• Korean Journal of Agricultural Science
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• v.45 no.2
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• pp.185-196
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• 2018

The fungus gnat, Bradysia difformis, damages various crops in greenhouses and is recognized as an important pest around the world. Additionally, in the future, many other greenhouse crops will be added to the list of crops damaged by the fungus gnat. In this study, to find effective control methods for the fungus gnat, the insecticidal effect of 20 chemical synthetic insecticides was tested with the potato disc and pot treatment methods; additionally, the control effect of 16 strains of B. thuringiensis was examined with the potato disk method. The fungus gnat larvae were treated for 2 days with each of the synthetic insecticides to determine insecticidal effect using the potato disc method. The results were as follows. Among the highly insecticidal active pesticides, chlorfenapyr exhibited a 100% insecticidal activity, and fenazaquin, acetamiprid, dinotefuran, fenthion and thiamethoxam exhibited more than a 90% insecticidal activity. For the pot treatment method, chlorfenapyr exhibited a 3.3% insecticidal effect, and thiamethoxam, acetamiprid, dinotefuran, fenthion, etc. exhibited an insecticidal effect of less than 10% of the emergence rate to adult fungus gnat after 14 days of treatment. To select the B. thuringiensis strains that have an insecticidal effect on the fungus gnat, 16 strains were biologically assayed using the potato disc method. Among the 16 strains, Bt-3, Bt-8 and Bt-13 had more than a 70% insecticidal effect. The $LC_{50}$ and $LC_{95}$ values of Bt-3, Bt-8 and Bt-13 were $3.7{\times}10^5$ and $4.7{\times}10^8cfu/ml$, $1.4{\times}10^5$ and $1.1{\times}10^7cfu/ml$, and $1.4{\times}10^5$ and $1.3{\times}10^7cfu/ml$, respectively.

• Korean Journal of Agricultural Science
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• v.41 no.3
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• pp.177-185
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• 2014

Aspiring to the new raw materials of insecticides is one of the plant extracts. The material structure of a variety of plant extracts have because the material to the defense of the plant itself, the case of insecticides, using plant extracts, safe, has low toxicity and has the advantage of highly distinctive and fall. Coltsfoot (Tussilago farfara L.) is belonging to the family Compositae, and distributed in all parts of China as medicinal plants and indigenous plants used. Coltsfoot is known that it is effect to respiratory disease and has an antiviral effect. However, the reported insecticidal activity of coltsfoot could be not found. Fortunately, I found insecticidal activities when I was screening the bioassay against several insects with a lot of plant extracts. Using the ethanol extract of the Tussilago farfara, there were insecticidal activities against Culex pipiens pallens and Tetranychus urticae. There were several fractions in ethanol extract of coltsfoot by using various organic solvents. Hexane fraction showed a higher insecticidal activity than any other fraction. It is confirmed that hexane fraction contained pyrethrin by using HPLC analysis. So, it might be suggested that extract of coltsfoot has an insecticidal activity and its effect due to a ingredient of pyrethrin.

• Journal of Environmental Health Sciences
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• v.21 no.1
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• pp.74-77
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• 1995

The insecticidal and antibacterial activity of new synthesized carbamate derivatives(8-Hydroxy-5-chloroquinolyl-N-methylcarbamate(I), 8-Hydroxy-5-chloroquinolyl-N-ethylcarbamate(II)) was examined using 0.2 w/v% acetone solutiolas and 50 r/ml~1000 r/m N,N'-dimethylformamide-$H_2O$(2:3) solutions of each compounds, respectively. 1) Two carbamates exerted insecticidal effects on Sogata furcifera HORVATH, Delphacodes Striatella FAUEN, Whereas no significant effects were observed on the Nilaparvate lugens STAL, Inazuma dorasails MOISCHIULSKY and Nephateffix apicalis Cincticeps UHLER. 2) These compounds exhibited growth-inhibitory activity against Staphylococcus aureus, Salmonella paratyphi A, Shigella dysenteriae 1a, Escherichia coli NL 1401,at the concentration range of 100~500 r/ml in general.

• Korean Journal of Agricultural Science
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• v.44 no.3
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• pp.348-358
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• 2017

The green peach aphid, Myzus persicae, is one of the most serious insect pest and a vector for a multitude of viral diseases to many crops, vegetables, ornamentals, and fruit trees in the world. A large number of aphids can reduce plant vigor and cause defoliation. Many insecticides have been developed and applied to control the green peach aphid. However, this aphid has displayed a remarkable ability to establish resistance to almost every insecticide. We treated 5 different insecticides registered for M. persicae on pepper leaves and investigated the effects of the insecticides by measuring the time it took to achieve 90% control of the aphids. Acetamiprid worked faster than any other insecticides while cyantraniliprole showed the slowest insecticidal effect. Pymetrozine, pyrifluquinazon, and spirotetramet provided 90% control within similar time. Iwol population's control value was higher than any other populations 24 hours after treatment. When five different unregistered insecticides for M. persicae were treated on pepper leaves, no insecticidal effect was found for gamma-cyhalothrin and novaluron and spinosad showed an insecticidal effect of up to 70% in Iwol population only. Although chlorfenapyr and dinotefuran were not registered for M. persicae, their insecticidal effects were found to be 90% or higher.

