• Applied Biological Chemistry
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• v.37 no.6
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• pp.492-497
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• 1994

Extracts of 43 species of plants were tested for their insecticidal and acaricidal activities against six species of insect pests and one mite species. The methanol extract of Ginkgo biloba leaves selectively was found to have potent insecticidal activity against Nilaparvata lugens (Stal), whereas steam distillate of Thujopsis dolabarata var. hondai sawdust showed potent insecticidal activities with a broad spectrum. The methanol extract of Pinus densiflora leaves and steam distillate of T. dolabrata var. hondai sawdust exhibited potent activities against Tetranychus urticae (Koch).

• The Korean Journal of Pesticide Science
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• v.11 no.1
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• pp.52-58
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• 2007

ALA (5-aminolevulinic acid) has been proposed as a tetrapyrrole-dependent photodynamic herbicide and insecticide by the action of the protoporphyrinogen IX oxidase (Protox IX). The present study was conducted to determine growth responses of plant and insects to ALA, biodegradable biopesticidal substance. In the paddy condition experiment, plant height and shoot fresh weight of barnyardgrass (Echinochloa crus-galli) was more reduced by ALA than rice plants, even though both plant species show great phytotoxicity. Hairy crabgrass (Digitaria sanguinalis), a monocot weed, was more sensitive to ALA at 5mM under upland condition when ALA applied on the foliage, compared with soybean (Glycine max) as a dicot crop. ALA solutions were tested for their insecticidal and larvicidal activities against Spodaptera exigua (Hubner) and Tetranychus urticae Koch. by foliar application and leaf-dipping method. The result showed higher insecticidal activity of ALA at 10mM and its mixture with insecticide luferon against S. exigua. Strongest insecticidal activity against T. urticae was observed from the ALA solution at 10mM 72 days after application. This results show that ALA solution had potent herbicidal and insecticidal activities against agricultural pests even though their activities were lower than those of synthetic pesticides.

• The Korean Journal of Pesticide Science
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• v.3 no.1
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• pp.20-28
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• 1999

Chloronicotinyl derivatives were synthesized by substitution of amino in 3-pyridylmethylamine with phosphite groups and their insecticidal and fungicidal activities were determined. At 500 ppm, compound 4 with methyl and butyl group in phosphonate and compound 5, 6, 7, and 8 with two butyl, 2,2,2-trifluorotehtyl, 2-ethylhexyl, phenyl, respectively, in phosphonate showed 90% insecticidal activities against brown plant-hopper (Nilaparvate lugens). These compounds showed, however, poor insecticidal activities against diamond-back moth (Plutella xylostella) and two-spotted spider mite (Tetranychus urticae) (<65%), suggesting that insecticidal activity of chloronicotinyl derivatives containing phosphorus moieties are species-dependent. Newly synthesized chloronicotinyl derivatives with halogen and/or heterocycle (compound $10{\sim}21$) did not show insecticidal activities. We also determined fungicidal activity of the synthesized chloronicotinyl derivatives against rice sheath blight (Pyricularia grisea), cucumber gray mold (Bortytis cinerea), tomato late blight (Phytophthora infestans), wheat leaf rust (Puccinia recondita), and barley powdery mildew (Erysiphe graminis). Compound 10 with butyl and 4-nitrophenyl in phosphonate at 10 ppm showed 85% fungicidal activity against rice blast, suggesting that chloronicotinyl derivatives containing phosphorus moieties could be developed as a fungicidal agent of a novel chemical structure.

