• International Journal of Industrial Entomology and Biomaterials
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• v.9 no.2
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• pp.273-277
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• 2004

Variation in the size of the silk filament will determine the uniformity and quality of the silk reeled. In the present study, an attempt has been made to study the filament size variation in 6 multivoltine parental breeds and 9 multivoltine ${\times}$ bivoltine hybrids in all three seasons of a year. All multivoltine breeds and multivoltine ${\times}$ bivoltine hybrids showed variation in filament size throughout its length from the outer layer to inner layer. Results of the present study indicated that the size of the filament decreased from outer to inner layer. The decrease in filament size was sudden in some breeds/hybrids whereas it was gradual in other. Relationship between filament length to that of slope, average filament size to slope, and maximum filament size to slope was determined based on regression analysis. Regression analysis revealed significant positive correlation between slope vs average filament length (r=0.92$^{**}$) in multivoltine${\times}$bivoltine hybrids. Among parental breeds, 96C showed lowest slope of the curve (b-value: -0.00428) and 96A showed highest slope of the curve (b-value: -0.00269). Among 9 hybrids, PM${\times}$N $B_4$ $D_2$ recorded lowest slope value (b-value: -0.00328) and BL24${\times}$N $B_4$ $D_2$ showed highest value for slope of the curve (b-value: -0.00234). The breed 96C, which showed lowest slope value can be utilized for future breeding programmes to breed strains with less size deviation. Three multivoltine${\times}$bivoltine hybrids viz., PM${\times}$N $B_4$ $D_2$, 96E${\times}$CSR19 and BL67${\times}$CS $R_{101}$ , which showed less slope values (b-values: -0.00328, -0.00300 and -0.00297 respectively) can be utilized for commercial exploitation to produce uniform silk.k.

• Korean journal of applied entomology
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• v.53 no.3
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• pp.199-207
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• 2014

It is true that the proper environmental risk assessments for many GM (Genetically Modified) insects almost have not been executed in Korea. Therefore, we tested the environmental risk assessment about GM silkworms if there is any difference between GM silkworms and non-GM silkworms by the following three measurements. First, we measured their mobility in the breeding environment conditions with food and without food. Secondly, we measured their viability at the artificial extreme environmental conditions (low and high temperature and humidity, absent/present of foods,) after escaping from their breeding environments. Thirdly, we observed the number of laying eggs and their hatchability between GM silkworms and non-GM silkworms with four different pair experiments. The mobility of GM silkworms and non-GM silkworms statistically did not differ, and the egg productivity and hatchability were not also different. The hatchability by couple of GM female silkworms and non-GM male silkworms was lower than by non-GM male and female couple between the GM silkworms and non-GM silkworms, and there was statistically different. Relatively, the viability of GM silkworms was lower than non-GM silkworms. We could not exactly test for viability of silkworms in low temperature conditions because of their hibernating. Although there was any difference in viability and hatchability between GM silkworms and non-GM silkworms, all ability of GM silkworms was lower than non-GM silkworms. Conclusively, the environmental risk of GM silkworm was relatively lower than non-GM silkworm in this study.

• Journal of Sericultural and Entomological Science
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• v.22 no.2
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• pp.1-7
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• 1981

Diallel crosses among six silkworm varieties were used as the materials by the randomized block design. and combining ability tests were conducted to determine the relationships between parents and their F$_1$ hybrids. The six parents and their 30 F$_1$ crosses were evaluated for five quantitative characters in each female and male silkworms. Mean values of period(days) of larval stage in mid-parent were more than those of each F$_1$ hybrids. Highly significant differences were shown in the total cocoon weight and weight of cocoon layer of silkworms in F$_1$ hybrids of 111$\times$114, 111$\times$ yunil, 114$\times$yunil and those of reciprocal crosses. From the results, it was recognized that varieties A(111), D(114) and F(yunil) were useful varieties as the parents in breeding of silkworms for increasing the total cocoon weight and weight of cocoon layer, etc. Differences among crosses in apparent degree of heterosis existed for total cocoon weight of cocoon layer and cocoon layer ratio, etc. Mean square values of GCA (general combining ability) were more greater than those of SCA(specific combining ability) for period(days) of larval stage, period (days) of 5th instar and cocoon layer ratio of silkworms. The effects of GCA were differ from parents and characters and the effects of SCA were also differ from parents, characters and crosses.

• Journal of Sericultural and Entomological Science
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• v.13 no.1
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• pp.23-29
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• 1971

