• 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.12 no.1
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• pp.29-34
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• 2006

A breeding programme was initiated during 2001 utilizing two polyvoltine silkworm breeds viz. $BL_{69}$, an evolved breed tolerant to high temperature and MAR, comparatively resistant to Bombyx mori nuclear polyhedrosis virus (BmNPV) with the objective to develop robust polyvoltine breeds and hybrids. The breed $NP_1$ was developed by exposing the fifth instar larvae to high temperature $(36{\pm}1^{\circ}C)$, high Relative Humidity ($85{\pm}5%$ R.H.) and inoculating third instar larvae with BmNPV inoculum. At $F_{12}$, the breed was tested for hybrid forming ability utilizing six bivoltine silkworm breeds viz. $CSR_2,\;CSR_4,\;CSR_{17},\;CSR_{18},\;CSR_{19}\;and\;NB_4D_2$. The hybrid $'NP_1{\times}CSR_{17}'$ exhibited its superiority by recording 97.2% survival, 1.892 g cocoon weight, 0.406 g cocoon shell weight, 21.5% cocoon shell ratio, 16.6% raw silk percentage and 890 m filament length whereas the control $(PM{\times}CSR_2)$ has recorded 90.2% survival, 1.599 g cocoon weight, 0.304 g cocoon shell weight, 18.9% cocoon shell ratio, 13.1 % raw silk percentage and 768 m filament length. Commercial exploitation of the new $polyvoltine{\times}bivoltine$ hybrid in sericulture industry has been discussed.

• Journal of Sericultural and Entomological Science
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• v.21 no.1
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• pp.30-35
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• 1979

This experiment was conducted to investigate the effects of $\alpha$-amylase, added to artificial diet, on the larval growth and on the amount of blood sugar of the silkworm Bombyx mori L.. The artificial diet containing 20% mulberry leaf powder was fed on the 5th instar silkworm. The results obtained were summarized follows: 1. The digestibility in both sexes was increased by feeding artificial diet with $\alpha$-amylase and increase of the digestibility was greater in the female than in the male. 2. Larval body weight was increased in the female but was the male, compared with those in each sex of the control, respectively. 3. There was an increase of the single cocoon weight and cocoon shell weight, as compared with that of the control. 4. It was evident that the artificial diet containing $\alpha$-amylase was more effective than the control, and the effect of the diet was considerable higher in the female than in the male. 5. The amount of the blood sugar on the 7th day of 5th instar was decreased as compared with that of the control.

• The Korean Journal of Pesticide Science
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• v.14 no.1
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• pp.54-64
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• 2010

Effects of thirteen essential oils (anise oil, clove oil, marigold, mustard oil, neem oil, quassia, quilaja, rosemary oil, rotenone, tea tree extract, thyme oil, wintergreen oil, and yucca) and caffeine on typical industrial insect, silkworm (Bombyx mori) and two entomopathogenic nematodes, Steinernema carpocapsae GSN-1 strain (Sc) and Heterorhabditis sp. Gyeongsan strain (Hg) were investigated in the laboratory. When 1,000 ppm of each essential oils was treated, neem oil showed the highest insecticidal activity against silkworm. Mortality of silkworm fed on neem oil treated mulberry leaf was 55.3 and 100% 5 and 10 days after treatment, respectively. The silkworm fed on neem oil treated mulberry leaf did not make cocoon and pupa. Weight of cocoon and pupa was low in rotenone treatment showing 0.27 g and 1.01 g, respectively. Mustard oil had the highest nematicidal activity against entomopathogenic nematodes. 20 ppm of mustard oil resulted in 69.0% and 100% mortality of Sc and Hg 3 days after treatment, but 4% and 36% at 5 ppm in X-plate, respectively. Mortality of baited Galleria mellonella larva by Sc was not different from control at the concentration of 100 ppm of mustard oil while 30% lower in Hg in sand barrier. Mean numbers of established infective juveniles of Hg in Galleria larva were lower than Sc in sand barrier. Survival rate of Sc was similar to control at the concentration of <200 ppm of mustard oil in sand barrier.

• Korean journal of applied entomology
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• v.36 no.4
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• pp.317-322
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• 1997

Hatched-larvae of the mulberry longicorn beetle, Apriona germari Hope, collected from mulberry fields were reared on artificial diet at 25$^{\circ}$C with 14 h light and 10 h dark to study the larval developmental characteristics. Artificial diet developed for rearing silkworm was used with minor modification adding mulberry branch powder. In case of artificial diet rearing, the head width of larval instar from the I st to the 12th instars was ranged from 0.12 to 0.69cm, and growth rate of each instar was significantly high between the I st and the 2nd instars. In addition, the weight of the 8th instar larvae was increased approximately 176-fold in comparision with that of the 1st instar larvae. Larval duration of each instar took long with larval developmental stages, and that of the 1st to the 9th or the 12th instars was 186.03 or 304.58 days, respectively. The survival rate of larvae was 40.8% by the 8th instar. The pupation rate was approximately 32.4%. Furthermore, although pupation stage was broadly appeared from the 7th to the I lth instars, pupation was majorly observed at the 8th and the 9th instars.

