• International Journal of Industrial Entomology and Biomaterials
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• v.17 no.1
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• pp.157-163
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• 2008

Infection of pathogenic microsporidia, Nosema bombycis and Nosema mylitta (Chakrabarti and Manna, 2006) decreased egg production, fecundity, hatching % and increased sterile eggs in heavily infected mulberry silkmoth, Bombyx mori L. On an average a disease free moth laid upto 442.67 eggs with high hatching % (99.53) and less sterile eggs ($0.47{\sim}2.00%$). While an infected moth laid less number of eggs ($7.00{\sim}412.00$) with low hatching % ($32.437{\sim}98.643$) and high sterile eggs ($2.143{\sim}129.571$). Fecundity of disease free laying was highest (468.714) during season-1 then gradually decreased during season- 2 (414.000) to season- 3 (404.285). But fecundity of an infected laying was highest during season-2 and hatched eggs were lowest during season-2. Higher inoculums concentration of N. mylitta infected to 5th stage larva of mulberry silkworm drastically decreased the fecundity in season - 3 and lower inoculums concentration of N. bombycis decreased the fecundity in season-1 and 3. Season-3 was most effective season to decrease the fecundity and increase sterile eggs when both temperature and humidity were fluctuated from the optimum level.

• International Journal of Industrial Entomology and Biomaterials
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• v.16 no.1
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• pp.1-5
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• 2008

The present study was carried out with the aim to evaluate the viability of layings (delivery of fertilized and unfertilized eggs) with egg laying duration of elite bivoltine races. The temporal aspect of mating in terms of egg layings duration may also have impact on the number of eggs laid, pattern of egg laying and their viability. After different interval of egg laying duration, moth of Bombyx mori are removed from oviposition site after they have completed egg laying. Present investigation confirmed that there are no significant difference in relation to the occurrence of viable (fertilized) and non viable (unfertilized) eggs and duration of oviposition. Percentage of unfertilized eggs varied from 2.41 to 3.42% in case of CSR-3, 2.59 to 3.62% in case of CSR-6, 2.82 to 3.66% in case of CSR-16 and 2.58 to 3.40% in case of CSR-17 in different treatments. The occurrence of unfertilized eggs are also not significant in the different treatments specially in those eggs which were laid 24 hours after oviposition and kept for 4 months hibernation schedule.

• International Journal of Industrial Entomology and Biomaterials
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• v.18 no.1
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• pp.1-7
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• 2009

Quality of seed in the mulberry silkworm, Bombyx mori (L.) is determined by many important factors, wherein unfertilized eggs play an important role. Unfertilization of eggs are caused by several reasons such as, abnormality in the sexual organs of the male and female, abnormal development of the micropylar end of the egg, unfavorable environmental conditions during spinning, cocoon preservation, imperfect handling of moths, mating, ovipostion, cold storing of pupae / moths and indiscriminate use of male moths etc. Though the presence of unfertilized eggs would in no way affect the fertilized ones and their quality directly, the frequency of their occurrence underrates the quality and brings down the hatching percentage. Lower the occurrence of unfertilized eggs, higher is the rating of seed quality. Of the various intrinsic and extrinsic factors and events involved in egg deposition of an adult silk moth, mating is an instinct and a biological obligation for the ultimate perpetuation of the species and a must to provide stimulus for oogenesis and bring about biochemical changes in the spermatophore of the silkworm in order to ensure the presence of sufficient number of normal sperms and testicular fluid in the female reproductive organ, activating ovulation and accelerating oviposition behavior and egg deposition. An attempt has been made in this article to briefly elucidate the characteristics of unfertilized eggs, causes of their occurrence and its impact as well as the significance in silkworm seed production.

