• 한국잠사곤충학회지
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• 제39권2호
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• pp.140-145
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• 1997

Silkworm fed on mulgerry leaves with 1000 times diluted Insegar(main component : Fenoxycarb, ethyl-2-(4-phenoxyphenoxy)ethylcarbmate) and its effects was investigated on increase of the 5th larval silkgland weight and silk quality. The oral application of fenoxycarb showed increase of the silkgland weight. The whole period of the silkgland weight falls on the 2nd instar treatment by 13%, the 3rd day of the 4th instar by 111%(3100 mg) and the whole period of the 5th instar treatment rather decreased it by 66%(497 mg), as compared to 1470mg of the control. Female and male both increased 15%(1779mg) and 12%(1554mg) of the silkgland weight with the 2nd instar treatment, as compared to 1548mg and 1391mg in control, respectively. 118%(3368mg) and 104%(2832mg) of increase in the silkgland weight were also showed with the 3rd day of the 4th instar treatment but 70%(463mg) and 61%(539mg) of decrease were shown with the 5th instar treatment. The maximum weight of the middle silkgland weight increased by 6%(1248mg) and 127%(2673mg) with the 2nd instar and with the 3rd day of the 4th instar, respectively but 67%(393mg) of decrease took place, as compared to 1175mg of the control. The maximum increase of the posterior silkgland weight with whole peried of the 2nd instar treatment increased 12%(419mg) and 75%(656mg) and 64%(135mg) of decrease was shown, as compared to 374mg of the control. The oral application of Insegar at the 2nd instar increased 26 m of cocoon length, 4.0 cg of the cocoon filament weight and 0.21d of the silk denier, as compared to 1147 m of the cocoon length, 38 cg of the cocoon filament, 2.99d of the silk denier, weight of cocoon filament and silk denier, respectively but denier variance narrowed to 0.33d, as compared to that of the control.

• International Journal of Industrial Entomology and Biomaterials
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• 제9권2호
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• pp.199-205
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• 2004

With the main objective to know the feasibility of exploitation of F$_1$ hybrids in semi arid and arid climatic conditions of India, the present study was carried out by utilising RD$_1$ as female parent and six bivoltine silkworm breeds viz., CSR$_2$, CSR$_4$, CSR$_{5}$, CSR$_{17}$, CSR$_{18}$ and CSR$_{19}$ along with NB$_4$D$_2$ as male parents. Different hybrids exhibited their superiority for various economic characters during different seasons. Among F$_1$ hybrids, RD$_1$${\times}$CSR$_{5}$ was adjudicated as the best hybrid in terms of expression of significant positive hybrid vigour over mid parental value for five economic characters namely hatching %, cocoon yield, cocoon weight, cocoon shell weight and filament size, highest multiple trait average evaluation index value of 56.77 and comparatively uniform cocoon size with coefficient of variation (CV%) of 3.80 and Standard Deviation (SD) of 7.99 during September - October 2003. Results of the present study revealed that the F$_1$ hybrid RD$_1$${\times}$CSR$_{5}$ can be successfully exploited on commercial in semi arid and arid climatic conditions in India. India.dia.

• 한국잠사곤충학회지
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• 제21권2호
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• pp.1-6
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• 1979

잠체의 몇가지 양적형질에 관여하는 유전자의 우성정도, 유전력, 유전자의 분포상태등을 알기 위하여 누에의 6개 품종을 교배친으로 하여 이면교잡을 한 F$_1$세대와 교배친품종을 재료로 유전분석을 한바 그 결과를 요약하면 다음과 같다. 1. 각 형질의 측정치는 품종과 조합에 따라서 다르고 특히 전견양과 견층양은 자잠이 웅잠보다 많고, 견층비율은 자잠보다 웅잠이 크게 나타났다. 2. 각 형질별 분산성분중 상가적효과에 의한 분산D보다 Herterosis등에 의한 분산 H가 크며 우성정도가 모두 1이상으로 나타났으므로 품종 자체가 hetero상태라는 것을 알 수 있었다. 3. 광의의 유전력은 모두 높았으나 협의의 유전력이 비교적 높은 형질은 전령경과일수, 5영경과일수, 견층비율의 3개형질이었다. 4. 유전자의 분포상태를 보면 전령경과일수, 5영경과일수, 견층비율의 3개형질은 불완전우성으로, 전견양과 견층양의 2개형질은 초우성으로 나타났다. 5. 전령경과일수와 5영경과일수에 관여하는 유전자는 B(112)품종에 우성유변자가 많고, A(111)품종이나 E(경추)품종에 열성 유전자가 많이 관여하고 있는 것으로 보인다. 견층비율에는 자웅에 따라서, 품종에 따라서 우성 또는 열성유전자가 관여하는 정도가 다르며 전견양과 견층양의 2개형질은 초우성으로 나타나고, F(연일) 품종과 E(경추) 품종에 우성유전자가 많이 관여하고 B(112)품종과 A(111)품종에 열성유전자가 많이 관여하고 있는 것으로 보인다. 이상의 결과를 미루어 보아 전견양과 견층양을 증가시키기 위한 교배친으로서는 F(연일) 품종이 제일 좋고 다음으로 E(경추)품종이 유리할 것으로 사료된다.