• Journal of Sericultural and Entomological Science
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• v.24 no.1
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• pp.28-31
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• 1982

Flacherie virus (FV) is an important pathogen in the silkworm, which often gives serious damage to farmers for cocoon production. The inbred parents and F$_1$'s from an eight-parent diallel were examined to determine the inheritance of resistance to flacherie virus in the silkworm. Three resistant (R), two intermediate (M) and three susceptible (S) inbreds were used in the diallel with no reciprocals. Mean resistance was measured by survival rates of larvae which were fed on mulberry leaves sprayed with diluted mid-gut homogenate of FV infected larvae. Broad-sense heritability was obtained according to inbreds and F$_1$ family performance. Estimation of general (GCA) and specific combining ability (SCA) was made according to Griffing's Model 1, Method 2. Mean FV resistance of F$_1$ family displayed additive effect of the major gene, while heterotic effect was not significant. Considerable variation in FV resistance within F$_1$ groups of R$\times$S and S$\times$S indicated that action of minor genes for FV resistance may have been involved. FV resistance of inbreds perse and predominant effect of the major gene over minor gene(s) satisfactorily predicted the FV resistance of the hybrids. Broadsense heritability value of FV resistance on the basis of F$_1$ family performance averaged 93%, which suggested that environmental effects might have not been important in this experiment. GCA was highly significant for FV resistant among inbreds. GCA effect of 13.1 in Jam 108 was highest and -17.7 in Gyeongchu lowest. Effective selection for high FV resistance would be possible, using inbreds with high GCA effect and low GCA variance. SCA was significant among hybrids. High SCA effect in the hybrid of Geumho$\times$Mudeung (13.7) and Hansaeng #4$\times$Jam 115 (11.6) indicated that the interaction effect of minor genes for resistance to FV in the silkworm could be exploited by standard silkworm breeding procedures.

• Proceedings of the Korean Society of Sericultural Science Conference
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• 2003.10a
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• pp.28-33
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• 2003

Over 100 million people worldwide are chronic carriers of hepatitis C virus (HCV)(1). Chronic viral infections of the liver can prouess to cirrhosis, which may ultimately lead to hepatic failure or the development of hepatocellular carcinoma. There are a limited number of antiviral drugs on the market approved fur clinical management of chronic HCV infections; interferon-alpha (IFN$\alpha$) and the nucleoside analog ribavirin. However, whether used as monotherapy or in combination, adverse side-effects are associated with each drug and better therapeutic regimens are needed. (omitted)

• Proceedings of the Korean Society of Sericultural Science Conference
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• 2002.04a
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• pp.39-39
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• 2002

• Proceedings of the Korean Society of Sericultural Science Conference
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• 1997.06a
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• pp.103-117
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• 1997

Decrease in the cocoon production of Japan is drastic because of low price of cocoon, scarcity of successors and so on. To tide over the difficulty, the automation system in the sericulture was discussed and some trials have been conducted by the Ministry of Agriculture, Forestry and Fisheries of Japan. The attempts are based on a low cost artificial diet which does not rely on mulberry leaves. Automatic machines developed until now are a rearing machine constituted with repeated belt conveyor, an reformation type of former rearing machine "Bombyx" and a mounting machine. Running parallel with them, utilization of 20-hydroxyecdysone extracted from a plant to the mounting was also studied to use their machines efficiently in the fields. In conclusion, 10 tons of law cocoon will come to be produced by two persons labor. At present, an automatic rearing system on low cost artificial diet has been developing for the future sericulture.

• International Journal of Industrial Entomology and Biomaterials
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• v.48 no.1
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• pp.19-24
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• 2024

For over five millennia, humans have benefited from the valuable byproducts of Bombyx mori silkworms nourished on mulberry leaves and a multitude of potential applications remains available due to the diverse array of silkworm varieties. In this work, we discuss the utilization of Daehwangjam (DHJ), golden silk (GS), and Juhwangjam (JHJ), distinctive colored silks found in Korea, as chemosensors. These novel silks emit fluorescence under external stimuli and show a diminishing fluorescence intensity when exposed to HCl vapor. The considerable surface-to-volume ratio of these cocoons allows for the identification of 5 ppm, 300 ppm, and 3000 ppm HCl vapors through decreased fluorescence intensity. The results show the suitability of natural DHJ, GS, and JHJ for applications in biosensing applications.