• International Journal of Industrial Entomology and Biomaterials
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• v.10 no.2
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• pp.107-117
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• 2005

Oral supplementation of minerals mixture of potassium bromide and nickel sulphate on $CSR_2,\;CSR_4\;and\;CSR_2{\times}CSR_4$ crossbreed races with different concentrations (70, 110 and $160\;{\mu}g/ml$) were fed to the fifth instar larvae. Two of the four normal feeds per day was substituted with treated leaves fed to silkworm at fifth instar larvae. The controls were fed with the leaves sprayed with distilled water and normal leaves. The $CSR_4$ race treated larvae showed a significant increase in silkgland weight, cocooning percentage, female cocoon weight, male cocoon weight, male cocoon shell weight, male cocoon shell ratio, filament length, filament weight, denier, fecundity, number of eggs per ovariole and length of the ovariole when compared with those of the corresponding parameters of the carrier control, whereas in $CSR_2\;and\;CSR_2{\times}CSR_4$ crossbreed races showed a significant increase in larva1 weight and other parameters similar to that of $CSR_4$ race. The results suggested that the silkgland showed good response to minerals mixture of potassium bromide and nickel sulphate only in $CSR_4$ race when compared with those of other two races of the silkworm, B. mori.

• Journal of Sericultural and Entomological Science
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• v.29 no.2
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• pp.15-23
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• 1987

The strain differences in larval walking behavior of 39 silkworm varieties, Bombyy mori, have been investigated. larval walking distance in silkworm varieties were remakably different. The walking distance was the longest in the matured larvae following the newly hatched larvae and in the other larval stage the distance was very short. The means of the walking distance in larval stages were as follows ; newly hatched larvae was 2.58cm, 3rd instar 0.72cm, 5th instar 1.18cm and matured larvae 2.94cm. The length of relative walking distances in each variety was not always in proportion to each larval stage. Therefore, the controlling factor of walking behavior was assumed to be different by the each larval stage. In the newly hatched larvae, 3rd instar and 5th instar larvae, the distribution range of walking distance was very broad in European races, narrow in Chinese races and medium in Japanese races. There was not much differences in the walking distance of mature larvae among European, Chinese and Japanese races.

• International Journal of Industrial Entomology and Biomaterials
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• v.2 no.2
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• pp.181-184
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• 2001

The effect of topical application with 10, 20 and 30 $\mu\textrm{g}$/ml cortisone and hydrocortisone to the fifth stadium larvae of the silkworm, B. mori on fat body glycogen, protein, total lipids, phospholipids, neutral lipids and haemolymph trehalose and protein has been studied. The fat body glycogen haemolymph trehalose significantly decreased in all the treated groups except in the 10 and 20 $\mu\textrm{g}$/ml treated groups. The fat body protein increased significantly in all the cortisone and hydrocortisone treated groups except in the group treated with 10 $\mu\textrm{g}$ hydrocortisone. Whereas that of haemolymph protein significantly increased in all the groups treated with cortisone and hydrocortisone. The total lipids, phospho1ipids and neutral lipids of the fat body decreased significantly in all the groups treated with cortisone and hydrocortisone when compared with that of carrier control.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.2
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• pp.136-140
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• 2008

In order to utilize the silkworm larvae (Bombyx mori) protein, defatted silkworm protein was hydrolysed by four enzymes (pepsin, trypsin, neutrase and alcalase) at various hydrolysis times (6, 12, 18, 24 and 30 hr) and suspension concentrations (2, 5, 10, 15 and 20%). Protein solubility index, ACE (angiotensin converting enzyme) inhibitory activity and antioxidative activity of silkworm protein hydrolysates were investigated. The optimum condition of hydrolysis was 10% suspension concentration and 18 hr. Protein solubility index of trypsin treatment was higher than other enzyme treatments. ACE inhibitory activity and $IC_{50}$ value of antioxidative activity of neutrase treatment were 86.16% at $100\;{\mu}g/mL$ and $352.75\;{\mu}g/mL$, respectively; also, these values were higher than other enzyme treatments.

