• International Journal of Industrial Entomology and Biomaterials
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• v.11 no.1
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• pp.75-78
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• 2005

Inheritance of cocoon and shell weight characters in silkworm crosses between sex-limited at larva stage lines, including three (NIG$_{1}$ $\times$ TV$_{3/2}$ ,NIG$_{1}$ $\times$ TBV$_{2/24}$ and NIG$_{1}$ $\times$ B$_{2/6}$ ) from Japanese type and three (NIG$_{2}$ $\times$ B$_{2/6}$ ,TV$_{3/2}$ $\times$ NIG$_{1}$ and NIG$_{2}$ $\times$ TBV$_{2/24}$ ) from Chinese type was studied at Regional Centre for Scientific­Applied Service - Vratza during the period of 2000 ­2002. Inheritance of tested characters in F I was deter­mined through genetic parameters, additiveness (a), dominance (d) and their ratio (d/a). Degree and frequency of transgressions in F$_{2}$ were calculated also. Over dominance (d/a(>) 1) with bigger contribution of the parent with higher value was determined at inheritance tested characters. Transgressions obtained at cocoon and shell weight characters were positive and varied in wide limits. The productivity of parent's lines had defined the variability of genetic parameters for degree and frequency of transgressions. Combination of positive transgressions at cocoon and shell weight characters in F2 hybrid populations from sex-limited at larva stage allow us to select individuals with high productive potential for further use in selection programs.

• International Journal of Industrial Entomology and Biomaterials
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• v.5 no.1
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• pp.59-65
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• 2002

Parthenogenetic development, hybrid vigour and cocoon shape variability were studied in bivoltine F1 hybrids of the silkworm, Bombyx mori L. Considerable breed differences were observed in parthenogenetic ability. Among the parental breeds, CSR18 exhibited maximum parthenogenetic development (79.65%) followed by CSR4 (67.90%). Among bivoltine F1 hybrids, CSR18 ${\times}$ CSR4 showed highest parthenogenetic development (73.32%) followed by CSR2 ${\times}$ CSR4 (55.43%). Study on hybrid vigour demonstrated that CSR18 ${\times}$ CSR19 expressed maximum significant hybrid vigour for all the seven economic characters over Mid Parent Value (MPV) followed by CSR2 ${\times}$ CSR4 and CSR18 ${\times}$ CSR4 exhibiting significant heterosis for six characters. Cocoon shape measurement study revealed that among ten bivoltine F1 hybrids, cocoons of three hybrids were found comparatively uniform. Importance of this study to know the level of paythenogenetic development, hybrid vigour and cocoon shape variability in different bivoltine F1 hybrids have been discussed.

• International Journal of Industrial Entomology and Biomaterials
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• v.13 no.2
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• pp.51-55
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• 2006

Since 1970, China has become the biggest cocoon producer in the world, and made the highest historical record of cocoon output for 759,800 tons in 1995. However, in 1996 cocoon production reduced sharply to 470,900 tons. After a ten-year adjustment and reform, sericultural areas have shifted from developed regions to developing regions and from the east to the west. From 2000, the cocoon output has started to increase restoringly. By 2004 it recovered to 547,091 tons. With the development of market economy, sericulture management has been changed, including mulberry fields concentrated to the specializated households and cooperatives, cocoons produced in larger scale instead of individuals, Silkworm egg producing enterprises gradually changed into non-governmental joint-stock ones. The mechanism of market cocoon price has been gradually established. The management model of combination of trade, industry and agriculture is pushing and improving. It is the fruit of modern science and technology, especially sericultural basic research, that provides China's sericulture with the opportunity and vital force. China's sericulture, therefore, will continue to develop steadily in future.

