• Korean journal of applied entomology
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• v.42 no.4
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• pp.353-360
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• 2003

Immunodepression can be required for entomopathogenic bacteria to induce their potent pathogenicities to the target insects. Here, we raise a hypothesis that the capacity of a pathogenic bacterium to induce the target insect immunodepression has positive relationship with the degree of pathogenicity. X. nematophilus had 1,200 times as potent as another entomopathogenic bacterium, Staphylococcus gallinarum against the fifth instar larvae of silkworm, Bombyx mori, when they were Injected into the hemocoel. Although both bacteria had significant cytotokic effect on the hemocytes of B. mori, X. nematophilus gave faster and greater cytotoxicity than did S. gallinarum. In cellular immune reactions, B. mori could form 20 hemocyte nodules against the bacterial injection with 5${\times}$10$\^$5/ cells. The number of the hemocyte nodules was significantly depressed when live X. nematophilus was inject-ed, but not in S. gallinarum. Activation of prophenoloxidase (proPO) was depressed in the bacterial injection. The depression of PO activation was significantly greater in X. nematophilus infection than in S. gallinarum injection. Lysozyme activity was induced by the injection of S. gallinarum at 4 h after the treatment, but not induced in X. nematophilus at all the time. These results showed that X. nemato-philus induced greater immunodepression against B. mori and resulted in higher pathogenicity than did S. gallinarum. Therefore, this study suggests that the immunodepression induced by entomopathogenic bacteria has positive relationship with their pathogenicity.

• Korean journal of applied entomology
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• v.47 no.1
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• pp.51-57
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• 2008

This study demonstrates a variability in efficacy of mating disruption against the oriental fruit moth, Grapholita molesta, populations infesting apples cultivated in differential environmental conditions. Throughout the growing seasons, trap catches of G. molesta male moths and damaged leaf and fruit were examined to evaluate the efficacy of a commercialized mating disruptor. Treatment of the mating disruptor significantly reduced the trap catches of male moth in treated plot, compared to those of the untreated plot. This reduced trap catches were significantly correlated with leaf and fruit damage. Moreover, the highest host damage occurred in June just after the highest overwintering adult peaks in both plots. The treatment of mating disruptors in Chungsong effectively disrupted the overwintering population in April and May, resulting in no noticeable host damage during the following growing seasons. However, there was a marked difference in host damage between two plots, especially in late seasons. Variation in the efficacy of mating disruption technology in terms of host damage appeared to be related with nearby pheromone-untreated orchards, which may result in the immigration of gravid females.

• Korean journal of applied entomology
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• v.47 no.1
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• pp.37-44
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• 2008

Oriental fruit moth, Grapholita molesta, is a serious pest on apples. To control this pest in an environmentally friendly method, mating disruption strategy using sex pheromone has been developed. Area-wide application of mating disruption has been needed to be effective, with little understanding on how much size of apple cultivating area should be treated in one time application of the mating disruption technique. On this matter, we needed to determine a minimal mating active zone of G. molesta that should be applied with mating disrupters to be effective. Molecular markers to discriminate a specific population should be developed to trace population migration for reproductive behaviors. Here we developed two effective molecular markers using random amplified polymorphic DNA (RAPD) technique. Different field populations of G. molesta, based on locations and seasons, were analyzed with these markers. In a specific location, G. molesta populations varied in genetic composition with different seasons. Different local populations showed differential variation according to their relative distances among apple orchards. In overall, genetic variation among different populations became lessen with progression of seasons.

• Korean journal of applied entomology
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• v.59 no.1
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• pp.41-54
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• 2020

Two mosquito species were collected in still-water near farming area in Andong, Korea. Based on morphological characters, these two mosquitoes were identified as Aedes koreicus and Culex vagans, respectively. DNA barcode analyses supported the identification. An entomopathogenic bacterium, Bacillus thuringiensis subsp. israelensis (BtI), exhibited insecticidal activities against the two mosquito species and its virulence was more potent than that of B. thuringiensis subsp. kurstaki. It has been known that the bacterial metabolites of Xenorhabdus spp. suppress insect immunity and enhance pathogenicity of B. thuringiensis. This study tested the effect of the bacterial culture broth of Xenorhabdus spp. on enhancing BtI pathogenicity. Among three Xenorhabdus spp., culture broth of X. ehlersii (Xe) was relatively effective to enhance BtI pathogenicity against both mosquito species. Indeed, organic extracts of Xe culture broth suppressed the hemocyte-spreading behavior, suggesting the presence of immunosuppressant in the culture broth. These results suggest a formulation of BtPlus by mixing BtI spore and Xe culture broth to be applied to control the two mosquito species.