• International Journal of Industrial Entomology and Biomaterials
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• v.12 no.2
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• pp.75-80
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• 2006

Changes in the levels of protein and free amino acids in the haemolymph of three selected races of the silkworm, Bombyx mori viz., PM, $NB_4D_2$ and $CSR_2$, were investigated during 4th moult, 5th instar and pupal period. The levels of total protein in the haemolymph, increased from first day of 5th instar till sixth day. From seventh day till spinning, the protein levels decreased in all the three races. A sustained decrease in the haemolymph proteins was observed during the pupal development in all the three races. The levels of free amino acids, which were high during 4th moult, declined through the 5th age of larval development till spinning. PM showed a relatively higher free amino acid level (3.192 mg/ml) in haemolymph followed by $NB_4D_2$ (2.601 mg/ml) and $CSR_2$ (2.35 mg/ml). The free amino acid levels decreased gradually from prepupal stage but increased again at the end of pupal period. Racial differences in the changes in the levels of protein and free amino acids in the haemolymph were observed in the larvae and pupae when subjected to two high temperature regimes of $30^{\circ}C$ and $35^{\circ}C$. The results showed that high temperature induces specific changes in the metabolism (reversible thermal stress) that have different adaptive value in different races of the silkworm. Relatively higher increase in the free amino acid levels in the haemolymph of Pure Mysore presumably provides protective cover to tissues against high temperature by an increase in osmolarity and reduction in evaporative water loss. The absence of such a mechanism may be responsible for temperature susceptibility of the bivoltine races like $NB_4D_2$ and $CSR_2$.

• Journal of Microbiology and Biotechnology
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• v.11 no.4
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• pp.585-591
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• 2001

To compare the p10 promoter activity of Bombyx mori nucleopolyhedrovirus (BmNPV)K1 and K4, recombinant viruses Bm101-LacZ and Bm104-LacZ with a lacZ gene under the control of each p10 promoter were constructed. The $\beta$-galactosidase activity due to Bm101-LacZ was about 5.5- and 1.1-fold higher than that due to Bm104-LacZ and BmK1-LacZ, respectively. expressing ${\beta}$-galactosidase under the control of a polyhedrin promoter. The recombinant virus BmK1-104LacZ with the same genome structure as Bm101-LacZ, except for a p10 promoter region, produced a similar ${\beta}$-galactosidase activity to that due to Bm104-LacZ and 5.5-fold lower than that due to Bm101-LacZ. The virus yield, expression level of polyhedrin, and polyhedra productivity for each recombinant virus was almost similar. These results suggested that the difference in the expression level of ${\beta}$-galactosidase resulted from a difference in the p10 promoter regions, and that an expression vector using the p10 promoter of BmNPV-K1 could be usefully exploited in the mass production of foreign proteins with silkworm larvae by means of oral ingestion.

• Current Research on Agriculture and Life Sciences
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• v.18
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• pp.43-51
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• 2000

Eleven inbred lines of silkworm, Bombyx mori L. were exposed to two main different temperature (23C and 25C) during the larval period in order to elucidate the effect of the temperature differences on their main characters under the, prevailing in Egyptial agro-climactic conditions. The results show that the temperature differences did not affect significantly the pupation ratio and cocoon shell ratio. However, they affected their larval duration to become shorter with the high temperature treatment ($27^{\circ}C$) and their cocoon shell weight and cocoon yield per box of silkworm eggs to be higher in the lower temperature($23^{\circ}C$). It was recommended that some inbred lines should be bred at the 23C throughout the whole larval period, particularly in being reared with high nutritional leaves in order to maximize the hybridization of cocoon yields.

