• Korean journal of applied entomology
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• v.40 no.2
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• pp.137-141
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• 2001

This experiment was conducted to investigate the control effect of nuclear polyhedrosis virus and NeemAzal-T/S on Spodoptera litura larvae. In laboratory test, values of$ LT_{50}$ and $LT_{95}$ when treated with S. litura nuclear polyhedrosis virus (SINPV) $1$\times$10^{8}$ PIBs/ml plus NeemAzal-T/S 200 ppm were 1.94 and 8.33 days, respectively. Control effect of the combination of SINPV $1$\times$10^{8}$ plus NeemAzal-T/S 200 ppm was higher than the other concentrations. This mixed treatment could reduce LT$_{95}$ by 3 days. When SINPV alone was sprayed to the S. litura larvae reared on chinese cabbage seedling, the mortalities were 10.7~6.7% at 4 days after treatment. In combinations of SINPV plus NeemAzal-T/S at each level of concentration, the mortalities appeared faster and higher at 4 days after application than single treatment. Especially, the mortalities by combinations of SINPV $1$\times$10^{8}$ /PIBs/ml plus NeemAzal-T/S at 75~200 ppm were 100% at 9 days after treatment. The body weight of untreated larvae was increased 9.4-folds from 235 mg to 2194 mg after 7 days. However, the increasing levels of larval weight were 4.8- and 7.0-folds in the separate treatments of NeemAzal-T/S and SINPV, respectively. Whereas in the combinations of SINPV $10^{4~8}$ PIBs/ml plus NeemAzal-T/S 75~200 ppm, larval weight was increased 3.9 to 2.9-folds. These results showed that the mortality and inhibition of larval weight in the combination of SINPV and NeemAzal-T/S were highly enforced by synergistic effect.

• Korean journal of applied entomology
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• v.12 no.3
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• pp.115-120
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• 1973

An experiment was carried out to investigate possible use of several systemic insecticides as seed treatment to control some insect pests of rice, barley and soybean. The insecticides were impregnated with active carbon dust and $2\%$ water solution of methyl cellulose as skicker. The seeds were dressed with the insecticides: Fussol (Monofluoroacetamide), Dimethoate (0, 0-dimethyl-S-(N-methyl carbamoylmethyl) phosphorodithioate), Metasystox (0, 0-dimethyl 0-2 ethylthioethyl phosphorodithioate), Dimecron (0, 0-dimethyl (diethylamide-1-chlorocrotonyl) Phosphate). The seeds were treated at the rate of $4\%$ by grain weight. Effects of seed treatments with systemic insecticides on the seed germination and insecticidal effectiveness were tested. Fer rice, no seed germination was observed in Fussol treatment. Dimethoate, Metasystox and Dimecron showed a slight reduction in germination when seeds were sown 1 day after treatment, but they showed gradual reduction in germination when seeds were sown 20 and 45 days after treatment. Especially Diriethoate treatment showed significant reduction in germination after 20 and 45 days of storage. All the insecticides reduced seedling stands of barley somewhat. No plant emergence was observed in Fussol treatments after 25 and :to days of storage. In case of the 40 days of storge in barley seed treated with Dimethoate, Hetasystox and Dimecron there was no gignificant reduction in plant emergence except Fussol treatment. Dimethoate was highly toxic to the soybean seed viability. However, there was no significant reduction in the soybean germination after 1 day of storage. in Fussol, Metasystox and Dimecron treatments After 25 days of storag in Fussol and Dimethoate treatments, no plant emergence was observed, and there was $13.3\%$ emergence in Metasystox treatment, and $93.0\%$ emergence in Dimecron treatment. Dimethoate treatment in rice seed(variety Suwon # 82) showed $90\%$ mortality at the twentieth day and $33.3\%$ at the thirtieth day after sowing against the green rice leafhopper, Nephotettix cincticeps But no visible effectiveness was observed in Metasystox and Dimecron treatments. Dimethoate treatment in barley seed resulted in low population density of aphids. Rhopalosiphum spp. Final observation on the number of eggs per plant was made at the fiftieth day after sowing; 2 in Dimethoate, 4 in Fussol, 6 in Metasystox, 7 in Dimecron, and 13 in check plots. All the insecticides tested resulted in good insecticidal effectiveness against the aphids, Aulocorthum solani on soybean plant at the ninth day infestation after sowing. Dimethote, Metasystox, and Dimecron treated soybean plants was still effective in controlling the aphids to the eighteenth day infestation.

• The Korean Journal of Pesticide Science
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• v.10 no.2
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• pp.124-130
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• 2006

Rice plant extracts of brown planthopper (BPH) resistant rice varieties, Jangseongbyeo (JSB) and Hwacheongbyeo (HCB) at different growth stages (seedling, tillering, heading and ripening) were sequentially fractioned using hexane, ethyl ether, ethyl acetate, butanol, and distilled water. The extracts were applied to BPH susceptible rice variety, Dongjjnbyeo (DJB), to investigate the insecticidal and repellent effects against BPH. BPH insecticidal effects were not clearly observed with almost all of the extract fractions obtained from both JSB and HCB varieties for 12 h, whereas the ethyl ether and hexane extract fractions showed about 10 to 30% of BPH mortality in 24 to 48 h of application periods. An effective BPH repellent activity was found with the applications of ethyl ether extract fractions obtained from JSB variety. The extract fractions obtained from HCB variety did not show any different repellence among the various fractions. The BPH repellent effects of the extract fractions obtained at different growth stages of either JSB or HCB varieties did not show any correlations. The effect of ethyl ether fraction on BPH repellent was continually increased by 30 h after treatment and thereafter decreased. In addition, the first sub-fraction separated by a flash column chromatography eluted with chloroform:methanol (9:1, v/v) from the BPH effective ethyl ether faction in JSB variety might be meaningful to repel BPH from BPH susceptible target rice plants. The results indicated that the ethyl ether fraction obtained from JSB was higher in repellent activity than in insecticidal activity, and suggesting that there might be specific substance(s) in the first sub-fraction (sF1) of the ethyl ether fraction in JSB that could provide repellent activity against BPH.