• International Journal of Industrial Entomology and Biomaterials
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• v.3 no.2
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• pp.169-175
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• 2001

A synthetic juvenoid, R394 (Ethyl 9-cyclohexyl-3, 7-dimethyl-2, 4-nonadienoate) which is known to be a strong pest control agent was administered to silkworm, Bombyx mori L. in minute quantity for improving the silk yield. Based on the result of an earlier preliminary screening, three concentrations of the compound, viz., 0.1563, 0.3125, 31.25 nl/ml were prepared in the form of an emulsion and administered topically as a single dose, to separate batches of $5^{th}$ instar silkworm at 24, 48, 72 and 96 hrs to determine the required concentration and critical time of application for an economically favourable response. Two popular commercial silkworm hybrids, PM ${\times}$ NB4D2 (multivoltine${\times}$bivoltine) and KA${\times}$NB4D2 (bivoltine$\times$bivoltine) were subjected to the experiment. The medium and absolute control were maintained in parallel to compare the results. The results showed that 0.3125 nl/ml was the best concentration of the compound and 72 hrs of $5^{th}$instar was the most favourable age for its administration to get the maximum improvement in the commercial traits. The possible role of exogenous juvenoids in eliciting favourable response in silkworm which ultimately leads to improvement in the commercial traits is discussed.

• International Journal of Industrial Entomology and Biomaterials
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• v.14 no.2
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• pp.81-85
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• 2007

White Muscardine is the most common fungal disease of silkworm, Bombyx mori L. caused by the pathogenic fungus, Beauveria bassiana (Balsamo) Vuillemin. In the present investigation, an attempt has been made to screen locally available medicinal/ weed plants against Beauveria bassiana. Among the plant extracts (PE) tested, 5% aqueous crude extract of the bulb of Allium sativum (Garlic) has been found to be most effective against Beauveria bassiana. The radial growth of Beauveria bassiana in vitro was inhibited to the tune of 54.9% in aqueous extract and 54.4% in ethanolic extract of Allium sativum and correspondingly mycelial dry weight gave rise to 110.7 mg and 108.7 mg against 201.7 mg in control 15 days post treatment. Similarly, silkworm larvae topically inoculated with the Beauveria bassiana conidia ($1.8{\times}10^6/ml$) registered survival up to 53.0% against 0.0% in control after treatment with aqueous extract of Allium sativum. Simultaneously, as a preventive measure, silkworm larvae were put to rear in conidia contaminated seat paper instantly treated with aqueous extract of Allium sativum that also increased survival up to 61.0% against 4.6% in control. It is also observed that the plant extract is absolutely innocuous to silkworm.

• International Journal of Industrial Entomology and Biomaterials
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• v.22 no.2
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• pp.59-64
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• 2011

Protein kinase C (PKC) is involved in many cellular signaling pathways, it participates in many physiological processes, such as cell cycle, growth, proliferation, differentiation and apoptosis. To investigate the effect of PKC on the silkworm midgut tissue infection of Bombyx mori parvo-like virus (BmPLV), a B. mori atypical protein kinase C (BmaPKC) gene was cloned from larval midgut tissue, expressed in E. coli and purified. Additionally, the BmPLV susceptible silkworm strain and resistant silkworm strain were used to test the effect of the B. mori infection on BmPLV. The result showed that BmaPKC encodes a predicted 586 amino acid protein, which contains a C-terminal kinase domain and an N-terminal regulatory domain. The maximum expression amount of the soluble (His)6-tagged fusion protein was detected after 0.8 mmol/L IPTG was added and cultured at $21^{\circ}C$. The (His) 6-tagged fusion protein revealed about 73 kDa molecular weight which confirmed by western blot and mass spectrography. Furthermore BmaPKC protein were detected at 0-72 h post-infection in BmPLVinfected larval midgut tissue, western blot showed that as time went on, the expression of BmaPKC increased gradually in susceptible strain, the expression quantity on 72 h is 5 times of 0 h. However, in resistant strain, the expression quantity is slightly lower than susceptible strain. But no significant change in resistant strain was observed as time went on. The available data suggest that BmaPKC may involve in the regulation of BmPLV proliferation.

