• International Journal of Industrial Entomology and Biomaterials
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• v.7 no.2
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• pp.203-208
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• 2003

Rearing temperature influences food consumption, conversion and cocoon production in silkworm Bombyx mori L. Young age $({1^st}to{3^rd} instar)$ worms of Pure Mysore, a multivoltine were reared at 26, 28, 30 and $32^{\circ}C$ followed by combinations of these temperature levels during late age $({4^th} and {5^th} instar)$. Food consumption, conversion, larval duration and growth for each instar were recorded. The influence of combinations of these temperature levels during rearing on survival and cocoon production was assessed. Food consumption increased with the temperature up to $4^th$ instar and decreased during $5^th$ instar. Temperature beyond $28^{\circ}C$ during young age followed by higher temperature ($30^{\circ}C$ and above) has shown deleterious effect on cocoon production. The paper discusses the rearing performance in relation to food intake and conversion under the tested temperature levels.

• International Journal of Industrial Entomology and Biomaterials
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• v.6 no.1
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• pp.21-25
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• 2003

The implications of temperature $(25, 30 and 35{\times}1^{\circ}C)$ and relative humidity $(60, 70 and 80{\times}2%)$ on the moulting pattern, moulting duration and moulting survival were studied in the silkworm, Bombyx mori L. Larvae of two pure silkworm breeds, Pure Mysore (PM) and NB$_4$D$_2$and their hybrid, $PM{\times}NB_{4} D_{2}$ were reared under experimental conditions under natural day photoperiodic (LD 12:12) condition. Two developmental marker events in the fourth moulting, settling for moult (SM) and completion of moult (CM) occurred at or around the middle of the photophase. The computed mean vector (equation omitted), based on the circular statistics also confirmed the above. Temperature and humidity did not alter the moulting rhythmicity much. However, extreme temperature and humidity conditions reduced moulting survival in PM and $PM {\times}NB_{4} D_{2}$. Further, moulting survival reduced below the economic level in $NB_{4} D_{2}$. The temperature and humidity together seem to exert synergic impact on the moulting survival of the silkworm Bombyx mori, at least in $NB_{4} D_{2}$.

• International Journal of Industrial Entomology and Biomaterials
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• v.2 no.2
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• pp.149-153
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• 2001

The influence of baculovirus Bombyx mori Nuclear Polyhedrosis virus (BmNPV) infection on intermediary metabolic pathways in silkworm Bombyx mori L. was investigated. Studies revealed that NADP-linked malate dehydrogenase activity in hemolymph of infected silkworms at 96 hrs post infection (p.i.) with visible symptoms of infection was enhanced in comparison to healthy larvae of the same age. Also, NADP-dependent MDH activity was significantly lower in fat body cytosol of infected larvae at 96 hrs p.i. when compared to healthy larvae. Similarly, some biometabolic parameters like growth, protein content and cholesterol titer were observed to be influenced by baculovirus infection. While the growth of infected larvae was significantly retardedi protein content was also drastically reduced in both hemolymph and fat body tissues. Cholesterol titers however, was enhanced in infected larvae. The results observed herein point to a significant change in the normal biochemical and biometabolic pathways required for growth and development following BmNPV infection.

• International Journal of Industrial Entomology and Biomaterials
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• v.19 no.2
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• pp.215-219
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• 2009

The effect of mating duration and multiple use of male on fecundity and fertility was investigated in the hybrids of Silkworm, Bombyx mori L. One hour to five hours of mating duration did not affect egg laying (fecundity) significantly, while fertilization affected significantly. Below 50% fertility was noticed when mating duration was reduced to below two hours. Similarly multiple use of male caused significant reduction in fertility but not fecundity. Till fourth mating no significant reduction in fertility was observed, thereafter fertility reduced considerably.

• International Journal of Industrial Entomology and Biomaterials
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• v.18 no.1
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• pp.49-52
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• 2009

An in vitro and in vivo studies were conducted to evaluate the antibacterial efficacy of certain botanicals viz., rhizomes of turmeric (Curcuma longa) and leaves of amla (Phyllanthus emblica), asparagus (Asparagus racemosus), bael (Aegle marmelos), boerhavia (Boerhavia diffusa), garlic (Allium sativum) and basil (Oscimum basicilum) against bacterial pathogens viz., Staphylococcus sp., Bacillus sp. and Klebsiella cloacae, of silkworm, Bombyx mori. Asparagus and basil, amla and boerhavia, basil and bael at concentration of 20, 000 ppm showed higher antibacterial activity against Staphylococcus sp., Bacillus sp., K. cloacae respectively, both in vitro and in vivo studies.

