• Journal of Sericultural and Entomological Science
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• v.23 no.2
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• pp.11-36
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• 1982

Forty-nine plant species as additives to silkworm artificial diet and 5 species as cellulose sources for artificial diet were screened for their economic values as feed-resources for the silkworm. Feeding response to artificial diet was tested on 82 silkworm strains. The effect of rearing conditions on feeding response and enzyme activities in the silkworm was investigated. The results were summarized as follows. 1. Seven species out of 49, Vigna sinensis ENDL, Ipomoea vatatas Lamarck, Cyperus anuricus Var. Laxus, Alnus japonica Stendel, Trifolium repens L, Prunus serrulata Lindley. Var, Glycine max L increased feeding response, compared with the basic formula of artificial diet. 2. The economic values of Vigna sinensis ENDL, Ipomoea vatatas Lamarck, Cyperus anuricus Var. Laxus, Ainus japonica Stendel, Cassia tera L, Erigeron canedensis L as feed-resources for artificiale diet were recognized, through feeding experiment during the entire larval stage. 3. Mulberry cellulose showed the best results in rearing and cocoon characteristics. 4. The extent of feeding response varied according to strains and varieties. Varieties in japanese strains showed higher feeding response than those in chinese and european varieties, with considerable variations among a varieties in strains. 5. The begining of 4th instar seems to be a proper time to convert from mulberry to artificial diet, or artificial diet to mulberry, however the middle of 3rd instar seems acceptable. 6. The optimum temperature for artificial diet rearing is 30$^{\circ}C$ during the period of 1st-3rd instar and 28$^{\circ}C$ for 4th-5th instar. 7. Electrophoretic isozyme patterns of esterase and acid phosphatase on agarose gel, as affected by strain. rearing temperature and feed-resources, were observed as follow. (1) Isozyme patterns of mid-gut esterase varied, depending on instar. One or two more isozyme bands were observed in the larvae than feed on the mulberry fed for the artificial diet. (2) A strain, chinese-15 with a higher feeding response, had 1∼2 more bands than chinese-60 with a lower feeding response. (3) Five bands of mid-gut esterase in 3rd and 4th instar larvae reared at 28$^{\circ}C$. and 4 for 3rd instar and 6∼7 for 4th instar larvae at 35$^{\circ}C$ were observed. (4) No similar esterase bands could be found among mid-gut, blood and silkgland. There are five esterase bands in the midgut, one in blood and three in silkgland. (5) There was rather small digerence in acid phosphatase types of mid-gut and blood according to varieties and rearing temperature. No active band was shown in silkgland. In midgut, there was one acid phosphatase band at 3rd instar, two at 4th instar and three at 5th instar. In blood, one active band at 3rd or 4th instar and three bands at 5th inster wire detected.

• Journal of Sericultural and Entomological Science
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• v.28 no.1
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• pp.15-23
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• 1986

This study has been carried out to acquire some basic informations on the digestive fluid of Silkworm, Bombyx mori for developing artficial diets. Silkworms reared on mulberry leaves and artificial diet, were used in this experiments. The results obtained are as follows ; 1. The Red Fluorescent protein was precipitated in 50% acetone solution and did not dissolved in n-butanol solution, but dissolved in methanol solution. 2. Electrophoretic analysis results of mulberry leaves rearing B. mori and artificial diet rearing B. mori, which has been treated with 50% acetone solution were as follows. i) There was distinct difference at the position of high mobility ii) Red Fluorescence was observed only at the position of first band of mulberry leaves rearing B. mori. iii) No different was shown in the electrophoretic patterns of mulberry leaves rearing B. mori on 5th instar 1st-3rd day, but some difference on 5th instar 4th, 5th day. 3. The RFP is the basic protein which has PI 8-9 according to the isoelectric electrophhoresis. 4. The SDS-polyacrylamide gel electrophoresis analysis showed that the molecular weight of RFP was 27,000. 5. The Sephadex G-75 chromatographic analysis showed that there was three peaks between number 16 and 28 in the mulberry leaves rearing B. mori chromatogram, but two peaks between number 18 and 31 in the artifical diet rearing B. mori chromatogram.