• Journal of Microbiology
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• v.43 no.5
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• pp.463-468
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• 2005

Studying the bacteria of hazardous insects allows the opportunity to find potentially better biological control agents. Therefore, in this study, bacteria from summer chafer (Amphimallon solstitiale L., Coleoptera: Scarabaeidae) we isolated and identified the insecticidal effects of bacteria isolated from A. solstitiale and Melolontha melolontha L. (common cockchafer, Coleoptera: Scarabaeidae) and the mixtures of these bacterial isolates were investigated on A. solstitiale larvae. Crystals from Bacillus sp. isolated from M. melolontha were also purified, and tested against the second and third-stage larvae of A. solstitiale. The bacterial isolates of A. solstitiale were identified as Pseudomonas sp., Pseudomonas sp., Bacillus cereus and Micrococcus luteus, based on their morphology, spore formation, nutritional features, and physiological and biochemical characteristics. The insecticidal effects of the bacterial isolates determined on the larvae of A. solstitiale were $90\%$ with B. cereus isolated from A. solstitiale, and $75\%$ with B. cereus, B. sphaericus and B. thuringiensis isolated from M. melolontha within ten days. The highest insecticidal effects of the mixed infections on the larvae of A. solstitiale were $100\%$ both with B. cereus+B. sphaericus and with B. cereus+B. thuringiensis. In the crystal protein bioassays, the highest insecticidal effect was $65\%$ with crystals of B. thuringiensis and B. sphaericus isolated from M. melolontha within seven days. Finally, our results showed that the mixed infections could be utilized as microbial control agents, as they have a $100\%$ insecticidal effect on the larvae of A. solstitiale.

• Journal of Environmental Health Sciences
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• v.23 no.1
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• pp.62-65
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• 1997

The insecticidal and antibacterial activity of new synthesized carbamate derivatives(5,7-dibromo-8-hydroxyquinolinyl-N-methylcarbamate(I), 5,7-dibromo-8-hydroxyquinolinyl-N-ethylcarbamate(II)) was examined using 0.2w/v% acetone solutions and 50 $\mu$g/ml-1000 $\mu$g/ml N,N'-dimethylformamide H$_2$O(2:3) solutions of each compounds, respectively. 1. Two carbamates exerted insectiddal effects on Sogata furcifera HORVATH, Delphacodes Striatella FAUEN and Nilaparvate lugens STAL, Whereas no significant effects were observed on the Inazuma dorasalis MOISCHIULSKY Nephateffix apicalis Cincticeps UHLER. 2. These compounds exhibited growth-inhibitory activity against Staphyloccus aureus, Salmonella paratyphi A, Shigella dysenteriae 1a, Escherichia coli NL 1401, at the concentration range of 100-500 $\mu$g/ml in general.

• Journal of Microbiology
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• v.40 no.2
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• pp.104-108
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• 2002

The hazelnut leaf holer (Anoplus roboris Sufr,, Coleoptera: Curculionidae) is a devastating pest of hazelnut and oak trees. It causes approximately 20-30% economic damage to hazelnut production per year in Turkey. In the present study, in order to fond a more effective and safe biological control agent against A. roboris, we investigated the bacterial flora of the hazelnut leave holer, and tested them for insecticidal effects on it. According to morphological, physiological and biochemical tests bacterial flora were identified as Bacillus circulans (Ar1), Bacillus polymyxa (Ar2), Enterobacter sp. (Ar3) and Bacillus sphaelicus (Ar4). Insecticidal effects of bacterial isolates were performed on adult A. roboris. The highest insecticidal effect determined was 67% by B. sphaericus within eight days. The insecticidal effects of the other isolates (Ar1, Ar2 and Ar3) were determined as 33%, 47% and 47% within the same period, respectively.

• Journal of Applied Biological Chemistry
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• v.60 no.1
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• pp.1-3
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• 2017

This study was conducted to evaluate the insecticidal effects of the Anethum graveolens and the Artemisia vulgaris oils against Sitophilus zeamais and Sitotroga cerealella, respectively, in granary. Insecticidal effects of the A. graveolens oil showed 100 % mortality against S. zeamais for 5 days. In the case of S. cerealella, the A. vulgaris oil showed 100 % mortality for 2 h. These results indicate that the A. graveolens and A. vulgaris oils have potential for development as insecticidal to control S. zeamais and S. cerealella, respectively.

• The Korean Journal of Pesticide Science
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• v.3 no.1
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• pp.46-50
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• 1999

Methanol extracts of 9 kinds of native medicinal plants(Taraxacum platycarpum, leaf; Pinus densiflora, leaf; Artemisia prinseps, leaf; Allium tuberosum, leaf; Cassia obtussifolia, whole; Sophora angestifolia, root; Stemonae sessilifolia, root; Lonicera japonica stem, leaf, flower; and Clivia miniata) were investigated for insecticidal effect. Methanol extracts of Pinus densiflora leaves and Sophora angestifolia radix showed relatively good insecticidal activity against Culex pipiens pallens larvae. Strong larvicidal activity against the Musca domestica larvae was produced from methanol extracts of Taraxacum platycarpum leaves and Allium tuberosom leaves. while Stemonae radix showed moderate activity. All materials tested revealed little or weak insecticidal activity against M. domestica adults.

• Korean Journal of Agricultural Science
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• v.37 no.3
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• pp.361-365
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• 2010

For the development of more effective insecticides for aphids, including the cotton aphid, Aphis gossypii Glover, control released insecticides were developed and tested as new type of formulation for the cotton aphid. Etofenprox is a target-of-control-released formulation that is toxic to insects with piercing-sucking type mouths including aphids and hoppers. The insecticidal effect of etofenprox is distinguished among others; however, continuance period of the effect of insecticide is shorter than other insecticides. In addition, the control effect of control released etofenprox on the cotton aphid was examined. The results show that control released etofenprox induced no control effects to the cotton aphid within 5 days of treatment. The cotton aphid's population was increased, and their reproduction rate was also high. However, control effect was shown to have very low levels 7 days after treatment, and it increased to higher effect. It is supposed that it is possible to control the cotton aphid using the type of control released etofenprox with a kitosan carrier. It is necessary to develop a more effective carrier type to release more of the insecticidal ingredient on the leaf after spraying.