• Journal of Sericultural and Entomological Science
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• v.47 no.1
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• pp.12-17
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• 2005

To develop technique for the production of P. tenuipes stromata on a large scale, the infection of P. tenuipes and the growth of stroma were investigated by silkworm (Bombyx mori) variety. Also, studied about biological activites of fruiting body formed on silkworm. Infection rate of the 5th instar larvae of the silkworm with P. tenuipes was the highest in Yangwonjam, followed by Hachojam, Baegokjam and Chilbojam in that order. Also, as the inoculation times was increased, infection rate tended to be raised. The rate of fruiting body formation of the silkworm pupae infected with P. tenuipes was the highest in Baegokjam, followed by Yangwonjam and Chilbojam in the order. But, actually the fruiting body formation of the 5th instar larvae of the silkworm tested was good in Chilbojam, followed by Yangwonjam and Baegokjam in that order in 3 times spraying inoculation. The fruiting bodies of Yangwonjam and Chilbojam infected with P. tenuipes had high amount of Mannitol, but Baegokjam and Hachojam had high concentration of Glucose on a dry weight basis. The mean content of total amino acid in the fruiting bodies of P. tenuipes was 1.03 ${\mu}mole/g$. The distribution rate of amino acid components decreased in the order of Arginine (12.2%)>Glycine (10.5%)> Proline (9.6)>Tyrosine (8.9%)>Serine>Leucine>Threonine. The most abundant amino acid in the fruiting bodies of the Baegokjam, Chilbojam and Hachojam infected with P. tenuipes was arginine, while Yangwonjam was Glycine. The most abundant fatty acid in P.tenuipes was Oleic acid on a dry weight basis. The unsaturated fatty acids such as Oleic acid, Linoleic acid and Linolenic acid accounted for more than 78% of the total fatty acids.

• Journal of Aquaculture
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• v.18 no.3
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• pp.147-153
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• 2005

The objective of this study is to elucidate the growth pattern of dark-banded rockfish, Sebastes inermis Cuvier, produced by aquaculture in Korea. Larvae from 250 maternal full-sibs were reared until 1,350 days after parturition. During the rearing period, growth equations on days after parturition (X) to the total length (TL) and body weight (BW) were estimated as TL=0.0217X $(r^2=0.8867)$ and $BW=0.0001X^2+0.0713X\;(r^2=0.9858)$, respectively. The relationship between BW and TL was $BW=0.0072TL^{3.4373}\;(r^2=0.9945)$. An increases in the eye diameter (ED) of dark-banded rockfish larvae on days after parturition (X) could be expressed as $ED=-2E-5X^2+0.0326X\;(r^2=0.9886)$. Relative growth equations on TL to head length (HL), snout length (SL), ED and postorbital head length (PHL) were calculated as $HL=0.2652TL\;(r^2=0.9758),\;SL=0.0613TL\;(r^2=0.9602),\;ED=0.0752TL\;(r^2=0.9715)$ and $PHL=0.2652TL\;(r^2=0.9501)$, respectively. Since there were few reports on the long-term growth experiment of this species due to difficulties in rearing techniques, results of this study would give a useful information to the biology and commercial culture techniques of dark-banded rockfish.

• Current Research on Agriculture and Life Sciences
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• v.1
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• pp.67-83
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• 1983