• International Journal of Industrial Entomology and Biomaterials
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• 제9권1호
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• pp.53-58
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• 2004

Studies on heterotic expression in the silk productivity of 66 thermo-tolerant bivoltine hybrids reared under high temperature $(36{\times}1^{\circ}C)$ and low humidity (60${\times}$5%) conditions revealed that manifestation of heterosis was highly significant for majority of the quantitative traits contributing to more cocoon productivity. Observations were made on 8 economically important traits such as fecundity, pupation rate, cocoon yield, cocoon weight, cocoon shell weight, cocoon shell ratio, cocoon filament length and raw silk. Analysis of variance results revealed great deal of variability indicating significant (P < 0.001) variations. Out of 66 hybrids, 7 hybrids exhibited positive heterosis for seven traits and 4 hybrids expressed significant hetero-beltiosis for 6 traits, out of 8 traits evaluated. Based on results, the hybrids ${SR_1} {\times} {SR_5}and {CSR_2} {\times} {SR_5}$ are adjudged as most promising ones and can be exploited commercially in tropical climates to increase the cocoon productivity.

• International Journal of Industrial Entomology and Biomaterials
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• 제7권1호
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• pp.29-36
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• 2003

Phytoecdysteroids with moulting hormone (MH) activity induce different responses in silkworms when used on different day of final instar, which can be manipulated for maximum benefit like early and uniform spinning behaviour, reducing crop loss and to increase cocoon yield. The results showed that application of this hormone on seed crop viz., CSR2, CSR4 and BL44 and BL67 in early stage of 5$^{th}$ instar i.e., at 72 hrs and 96 hrs though induced early and uniform spinning behaviour, there was an adverse effect by 9-36% on the economic characters like cocoon yield, cocoon weight, cocoon shell weight and also on fecundity etc. Application of this hormone in late stage of $5^th$ instar i.e., at the onset of spinning showed non-significant variations in some of the characters like cocoon weight, cocoon shell weight, cocoon shell ratio and fecundity. The physiological implications of phytoecdysteroid in hastening the maturation events and synchronization of spinning activities in different breeds are discussed.

• International Journal of Industrial Entomology and Biomaterials
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• 제6권1호
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• pp.75-79
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• 2003

Oral supplementation of zinc chloride to silkworm larvae in different concentrations (30, 60 and 90 ${\mu}g$/ml) to the fourth and fifth instar resulted in a significant increase in commercial traits, like larval weight, silk gland weight, cocooning percentage in lower concentrartion (30 ${\mu}g$) treated group. The female cocoon weight, shell weight and its ratio were significantly increased in 30 and 60 ${\mu}g$ treated groups, male cocoon weight, and shell weight in 30 ${\mu}g$ treated group and its ratio in 60 and 90 ${\mu}g$ treated groups, filament length, weight and moth emergence percentage in all the treated groups and egg productivity in 90 ${\mu}g$ treated group were increased significantly. The remaining groups did not show any significant changes compared with that of carrier control.

• International Journal of Industrial Entomology and Biomaterials
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• 제2권1호
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• pp.69-74
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• 2001

The effect of topical application with androstenedione on economic parameters was analyzed following treatment of last larval stadium. The treated larvae showed significantly increased larval weight along with other enhanced larval, cocoon and adult parameters. The larval period was significantly shortened in all the treated groups with increased cocooning percentages cocoon weight and its shell weight in female and filament length, weight and denier in all the treated groups. Hatching percentage increased significantly in dose dependent manner in all the treated groups when compared with the corresponding parameters of the carrier control group. This suggests that androstenedione can be used effectively for commercial silkworm rearing.

• International Journal of Industrial Entomology and Biomaterials
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• 제2권1호
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• pp.79-81
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• 2001

A study was conducted to establish the degree of genetic divergence between different hybrid forms and rearing conditions through estimation of the minimum number of genes (allelic pairs) differentiating parents in terms of specific quantitative traits. It was established that the minimum gene numbers differentiating parental lines in the inheritance of cocoon was 1, of cocoon shell weight- between 1 and 2, and of silk filament length- between 2 and 3. The variability in the specific genetic parameter could be explained by the reliability of the statistical-and-genetic method used and the expression of genes affecting the formation of each of the characters tested. Gene expression, in its turns is conditioned both by the gene interaction within the genotypes and the different genotype response to environmental change. To go deep in the problem, experiments should be conducted under strictly controlled conditions, reducing the mathematical-and-genetic analysis to a physiological levels and hence to analyse the genetic nature of the specific quantitative character formation and its genetic control.

• 한국잠사곤충학회지
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• 제18권1호
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• pp.11-15
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• 1976

한국의 잠병피해율을 알고자 경북 전역에 걸쳐 1975년 추기 조사하여 분석한 결과 1. 병피해 농가비율은 18.5%이고 상자당 공판량은 무피해 농가가 27.0kg인데 비하며 18.2kg으로 변이의 폭이 크고 평균 미달농가가 상대적으로 많았다. 2. 한국의 총수잠량중 잠병에 의한 감산량은 약 838M/T으로 추산되며 피해율은 5.6%으로 추산되었다. 3. 농병ㆍ연화병이 각각 40.9%, 34.5%로 추잠기잠병의 대부분이었다.

• International Journal of Industrial Entomology and Biomaterials
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• 제1권1호
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• pp.47-52
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• 2000

The effect of supplementation with potassium nitrate on economic parameters was analysed following treatment of last larval stadium. The treated larvae showed a significant increase in larval weight at 500$\mu\textrm{g}$/ml and silk gland weight in all the treated groups along with other enhanced larval, cocoon and adult parameters. The larval period was significantly decreased in all the treated groups with increased female and male cocoon weights its shell weights filament lengths at 500$\mu\textrm{g}$/ml. The denier was significantly decreased in all the groups. The filament weight moth emergence percentaged length of the ovariole were unaffected. However, eggs per ovariole, fecundity and hatching percentage significantly decreased compared with the corresponding parameters of the carrier control.