• Journal of Mushroom
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• v.9 no.1
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• pp.17-21
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• 2011

Dahyang, a CNARES's newly bred cultivar, is a CM061202 strain isolated and selected from 161 single-spores of brown button mushroom. It was selected as a new cultivar after comparison of yield, mycelial growth and quality with No. 705. Mycelial growth of Dahyang on compost extract mushroom complete medium at $25^{\circ}C$ for 15 days was 63mm when it was compared with that of No. 705 with 38mm. The cultivation temperature of Dahyang was 15 to $19^{\circ}C$ which was $2^{\circ}C$ higher than that of No. 705 with 15 to $19^{\circ}C$ cultivated on rice straw bed. The color of pileus of Dahyang was brown. Pinhead producing period was 30 days which is 1 day late than that of No. 705 with 29 days. Dahyang yielded 37% more with $49.1kg/3.3m^2$ than that of No. 705 with $35.8kg/3.3m^2$, respectively. The weight was 16.0g which was heavier than 14.0g of No. 705. The thickness and diameter were also more than those of No. 705. The stipe was shorter and thicker than that of No. 705. Also physical characteristics such as hardness and elasticity were better than that of No. 705.

• Journal of Life Science
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• v.8 no.5
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• pp.532-536
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• 1998

This study was designed to observe the effects of the feeding Gentiana scabra Bunge var.buergeri Max. extract on the improvement of the blood glucose, lipids in the serum of dietary hyperlipidemic rats (S.D. strain, ♂) fed the experimental diets for 4 weeks. Concentration of blood glucose was significantly higher in the cholesterol administration groups (group 2(cholesterol+water), 3(cholesterol+Gentiana scabra Bunge extract) than those in the control group(group 1 (water)). Blood glucose concentration was rather lower in the group 3(cholesterol+Gentiana scabra Bunge extract) than in the group 2(cholesterol+water). There was almost little significance among the groups. Concentration of total cholesterol in serum was significantly lower in the group 3 than those in the group 2. Concentration of LDL-cholesterol in serum was significantly lower in the group 3 than that in the group 2. In the ratio of HDL-cholesterol concentration to total cholesterol concentration, Gentiana scabra Bunge extract administration group was higher percentage than in the group 2. Concentration of free cholesterol and cholesteryl ester in serum was significantly lower in the group 3 than in the group 2. Concentrations of triglyceride and phospholipid in serum were decreased in the group 3 than in the high fat diet group. The activities of aspartate aminotransferase and alanine aminotransferase in serum were increased in the all experimental groups than in the control group. From the above research, the Gentiana scabra Bunge var.buergeri Max. exacts were effective on the improvement of the lipid composition in serum of dietary hyperlipidemic rats.

• Journal of Life Science
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• v.19 no.10
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• pp.1463-1467
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• 2009

Telomeres, comprised of tandem repeats of TTAGGG sequences, are special nucleoprotein structures that protect and stabilize chromosome ends. These structures form the crux of the telomere concept of aging, senescence and genomic instability. The classic terminal restriction fragment (TRF) analysis to quantify the amount of telomeric DNA is disadvantageous in species containing ultra long telomeres like in mice (100Kb). In this study, we used a more sensitive quantitative fluorescence in situ hybridization (Q FISH) technique to quantify telomeric DNA, and used it as a biological aging marker in mice. 12 litters each of Senescence-Resistant (SAMR1) and -Prone (SAMP1) known as senescence accelerated mouse strains were purchased from Central Lab, Animal Inc. We quantified the amount of telomeric DNA using telomere specific DNA probes on the two strains of male mice at 8 weeks, 18 weeks and 26 weeks of age. The amount of telomeric DNA correlated with aging and age associated changes in body and organ weight between SAMR1 and SAMP1 strains of mice. These data suggest the usefulness of the amount of telomeric DNA as a biological aging marker in human aging studies.