• Applied Biological Chemistry
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• v.39 no.2
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• pp.140-146
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• 1996

Imidacloprid and a series of the related compounds were synthesized, and influence of 3-N substituents(R) on the insecticidal activities against Brown plant hopper(Nilaparvata lugens) and Green peach aphid(Myzus persicae) were examined quantitatively from the structure-activities relationships(Shh) techniques. The results indicated that the molecular hydrophobicity$({\pi})$ and inductive substituent constant$({\sigma}^{\ast})$ of substituents(R) at 3-nitrogen position on the imidazolidine ring were important factors. Variations in the potency were parabolically related to the both constants. In case of Brown plant hopper, optimum value of ${\pi}$ constant was 0.52, whereas the value of ${\sigma}^{\ast}$ constant against Green peach aphid was 1.17, respectively. Among them, the strong electron withdrawing groups$({\sigma}^{\ast}>0)$ such as methyl and benzenesulfonyl group(7 & 8) showed lower insecticidal activity and non-substituted, 1(imidacloprid) showed the best insecticidal activity. It seems that the intramolecular associated(H-bond) form between 2-N-nitro group and 3-imid group may contribute to the higher insecticidal activity to the both sucking insects. And in aqueous solution, 1 showed higher residual activity below pH 6.0, and the half-life$(T_{1/2})$ was about 6 month at pH 7.0 $(ca.\;k_{obs.}:5{\times}10^{-8}sec.^{-1})$ and $45^{\circ}C$.

• Korean journal of applied entomology
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• v.43 no.2
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• pp.169-173
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• 2004

Control effects of some insecticides were evaluated against the stone leek leafminer, Liriomyra chinensis Kato (Diptera： Agromyzidae) with the some different treatment methods. Insecticidal activities effects were estimated on the different development stages of the insects on welsh onion. The insecticides that controlled L. chinensis eggs with over 83％ efficacy were spinosad, dimethoate, emamectin, and cartap. The insecticides that showed over 87％ of larvicidal activity were dimethoate and cartap. Dimethoate showed 93.3％ insecticide residual activity for 3 days a(ter treatment as a foliar spray. For control of pupae, the insecticides that showed over 88％ of contact insecticidal activity were terbufos GR and cartap GR. Both dimethoate and cartap had high adulticidal activity with over 95％ control efficacy.

• The Korean Journal of Pesticide Science
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• v.14 no.4
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• pp.394-400
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• 2010

Insecticidal activities of methanol extracts of the different parts of Prunus mume were investigated against the larvae of Cnaphalocrocis medinalis (C. medinalis) by topical application. The mortalities of the larvae of C. medinalis were 34% at the concentration of 4,000 ppm, 36% of 8,000 ppm, 40% of 16,000 ppm and 58% of 32,000 ppm of the extracts from the fruits, and 38% of 4,000 ppm, 45% of 8,000 ppm, 58% of 16,000 ppm and 75% of 32,000 ppm from the stem + flower of Prunus mume (P. mume), respectively. The rates of pupation of C. medinalis treated with either fruit or stem+flower were gradually low according to the concentration of extracts increased. The weight of pupae of C. medinalis has no significantly different in between the control and the treated groups of the extracts from both of fruit and stem+flower. However, the differences of the pupal weight and the rate of pupation of C. medinalis treated with the extracts from the stem+flower and fruit of P. mume were significant as the level of 56% ($R^2$=0.56363, P=0.4364). Both of stem+flower and fruit extracts of P. mume showed good effects of anti-feeding against C. medinalis. The extracts of the stem+flower of P. mume could be advocated for developing as birational agent for the control of C. medinalis.

• The Korean Journal of Pesticide Science
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• v.6 no.4
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• pp.271-278
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• 2002

Methanol extracts from 420 samples of 173 plant species in 58 families were tested at 5000 ppm for their insecticidal and acaricidal activities against five economically important arthropod pests by spray method. The responses varied with arthropod pest species, plant species and plant tissue sampled. In a test with Nilaparvata lugens Stal, extracts from Zanthoxylum piperitum barks, Chamaecyparis obtusa leaf and Quercus salicina leaf showed potent insecticidal activity. With Plutella xylostella L., potent larvicidal activity was observed from extracts of Platycarya strobilacea wood, Meliosma myriantha barks, Sophora japonica leaf, Zanthoxylum piperitum barks, and Pinus thunbergii wood. Methanol extracts of Sophora japonica leaf and Zanthoxylum piperitum barks showed high insecticidal activity against Spodoptera litura. In a test with Tetranychus urticae Koch, extract from Carpinus coreana leaf, Firmiana simplex barks, Elaeagnus macrophylla leaf, Aralia elata leaf, Comus controversa barks and Chamaecyparis obtusa leaf exhibited strong acaricidal activity. As a naturally occurring pest control agent, Zanthoxylum piperitum barks could be useful as new insecticidal and acaricidal products against various arthropod pests.