• Journal of Sericultural and Entomological Science
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• v.23 no.1
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• pp.32-37
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• 1981

It is necessary to improve new silkworm variety suitable for the artificial diet different from the mulberry leaves in physical and chemical natures. The silkworms fed on artificial diet show low productivity in general. So the effectiveness of selection for cocoon characters was studied when the silkworms were reared on the artificial diet for several generations. The results obtained are as fellows: 1. There is no correlation between the cocoon shell weight and the cocoon shell percentage in female cocoons of both Sa and Y strains but in male cocoons. 2. No correlation exists between the weight of a cocoon and a cocoon shell percentage of male cocoons in Sa strain. 3. There is a specific effect of the artificial diet on selection between Japanese and Chinese strains compared with the mulberry leave rearing. 4. The cocoon quality of first generation in artificial diet rearing was very inferier to that of previous generation in mulberry leave rearing in both Sa and Y strains, but the effect of selection rapidly increased in first and second generation.5. Very high mortality was noted in 4th generation to the degree of hardness for successive generation. 6. From 6th generation to 10th generation, the effectiveness of selection for cocoon characters increased continuously except the cocoon shell percteage.

• Journal of Sericultural and Entomological Science
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• v.44 no.1
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• pp.22-27
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• 2002

The Yongcheonppong was cultured in the form of a dense mulberry field coverd with polyethylene film and was tested in Suwon and Chunchon. The agronomic characteristic and some consideration on the result of the silkworm rearing were as follows. The Yongcheonppong was the medium budding variety and was longer in length of young shoots than the Kaeryangppong. The Yongcheonppong was higher in leaf yield in spring than the Kaeryangppong and was lower in leaf yield in autumn than the Kaeryangppong to the contrary. The Yongcheonppong was a little higher in the number of branches and was longer in the length of the branch than the Kaeryangppong and so was appropriate for rearing with mulberry shoots. Yongcheonppong was more resistant to twig blight and die-back and was a little susceptible to dwarf disease. As the Yongcheonppong was most resistant to the freezing injury, it was appropriate for the cold region and enabled the farmers to rear some amount of silkworms every year. In Chunchon, The Yongcheonppong increased by 11% in cocoon yield than the Kaeryangppong when the freezing injury occurred 1 year out of 2 years and produced about the same as the Kaeryangppong in cocoon yield when the freezing injury occurred 1 year out of 3 years.

• Journal of Sericultural and Entomological Science
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• v.46 no.1
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• pp.18-22
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• 2004

For the purpose of accumulating the research outcomes on Cordyceps and retrieving them efficiently, this study was carried out to identify and standardize the key factors in cultivating Paecilomyces tenuipes and classifying characteristics of Cordyceps. The key factors in cultivating Paecilomyces tenuipes are divided into three major sections according to its stage: silkworm rearing period, cultivation period, and preservation period. Silkworm rearing and cultivation sections are divided into three sub-sections: temperature, humidity, and duration. There are other factors including rearing tools, equipment etc. The key factors in classifying characteristics of Cordyceps are divided into 14 items, 41 divisions on the basis of its general features and its taxonomic features. 14 items contain general article, host, perithecium, conidia, etc. 41 divisions are partitioned by its size and color. The classification system of Kobayasi (1940) or of Shimizu (1994) was adopted for the key factors of Cordyceps species and their anarmorphs.

• Journal of Sericultural and Entomological Science
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• v.35 no.1
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• pp.11-16
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• 1993

Field experiment and silkworm rearing were conducted for 4years in an attempt to reduce phosphorus fertilizer in mulberry field with high levels of phosphate. Experiments consisted of four treatments; normal recommended P application(13kg P2O5/10a), half, null and no fertilizer on each of 3 mulberry fields, two fields with 300ppm and one filed begining with 450ppm of aviable P2O5 content in soil. One of 300ppm fields was used for leaf quantity and one for leaf quality test by silkworm rearing. Leaf yield in the 300ppm field decreased after the 3rd spring in the no phosphorus treatment and in the 4th fall in the half phosphorus treatment. No yield decrease occurred in 450ppm field for 4 years. Yield decrease did occur in the next rearing season after soil phosphate content in the 10~20cm zone dropped below 150ppm. Phosphorus fertilizer should be applied at this time. Though P2O5 concentration in leaves of no phosphorus treatment was 0.18% lower that that of conventional treatment, there were no difference in cocoon quality.

