• Journal of Sericultural and Entomological Science
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• v.29 no.2
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• pp.31-37
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• 1987

Mulberry leaf sprayed on at the various concentrations of cadmium (Cd) was fed on the just molted fifth instar through the 6th day of the fifth instar and content of cadmium and zinc in the feces, organs and tissues involved were analyzed by spectrophotometer. Along with the effect of those heavy metals on development of the relevant organs and tissues sexwise. 1. The residual content of cadmium on mulberry leaf was about 50% of the total cadmium and the weight of feces disposed from the cadmium fed larvae was less than the control. There was distinctive differences in female-wise disposal of feces between cadmium treatment and control ; cadmium treatment female larvae disposed less feces than female of control. 2. Fourteen percent of the total dry weight of the anterior plus the middle silkgland and of the posterior silkgland in cadmium 100ppm treatment was decreased in female but only 9% of the anterior plus middle silkgland in male was made, showing no decrease the weight of the posterior silkgland in male. 3. Decrease of the dry weight of the silkgland, fat body and hindgut was made in cadmium 100ppm treatment and contrarily the weight of midgut and malphihian tube were increased. The total larval weight of the female and male were decreasd in cadmium 100ppm treatment and the decreasing ratio was higher in famale. 4. There wasa no detection of cadmium in all of the organs and tissues of the control and in those of the cadmium treatment the high residual content was in order of the midgut, hindgut, malphighian tube and head. A slight accumulation of cadmium was shown in fat body and silkgland. 5. Cadmium accumulation in the midgut was higher than in female but in the fat body, malphighian tube, trachea and integument was contrarily high in the female than male. 6. The total zinc content of the larvae was below 60ppm in the control and 80ppm in cadmium 100ppm treantment. The increase of zinc content in cadmium treatment was made on silkgland, malphigian tube and midgut but contrarily the decrease of zinc content in fat body was resulted. 7. In cadmium treatment, much more cadmium accumulation took place in the female and zinc accumulation was made much more in the male.

• Journal of Sericultural and Entomological Science
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• v.25 no.1
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• pp.1-20
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• 1983

It has been known that the insect molting hormone and its analogues exist also in plant kingdom and their concentration has been found to be about 0.1~2.0% of dry matter, which is equivalent to $10^3{\sim}10^5$ times of those in insects. This study was carried out; 1) to isolate the phytoecdysones from Korean Achyranthes radix and characterize their physico-chemical properties. 2) to investigate the biological activity of this phytoecdysone on Bombyx mori larvae. The resuls were summarized as follows; 1. The extraction method of phytoecdysones was optimized by three consecutive reflux for 1hr using 200g of dried and milled radix per 1l methanol. 2. The purification from the crude extract was made by a series of steps such as precipitation of gum-type polymer with n-Butyl acetate, adsorption on technical grade silica and chromatography with neutral alumina. The conditions of each step were optimized and the resulting crude crystal was about 500mg per kg dry radix. 3. The crude crystal from the cultivated Achyranthes(Achyranthes japonia) contained ecdysterone (20-hydroxyecdysone) and inokosterone in the proportion of one to one. In order to separate these, a series of processes such as acetylation, separation by alumina column chromatography deacetylation by alcoholysis, deionization and crystallization were introduced and optimized 125mg of ecdysterone and 18mg of inokosterone per kg dry radix were thus obtained. 4. The wild Achyranthes (Achyranthes obtusifolia) radix was found to contain the ecdysterone only. A 285mg of ecdysterone was crystallized per kg dry radix. 5. Isolated ecdysterone, inodosterone and acetylated compounds were characterized by IR., UV., NMR spectroscopy, mp, TLC and densitometry. 6. Ligation experiment was undertaken to confirm the biological activity of the purified ecdysterone; the ecdysterone could induce larval-pupal metamorphosis in the ligated abdomen of 4th instar larvae injecting 0.5~1.0${\mu}g$. 7. By ecdysterone feeding experiment using artificial diet, it was elucidated that the critical time of feeding would be the first half of each instar resulting in increased weight of silk layer. 8. The ecdysterone was fed to 5th instar silkworm at the level of 1, 2, 3, 5ppm of dry feed of artificial diet containing 5% mulberry leaves for 72hrs. At 2ppm of the concentration. body weight and silk layer weight were arrived at maximum. But at higher concentrations body weight and silk layer weight decreased than the control group. At 2ppm of the concentration, body weight was increased by 12.5%. 9. Feeding 2ppm of ecdysterone at the later half of 5th instar, the duration of larvae was shortened.

