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

• Journal of Microbiology and Biotechnology
• /
• v.8 no.6
• /
• pp.685-691
• /
• 1998

Baculovirus Hyphantrin. cunea nuclear polyhedrosis virus (HcNPV) insecticide containing the insecticidal protein (ICP) gene from Bacillus thuringiensis subsp. kurstaki HD1 was constructed using a lacZ-HcNPV system. The ICP ($\delta$-endotoxin) gene was placed under the control of the polyhedrin gene promoter of the HcNPV. A polyhedrin-negative virus was derived and named ICP-HcNPV insecticide. Then, the insertion of the ICP gene in the ICP-HcNPV genome was confirmed by Southern hybridization analysis. Polyacrylamide gel electrophoresis (PAGE) analysis of the Spodoptera frugiperda cell extracts infected with the ICP-HcNPV showed that the ICP was expressed in the insect cells as 130 kDa at 5 days post-infection. The ICP produced in the cells was present in aggregates. When extracts from the cells infected with the ICP-HcNPV were fed to 20 Bombyx mori larvae, the following mortality rate was seen; 8 larvae at 1 h, 10 larvae at 3 h, and 20 larvae at 12 h. These data indicate that the B. thuringiensis ICP gene was expressed by the baculovirus insecticide in insect cells and there was a high insecticidal activity. The biological activities of the recombinant virus ICP-HcNPV were assessed in conventional bioassay tests by feeding virus particles and ICP to the insect larvae. The initial baculovirus insecticide ICP-HcNPV was developed in our laboratory and the significance of the genetically engineered virus insecticides is discussed.

• Journal of Microbiology and Biotechnology
• /
• v.17 no.1
• /
• pp.15-20
• /
• 2007

To clone novel cry1-type genes from the Bacillus thuringiensis K1 isolate, about 2.4-kb-long PCR fragments were amplified with two primer sets of ATG1-F/N400-R and 1BeATG1-F/N400-R. Using PCR-RFLP, three novel cry1-type genes, cry1-1, cry1-7, and cry1-44, were obtained from B. thuringiensis K1 and the complete coding sequences of these novel genes were analyzed. The Cry1-1, Cry1-7, and Cry1-44 proteins showed maximum similarities of about 78.0%, 99.7%, and 91.0% with the Cry1Ha1, Cry1Be1, and Cry1Ac2 proteins, respectively. These novel cry1-type genes were expressed using a baculovirus expression vector system and their insecticidal activities were investigated. Whereas all three novel genes were toxic to Plutella xylostella larvae, only Cry1-1 showed insecticidal activity against Spodoptera exigua larvae.

• The Korean Journal of Pesticide Science
• /
• v.12 no.3
• /
• pp.295-301
• /
• 2008

Phenylformamidines are well known as insecticides for their specific activity against the insects. It has now been established that they show insecticidal activity as agonists on the octopamine receptor which is located in the synapse membrane. In this study we tried to test the effect of fluorine substituted aromatic formamidines and 1,3,5-triazapenta-1,4-dienes. Among the compounds, 2h, 2k, 21, 3g, 3h, 3k showed good activity against mite and aphid and 4f and 4g showed high activity against mite.

• Korean Journal of Agricultural Science
• /
• v.11 no.1
• /
• pp.176-181
• /
• 1984

Linear free energy relation ship(LFER) on the insecticidal activity of O,O-diethylphenylphosphate (A) and 3,5-dimethylphenyl-O,O-diethylphosphate (B) derivatives were studied by EHT MO calculation method and regression analysis method. LFER between varying substituent constants and $pI_{50}$ constants of phosphates, (A) & (B) were calculated with applying Hammett, Okamoto-Brown, Taft and Swain-Lupton's DSP equations;percent resonance effect(R) and field effect(F) of (A) were %R=33.5 & %F=66.5 and also that of (B) were %R=2 & %F=98, respectively. On the basis of above findings, the insecticidal activities were similar for both (A) and (B), but (B) have larger field and inductive contribution than (A), due to the 3,5-dimethyl group of (B).

• Applied Biological Chemistry
• /
• v.37 no.2
• /
• pp.110-114
• /
• 1994

In searching for new insecticidal compounds from soil microorganisms, strains of streptomyces species showed insecticidal activities on Musca domestica and Bombyx mori were selected. Compounds I-IV, which were isolated from the metabolites of no. 46 strain, were identified as piericidin $C_1$, $C_2$, $C_3$ and $D_1$, respectively by UV and NMR data analyses.

• Korean Journal of Agricultural Science
• /
• v.35 no.2
• /
• pp.127-136
• /
• 2008

Beauveria bassiana can be used as a biological insecticide to control a number of pests. It has been known as that B. bassiana TBI-1 have a insecticidal effect on the twospotted spider mite (Teranychus urticae) and the greenhouse whitefly (Trialeurodes vaporariorum) these days. The biological pest control agent, B. bassiana, showed somewhat insecticidal activities against the cotton aphid, Aphis gossypii, too. After treatment with biological insecticide, the mean of increasing rate of aphids was at around recorded at around 0.21 while at around 0.24 in non-treated TBI-1 biological insecticide condition during 1 week. Consequently, it was found that treatment of Beauveria bassiana reduced an increasing rate of aphid population. Also, we could visually observe dead aphids changed as a reddish mold due to this insecticidal fungus. B. bassiana TBI-1 can significantly reduce an increasing rate of aphid population, so effective biological control against the cotton aphid are possible.

• Proceedings of the Korean Society of Sericultural Science Conference
• /
• 2005.04a
• /
• pp.47-47
• /
• 2005

• Proceedings of the Korean Society of Applied Pharmacology
• /
• 1998.11a
• /
• pp.163-165
• /
• 1998

The use of synthetic pesticides in crop production, brings the possibility of a nonselective toxicity and accumulation of toxic compounds in the environment. As an alternative, bioactive compounds from actinomycetes can provide a rich source for biodegradable pesticides. A variety of biological activities such as antibacterial, antifungal, herbicidal, insecticidal and anticoccidial are associated with these microbial metabolites. Studies on the production of bioactive compounds from marine-derived actinomycetes have been very few, compared to the terrestrial actinomycetes. With their unique metabolic and physiological capabilities, the marine actinomycetes can be useful producers of novel metabolites.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2018.04a
• /
• pp.17-17
• /
• 2018