• Korean Journal of Microbiology
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• v.8 no.1
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• pp.21-34
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• 1970

This experiment was undertaken to examine the injurious environment conditions for occuring of the virus disease, grasserie and cytoplasmic polyhedrosis in rearing of silk worms, to observe of cytoplsamic polyhedrosis diseased silkworms with histological preparation and to define the virus origin on the gattine and the disease of shrinked form after moulting (Okichijimi). The results obtained are as follows. 1) The grasserie in spring season rearing was remarkably infected in highly percent with 20.1 % in high temperature condition during 3rd to 4th instar, the high temperature during 1st to 2nd instar and 5th instar in 16.5% and 16.3%, respectively. In the fall season rearing, the disease was infected by the feeding of soft leaves plot in 5.3% and 4.8%, respectively with significant difference in 5% level, accordingly, it was thought to the nutritional condition is a factor in occuring of the disease. 2) In spring season rearing, the number ofl infected silk worms of cytoplasmic polyhedrosis was increased in the high temperautre and high humidity conditions, and in fall season rearing, order of the low temperature and high humidity plot, first feeding plot and feeded with hard leaves plot were found insome high infected ratio of the disease than control plot. 3) The occuring of cytoplasmic polyhedrosis was observed even in control rearing plot with the examining of anatomical and histological preparation in spring and fall. 4) It was found that the high diseased ratio of the gattine and disease of shrinked form after moulting in 21.8% of control and 93.2% in feeded with inocylated plot in the biosassay of inoculum. It was defined as a virus flacherie acoording to the Danaka and Shimizu's examine method.

• Journal of Sericultural and Entomological Science
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• v.13 no.2
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• pp.109-117
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• 1971

Today most of farmers rear the silkworms two time a year, spring and autumn (Fig. 1). But from now on, we can rear whenever mulberry tree is grown, and it is expected that we can rear many times (Fig.2). Because the silkworm eggs can not always be hatched, we have to study a special method for rearing many times a year. The writer, in these problems, hatched the silkworm eggs from the beginning of June to the beingning of September, once every 10 days, and reard 10 times. The results are as follows; 1) The silkworm eggs for the beginning and middle of June have no difference between the double cooling method and the single cooling method. But the eggs for the end of June in the double cooling method is better. 2) For the silkworm eggs for the middle of July, the cooling method after acid treatment for eggs is better. 3) For the silkworm eggs for the end of July, the reeling method after acid treatment is better. But it is needed to study the short artificial treatment. 4) For the eggs for the beginning of August, the further study of the short artificial treatment is also needed. 5) For the eggs for the middle of August, after cooling treatment is better. The short artificial treatment is possible for them. But further study is needed. 6) For the eggs for the beginning of September, after cooling treatment is needed for further study.

• Journal of Sericultural and Entomological Science
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• v.48 no.1
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• pp.16-20
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• 2006

To shorten the labor cost for the production of the fungus, Paecilomyces tenuipies, uncocooning mutant hybrid silkworms as a host was used. The yield of P. tenuipies was reduced when Nd (uncocooning mutant) was used as a host because Nd was smaller than the hybrid Baegokjam that has been used as a typical host. To increase the host weight, Nd was crossed with Jam l23 or Jam 124, and resulted in not only greater weighter but also higher yield of P. tenuipies. The optimum temperature for rearing Nd hybrid silkworms was $3^{\circ}C$ higher than standard temperature of rearing silkworms to increase the naked pupation rate. The optimum time for the infection of P. tenuipies was 12 h at $28.5^{\circ}C$ and 95% R.H., when $1{\times}10^7spores/ml$ of P. tenuipies were sprayed on the surface of the silkworm. The conditions were applicable to both spring-rearing and autumn-rearing.

• International Journal of Industrial Entomology and Biomaterials
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• v.2 no.1
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• pp.69-74
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• 2001

The effect of topical application with androstenedione on economic parameters was analyzed following treatment of last larval stadium. The treated larvae showed significantly increased larval weight along with other enhanced larval, cocoon and adult parameters. The larval period was significantly shortened in all the treated groups with increased cocooning percentages cocoon weight and its shell weight in female and filament length, weight and denier in all the treated groups. Hatching percentage increased significantly in dose dependent manner in all the treated groups when compared with the corresponding parameters of the carrier control group. This suggests that androstenedione can be used effectively for commercial silkworm rearing.