The new microsporidia S80 isolated from, Bombyx mori L. in Korea showed ovoid in the morphology of the spores and the size were measured $2.9{\pm}0.28{\mu}$ in length and $1.7{\pm}0.29{\mu}$ width. No other microsporidian spore like this has not been so far isolated from Silkworm. The length of the polar filament extruded in hydrogen peroxide ($H_2O_2$) at $30^{\circ}C$ was $26{\mu}$ of a round cytoplasm on the top. The spores were partly stained with Giemsa, Safranin-O and Gram as the same staining properties as Nosema bombycis, Microsporidia K 79 and other microsporidian spores. The fine structures were observed under scanning eleceron microscope through ultrathin sectioning. The spore wall was composed of three layers ; the thin exospore of an electron dense rippled layer, the thick electron lucent endospore which was thinning considerably at the polar filament insertion point, and the inner limiting membrane. Polar cap present at the sporeapex, with a long polar filament of 12-13 coils, subtending angle of $60^{\circ}$ to spore axis, which is tubular made up of a multilayered and are a benes core, light ring structure enclosing the dance core, the dark ring structure enclosing the inner light ring structure and the other than and light ring structure bounded from cytoplasm. Lamellate polaroplast occupied the anterior part of the spore, and the two neclei with dense nucleoplasm bounded by a double nuclear envelope were cited in the slight downer middle portion of spore. From the characteristics of the shape, size and fine structures, it is certain to reason the Microsporidia S80 belong to the phylum Microspora, class Microspora, order Microsporida, order Microsporida. The shape of two nuclei cited seems to be genus Nosema, but in the classification for the suborder it should be defined wheather pansporoblasts be formed or not and for the genis especial attempts have been made to define the characters which distinguish the disporous genera in the life cycle. Survey through the infection of the bad cocoons during 1980 to 1982 in South Korea the areas contaminated with new microsporidia were revealed 5 provinces of Kyung-Gi, Kang-Won, Chung-Nam and Chun-Nam. Pathological effects inoculated per os at second instar larvae of silkworm, the LD 50 was $7.1{\times}10^7/ml$ as lower pathogenecity than that of Nosema bombycis Naegeli of $1.2{\times}10_7/ml$. While on the other hand the inoculation of the microsporidia at fourth instar larvae lowerd the whole cocoon weight and cocoon shell weight and significant at 1% level. The microsporidia S80 defined it can not be transmitted transovarially from the result of predictive and collective examination of 21 egg batches from the infected female moth.

• Ocean and Polar Research
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• v.27 no.3
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• pp.299-309
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• 2005

The community structure of meiobenthos was studied in the sediment of Kongfjorden, Spitsbergen of Svalbard Island in the Arctic Sea. Samples of meiobenthos were collected in August, 2003. Meiobenthic organisms were collected by SCUBA and van veen grab or acryl sub-corers 34mm in internal diameter, and were taken from upper sediment to a depth of 3cm at each station. A total of 26 meiofaunal groups were found in the sediment of Spitsbergen in Svalbard Island. Nematodes were the most dominant faunal group. Sarcomastigophorans, benthic harpacticoids, and nauplius larvae of crustaceans, were also important components of the meiobenthic community of Kongsfjorden. All of these low faunal groups were comprised of more than 90% of total meiobenthos at every station. The total density of meiobenthos at each station was highest at station MeG 6 $(3,583{\pm}1,137inds./10cm^2)$, and lowest at station $MeG9(28{\pm}1inds./10cm^2)$. Meiobenthos in general showed the highest density in the upper 1cm layer. This may be associated with food and oxygen supply to subsurface. Harpacticoids showed extreme preference at the surface and little presence in layers deeper than 2cm. These animals may be less resistant to oxygen deficiency, and nauplius also showed the same trend. However, in St. MeG 8 and 9, meiobenthos were dense at depths of more than 0-1cm, at especially at depths of 2-3m because of relatively easy penetration of oxygen. Based on the results of cluster analysis, three meiobenthos assemblages were distinguished: one was in the outer and two were in the inner fjord. Station SCU 5 was grouped with the meiobenthos assemblage located in the outer fjord. The outer ford community was characterised by : 1) a relatively low mean number of meiobenthos taxa, 2) a relatively high density of harpacticods and nauplius. One of the inner ford communities (a group of four nation: MeG 2, 3, 8, 9) was in the proximity of the glaciers. Specifically, it was characterised by : 1) a low mean number of meiobenthos taxa, 2) a low density. The other inner ford community was characterised by both a high density and great mean number of meiofaunal taxa.

