• International Journal of Industrial Entomology and Biomaterials
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• 제8권2호
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• pp.123-127
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• 2004

Normally, silkworms, Bombyx mori, generate offspring by sexual activity. As we known, the hybrids of the first generation of the silkworm have higher cocoon production than pure lines. During the sericulture production, many processes are related with sex control. For example, sex sorting in the egg grainages, rearing of only male silkworm to save the mulberry leaf consumption and increase silk output and quality. Therefore it is very interested in understanding the sex control of the silkworm in theory and practice. Chinese sericultural scientists have been being engaged in the researches in the fields of artificifial parthogenesis, dispermic androgenesis, sex-limited varieties, sex linkage balanced lethal strain and high temperature sensitive male stocks for several decades and gained substantial achievement. Some of the achievements have been used in the commercial production. In this review, the authors introduced that the methods for control of the silkworm sex, and regulate the silkworm sex ratio according to different producing aim in the world and especially in China.

• Mycobiology
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• 제38권3호
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• pp.180-183
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• 2010

This study was conducted out to select a silkworm variety suitable for synnemata production of Isaria tenuipes. Four kinds of the mulberry silkworm varieties, Bombyx mori, were hybridized using a Japanese parental line and a Chinese parental line, and used to test for synemata formation in I. tenuipes. The larval period of normal silkworms was 22 hr longer than the silkworms inoculated with this fungus. Among the silkworm varieties tested, Hachojam had the shortest larval period with 23.02 days. The non-cocooning silkworm had a shorter larval period than the cocoon producing silkworms. The pupation rate of normal silkworms was about 9% higher than that of silkworms sprayed with I. tenuipes. Hachojam had the highest infection rate at 99.8%, but no significant difference was observed for the infection rate by silkworm variety. The production of synnemata was the best in JS171 $\times$ CS188 with an incidence rate of 99.3%, followed by Hachojam, and Chugangjam. The synnemata produced from Hachojam were the heaviest and showed white or milky-white in color.

• Human Ecology Research
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• 제56권4호
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• pp.407-416
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• 2018

This study investigated the characteristics and changes of Jeongbang-village silk culture Jeollanam-do Province during Japanese Colonial Rule with a focus in on Gokseong-gun & Damyang-gun Jeongbang-village. The results of the study are as follows. First, after Japanese occupation, it changed from a traditional silkworm species, the Joseon Silkworms and the mulberry tree to an improved Japanese species. Japan established a silk spinning mill called Jongyeon Textile factory in Gwangju and Jeongbang Village was formed in poor rural areas. Second, the way of village management consisted of buying a large number of land for mulberry plans and creating mulberry fields as a cheap way to utilize the labor force for women and men in rural areas. Third, since the end of the Japanese colonial era, mulberry fields in Jeongbang villages which the Japanese left, were sold at a cheap price to Koreans. After the Korean War, the Korean government's efforts to modernize the silkworm industry resulted in a continuous plan to increase the number of silkworms. The impact of government policies has also increased the production of silkworms in these areas. However, since the early 1980s, Korean companies have been affected by Japanese economic policies and dumping by China that has resulted in in a sharp decline in their production. In the case of Gokseong-gun and Damyang, the production of silk products was halted and switched to other crops in the early 1990s when the farming industry began to decline.

• 한국잠사곤충학회지
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• 제35권1호
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• pp.11-16
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• 1993

인산이 축적된 뽕밭에서 인산 시비량을 조절하기 위하여, 유효인산 300ppm 정도 포장 2개소, 450 ppm정도 포장 1개소에서 인산 표준시비량구(13kg/10a), 반량구, 무인산구, 무시비구 등을 설정하여 4년동안의 포장시험과 엽질검정을 위한 누에 사육시험을 3년동안 수행한 결과 다음과 같았다. 1. 토양유효인산 함량이 450ppm포장에서는 4년간 계속된 인산 무시비구에서도 뽕잎 수량감소가 없었으나, 300ppm포장에서의 무인산구에서는 3년차 봄부터, 인산 반량구에서는 4년차 가을부터 감수가 시작되었다. 2. 연차별로 토양 인산의 감소에 따른 수량감소와의 관계에 의하여 인산시비 개시 시기를 조사한 결과, 토심 10~20cm 부위에서 유효인산의 함량이 150ppm 이하로 떨어졌을 때 인산시비를 개시하는 것이 적당한 것으로 나타났다. 3. 인산 감량시비에 따른 뽕잎 중의 인산함량은 표준량 시비구 대비 0.18%까지 감소하였다. 4. 인산의 감량시비가 뽕잎의 질에 미치는 영향을 알기 위하여 3년간 토양인산 300ppm 포장의 뽕잎으로 누에를 사육하여 검정한 결과, 인산 무시비에 의해 수량이 감소하고, 엽중의 인산 함량이 최저 1.13%까지 감소하였어도, 수견량 및 견질에는 영향을 주지 않았다.