• The Korean Journal of Pesticide Science
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• v.3 no.1
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• pp.13-19
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• 1999

Insecticidal potentials of polar and non-polar tractions obtained from 84 medicinal plants were screened against five major agricultural insects. Based on the primary and secondary screening results, non-polar fraction of Atractylodes koreana Kitam. rhizomes was selected to isolate and identify an active compound effective to diamondback moth (Plutella xylostella L.) larvae. Counter-current distribution separation on the non-polar fraction and TLC and spectroscopic analyses (GC-MS and $^{1}H$- and $^{13}C$-NMR) revealed that molecular formula of the active compound was $C_{15}H_{22}O$ known as a sesquiterpenoid 4,11-selinadien-3-one (${\alpha}$-cyperone). However, ${\alpha}$-cyperone was not detected in the non-polar fractions that showed high insecticidal potential against the diamondback moth. Although ${\alpha}$-cyperone has been first identified from Cyperus rotundus, the compound did not occur in C. rotundus cultivated in Korea.

• The Korean Journal of Pesticide Science
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• v.11 no.3
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• pp.194-200
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• 2007

Insecticidal activity of 33 registered insecticides was tested against last nymphal instars and adults of ussur brown katydid (Paratlanticus ussuriensis). All experiments were tested at the recommended concentration of each insecticides by producer. Acephate, chlorpyrifos, diazinon, EPN and fenitrothion which were organophates, and a mixture combined with chlorpyrifos+${\alpha}$-cypemethrin showed 100% mortality of P. ussuriensis. But fipronil showed only 100% mortality in leaf-dipping method. Carbamates insecticidal groups, benfuracarb and furathiocarb were showed over 80% and phenthoate was $60{\sim}80%$ in mortality of P. ussuriensis. Among the mixture, etofenprox+diazinon and esfenvalerate+fenitrothion were showed 60-80% against last nymphal instars of P. ussuriensis. Otherwise, acephate, chlorpyrifos, diazinon, EPN and fenitrothion were showed 100% mortality of P. ussuriensis within only 24 hours after treatment, but there was no effective after then in residual tests with leaves.

• Korean journal of applied entomology
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• v.43 no.4 s.137
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• pp.323-328
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• 2004

These studies were carried out to investigate the fumigation and contact toxicities of spearmint oil (Mentha spicata) against adults of greenhouse whitefly, Trialeurodes vaporariorum and sweet-potato whitefly, Bemisia tabaci. And we carried out the constituent analysis of spearmint oil using gas chromatograph (GC) and gas chromatograph mass spectrometry (GC/MS). Spearmint oil showed $99.1\%,\;91.7\%,\;41.1\%$ fumigation toxicity against T. vaporariorum adults at $10{\mu}L/954mL,\;5{\mu}L/954mL,\;1{\mu}L/954mL$ air concentration, respectively. In case of B. tabaci adults, spearmint oil showed $100\%,\;100\%,\;61.3\%$ fumigation toxicity, respectively. However, spearmint oil showed < $30\%$ contact toxicity against adults of T. vaporariorum and B. tabaci. Through the constituent analysis using GC and GC/MS, we confirmed main constituents of spearmint oil were limonene ($16.1\%$), ${\gamma}$-terpinene($13.8\%$), ${\rho}$-cymene($5.8\%$), 3-octanol($6.9\%$), carvone($40.9\%$). Carvone, major constituent of spearmint oil, also showed $100\%$ fumigation toxicity at $10{\mu}L/954mL$ air concentration.