was above 97% against T. palmi larva and larva+adults after 2 times weekly application in vinyl house.

• Korean journal of applied entomology
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• v.9 no.1
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• pp.25-32
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• 1970

This experiment was conducted to find out the simultaneous control effect of granulated insecticides on the several major rice insect pests in Korea. The granulated insecticides used were Terracur P$5\%$ (one of the phosphoric insecticides), Lebaycid $5\%$, and Sang-gamma (gamma-BHC) $6\%$. Those insecticides were broadcasted by hand on the paddy field at the ratio of 3kg. in June and 4kg. in August per 10 a, and the date of insecticidal application was based on the maximum moth occurrence of the rice stem borer in 1969. The rice insect pests tested in this study were rice stem borer (Chilo suppressalis W.), green rice leafhopper (Nephotettix bipunctatus cincticeps U.), smiller brown planthopper (Laodelphax striatellus F.), and white back planthopper (Sogotella furcifera H.). For the study of residual effectiveness of the insecticides, the rice stem borer larvae just hatched from the eggs were installed on the sheath of rice plants collected from the paddy field after insecticidal treatment, and the mortality was made at 48 hours after installation. High mortality was observed in Terracur P and Sang-gamma treatments and low mortality in Lebaycid treatment. The duration of residual effects giving about 50% mortality was about 14 days in Sang-gamma and about 6 days in Terracur P treatments. The study on the effectiveness of the insecticides to the rice stem borer in the paddy field was made by the number of dead blades and white heads of the rice plants injured by the larvae, and the number of survival larvae in the straws after crop harvest. The order of insecticidal effectiveness to the rice stem borer was Terracur P=Sang-gamm>Lebaycid. The study on the effectiveness of the insecticides to the leafhoppers and planthoppers in the paddy field was made by the population density by sweeping (5 times) at the given day intervals after treatments. Terracur P was highly effective for the control of the green rice leafhoppers and Lebaycid was moderately effective, but Sang-gamma seemed not to be effective. The effectiveness of the insecticides tested to the planthoppers was not clear, and it seemed to related with the low insect population density. Study on the determination of proper timing of insecticidal application was not also made clear, and it seemed to be short in the range of day intervals in the insecticidal application. For the study on the control effects of the rice insect pests, rice yield per 100 hills per plot was observed. There was no statistically significant difference among the treatments in rice yields, but the order of yield (Terracur P>Sang-gamma>Lebaycid>Control) was paralleled with the tends of control effects above mentioned. In a view point of simultaneous control of the rice stem borers and green rice leafhoppers by the application of granulated insecticides, Terracur P and Lebaycid were more effective than Sang-gamma which have been used.

• The Korean Journal of Pesticide Science
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• v.14 no.4
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• pp.440-445
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• 2010

This study was carried out to investigate the toxicities of five registered insecticides to the Lycorma delicatula nymphs and adults. Insecticidal activities were evaluated by testing systemic and residual effects in the laboratory, and control efficacy in the vineyard. For the 3rd nymphal instars and adults, etofenprox+diazinon, chlorpyrifos, etofenprox, dinotefuran and imidacloprid showed perfect insecticidal activity. The systemic effects of dinotefuran and etofenprox+diazinon on grape roots at half concentration were showed the adult mortality of 82.2% and 84.4%, respectively. Chlorpyrifos at recommended concentration was showed mortality of 86.0%. The leaf systemic effects at recommended and half concentrations of all insecticides except dinotefuran were lower than 65% but the mortality at double concentration of chlorpyrifos, dinotefuran, etofenprox were more than 82%. The residual effect between etofenprox+diazinon and dinotefuran at recommended and double concentrations were 100% at 14 days after treatment, the other insecticides have low efficacy. All the four insecticides showed 87% control value on nymphs in the field test and adults appeared more than 96% control value st and adinotefuran, etofenprox+diazinon, however, the other insecticides decreased to 59.1 % and 61.2%. Therefore, dinotefuran and etofenprox+diazinon showing high systemic effects to roots and long residual effects to leafs have high control efficacies.

• Journal of Applied Biological Chemistry
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• v.60 no.2
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• pp.137-140
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• 2017

Agricultural pests, diamondback moth (Plutella xylostella), green peach aphid (Myzus persicae) and two-spotted spider mite (Teyranychus urticae), are becoming major pests in human dwellings in a variety of ways across the world. For management of these pests, the essential oils of Coriandrum sativum and Cinnamomum cassia prepared by steam distillation, hexane extraction and supercritical extraction methods were evaluated for the insecticidal effects. Using the contact bioassay, the $LD_{50}$ value of C. sativum oil by steam distillation extraction method was $30.59{\mu}g/cm^2$ against M. persicae adults. The $LD_{50}$ values of C. cassia oils prepared by steam distillation and hexane extraction methods were 5.96 and $4.64{\mu}g/cm^2$, respectively, against T. urticae adults, and $LD_{50}$ value of the essential oil by supercritical extraction method was $6.50{\mu}g/cm^2$ against M. persicae adults. This study showed that C. sativum and C. cassia oils could be an effective natural acaricide and insecticide against agricultural pests.