• International Journal of Industrial Entomology and Biomaterials
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• v.7 no.2
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• pp.235-239
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• 2003

The silkworm Bombyx mori L. was studied as the potential “host” of popular in Uzbekistan biocontrol ectoparasite, entomophagous Bracon hebetor Say. Being one of representatives of economic-beneficial insects, the silkworm (larvae, pupae and imago) can be used as highly sensitive test organism for revealing of neuro toxic effects of insects venom as well as of their purified components in screening assays. In comparative aspect, except a mulberry silkworm, representatives of Uzbekistan pests cotton-boll worm Helycoverpa armigera Hbn., lesser mulberry pyralid Glyphodes pyloalis Wlk., codling moth Corpocapsa pomonella L., malaria mosquito Anopheles claviger and Colorado potato beetle Leptinotarsa decemlineata Say have been subjected to insect toxic test of bracon venom gland extract (VGE) and its fractions which were obtained by gel-chromatography on Sephadex G-100. The paralyzing effect of the VGE and its fractions was shown in a various degree on the pests.

• International Journal of Industrial Entomology and Biomaterials
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• v.6 no.1
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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.

• Journal of Sericultural and Entomological Science
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• v.36 no.1
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• pp.26-29
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• 1994

The topical application of methoprene a kind of juvenile hormone(JH) on 4th instar larvae at 48th hour after ecdysis-3 , followed by insulin on 5th instar larvae and silkgland weights, cocoon weight and cocoon shell weight, and fecundity ; and significantly decreases percent of cocooning and moth emergence. After treatment with methoprene followed by insulin, cocoon weight increase by 17~20% and cocoon shell weights by 18~32% respectively.

• International Journal of Industrial Entomology and Biomaterials
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• v.9 no.2
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• pp.261-264
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• 2004

Kolar gold (PM${\times}$CSR2) is the most popular cross breed of India, especially in Karnataka. During January - February 2004 we observed several phenotypic variations leading to poor survival. Though occurrence of morphologically abnormal individuals is common, the extent of occurrence in the present report was on the higher side (upto 6 percent). It is unwarranted and not desirable in commercial silkworm rearing. The variations exhibited might be due to change in the environmental conditions like incubation temperature during embryonic stage or spontaneous mutation resulting out of environmental stress.

• International Journal of Industrial Entomology and Biomaterials
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• v.1 no.1
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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.

• International Journal of Industrial Entomology and Biomaterials
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• v.1 no.1
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• pp.41-45
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• 2000

The effect of topical application with hydrocortisone on economic parameters was analysed following treatment of last larval stadium. The treated larvae showed a significant increase in larval weight at higher concentrations along with other enhanced larval, cocoon and adult parameters. This suggests that hydrocortisone can be used effectively for commercial silkworm rearing. The larvas period was significantly increased in all the treated groups with increased female cocoon weights, its shell weights and male cocoon shell weight at 20$\mu\textrm{g}$/ml treated group. Filament length, weight and denier were increased significantly in all the treated groups. Moth emergence percentage, length of the ovariole, eggs per ovariole, fecundity and rind hatching percentage were unaffected when compared with that of the carrier control group. This suggests that hydrocortisone in addition to affecting larval growths also affect silk crop.

• International Journal of Industrial Entomology and Biomaterials
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• v.45 no.1
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• pp.17-21
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• 2022

The present study aimed to determine whether a hemolymph prepared from Antheraea yamamai larvae had the same biological activities using a Bombyx mori hemolymph prior to exposure to lipopolysaccharide (LPS) in order to induce an inflammatory response. The effects of the hemolymph were determined using a reverse transcription-quantitative polymerase chain reaction to assess the expression of pro-inflammatory molecules. The A. yamamai hemolymph exerted anti-inflammatory effects on LPS-activated human monocytic leukemia cells via Toll-like receptor (TLR) 4-mediated suppression, similar to the B. mori hemocyte extract. Treatment with the A. yamamai hemolymph significantly suppressed LPS-induced upregulated inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) mRNA expression at all tested concentrations compared with the control, similar to the B. mori immune-challenged hemolymph. Finally, the A. yamamai hemolymph, like the B. mori immune-challenged hemolymph, suppressed all of these concentrations in a dose-independent manner. These results demonstrate that the hemolymph of A. yamamai exhibited important biologically active substances. Further in-depth functional studies are required to fully understand the mechanisms underlying the biological activities of wild-type silkworm hemolymphs.