• International Journal of Industrial Entomology and Biomaterials
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• v.8 no.1
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• pp.33-41
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• 2004

The type of trichomes, their density and pattern of distribution on leaves of 16 genotypes of mulberry, belonging to both diploid and polyploid categories, were studied by scanning electron microscope. The present investigation was undertaken to find out the relationship of physical attributes, especially the density and trichome types with higher acceptability and better rearing performance by the silkworm Bombyx-mori L. Two types of trichomes glandular and non-glandular types were observed on both the leaf surfaces of all the mulberry genotypes studied. In general, greater densities of trichomes were observed on the abaxial surface than the adaxial surface of leaves in most of the genotypes. Distribution of glandular trichomes were more in abaxial surface and non-glandular trichomes were more in adaxial surface. Overall, distribution of glandular and non-glandular trichomes per unit area of leaf did not follow any regular pattern. When leaves of those genotypes were fed to silkworms, trichome density was found to be significantly negatively correlated with the survival of larvae i.e., effective rate of rearing, but trichome density did not influence the economic characters of rearing. As the distribution of glandular trichomes (GT) and non-glandular trichomes (NGT) did not follow any definite pattern, no relation could be established between the GT and NGT densities with silkworm rearing performance. However, the ratio of GT and NGT in a particular genotype influenced the rearing parameters, higher the ratios better the rearing performance. High GT and NGT ratio (＞1.00) was found positively significant when correlated with economic parameters viz., larval weight, single cocoon weight and single shell weight. The study is useful in screening different mulberry genotypes for their better acceptability to silk-worm and higher rearing performance at the early stage of selection without actually conducting the rearing.

• International Journal of Industrial Entomology and Biomaterials
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• v.8 no.2
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• pp.151-159
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• 2004

A detailed evaluation of relative toxicity of fluoride to die 5th instar larvae of PM and NB$_4$D$_2$ races of silkworm and the effects of lethal, sublethal and prevailing levels of fluoride in groundwater on the growth, economic characters and fecundity of the silkworm, Bombyx mori (Lepidoptera: Bombycidae) were studied. The feeding of mulberry, Morus alba leaves treated with lethal and sublethal doses of fluoride to PM and NB$_4$D$_2$ races of silkworms from the beginning of the 5th instar to the end of the feeding period resulted in significant reduction in growth, single cocoon weight, single shell weight, silk index, average filament length, and fecundity when compared to controls. These manges were more pronounced on exposure to lethal dose than sublethal dose and in general, the changes induced by fluoride were more striking in NB$_4$D$_2$ than PM, indicating the greater resistance of PM to higher fluoride levels. Groundwater quality in sericulturally important villages of Karnataka and Andhra Pradesh States has been studied with special reference to the presence of fluoride. On exposure to dose of prevailing levels in the waters of sericulturally important areas, die changes observed on growth, economic characters and fecundity were slightly lower when compared to controls and the decrease was found to be insignificant (P$\geq$0.05). It was concluded that, though minute dose (4.0 ppm) of fluoride did not have any toxic impact, it is toxic at higher concentrations to silkworms.

• International Journal of Industrial Entomology and Biomaterials
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• v.31 no.2
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• pp.85-89
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• 2015

This peptide has antibacterial activity against several Gram-positive and Gram-negative bacteria. Bombyx mori cecropinB1(BmCecB1) is antimicrobial peptides from Bombyx mori and belongs to cecropin family. Antimicrobial peptides are important components of the innate immune systems in all living organism. To produce the BmCecB1 antimicrobial peptide, we constructed transgenic silkworm that expressed BmCecB1 gene under the control BmA3 promoter using piggyBac vector. The use of the 3xP3-driven EGFP cDNA as a marker allowed us to rapidly distinguish transgenic silkworm. Mixtures of the donor vector and helper vector were micro-injected into 600 eggs of bivoltin silkworms, Baegokjam. In total, 49 larvae (G0) were hatched and allowed to develop into moths. The resulting G1 generation consisted of 22 broods, and we selected 2 broods containing at least 1 EGFP-positive embryo. The rate of successful transgenesis for the G1 broods was 9%. We identified 9 EGFP-positive G1 moths and these were backcrossed with wild-type moths. With the aim of identifying a BmCecB1 as antimicrobial peptide, we investigated the Radical diffusion Assay (RDA) and then demonstrated that BmCecB1 possesses high antibacterial activities against Gram-negative bacteria.