• Korean journal of applied entomology
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• v.45 no.2 s.143
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• pp.145-152
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• 2006

Predation of Neoseiulus fallacis was observed for biological control of Panonychus citri that is one of the major insect pests on citrus. The daily predation of development stages of P. citri by an adult female of N. fallacis were 20.1 eggs, 26.1 larvae, 18.2 protonymphs, and 7.4 deutonymphs at 25$^{\circ}C$, The daily predation of P. citri eggs by N, fallacis was observed under different temperatures. The predation was increased as the temperature rise. At this time, ratio of eggs production of l! fallacis after predation of P. citri eggs (number of eggs N. fallacis/number of eggs P. citri consumed by N. fallacis) was 0.09. The daily predation of P. citri eggs by N, fallacis was 21.1, 17.3, and 16.7 on the different arenas (diameter: 20, 40, and 60 mm), respectively. The predation was decreased as the arena of the leaf increase. The functional response of M fallacis to P. citri showed Holling's Type II response: the consumption of prey by N. fallacis increased as the density of prey increase but increasing rate was gradually reduced. As the result, it seemed that N. fallacis can be use for biological control of P. citri.

• 보존과학연구
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• s.21
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• pp.5-55
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• 2000

The cultural properties are damaged by various causes according to the characteristics of material, the condition of preservation, and the period of time. Especially, biodeterioration makes lots of damages in organic properties than inorganic ones. The damages of wooden cultural properties by insects usually are caused by the three orders; Isoptera, Coleoptera, and Hymenoptera. As the result of investigation on the state of 141 buildings of wooden cultural properties in 1999, some of them were damaged by many kinds off actors; wasp, powder post beetle, cigarette beetle, termite, decay, and physical cracking. And it was found that the patterns of damages were related to species-specific habits of insects. There are several methods of pest control for the prevention of wooden cultural properties from damages caused by insects. Those are as follows; physical control, chemical control, biological control, and integrated pest management. When insects and fungi were detected at the wooden buildings, the fumigation is best treatment to stop biodeterioration. And then, wood materials also need to be treated with insecticidal and antiseptic chemicals to avoid a reinfestation, because the fumigant is volatile. The six commercial chemicals which are applied to the insecticidal and antiseptic treatment of wooden cultural properties were purchased to test their abilities. According to the comparative results of efficacy of them in laboratory, chemical D showed excellent efficacy in all items, including antiseptic and termiticidal items. The goal of these pest controls is to protect wooden buildings from insects and microorganisms. The most effective method used currently is chemical control(fumigation, insecticidal and anticeptic chemical treatment), but it has to be treated periodically to control pest effectively. Recently environmentally-friendly control methods such as bait system or biological treatments are replacing traditional barrier treatments using large amounts of chemicals. Especially, termite is a social insect which makes a colony. Although a building with fumigation treatment is safe for a while, once attacked building has a risk of damage by reinfestation of termite. Therefore, to control termites from damaged building, the entire colony including reproductives(queen and king) and larvae around buildings must beeliminated. Bait system can be used as a preventive measure in early detection of them through termites colony monitoring and baiting. It would be the most effective for termite control if bait system would be used together with the chemical controls.

• Korean journal of applied entomology
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• v.61 no.4
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• pp.563-575
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• 2022

Maruca vitrata is one of important pests in leguminous crops, especially red bean. We investigated the effects of temperature on development of each life stage, adult longevity and fecundity of M. vitrata for understanding the biological characteristics of the insect species at eight constant temperatures of 13, 16, 19, 22, 25, 28, 31, and 34℃. Eggs hatched successfully at all temperature subjected and larvae successfully developed to the adult stage from 16℃ to 31℃. The developmental period of egg decreased up to 31℃ and after then increased. The developmental period of larva and pupa, and adult longevity of M. vitrata decreased with increasing temperature. Lower and higher threshold temperature (TL and TH) were calculated by the Lobry-Rosso-Flandrois (LRF) and Sharpe-Schoolfield-Ikemoto (SSI) models. The lower developmental threshold (LDT) and thermal constant (K) from egg hatching to adult emergence of M. vitrata were estimated by linear regression as 12.8℃ and 280.8DD, respectively. TL and TH from egg hatching to adult emergence using SSI model were 14.2℃ and 31.9℃. Thermal windows, i.e., the range in temperature between the minimum and maximum rate of development, of M. vitrata was 17.7℃. In addition, we constructed the oviposition models of adult, using the investigated adult traits including survival, longevity, oviposition period and fecundity. Temperature-dependent development models and adult oviposition models will be helpful to understand the population dynamics of M vitrata and to establish the strategy of integrated pest management in legume crops.