• International Journal of Industrial Entomology and Biomaterials
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• v.24 no.1
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• pp.1-5
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• 2012

A newly developed silkworm variety, GoldenSilk makes bright yellow cocoon. In this article, the basic characteristics of GoldenSilk cocoon were examined through color analysis, degumming characteristics and UV spectrophotometer. The colorant of GoldenSilk cocoon was not distributed evenly throughout the cocoon layer but existed in the outer layer of the cocoon. The colorant has not good resistance against sunlight. The degumming loss percentage of GoldenSilk cocoon was 29.2%, which is relatively higher than that of the authorized one. UV spectrophotometer showed specific absorption band around 400 to 500 nm, which is the specific yellow colorant of the GoldenSilk cocoon extracted to the degumming solution during the degumming process.

• Journal of Sericultural and Entomological Science
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• v.31 no.2
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• pp.91-101
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• 1989

This experiment was carried out to analyze genetic parameters for the selection of silkworm by diallel-crossing with three Japanese and four Chiness silkworm races. Heritability, genetic correlation and path coefficient were calculated as the statistical parameters to evaluate direct or indirect effects of various gentic characters on bave weight. The heritabilities of fifth instar period, cocoon weight, cocoon layer weight, cocoon layer ration, fibroin contents, boiling off ratio and bave weight were over 76.65% in both F1 and F2 generations. There were positive coefficients in both phenotypic and genotypic correlations between male and female of both F1 and F2 generations. The latter showed greater values in general. The correlation between bave weight and the characters of cocoon weight, cocoon layer weight, cocoon layer ratio, fibroin contents were over 0.727 in both sexes of F1 and F2. Therefore, these results suggest that above characters would be useful for genetic selection of silkworms. As result of path coefficient analysis, there was a direct effect with path coefficient value of 0.991 between bave weight and F1 female cocoon layer weight, and with the value of 0.803 between bave weight and F1 male cocoon weight. In F2 the effect showed 0.938 between bave weight and male cocoon weight and cocoon layer weight had greater influence on direct or indirect effects (in path coefficient) than the others.

• International Journal of Industrial Entomology and Biomaterials
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• v.18 no.1
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• pp.8-12
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• 2009

A study has been made to know the effect of a phytoecdysteroid 'Sampoorna' on uniform maturation of silkworms during spinning and its effect on diseased silkworms infected by major silkworm disease viruses, Bombyx mori nuclear polyhedrosis virus (BmNPV) and Bombyx mori infectious flacherie virus (BmIFV). In the present investigation, the effect of the phytoecdysteroid "Sampoorna" on Grasserie disease caused by BmNPV have shown an average cocoon melting of 11.91% with a disease incidence of 5.83%. The values of 't' test for different treatments of BmNPV indicated low survival rate and cocoon traits were drastically reduced. Another major disease Flacherie caused by BmIFV has shown considerable levels of larval disease incidence (22-32%) and cocoon melting (3-7.67%) with an average melting of 12.95% and 20.24% disease incidence. There is a drastic reduction in survival rate, cocoon yield and other economic traits. The control batches were indicated negligible values for disease incidence and cocoon melting with Sapoorna application and without the inoculation of the two disease-causing viruses. The application of Sampoorna on already infected batches with major pathogens triggered high mortality and disease incidence and melting percentage was also significantly increased with reduced economic traits. Hence, it is suggested that application of Sampoorna in infected batches should be done only in the extreme conditions of rearing. Application of Sampoorna on healthy batches led to uniform maturation and improvement in productivity with the added advantage of better quality cocoons and labour saving.