As a result of analyzing the change of material substance of all sorts biochemically and comparing the control with ${\gamma}$-ray irradiation (800${\gamma}$, 40 Min), incubating the silkworm eggs (Bombyx mori L.) as the objective in the process of growth of embyro shortly before hatching, the following conclusion has been found. 1. Ascorbic acid has shown the maximum increase of 319 r/g in the Byong B embyro stage and in other words it has increased during the period of vigorous metabolism of the materials in eggs but it has decreased before hatching after that period. 2. Triglyceride has shown the increase of 27.54 mg/g in the Byong A stage, the early period of incubation and in other words it has increased in the period of activation of cells in eggs but it has gradually decreased during the growth of embyro after that period. Great change of either total cholesterol or free cholesterol has not been shown from the early period till shortly before hatching. 3. Free fatty acid has shown the minimum decrease of 257.4$\mu$ mole/g in the Byong A stage in which triglyceride increases greatly. On the contrary, it has shown the increase of 1, 020.0$\mu$ mole/g in Ki A stage in which triglyceride decreases. As a whole, the fact that free fatty acid increases according to the growth of embyro in eggs has been found. 4. Glucose has shown the increase of 281.2 mg/g in control during tile Pigment stage and it has shown the increase of 179.6 mg/g in ${\gamma}$-ray irradiation during the same period. The difference in quantity between the former and the latter is due to the fact that the growth of embyro has been influenced by the radio active. Glucose has changed with free fatty acid and phosphorus the other way round. 5. Control organic phosphorus has shewh the increase of 5.23mg/g during the Byong B or Ki A in which organ and tissue in the emhyro has been formed. Organic phosphorus in ${\gamma}$-ray irradiation has shown the increase of 5.73mg/g during Ki B. Inorganic phosphorus has shown only a little change in the control and ${\gamma}$-ray irradiation. The phosphorus in both has shown a little quantity in the ${\gamma}$-ray irradiation in the early period of incubation. After the Ki A embyro, it has increased rapidly and it has increased till the hatching more continually than in control. The about results of the research will be helpful and instructive to the betterment and improvement, breeding and management of animals and plants.

• Journal of Sericultural and Entomological Science
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• v.2
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• pp.73-81
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• 1962

This treatise is to analyze the chemical components in the mulberry varieties which are cultured in Korea and to estimate the nutritive values for them. Some of these varieties were developed lately in this country just by the general breeding aspect of mulberry leaf producing and silkworm raising experimentation without analysing the nutritive values of them which may be differed by various culturing condition. This work will be helpful for the improvement of mulberry varieties and the correct judgement of them. The varieties used for the analysis are as followings; A. Morus bombycis Koridz species. 1.Ichi-Hei. 2. Shimano-Uchi B. Morus alba L. species. 3. Kairyo-Nezumigaeshi. 4. Suwon-Daeyop. 5. Suwon No. 3. 6. Suwon No. 4. 7. Yongchon-Chuwoo. C. Morus Ihou (Ser.) Koidz species. 8. Ro-Soh. The specimens were eventually taken under the air and soil dry season because of the rain shortage during the sampling period and the results are found as a rather different from the normal specimen under the normal climate. Therefore, this treatise will be an important report on a special culturing condition and the nutritive values by the mulberry varieties, and still comparable because they were grown under the same condition. The individual conclusions are; 1. Yongchon-Chuwoo which was originated in this country, was found as an important variety for this country from the aspect of mulberry nutritive value and leaf producing amount, and it is believed that this is the best suitable variety for the soil of Korea. 2. Ichi-Hei occupies the better situation as well as Yongchon-Chuwoo from the nutritive criticizing even though it was originated in Japan. 3. The lately developed Suwon No.3 and No.4 are best from the leaf producing point of view, but they are not found such a good varieties from the nutritive aspect. The result may be happened as poor because they were cut before spring sprout started. 4. Ro-Soh which was normally recognized as a poor variety, was also found as a poor nutritive and leaf producing variety. 5. The crude protein and crude fat components in the mulberry leaves decreased as the leaf maturity was progressed, but the crude fiber and crude ash components increased reversively in general view. It was also found that there were some specific changing nature by the mulberry varieties and could not rule them by just one conclusion. 6. During the air and soil dry season, the ash component increases but the hydrocarbon and moisture contents decrease considerably, and which resulted to the increase of mulberry hardness ratio and the decrease of sugar-protein ratio, eventually it causes the decrease of the nutritive value. It was also found that Ichi-Hei, Ro-Soh, and Suwon No. 3 had a strong recovering nature to their normal nutritive condition after raining. 7. Mulberry is of course a rich calorie diet, and is calculated as 50 to 60 Cal. per gram.

• Korean journal of applied entomology
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• v.61 no.4
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• pp.605-614
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• 2022

Two major problems currently threaten human survival on Earth: climate change and the rapid aging of the population in developed countries. Climate change is a result of the increase in greenhouse gas (GHG) concentrations in the atmosphere due to the increase in the use of fossil fuels owing to economic and transportation development. The rapid increase in the age of the population is a result of the rise in life expectancy due to the development of biomedical science and technology and the improvement of personal hygiene in developed countries. To avoid irreversible global climate change, it is necessary to quickly transition from the current fossil fuel-based economy to a zero-carbon renewable energy-based economy that does not emit GHGs. To achieve this goal, the dairy and livestock industry, which generates the most GHGs in the agricultural sector, must transition to using low-carbon emission production methods while simultaneously increasing consumers' preference for low-carbon diets. Although 77% of currently available arable land globally is used to produce livestock feed, only 37% and 18% of the proteins and calories that humans consume come from dairy and livestock farming and industry. Therefore, using edible insects as a protein source represents a good alternative, as it generates less GHG and reduces water consumption and breeding space while ensuring a higher feed conversion rate than that of livestock. Additionally, utilizing the functionality of medicinal insects, such as silkworms, which have been proven to have certain health enhancement effects, it is possible to develop functional foods that can prevent or delay the onset of currently incurable degenerative diseases that occur more frequently in the elderly. Insects are among the first animals to have appeared on Earth, and regardless of whether humans survive, they will continue to adapt, evolve, and thrive. Therefore, the use of various edible and medicinal insects, including silkworms, in industry will provide an important foundation for human survival and prosperity on Earth in the near future by resolving the current two major problems.