• Journal of Sericultural and Entomological Science
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• v.28 no.2
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• pp.35-37
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• 1986

To reduce the number of rearing season required for preservation of multivoltine silkworms which do not produce diapause eggs, the optimal egg stage, temperature, and period of cold storage were examinede using hatchability as an indicator of viability. Multivoltine silkworm starains MR, SPT, and HM were used in the study. 1. The hatchability of multivoltine silkworm eggs (MR and STP) preserve at 5$^{\circ}C$ for 30 days was 80% for the eggs chilled from 2 days after oviposition but less 5% for those chilled from 7 days after ovipostion. 2. When 2 day-old eggs of multivoltine silkworm (HM) were preserved between -2.5$^{\circ}C$ to 7.5$^{\circ}C$ for 15 to 60 days, $0^{\circ}C$ and 2.5$^{\circ}C$ showed the highest hatchability with 91% at 30 days and 61% at 60 days storage, respectively. 3. From these results, it can be concluded that by preserving 2 day-old eggs at 2.5$^{\circ}C$ for 50 to 60 days, rearing seasons required for preservation of the multivoltine silkworm can be reduced to half per year.

• Journal of Sericultural and Entomological Science
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• v.37 no.2
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• pp.188-190
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• 1995

The eggs of the silkworm, Bombyx mori, were treated topically with 10-3, 1-0-4, 10-5 aqueous Insegar and the hatchability was checked. The chemical affected all the tested developmental stages, but the results varied according to the stages and the degree of density. The hatchability was reduced upto 0% for the eggs treated at the 1 and 3 day stages, compared to 97% of control eggs.

• 한국관개배수회지
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• no.37
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• pp.33-35
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• 2007

• Journal of Sericultural and Entomological Science
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• v.50 no.2
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• pp.101-108
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• 2012

This study was conducted to confirm the mass production of male pupae and sex-limited larval marking variety as a host for synnemata production of Isaria tenupes in RDA(Rural Development Administration). Silkworm pupation, infection rate and synnemate formation of I.tenuipes were examined. Among the silkworm varieties tested, male Hansaengjam showed the highest pupation rate at 98.7%. I. tenuipes infection rate of larvae of newly-exuviated 5th instar silkworm was 83.7 ~ 90.4% in the spring rearing season and 91.7 ~ 96.6% in the autumn rearing season. Synnemata production of I. tenuipes was execellent in female Yangwonjam with an incidence rate of 99.5% followed by male Yangwonjam(99.5%) and Baegokjam(99.4%) in the spring and autumn rearing season. Synnemata living weight ranged from 0.93 ~ 1.25 g in the spring rearing season. The female Hansaengjam had the heaviest synnemata weight(1.25 g). Synnemata dry weight ranged from 0.27 ~ 0.35 g in the spring rearing season. The female Yangwonjam had the heaviest synnemata weight(0.35 g).

• Journal of Sericultural and Entomological Science
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• v.35 no.2
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• pp.105-113
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• 1993

To produce F1 hybrid of silkworm sex discrimination has to be followed at the pupal stage by sexual organ. However it requires a lot of labour and may bring about a wrong classification. In these regards, this study has been implemented to find out an effective measure for the pupal sex discrimination by use of variation of cocoon weight and image analysis of cocoon. As a result, it was found that in case of the pupal weight the percentage of a wrong classification fell on 0.3% and in case of single cocoon weight 0.4%. The discrimination rate was 99% in the weight variables of cocoon but analysis by single cocoon weight and cocoon shape variables, it was 98.7%. Efficiency of discrimination was increased by 2.7% as compared to variable of single cocoon weight. The minimum cocoon sampling size may be 15 cocoons sexual-wise.