• International Journal of Industrial Entomology and Biomaterials
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• v.9 no.1
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• pp.131-135
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• 2004

Oral supplementation with potassium permanganate (30, 50 and 100 $\mu\textrm{g}$) to fifth instar larvae of the ${CSR_2}{\times}{CSR_4}$ race of the silkworm, B. mori resulted in a significant increase in the glycogen content of the fat body and haemolymph trehalose. The protein content of the fat body is also significantly increased in all the potassium permanganate treated groups where as that of the haemolymph is significantly increased only in the 30 ${\mu}g4 fed group. The total lipids content of the fat body increased significantly in all the potassium permanganate treated groups. This indicates that the potassium permanganate may stimulate metabolic activity, there by influencing the biochemical contents in the fat body and haemolymph of the silkworm, B. mori.

• International Journal of Industrial Entomology and Biomaterials
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• v.9 no.2
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• pp.249-254
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• 2004

Dietary supplementation of sodium nitrate with different concentrations 50, 100, 200, 500, 700 and 1000 $\mu\textrm{g}$/ml of single, two, three and four feeds to fifth instar larvae of biovoltine NB$_4$D$_2$ race of the silkworm, B. mori resulted in significant increase in the food conversion, conversion rate and conversion efficiency $K_1$ and $K_2$. However, there were significant decrease in the food assimilation, assimilation rate and assimilation efficiency in the sodium nitrate treated groups as compared with that of the corresponding parameters of the carrier control. This indicates that the administration of sodium nitrate may stimulate metabolic activities, thereby influencing conversion of food into body weight in the bivoltine silkworm, B. mori.

• Journal of Sericultural and Entomological Science
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• v.37 no.2
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• pp.121-126
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• 1995

The effects of oral application of fenoxycarb, the commercial formulation Insegar, to the selected developmental stages of the silkworm, Bombyx mori, was investigated. An oral application of the chemical to the silkworm from the 2nd- to the 5th-instar larvae delayed the larval development upto more than 40 days and increased the larval body weight in the range of 1.1 to 1.7 folds. When the chemical was orally applied to the final instar larvae, spinning and pupation were prevented, and consequently permanent larvae occurred. The weight of a cocoon and its shell of silkworm(bombyx, mori, L) increased following the application of fenoxycarb to the 2nd- and the 3rd-instar larvae.

• International Journal of Industrial Entomology and Biomaterials
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• v.6 no.1
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• pp.27-31
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• 2003

Infectious flacherie of silkworm Bombyx mori is caused by B. mori infectious flacherie virus (BmIFV) and causes severe crop loss to sericulturists. In the present study, a colloidal textile dye-based dipstick immunoassay is developed for the detection of infectious flacherie in silkworms. Colloidal textile dye (blue D2R) with Aλ$_{max}$ at 620 nm was sensitised with 500 $\mu\textrm{g}$/ml of purified anti-BmIFV IgG. The dye-antibody reagent detects purified antigen up to 10 ng/ml and BmIFV infection in diseased larval extracts $(up to a dilution of {10^-5})$ and faecal matter extracts $(up to a dilution of {10^-2})$ by forming clear blue dot within 30 min. It was observed to be stable for three months period at $4^{\circ}C$. The efficacy of textile dye-based dipstick immunoassay was on pay with HRP-based dipstick immunoassay and fluorescent antibody test, and better than latex agglutination and ouchterlony tests in the detection of BmIFV The dye-based dipstick immunoassay method provides a simple, sensitive and less expensive test for the detection of BmIFV infection in silkworms.s.

• Journal of Sericultural and Entomological Science
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• v.36 no.2
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• pp.186-188
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• 1994

• Journal of Sericultural and Entomological Science
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• v.17 no.2
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• pp.125-132
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• 1975

• Proceedings of the Zoological Society Korea Conference
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• 1994.10a
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• pp.183.2-183
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• 1994