• International Journal of Industrial Entomology and Biomaterials
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• v.11 no.2
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• pp.93-98
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• 2005

Studies on extended egg preservation schedule from 120 days to 180 days was taken up with 20 germplasm accessions of mutant silkworm genetic stocks of Bombyx mori L. Statistical analyses of the data collected over three trials revealed no significant changes both in the qualitative and quantitative traits of the genetic stocks between treatment (6 months egg preservation) and control (4 months egg preservation), except for fifth instar larval duration in TMS-61, TMS-62, TMS64, TMS-31 and TMS-34 shell weight in TMS-62, TMS-64 and TMS-66. Thus, the results indicate that extended schedule of 6 months egg preservation can safely be adopted, which will reduce the cost of conservation and minimize the genetic erosion owing to reduced crop cycle.

• International Journal of Industrial Entomology and Biomaterials
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• v.11 no.2
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• pp.135-138
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• 2005

Two pairs of DNA primers were designed for the detection of the Zhenjiang (China) strain of Bombyx mori densonucleosis virus (BmDNV-Z). These primers were designed from the nucleotide sequence of major structural protein gene (putative VD1-ORF2). PCR amplification was attempted from different issues (including silk gland, blood, skin and midgut) and feces of the silkworm which infected wit BmDNV-Z were amplified by PCR. Both of the primers gave expected size of in the DNA bands from midgut and feces, but not in the DNA of silk gland, blood and skin. The two bands were sequenced, and their sequence were same as the sequence designed for. BmDNV-Z could be successfully detected in single silkworm after it was infected for 12 hrs, and could not be detected before 9 hrs after infected.

• International Journal of Industrial Entomology and Biomaterials
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• v.7 no.1
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• pp.87-91
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• 2003

BmNPV (Bombyx mori nuclear polyhedrosis virus) causes nuclear polyhedrosis in silkworms. The tolerance of silkworms to BmNPV is controlled by polygenes. This paper reports on the relative tolerance of silkworm breeds among the germplasm maintained at Andhra Pradesh State Sericultural Research ＆ Development Institute (APSSRDI), Hindupur, India. The silkworm larvae out of second moult were per orally inoculated with BmNPV polyhedra $(l{\times}l0^{th}//ml)$ and reared upto spinning. The response to BmNPV had been categorized into apparent tolerance, real tolerance and susceptibility. Among the 145 silkworm breeds screened, 18 bivoltines and 16 polyvoltines were found to have real tolerance to BmNPV.

• International Journal of Industrial Entomology and Biomaterials
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• v.5 no.1
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• pp.53-57
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• 2002

The growth and multiplication of Aspergillus flavus Link and A. tamarii Kita were observed in vitro under variable temperatures of $22-31^{\circ}C$. The matte weight of mycelium and number of conidia/ml were significantly higher (P < 0.01) at the higher temperature than the lower temperature in both the species of Aspergillus. In vivo the mortality in silkworm, Bombyx mori L. with the infection of Aspergillus species was significantly (P < 0.01) different at different temperature and relative humidity conditions.

• International Journal of Industrial Entomology and Biomaterials
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• v.13 no.2
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• pp.119-122
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• 2006

As the Selenium is known to be growth promoter in sheep and cattle, the efficacy of selenium has been tested in silkworm Bombyx mori L. The V instar larvae were fed with lethal and sub-lethal doses of selenium treated leaves. The larvae fed with lethal dose showed a significant decrease in growth and Cocoon commercial characters. The treatment with sub lethal dose exhibited a significant increase in the growth of the silkworm. Correspondingly, the cocoon commercial characters on exposure to the lethal dose showed significant decrease and sub lethal dose showed a significant increase. In the light of similar findings reported earlier in other cocoon crops and vertebrates, it can be inferred that selenium at lower doses acts as a growth stimulator, resulting in the higher yield of cocoon crop.