• The Korean Journal of Pesticide Science
• /
• v.15 no.4
• /
• pp.471-478
• /
• 2011

The ginseng stem fungus gnat, Phytosciara procera, overwintered in old stems and roots of ginseng as a larvae from late September to early May in next year. In the late Spring they become pupa then emerged. Therefore, the first control period has to be set between late May and early June. It is a same period of elimination of ginseng flower stalks. Two or three times pest control might be needed per month for controlling adult of P. procera. Otherwise, the overwintered form as larva in old stem by removal of old stems of ginseng, the population of first generation of P. procera adults could be reduced. However, it seemed that the removal of old stems was not necessarily correlated with the population of P. procera adults in the next generation. Three kinds of environmental-friendly control agents that were mainly contained sophora extract, showed the highly insecticidal activities against larva of P. procera. Among them, one agent containing sophora extract and paraffin oil showed an ovicidal action as well as oviposition repellency.

• Korean journal of applied entomology
• /
• v.45 no.2 s.143
• /
• pp.195-200
• /
• 2006

This study was carried out to clarify the biologies and morphological characteristics of Rhynchaenus sanguinipes. Also some chemicals were tested to screen the effective insecticide for the control of the species. Up to date, Zelkova serrata has been hewn as host plant of Rhynchaenus sanguinipes, which shows serious damage in this country. In the present study, Ulmus pumila was first found as host plant in this study. Body lengths of larvae, pupa and adult were 4.53$\pm$0.30 mm, 3.30$\pm$0.42 mm and 2.96$\pm$0.12 mm, respectively. The overwintered adult of the species emerged on early April to late April, and adult of nekt generation emerged on early May to late May, Pupal periods were 10, 7.2, 5.1 and 4 days on 16, 20, 24 and 28$^{\circ}C$, respectively. The lower developmental threshold temperature was 5.8$^{\circ}C$. Four braconid parasitoids were found as natural enemies, which emerged mainly on late April to early June. Insecticidal activities with treatments of fenitrothion 50% EC, indoxacarb 30% WG, ethofenprox 20% EC and thiacloprid 10% SC was investigated against adult of R. sanguinpes, and they showed >90% mortality.

• Journal of Life Science
• /
• v.27 no.2
• /
• pp.247-266
• /
• 2017

Cordyceps is a traditional Chinese medicinal herb well-known in China, Korea and Japan since B.C. 2,000. The original entomopathogenic fungus, Cordyceps sinensis belonging to the genus Cordyceps could not be found inside Korean peninsula due to the absence of the host insect for the corresponding entomogenous fungus. The development of artificial production methods of Korean type Cordyceps using the silkworm Bombyx mori as in vivo culture medium for the the entomopathogenic fungus Paecilomyces tenuipes is the first, and wonderful occasion in the research history of insect industry of this global world. The aim of this article is to review the historical research background, mass-production methods, and pharmacological effects of the silkworm-dongchunghacho (Paecilomyces tenuipes) which is a newly developed Korean medicinal insect-borne mushroom, and another non-insect-borne medicinal mushroom (Cordyceps militaris and Cordyceps pruinosa). Their biological actions include anti-tumor, immunostimulating, anti-fatigue, anti-stress, anti-oxidant, anti-aging, anti-diabetic, anti-inflammatory, anti-thrombosis, hypolipidaemic and insecticidal effects. The bioactive principles are protein-bound polysaccharides (hexose, hexosamin), cordycepin, D-manitol, acidic polysaccharide etc. Protein-bound polysaccharides and n-butanol fractions were demonstrated to show a significant anti-tumor activities but did not show a cytotoxicities. D-mannitol exhibited a significant prolongation of the life span in tumor bearing mice. Ergosterol did not show an efficient anti-tumor activity, but showed a significant phagocytosis enhancing activity. Anti-tumor activity of silkworm-dongchunghacho might be attributed to immuno-stimulating activities rather than cytotoxic effects [164]. Also this review comprises the breeding of Dongchunghacho varieties, optimization of culture conditions, improvement of learning and memory by Dongchunghacho, application of them as foods and chemical constituents.

• The Korean Journal of Pesticide Science
• /
• v.7 no.1
• /
• pp.38-44
• /
• 2003

In vitro inhibitory activity of 34 insecticides and 31 fungicides to glutathione-S-transferase and esterases extracted from rats was determined. Of tested pesticides, the pesticides with high activity on both detoxifying enzymes were mixed with pesticides that are known to be detoxified by detoxifying enzymes. Glutathione-S-transferase was inhibited by thiodicarb $(I_{50}:1.87\times10^{-4}M)$, thiocyclam $(7.40\times10^{-4}M)$, dithianon $(7.55\times10^{-5}M)$, and tolylfluanide $(8.66\times10^{-5}M)$, while esterases by dichlorvos $(8.95\times10^{-8}M)$, pirimicarb $(2.74\times10^{-6}M)$, pyrazophos $(3.31\times10^{-5}M)$, and benomyl $(4.96\times10^{-5}M)$. After acephate known to be detoxified by glutathione-S-transferase was mixed with glutathione-S-transferase-inhibiting pesticides and phenthoate known to be detoxified by esterases was mixed with esterases-inhibiting pesticides, insecticidal activities of such mixtures were determined against diamondback moth (PlutelLa xylostella L.). Synergistic action was observed in all pesticide combinations. The highest synergistic action was obtained when phenthoate was combined with dichlorvos, showing that co-toxicity coefficients were 1512 and 1877 after 24 and 48 hours of treatment, respectively. Several other combinations of pesticides, such as phenthoate with benomyl, and acephate with dithianon, also showed synergism, showing that their co-toxicity coefficients were about 1,000 and 500, after 24 hours of treatment, respectively. Our results showed that combinations of pesticides inhibited by detoxifying enzymes and ones detoxified by detoxifying enzymes resulted in increased toxicities of pesticides, suggesting that such combinations could be used to develop pesticide mixtures with more broad spectrum and high effectiveness.