• Journal of Life Science
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• v.19 no.10
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• pp.1432-1437
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• 2009

The aim of this study is to investigate cane molasses pretreatments for the production of cellulose by Acetobacter sp. V6, which has excellent bacterial cellulose (BC) producing capacity in the shaking culture. Among pretreatments of cane molasses, 1% (w/v) tricalcium phosphate (TP) treatment was more efficient in BC production. The physico-chemical properties of BCs that were produced in static and shaking cultures were also investigated. Although BC had an emulsifying ability, its emulsion stability was low. Water holding capacity (WHC) of BC was high; the WHC of BC produced in static culture was 14 times higher than that of $\alpha$-cellulose. In addition, the viscosity of BC was higher than that of $\alpha$-cellulose. Composition analysis by FT-IR showed no difference in composition between BC and plant cellulose. In the crystallinity analysis by XRD, all BC samples showed crystallinity. All BC samples showed reticulated structures consisting of ultrafine cellulose fibriles. Microfibriles of cellulose from static culture were especially more compact than those of cellulose from shaking culture.

• Korean journal of applied entomology
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• v.38 no.1
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• pp.53-57
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• 1999

Simple diagnostic kits for monitoring insecticide susceptibility of beet armyworm, Spodoptera exigua (Hiibner) were developed and applied to the field populations. The operation of the kits was based on the correlations between enzyme activities of esterase (EST) and acetylcholinesterase (AChE) and the insecticide susceptibilities. Four different kinds of diagnostic kits (ED, EM, AD, and AM) were designed and classified by diagnostic enzymes (E for esterases and A for acetylcholinesterase) and inhibitors (D for dichlorvos and M for monocrotophos). Diagnostic inhibitor concentrations were 1 mM for ED, 10 mM for EM, 100 mM for AD, and 100 mM for AM. Resistant larvae which were not inhibited by the diagnostic amounts of insecticides developed positive staining (red color), but susceptible~ s howed negative (no color). An insect was used for both EST and AChE diagnostic kits, but different in their samples: hemolymph for EST and the head for AChE. These four diagnostic kits were applied to 1 1 different populations which showed variations of insecticide susceptibilities. Four kits were different in the capability discriminating the insecticide susceptibilites according to insecticides: ED to bifenthrin, AD to methomyl, and ED and AM to chlorpyrifos-methyl. These diagnostic devices can be used for insecticide-resistance management program for this insect pest. It also provide a technical guide to insect pest management for farmers, directors, and researchers.

• Korean journal of applied entomology
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• v.45 no.3 s.144
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• pp.375-380
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• 2006

A solitary endoparasitoid, Cotesia plutellae, parasitizes diamondback moth, Plutellae xylostella. It has been suggested that its antennae are a major sensory organ to search host and recognize host developmental and other physiological condition during parasitization. This research was performed to understand the parasitic behavior of C. plutellae by analyzing sensory types and their numbers on the antennae using scanning electron microscope. There was no significant difference in antennal length in both male and female C. plutellae, in which both sexes had 16 flagellomeres. Three different types of sensilla (trichoid, seta, and placodea sensilla) were located mostly on flagella and analyzed in their density on the different antennomeres. Trichoid sensillum was the major sensory type and showed about 87% density among all sensilla. Both trichoid and placodea types of sensilla exhibited even numbers on all flagellomeres with some decrease at terminal segments. In contrast, seta form of sensilla showed drastic increase in its density at distal part after 9th flagellomere. When distal half of flagellomeres were cut off, the C. plutellae could not parasitize host larvae. Even when only four distal flagellomeres were removed, the parasitism showed only 30%. These results indicate that C. plutellae antennae are required for parasitism and suggest that seta form of sensilla may play significant roles in recognizing host for parasitization.