• The Korean Journal of Pesticide Science
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• v.21 no.1
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• pp.33-41
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• 2017

Susceptibility and persistence of Japanese pine sawyer, Monochamus alternatus adults, and acute contact toxicity, foliage contact toxicity, and residual toxicity to honeybee, Apis mellifera were evaluated by using 5 kinds of neonicotinoid pesticides. All neonicotinoids pesticides showed over 80% mortality 48 hour after body spray treatment. However, only 2 kinds of acetamiprid ME and acetamiprid+buprofezin showed over 80% mortality in the twig dipping treatment. All of the five neonicotinoides pesticides used in M. alternatus adults showed residual effect of 60-80% mortality, but the efficacy decreased rapidly after 1 day of treatment. Acetamiprid ME showed the lowest toxicity in the acute and foliage contact toxicity test of A. mellifera. The residual toxicity of leaves on A. mellifera was very low in acetamiprid ME and acetamiprid+buprofezin. However, the residual toxicity of all pesticides treatments decreased to 10-30% after 1 day of treatment and further decreased with time. These results indicate that acetamiprid ME among five neonicotinoid agents showed a high insecticidal activity in the M. alternatus adults, while it exhibited relatively low contact and residual toxicity in the A. mellifera. It is thought that acetamiprid ME can be effectively used for the control of the M. alternatus adults as vector of pine wilt disease.

• Korean journal of applied entomology
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• v.49 no.4
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• pp.333-342
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• 2010

The possibility of commercializing the controlled release of chitosan carrier nano formulation was examined with mortalities and population increase rates of Aphis gossypii and Myzus persicae after treatment of 2 ${\alpha}$-cypermethrin nano type formulations of different chitosan carrier molecular weight (M.W. 3,000 and 30,000) and 2 etofenprox nano types of chitosan content (70% and 80%). After 14 days of treatment, ${\alpha}$-cypermethrin nano formulation showed over 40% mortality against A. gossypii. Therefore, it was confirmed that the insecticide release was controlled through chitosan carrier. Results of the investigation of insecticidal activity of ${\alpha}$-cypermethrin nano formulation showed there were no differences between nano types at 4 days after treatment. However, after 14 days, the population increase rate treated with chitosan M.W. 30,000 formulation was -0.037, much lower than that of M.W. 3,000 formulation with 0.231. The result exhibits that chitosan M.W. 30,000 formulation would be a suitable controlled release formulation. On the other hand, etofenprox formulations didn't show any significant insecticidal effect or persistency difference against both aphid species.

• Journal of the Korean Chemical Society
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• v.34 no.5
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• pp.483-489
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• 1990

The rate of hydrolysis of insecticidal 2-chloro-l-(2,4,5-trichlorophenyl)-vinyldimethylphosphate(Gardona) have been investigated in 25${\%}$ aqueous methanol. Studies at varying pH suggest that the hydrolysis of Gardona proceeds through the bimolecular (Ad$_{N-E}$) mechanism involving the transition state and carbanion intermediate as evidenced by solvent effect (m < 0.4, n < 0.7, [m] ${\ll}$ [l](associative SN$_2$ type)), thermodynamic parameters (${\{Delta}S^{\neq}$ = -27∼-32 e.u. & ${\{Delta}H^{\neq}$ = 13∼18 Kcal/mole), hydrolysis rate equation (k = k$_A+_B$ [OH-]), general base catalysis and hydrolysis product analysis, respectively.

• Journal of Microbiology and Biotechnology
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• v.23 no.11
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• pp.1536-1543
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• 2013

Proteases produced by Xenorhabdus are known to play a significant role in virulence leading to insect mortality. The present study was undertaken to purify and characterize protease from Xenorhabdus indica, an endosymbiont of nematode Steinernema thermophilum, and to decipher its role in insect mortality and its efficacy to control Helicoverpa armigera. A set of 10 strains of Xenorhabdus isolated from different regions of India were screened for protease activity on the basis of zone of clearing on gelatin agar plates. One potent strain of Xenorhabdus indica was selected for the production of protease, and the highest production (1,552 U/ml) was observed at 15-18 h of incubation at $28^{\circ}C$ in soya casein digest broth. The extracellular protease was purified from culture supernatant using ammonium sulfate precipitation and ion-exchange chromatography. The enzyme was further characterized by SDS-PAGE and zymography, which confirmed the purity of the protein and its molecular mass was found to be ~52 kDa. Further MALDI-TOF/TOF analysis and effect of metal chelating agent 1,10-phenanthrolin study revealed the nature of the purified protease as a secreted alkaline metalloprotease. The bioefficacy of the purified protease was also tested against cotton bollworm (Helicoverpa armigera) and resulted in $67.9{\pm}0.64%$ mortality within one week. This purified protease has the potential to be developed as a natural insecticidal agent against a broad range of agriculturally important insects.