• KSBB Journal
• /
• v.20 no.5 s.94
• /
• pp.376-382
• /
• 2005

Avermectin (AVM) $B_{1a}$ produced by Streptomyces avermitilis via polyketide pathway is a secondary metabolite with powerful anthelmintic and insecticidal activities, thus being used as an efficient agent in the field of agriculture and animal health. It has been reported that a precursor for AVM $B_{1a}$ biosynthesis was isoleucine and the biosynthetic pathway of AVM $B_{1a}$ was closely similar to that of fatty acid. Based on understanding of the biosynthetic pathway of AVM $B_{1a}$, we intended to screen various mutants resistant against O-methyl threonine (OMT), an isoleucine-anti metabolite, and/or mutants resistant against p-fluoro phenoxy acetic acid (pFAC), an inhibitor of fatty acid biosynthesis. It was inferred that these mutants could produce AVM $B_{1a}$ more efficiently, due to the acquired capability of not only overproducing isoleucine intracellularly but also channelling metabolized carbon-sources into the polyketide pathway, thus leading to enhanced biosynthesis of AVM $B_{1a}$. The resulting mutant (PFA-1 strain) resistant against 100 ppm of pFAC was able to produce approximately 42 fold higher amount of AVM $B_{1a}$ compared to the parallel mother strain (4,200 vs. 100 units/l). In addition, through the process of continuous strain improvement program carried out by gradually increasing the OMT concentration, it was possible to obtain a more attractive mutant with greater AVM $B_{1a}$ production capacity (9,000 units/l). Notable was that significantly higher producer (12,000 units/l) could be selected through further screening of the resistant mutants, this time, to even higher concentration of PFAC. Meanwhile, through the analysis of AVM Bla production histograms (i.e., number of strains according to their AVM $B_{1a}$ biosynthetic ability) for the earlier strains in comparison with the high producers having the characteristics of resistance to OMT and pFAC, it was found that production stability of the high-yielding producers were remarkably improved, as demonstrated by the fact that larger proportion of the mutated strains had greater capability of AVM $B_{1a}$ biosynthesis ($71\%$ in the range between 5,000 and 7,000 units/L; $47\%$ in the range between 6,000 and 7,000 units/l). Based on these consequences, it was concluded that the rational screening strategy based on the understanding of the biosynthetic pathway of AVM $B_{1a}$ was very effective in obtaining high-yielding mutants with the features of enhanced production stability.

• The Korean Journal of Mycology
• /
• v.34 no.1
• /
• pp.7-14
• /
• 2006

Entomopathogenic fungus Cordyceps militaris is famous for its medicinal efficacies. It has been reported to have various pharmacological activities such as anti-tumour, insecticidal, antibacterial, immunomodulatory and antioxidant. In this study, we investigated the effect of the extract of C. militaris (MPUN8501), which was identified by the analysis of the nucleotide sequences of 5.8S ribosomal RNA, on the function of liver. C. militaris powder was extracted using hot water extracts method as time, volume and temperature and using method as differential polarity of organic solvent. Each fraction was tested for the improvement of hepatic enzyme alcohol dehydrogenase (ADH) and acetaldehyde dehydrogenase (ALDH) activity. The BuOH extracts (CME) had highest activity which was used for the test of toxicity and efficacy of C. militaris. The enhancing effect of CME on the activity of ADH and ALDH was much more than medicine, drink, natural tea etc. Thus CME promoted the resolution of alcohol and acetaldehyde in rats, inducing recovery to normal condition rapidly. Furthermore, oral administration of CME effectively protected the carbon tetrachloride-induced acute hepatic injury as revealed by the hematological parameters (levels of sGOT and sGPT) and histological observation. CME was ascertained to be safe by regulatory toxicity studies of single dose toxicity and genotoxicity. These results suggest that CME would be useful for the maintaining normal hepatic activity as a functional health food.

• Journal of Life Science
• /
• v.32 no.1
• /
• pp.1-10
• /
• 2022

Natural products have gained increasing attention due to their advantage of long-term safety and low toxicity for a very long time. Torreya nucifera is widespread in southern Korea and Jeju Island and its seeds are commonly used as edible food. Oriental ingredients have often been reported for their insecticidal, antioxidant and antibacterial properties, but there have not yet been any studies on their antidiabetic effect. In this study, we investigated several biological activities of T. nucifera pericarp (TNP) and seeds (TNS) extracts and proceeded to characterize the antidiabetic compounds of TNS. The initial results suggested that TNS extract at 15 and 10 ㎍/ml concentration has inhibitory effects on α-glucosidase and protein tyrosine phosphatase 1B, that is 14.5 and 4.35 times higher than TNP, respectively. Thus, the stronger antidiabetic TNS was selected for the subsequent experiments to characterize its active compounds. Ultrafiltration was used to determine the apparent molecular weight of the active compounds, showing 300 kDa or more. Finally the mixture was then partially purified using Diaion HP-20 column chromatography by eluting with 50~100% methanol. Therefore we concluded that the active compounds of TNS have potential as therapeutic agents in functional food or supplemental treatment to improve diabetic diseases.