• International Journal of Industrial Entomology and Biomaterials
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• v.17 no.1
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• pp.109-113
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• 2008

Realizing the scope of utilizing by-products of silk cocoons by applying appropriate methods is the immediate crave to optimize returns. The nutritive value of pupae suits for human diet, feed for poultry, carps, fish, rabbits, piggery and dogs. The pupal skin, fat, oil, cocoon palade have applications in oleo chemical, soap, glycerin, cosmetic, artificial fibres, membranes and n-triacontanol isolation. The pupal proteins Chitin, Shinki fibroin, Serrapeptidase, glucosamine are latent precursors of post surgical, anti-carcinogenic, anti-inflammative, anti-bacterial, anti-histaminic, gastric, hepatitis, pancreatitis, leukocytopenia, neurological, ophthalmic, blood pressure, cardiac and diabetic medicines and for preparation of vitamins A, E and K. The silk and its proteins sericin and fibroin are potentially used for wound healing, diabetes, impotence, sinusitis, arthritis, edema, cystitis, epididymitis, tissue regeneration, cancer, post-surgical trauma and used as anti-oxidatives, bio-adhesives, ultra violet screens and bio-active textiles. The waste cocoons can be used in making art crafts like garlands, carpets, overcoats, decoratives and greeting cards. The in-depth research towards utility optimization and make aware this reality to sericulturists, reelers, weavers, traders, entrepreneurs, policy makers etc., is the upright want of the today's Sericulture industry.

• International Journal of Industrial Entomology and Biomaterials
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• v.1 no.1
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• pp.41-45
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• 2000

The effect of topical application with hydrocortisone on economic parameters was analysed following treatment of last larval stadium. The treated larvae showed a significant increase in larval weight at higher concentrations along with other enhanced larval, cocoon and adult parameters. This suggests that hydrocortisone can be used effectively for commercial silkworm rearing. The larvas period was significantly increased in all the treated groups with increased female cocoon weights, its shell weights and male cocoon shell weight at 20$\mu\textrm{g}$/ml treated group. Filament length, weight and denier were increased significantly in all the treated groups. Moth emergence percentage, length of the ovariole, eggs per ovariole, fecundity and rind hatching percentage were unaffected when compared with that of the carrier control group. This suggests that hydrocortisone in addition to affecting larval growths also affect silk crop.

• International Journal of Industrial Entomology and Biomaterials
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• v.47 no.1
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• pp.63-71
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• 2023

In this study, the structural characteristics of sericin recovered from wastewater released from the silk textile industry (Plant sericin) were comparatively analyzed with those of sericin extracted from a silkworm cocoon produced in a laboratory (Lab sericin). To prepare Plant sericin, ethanol was added to wastewater (i.e., a sericin aqueous solution) after the degumming process to remove nonprotein materials, affording a sericin precipitate. To prepare Lab sericin, nonprotein materials were removed from a silkworm cocoon and sericin was subsequently extracted from the cocoon. Lab sericin and Plant sericin exhibited similar solution viscosities, gel strengths, and crystallinity indices, indicative of the similar molecular weights (MWs) of the two sericin samples. In the case of sericin powder, Plant sericin was more crystalline than Lab sericin due to its treatment with ethanol. The findings of this study revealed that sericin recovered from industrial wastewater can be used equally as its MW is similar to that of sericin obtained through laboratory-scale extraction.

• Journal of Sericultural and Entomological Science
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• v.40 no.2
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• pp.150-157
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• 1998

This study was carried out to define the effects of anti-juvenile hormone analogue(AJH) treatment at different silkworm larval stages on some silk filament properties. It was revealed that the treatments at the 1st and 2nd days of the 3rd instar as well as the 1st day of the 4th instar resulted to trimolters induction without lethal effect. The trimolters induced by treatment at the 1st day of the 4th instar showed the shortest larval duration and the lowest single cocoon weight, cocoon shell ratio, cocoon size, single filament length and denier of filament compared with those of the control, while the trimolters induced by the 3rd-instar treatment showed intermediate values. All treatments showed no significant differences from the aspect fo degumming ratio, elongation rate and crystallinity index of fibroin. However the silk filament obtained from the treatment at the 1st day of the 4th instar showed the highest tenacity which was revealed to be related to the better uniformity of filament by the means of microscopic photographing. FT-IR spectroscopy of the silk fibroin showed a sharp and strong peak at the position of 794.72 cm-1 in all AJH-treated samples regardless of trimolters induction, which was absent in control.