• International Journal of Industrial Entomology and Biomaterials
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• 제4권2호
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• pp.83-91
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• 2002

The protection of silkworm and its host plants from various kinds of pests parasite and predator is a chronic problem in sericulture. Silkworms and its primary food plants are heavily damaged by large number of pest. The major pests of primary tasar food plants (Terminalia arjuna and Terminalia tomentosa) are the gall insect (Trioza fletcheri minor). Various species of aphids (Eutrichosiphum sp.) have been recorded to damage oak tasar food plants whereas muga silkworm host plants (Machilus bombycina and Litsaea polyantha) are generally attacked by stem bores (Zeuzera multistrigata). Castor (Ricinus communis) is one of the primary host plant of eri silkworm and extensive damage is caused by the castor white fly (Trialeurodes ricini). Insects pests are major enemies of silkworms. Parasites (Blepharipa zebina, Exorista bombycis, Apateles glomeratus), predators (Canthecona furcellata, Sycanus collaris, Hierodulla bipapilla), wasps (Vespa orientalix) and ants (Oecophylla smargdina) continues to cause damage to silk industry. It is estimated that the losses due to parasites and predators are to an extent of 15-20 percent and varies from crop to crop. The complexities in the behaviour and life cycle of pest population existing in semi ecosystem warrant a special attention for their effective management specially in changing scenario for our modern sericulture. Though use of synthetic insecticides has provided us with effective control of almost all major pests and predators, yet their undesirable side effects limit their continued use. Biological control is one of the most important method which can be used to control the pests, parasites and predators population in sericulture. Various potential parasitoids, which can be utilized as an agent of biological control in sericulture have been screened. The natural enemies of the uzi fly (E. bombycis and B. zebina ) are already present in the nature. Nesolynx thymus, Trichria sp., Splangia endius, Dirhinus sp., Trichopria sp., Trichomalopsis apanteloctena and Pediobius sp. are the major parasitoids effective against uzi fly pupa. The scelionid Psix striaticeps and Trissolcus sp. are the Potential egg Parasitoids against stink bug (Canthecona furcellata). Various other native natural potential parasitoids have been screened and suitable strategies have been developed to check the population of pest insect in sericulture.

• International Journal of Industrial Entomology and Biomaterials
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• 제33권1호
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• pp.6-14
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• 2016

The mulberry silkworm, Bombyx mori has been one of the most important domestic animals which have provided with silk fibers for weaving fabrics and a food for a protein and lipid source. In addition, various health improvement effects of diverse silkworm larval powders were reported. Recently we found that steamed and freeze-dried mature silkworm larval powder (SMSP) generated using white-jade (also known as Backokjam) silkworm variety extended healthspan and increased resistance to Parkinson's disease in animal models. Because the colors of cocoons in silkworm varieties were caused by altered signal transduction pathways transporting phytochemicals from intestinal lumens to silk glands, we performed the proximate, amino acid, mineral, carbohydrates, fatty acid, and cholesterol composition analyses of SMSPs of 3 silkworm varieties which were weaving light yellow, golden, and red cocoons. Although most of nutrient compositions among 3 SMSPs were similar, there were significant differences in certain amino acids, minerals, and fatty acid compositions. Red silk silkworm (RS)-SMSP had higher contents of crude proteins and total amino acids than other SMSPs. In addition, the ratio of n-3/n-6 unsaturated fatty acids were higher than the other SMSPs. In contrast Golden silk silkworm (GS)-SMSP had higher ratio of potassium/sodium than the other SMSPs. These nutrient analysis results suggested that 3 SMSPs might have common and unique health improvement effects. Thus, further studies in the functionalities of the 3 SMSPs will reveal unknown their health improvements effects.