• Korean Journal of Veterinary Research
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• v.43 no.2
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• pp.181-188
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• 2003

Cordyceps has a reputation for its broad biological activities and as a tonic which replenishs vital function in Chinese traditional medicines. As an attempt to obtain fundamental data for the development of new type Cordyceps, the effects of the fruiting bodies of cultivated fungus of Paecilomyces japonica grown on silkworm larvae on radiationinduced damages were investigated. We performed this study to determine the effect of Dongchongxiacao (Paecilomyces japonica) on jejunal crypt survival, endogenous spleen colony formation, and apoptosis in jejunal crypt cells and hair follicles of mice irradiated with high and low dose of gamma-radiation. Treatment with Dongchongxiacao showed no significant modifying effects on the jejunal crypt survival and endogenous spleen colony formation. The frequency of radiationinduced apoptosis was reduced by pretreatment of Dongchongxiacao (i.p.: 50 mg/kg of body weight, at 12 and 36 hours before irradiation, p<0.01). The spontaneous levels of apoptotic cells are $0.082{\pm}0.041$ in intestinal crypts and $0.231{\pm}0.084$ per hair follicle section of skin. Pretreatment of Dongchongxiacao was associated with decreases of 26.86% in intestinal crypt and 66.36% in hair follicle decrease in the number of cells with nuclei positively stained for apoptosis compared with the irradiation control group. We demonstrated for the first time that Dongchongxiacao administration could reduce the extent of apoptosis produced by radiation in the hair follicle. The results presented herein that Dongchongxiacao given before irradiation is capable of reducing the severity of cell loss as a result of apoptosis.

• 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.

• Journal of Sericultural and Entomological Science
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• v.15 no.1
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• pp.1-7
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• 1973

his study has been carried out to investigate amylase activity of digestive juice in the 5th day of the 5th instar influenced by the dietary composition (quantitative ratio between carbohydrate and protein) and the rearing temperature during the 4th moulting period. The larvae grew on three kinds of semi-synthetic diets. The A-diet has more carbohydrate than the others, the B-diet has carbohydrate in 1 : 2 with protein, and the C-diet has more protein than the others. All the diets were kept at 16$^{\circ}C$, 25$^{\circ}C$ and 32$^{\circ}C$ during the 4th moulting period. Amylase activity of digestive juice at the 5th day of the 5th instar was analyzed by Fuwa's method. The results were as follows. 1. Both A and C-diets were worse than B-diet in the larval growth and development. 2. The dietary composition influencing amylase activity of digestive juice was not related to the rearing temperature during the 4th moulting period. Amylase activity was stronger in C-diet, B-diet and A-diet order. 3. It was found that amylase activity at 32$^{\circ}C$ was stronger than that at 16$^{\circ}C$ in all kinds of diets. 4. There was an inter-action in amylase activity of male larval digestive juice between the dietary composition and the rearing temperature during 4th the moulting period.

• Journal of Sericultural and Entomological Science
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• v.50 no.2
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• pp.53-62
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• 2012

Silkworm larvae often suffer from viral infections causing heavy losses to the economy of silk industry. Insects exhibit both humoral and cellular immune responses that are effective against various pathohens like bacteria, fungi, protozoa, etc., but no insect immune responses is effective against viral infection. To obtain genes related to insect antiviral immunity from Bombyx mori, the cDNA library was constructed from B. mori nucleopolyhedrovirus (BmNPV)-infected B. mori. From the cDNA library, we selected 411 differentially expressed clones, and the 5' ends of the inserts were sequenced to generate ESTs. In this work, 135 unigenes were generated after the assembly of 411 differentially expressed clones ESTs. Of these 135 unigenes, we selected 109 antiviral response-related candidates except 26 clones that high similarity with genes derived from BmNPV. Among 109 unigenes, a total of 80% had significant matches to genes from other organisms in the database, wheres 20% of the unigenes had not matched in the database. Functional groups of these sequences with matches in database were constructed according to their putative biological function. Three largest categories were control of cellular oraganization (52%), metabolism (20%), and protein fate (10%). The genetic information reported in this study will provide more information about antiviral-related genes in silkworms.

• Animal Bioscience
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• v.35 no.2_spc
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• pp.332-346
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• 2022

Shortage of protein feed resources is the major challenge to the world farm animal industry. Insects are known as an alternative protein source for poultry. A wide range of insects are available for use in poultry diets. Insect larvae thrive in manure, and organic waste, and produce antimicrobial peptides to protect themselves from microbial infections, and additionally these peptides might also be functional in poultry feed. The feed containing antimicrobial peptides can improve the growth performance, nutrient digestibility, intestinal health, and immune function in poultry. Insect meal contains a higher amount of essential amino acids compared to conventional feedstuffs. Black soldier fly, mealworm, housefly, cricket/Grasshopper/Locust (Orthoptera), silkworm, and earthworm are the commonly used insect meals in broiler and laying hen diets. This paper summarizes the nutrient profiles of the insect meals and reviews their efficacy when included in poultry diets. Due to the differences in insect meal products, and breeds of poultry, inconsistent results were noticed among studies. The main challenge for proper utilization, and the promising prospect of insect meal in poultry diet are also addressed in the paper. To fully exploit insect meal as an alternative protein resource, and exert their functional effects, modes of action need to be understood. With the emergence of more accurate and reliable studies, insect meals will undoubtedly play more important role in poultry feed industry.

