• Journal of Sericultural and Entomological Science
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• v.14 no.2
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• pp.113-123
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• 1972

The authors studied on the effect of silkworm eggs collected from the whole silkworm egg producers in Korea to know the cocoon crops, and the results are as follows. There was no remarkable correlation on the effect of silkworm eggs quality for the cocoon crops but can be concluded as follows. 1) There was a weak correlation between the hatching ratio and economical hatching ratio but no correlation between economical hatching ratio and cocoon crops. In other word, hatching ratio couldn't be influenced for the silkworm health. 5) Non-hybrid ratio (miss-crossing ratio) influenced to the amount of reelable cocoons and pupation ratio but on this experiment, there was a little influence for the cocoon crops. The authors found that there is no difference between origin and its F$_1$crops under the more suitable conditions. Non-hybrid ratio can be determined the silkworm eggs quality, but notice that the ratio decrease only when used pure origin. 3) There is some correlation between harvesting amounts of reelable cocoon and pupation ratio. In general, the eggs which harvest small amounts of reelable cocoon are lower on the pupation ratio. 4) The influence of cocoon layer ratio is based on the variety absolutely but cocoon crops also has a little influence on the cocoon layer ratio.

• International Journal of Industrial Entomology and Biomaterials
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• v.34 no.1
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• pp.11-15
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• 2017

We constructed the fibroin H-chain expression system to produce enhanced cyan fluorescent proteins (ECFP) in transgenic silkworm cocoon. Fluorescent cocoon could be made by fusing ECFP cDNA to the heavy chain gene and injecting it into a silkworm. The ECFP fusion protein, each with N- and C-terminal sequences of the fibroin H-chain, was designed to be secreted into the lumen of the posterior silk glands. The expression of the ECFP/H-chain fusion gene was regulated by the fibroin H-chain promoter. The use of the 3xP3-driven EGFP cDNA as a marker allowed us to rapidly distinguish transgenic silkworms. The EGFP fluorescence became visible in the ocelli and in the central and peripheral nervous system on the seventh day of embryonic development. A mixture of the donor and helper vector was micro-injected into 1,020 Kumokjam, bivoltin silkworm eggs. We obtained 6 broods. The cocoon was displayed strong blue fluorescence, proving that the fusion protein was present in the cocoon. Accordingly, we suggest that the ECFP fluorescence silk will enable the production of novel biomaterial based on the transgenic silk.

• Journal of Sericultural and Entomological Science
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• v.37 no.2
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• pp.235-243
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• 1995

Recently, the cocoon production is reducing very steeply in Japan. The main reason for this cocoon reduction is due to high labor cost and the production expense is apt to rise year by year. Accordingly, the improvement of cocoon productivity by retrenchment of the production expense is intensively required in my country. Therefore, the silkworm rearing on the artificial diet is largely expected as the innovation techniques of sericulture. Since rearing of the silkworm on artificial diets has first been achieved in 1960, and the silkworm larvae were reared throughout all the instars on artificial diets(Fukuda et al., 1960, Ito & Tanaka, 1960). The artificial diets used at this time contained 50% or more of dried, pulverized mulberyy leaves as one of the main ingredients, and the composition was rather simple. When reared on these diets, larval growth and development were retarded, small cocoons appeared, and the adults laid only a small number of eggs. At first, we would like to study about nutritional requirement of the silkworm, using the chemically defined diet which prepared artificially. Subsequently, attempts were made to improve the diets by replacement of crude ingredients with possibly purer compounds, as mentioned later. Before giving the details on individual nutrient, I would like to summarize about the outline of utilization flow of various nutrients through the larval-pupal development and these daily quantitative requirements per body weight in the silkworm when they were reared on mulberry leaves.