• International Journal of Industrial Entomology and Biomaterials
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• 제6권2호
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• pp.139-143
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• 2003

Mathematical constants for multiplication with leaf length (I) or breadth (b) or l ${\times}$ b have been worked out for determining leaf area in promising mulberry genotypes viz., Chinese White, S-146, Chak Majra and Sujanpur Local of sub-tropical India. When pooled, the mathematical constants worked out were 8.1132, 10.1019 and 0.5992 for multiplication with leaf length, breadth and l ${\times}$ b, respectively, for genotypes bearing un-lobbed leaves and 6.9447, 8.2761 and 0.5009 for multiplication with leaf length, breadth and l ${\times}$ b, respectively for genotypes bearing lobbed leaves. Leaf area can be worked out by using any constant by multiplying either with leaf length or breadth or both (l ${\times}$ b). Estimated leaf areas worked out were found significantly and positively correlated with actual leaf area (r＝999$^{＊＊}$). The suggested present non-destructive method by using mathematical constants is very quick and alternative to electronic leaf area meter for spot leaf area determination in mulberry which is the only food source for mulberry silkworm in sericulture industry.

• International Journal of Industrial Entomology and Biomaterials
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• 제1권2호
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• pp.155-159
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• 2000

In the spring silkworm rearing period of year 1998, some nutritional aspects were studied in the Agricultural Research Station of the Komotini town in Greece, to investigate the feeding behaviour of some Bulgarian silkworm hybrids, suitable for spring rearing, during the fourth and fifth instal under the local climatic conditions. The silkworms were fed by locally cultivated Japanese Kinriu mulberry (Morus alba L.) variety leaves. Eight Bulgarian hybrids had been used, namely Vratza-53xVratza-52, Ukraine-20xVratza-53, Super 1xHessa 2, Merefa 2xVratza 35, as well as their reciprocal crosses. The studies showed out a remarkably higher feed intake and feed utilization by the hybrids Hessa 2xSuper-1, Merefa 2xVratza 35 and Vratza-52xVratza-53. The same hybrids showed an efficient food utilization by means of daily growths cocoon shell ratio and raw silk output. In terms of food to silk conversion efficiency Hessa 2xSuper-1 hybrid gave the best results. Larval stage duration for fourth and fifth instar was not affected by feed intake and utilization. All hybrids showed a good adaptation to the local environment and their feeding performance was equal to the international existing standards. All calculated parameters were found to be around the mean values of other up to date presented results and thus considered as acceptable for the needs of the local production.

• 한국잠사곤충학회지
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• 제26권2호
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• pp.32-36
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• 1984

전국 621개 양잠시범부락의 84가을 누에병 발생율과 그 원인을 조사한 결과는 다음과 같다. 1. 누에 사육 기간중 누에병 발생율은 약 17%이었다. 2. 누에병 종류별 발생율은 농병(38.5%), 경화병 (20.3%), 연화병(17.9%) 및 쉬파리병 (9.4%)의 순이었다. 3. 누에병은 종잠기보다 장잠기 이후에 주로 발생하였다. 4. 누에병 발생의 주원인은 기상환경불량, 농약피해 및 소독불량이었고, 엽질불량, 사육기술부족 및 공해는 큰 문제가 되지 않았다.

• International Journal of Industrial Entomology and Biomaterials
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• 제13권2호
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• pp.109-112
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• 2006

The use of commercial silkworm hybrids resistant to important silkworm diseases is economical and better option particularly in tropical areas. This necessitated the evolution of productive bivoltine silkworm breeds non-susceptible to $BmDNV_1$. Non-susceptibility to $BmDNV_1$, infection was found to be controlled by a single recessive gene, nsd-l or a dominant gene, Nid-l. A major dominant/recessive gene confers resistance to $BmDNV_1$, from potent donor parents have been transferred to 10 productive but susceptible bivoltine silkworm strains through conventional breeding methods. By utilizing these breeds prepared 25 hybrids $(5{\times}5)$ and hybrid evaluation was carried out to identify most promising hybrids resistant to $BmDNV_1$. All these hybrids are inoculated with $BmDNV_1$ inoculum along with productive control hybrid $CSR2{\times}CSR4$ and reared under standard rearing procedure. Based on inoculated rearing and test reeling results, two most promising hybrids $(CSR18DR{\times}CSR29DR\;and\;CSR21DR{\times}CSR50DR)$ were selected for commercial exploitation. The selected hybrids have shown a survival rate of >85% with productive traits, where as control hybrid have shown 11.1% survival with inferior cocoon traits. The methodologies adopted were discussed.