• Journal of Sericultural and Entomological Science
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• v.26 no.2
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• pp.11-15
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• 1984

To save the labour reguired for separation of copulated moth during egg Production, some of the chemicals available at the market were on screen test for easy separation of copulated moth of silkworm. The obtained results are summarized as following. 1. In a separation ratio of copulated moth along with a treating time, TCTFE(Trichloro-trifluoroethane) completely separated the copulated moth in 10 minutes. The combinations of TCTFE plus Acetone (87.5 : 12.5 V/V) and TCTFE plus Acetic acid (50 : 50 V/V) take 25minutes for the complete separation of copulated moth. Use of Acetic acid solution only makes 100% separation of copulated moth in one hour and foully minutes and non$.$treatment shows only 47.5% of separation in three and half hours. On the other hand. There is no statistical significance between TCTFE Plus Acetone and control in the egg productivity. 2. The combination of TCTFE Plus Acetone (87.5 : 12.5 V/V) does not infuluence the egg productivity of the moth, showing 443 grains for an average number of egg per moth out of which 417 grains are for the number of fertilized eggs while control shows 452 grains for an avarage number of egg/moth and 428 grains for the number of fertilized eggs. However a sing1e use of TCTFE and Acetic acid shows less egg productivity and number of ferilized eggs per moth, respectively as compared to those of the control. In particular, a single use of acetic acid makes an increase of number of non-egg prodncible moth and it seems to be brought due to a chemical damage. 3. In a rearing test of the egg laid by the chemical treated moth, there are no differences among the treatments in all of the useful characters of the larvae; larval duration, survival rate, cocoon yield, single cocoon weight, single cocoon shell weight and cocoon shell ratio. In these regards, it is recognized that TCTFE can be practically used for the separation of copulated moth and the combination of TCTFE and Acetone promote its efiectiveness on the separation of copulated moth.

• Journal of Sericultural and Entomological Science
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• v.23 no.2
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• pp.37-49
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• 1982

Larvae of the silkworm (Bombyx mori L.) were reared during the 5th instar on the four kinds of artificial diets on the basis of the different amounts of soybean meal used as the protein source. In this experiment it was shown that the various levels of protein in the diet affected not only the growth and silk production but the digestibility of the diet. haemolymph protein and uric acid excretion. The results obtained are summarized as follows; 1. By an increase of the level of protein in the diet the apparant digestibility was increased. but the protein digestibility was comparatively decreased. 2. Larval body weight increment was not observed by the 3rd day of the 5th instar, but was increased from the 4th day as the level of protein was increased in the diet. 3. After the 3rd day of the 5th instar, protein content in the hemolymph was increased steeply by an increase of the protein content in the diet. However, the percentage of hemolymph protein to the ingested protein was decreased from the 2nd day of the 5th instar and increased more or less after the 4th day. 4. An increase of the uric acid excretion was observed as the content of protein in the diet was increased but the pattern of the uric acid excretion was different between high and low-protein diet. However, the percentage of the uric acid excretion to the ingested protein and to the hemolymph protein were both decreased steeply after the 2nd day of the 5th instar. 5. It was also evident that the high-protein diet increased the cocoon productivity. 6. It showed that the feed efficiency for body weight increment and silk formation was high by an increase of the level of protein in the diet, but the protein efficiency was not.

• Journal of Sericultural and Entomological Science
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• v.15 no.1
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• pp.9-14
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• 1973

This study has been carried out to investigate proteinase activity of digestive juice and sucrase activity of midgust tissue in the 5th day of the 5th instar influenced by the dietary composition (quantitative ratio between carbohydrate and protein) and tile rearing temperature during the 4th moulting period. The larvae grew on three kinds of semi-synthetic diet. The A-diet has more carbohydrate than the others, the B-diet has carbohydrate in 1 : 2 with protein, and the C-diet has more protein than the others. All the diets were kept at 16$^{\circ}C$, 25$^{\circ}C$ and 33$^{\circ}C$ during the 4th moulting period. Proteinase activity of digestive juice at the 5th day of the 5th instar was analyzed by Anson's hemoglobin method. Sucrase activity of midgut tissue at the 5th day of 5th instar was analyzed by Somogyi-Nelson's method. The results were as follows. 1. The dietary composition influencing contents of blood sugar was not related to the rearing temperature during the 4th moulting period. The contents of blood sugar appeared to increase in A-diet, B-diet and C-diet order, while proteinase and sucrase activity were stronger in C-diet, B-diet and A-diet order. 2. All kinds of diets showed almost the same fact that proteinase activity at 16$^{\circ}C$ was stronger than that at 32$^{\circ}C$. 3. It was found that sucrase activity became gradualy stronger at 32$^{\circ}C$, 25$^{\circ}C$ and 16$^{\circ}C$ in order in all kinds of diets. 4. There was an interaction in proteinase activity between the dietary composition and the rearing temperature in male larval digestive juice during the 4th mouiting period. On the other hand, there was an inter-acion in sucrase activity between the dietary composition and the rearing temperature in both female and male larval midgut tissue during the 4th moulting period.