• International Journal of Industrial Entomology and Biomaterials
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• v.33 no.2
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• pp.96-102
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• 2016

Recently silk polymer produced by Bombyx mori silkworm has been considered as biological macromolecules. Silk polymer was extracted in PBS solution at $37^{\circ}C$ for 72 h or $72^{\circ}C$ for 24 h. The effect of EtOH treatment on the cocoon extraction was also examined. The extraction yield of cocoon was less than 1 wt% regardless of extraction conditions. UV spectroscopy showed that the experimental extracts have absorption bands at 280 nm. There is no cytotoxicity effect on the mouse fibroblast L929 cell. The phenotype of L929 cell was not changed under the experimental conditions. The proliferation behavior of L929 cell was not affected by the addition of cocoon extract. Therefore, cocoon extract might be cytocompatible and can be used as promising biomaterials.

• International Journal of Industrial Entomology and Biomaterials
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• v.46 no.1
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• pp.1-8
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• 2023

Mulberry (Morus spp.) production is a vital activity in sericulture along with rearing of silkworms (Bombyx mori L.) for silk production. The Sericulture Research and Development Institute (SRDI) conducted a study that evaluated 11 mulberry varieties, including nine newly-evolved mulberry hybrids and two check varieties. These mulberry varieties were fed to silkworm hybrid, DMMMSU 115 x 100. The rearing performance of DMMMSU 115 x 100 was determined based on the silkworm economic traits such as weight of 10 matured larvae, cocoon weight, shell weight, shell percentage, cocoon yield, reelability percentage, filament length and filament size. Six silkworm rearing trials were conducted with 50 silkworm larvae per treatment in three replicates. The data were analyzed in a one-way Analysis of Variance. Significant differences were tested further using Tukey's Honest Significant Difference. Mulberry varieties that garnered an evaluation index value of higher than 50 were identified and selected. Results of the study revealed significant variations among the mulberry varieties based on the parameters gathered except on the reelability of cocoons, filament length and size. Matured silkworm larvae fed with Alf 55 were significantly heavier and higher cocoon yield compared to those fed with Alfonso and S₅₄. Alf 32, Alf 55, Alf 58, Bat 37 and Bat 73 were identified as potential varieties and highly recommended as feed for the silkworm hybrid, DMMMSU 115 x DMMMSU 100.

• Journal of Sericultural and Entomological Science
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• v.16 no.1
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• pp.93-100
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• 1974

It is reported that the useful larval characteristics and cocoon quality is damaged when the silkworm is fed on the insecticides contaminated mulberry leaf. The results obtained are as follow： 1) Mortality is growing when the silkworm is fed with the leaf treated with 1,000 folds insecticides and left for 25 days. 2) There are differences in the effects on the useful larval characteristics according to the insecticides, 3) Hernial larvae are brought about when the silkworm is fed with lebaycid stained leaf. 4) Malformed cocoon and abnormal silk is caused by the insecticide stained leaf feeding.

• International Journal of Industrial Entomology and Biomaterials
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• v.26 no.1
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• pp.1-12
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• 2013

The commercial rearing of polyphagous Indian tasar silkworm, Antheraea mylitta Drury being practiced on naturally grown primary food plants like Terminalia arjuna, (Arjun) Terminalia tomentosa (Asan), and Shorea robusta (Sal) available in the tropical forests of central India, at times, is seriously affected by the disease- Pebrine, caused by Nosema sp., a microsporidian pathogen. The present investigation on comparative larval, silk gland weight and also cocoon parameters in Pebrine-free and Pebrine-infected ecorace of tasar silkworm Antheraea mylitta Drury (Daba TV), illustrates the tasar silkworm larvae infected with pebrine disease causing heavy losses to the economy of the silk industry.