• Korean journal of applied entomology
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• v.61 no.4
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• pp.577-590
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• 2022

Ostrinia scapulalis is one of important pests in leguminous crops, especially red bean. In order to understand the biological characteristics of the insect, we investigated the effects of temperature on development of each life stage, adult longevity and fecundity of O. scapulalis at eleven constant temperatures of 7, 10, 13, 16, 19, 22, 25, 28, 31, 34, and 36℃. Eggs and larvae successfully developed next life stage at most temperature subjected except 7, 10 and 13℃. The developmental period of egg, larva and pupa decreased as temperature increased. Lower and higher threshold temperature (TL and TH) were calculated by the Lobry-Rosso-Flandrois (LRF) and Sharpe-Schoolfield-Ikemoto (SSI) models. The lower developmental threshold (LDT) and thermal constant (K) from egg hatching to adult emergence of O. scapulalis were estimated by linear regression as 13.5℃ and 384.5DD, respectively. TL and TH from egg hatching to adult emergence using SSI model were 19.4℃ and 39.8℃. Thermal windows, i.e., the range in temperature between the minimum and maximum rate of development, of O. scapulalis was 20.4℃. Adults produced viable eggs at the temperature range between 16℃ and 34℃, and showed a maximum number, ca. 416 offsprings, at 25℃. Adult models including aging rate, age-specific survival rate, age-specific cumulative oviposition, and temperature-dependent fecundity were constructed, using the temperature-dependent adult traits. Temperature-dependent development models and adult oviposition models will be useful components to understand the population dynamics of O. scapulalis and will be expected using a basic data for establishing the strategy of integrated pest management in leguminous crops.

• The Korean Journal of Soil Zoology
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• v.5 no.2
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• pp.97-100
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• 2000

We report here an improved collecting method of the infective juveniles multiplied in the host insect with the entomopathogenic nematodes, Steinernema carpocapsae Weiser. The specific characteristics of this method involved the opening of the host insect hemocoel after the population of their infective juveniles reached at the maximum (6 days at 25$\^{C}$ after nematode treatment to nonimmunized host insects) to facilitate the escape of the multiplied nematodes. It also used 'Baermann funnel'method to select the infective juveniles effectively. This improved 'Baermann funnel'method was compared with a traditional collecting method, which was characterized with a combination of untreated host insects and 'White trap'collecting method, in both yield and pathogenicity of the collected infective juveniles to the fifth instar larvae of beet armyworm, Spodoptera exigua (H bner). More than 95% of the nematode populations collected by the two methods represented the morphological infective juveniles. To prove the nematodes to be infective juveniles functionally, pathogenicity and infective activity were compared in the nematodes collected by the two methods. They were not different in both pathogenicities and infective activities which were measured by the numbers of nematodes penetrated into the hemocoel of the insect hosts after exposure for the specific times to the same dote of infective juveniles. Significant difference between two collecting methods was found in the total yields of the infective juveniles per host insect About 50,000 infective juveniles per infected fifth instar larva of S. exigua after 6 day incubation at 25$\^{C}$ were collected only for 2 days by the improved 'Baermann funnel'method, while about 20,000 infective juveniles per host were collected for 10 days by the classical 'White trap'method.

• Journal of Sericultural and Entomological Science
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• v.52 no.1
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• pp.39-44
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• 2014

We isolated highly-expressed genes in the posterior silk glands of silkworm on a previously study, which one of these was identified as RNA binding protein-1 homologue (RBP-1) gene. In this study, we investigated gene expressional characteristics of the RBP-1 depending on silkworm development stages and several tissues of the larvae, respectively. Northern blot hybridization analysis showed that the RBP-1 gene was expressed high in larval and pupal periods, and highly expressed than endogenous internal control gene (BmA3) on all tested larval tissues. In addition, we isolated and analyzed a phage DNA having 1,660 bp-long promoter region of the RBP-1 gene from a genomic DNA library. To study the RBP-1 gene promoter activity, RBP-1 (-740/+ 30) was amplified by PCR and subcloned into a pGL3 basic vector to generate pGL-RBP1. A luciferase report vector carrying RBP-1 gene promoter (770 bp) was tested by luciferase assay in Sf9 cells. In the result, the RBP-1 gene promoter was more efficient than constitutive promoter (BmA3) by approximately ten percent.