• Journal of Sericultural and Entomological Science
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• v.28 no.2
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• pp.28-34
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• 1986

The general combining ability (GCV), the specific combining ability (SCA) and the reciprocal combining ability (RCA) effects wereobtained by 8$\times$8 diallel crosses of the silkworms with four Japanese races and four Chinese races, total eight lines. The result are as follows ; 1. The general combining ability (GVA) effects appeared high significant level in the total and the fifth instar periods (TP, FP), a female and a male cocoon weights (FW, MW), a female and a male cocoon layer weights (FL, ML) and a female and a male cocoon layer ratios (FR, MR). Only the reciprocal combining ability (RCA) effects appeared high significant level in the total and the fifth instar periods (TP, FP). 2. The Japanese original silkworm lines varied in the general combining ability effects from -0.864 to 0.578, and the Chinese original silkworm lines did in ones from -0.570 to 1.018. 3. The specific combining ability effects of the silkworm lines made in order of the crossing types of JL (Japanese lines) $\times$CL (Chinese lines)>CL$\times$JL>JL$\times$JL> CL$\times$CL in a total cocoon weights and a cocoon layer weights. 4. The reciprocal combining ability effects of the silkworm lines was in order of the crossing types of JL$\times$CL>JL$\times$JL> CL$\times$CL>CL$\times$JL in a total cocoon weights and cocoon layer weights.

• International Journal of Industrial Entomology and Biomaterials
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• v.7 no.1
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• pp.15-20
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• 2003

The present investigation was carried out to study the possible cause for reciprocal difference in silkworm hybrids. By utilising the polyvoltine race Pure Mysore (PM) and newly evolved breeds (CSR2, CSR5, CSR16 and CSR17), the direct and reciprocal crosses of polyvoltine ${\times}$ bivoltine and also bivoltine hybrids were studied. The hybrids of polyvoltine ${\times}$ bivoltine (direct) are superior to their reciprocal crosses in respect of cocoon yield, cocoon weight and filament length. The reciprocal crosses of polyvoltine ${\times}$ bivoltine are superior to their direct crosses in respect of fecundity and short larval duration. No significant differences were observed in the characters like cocoon shell ratio, raw silk percentage, denier, reelability and neatness in both polyvoltine ${\times}$ bivoltine direct crosses and their reciprocals. The expression of cocoon characters as a function of sex revealed that direct crosses (polyvoltine ${\times}$ bivoltine) showed higher cocoon weight, pupal weight, shell weight and longer filament length in females than the reciprocal crosses (bivoltine ${\times}$ polyvoltine), where as these characters in males were almost the same in both direct and reciprocal crosses, indicating that the sex-linked genetic factor played a more important role. it was clear that difference in cocoon yield observed in reciprocal crosses of polyvoltine ${\times}$ bivoltine was due to the low cocoon and shell weight in females which was turn due to presence of early maturity genes (Lme) linked with sex-chromosome (X) which effect on larvae period of the silkworm. In bivoltine hybrids, i.e., both direct and their reciprocals crosses, all the characters viz., hatching percentage, larval duration, survival, cocoon weight, cocoon shell weight, cocoon shell ratio, raw silk percentage, filament length, denier, reelability and neatness did not show any significant difference (except number of eggs laid by moth) which could account for presence of same maturity genes (Lm) in both direct and reciprocal crosses. it was clear that reciprocal differences occur when the hybrids are prepared from the parental strains with different voltinism.

• Korean Journal of Poultry Science
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• v.38 no.3
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• pp.197-204
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• 2011

To investigate the effects of Cordyceps ochraceostromat, silkworm cocoon and conjugated linoleic acid (CLA) addition on the quality of cremi during storage, this study was conducted. Cremis were prepared using a 20% spent layer breast recovered protein to replace Alaska pollack with the addition of 0.1% silkworm cocoon powder (T1), 0.05% silkworm cocoon powder + 0.05% Cordyceps ochraceostromat powder (T2), and 0.05% silkworm cocoon powder + 0.05% CLA. All manufactured cremis were vacuum-packaged, stored at $10{\pm}1^{\circ}C$ and finally evaluated for their quality on 0, 2, 4 and 6 weeks of storage. The pH, whiteness, gel strength and breaking force of cremis from T2 were higher than those of samples derived from either T1 or T3. However, cremis from T2 showed low shear force values when compared to other cremis (p<0.05). Therefore, the results indicate that cremis contained 0.05% silkworm cocoon powder and 0.05% Cordyceps ochraceostromat combination (T2) may be recommendable to induce customers to buy, thereby, it may be beneficial to both manufacturers and consumers in market.