• Proceedings of the Korean Society of Sericultural Science Conference
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• 2002.10a
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• pp.74-74
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• 2002

No Abstract, See Full Text

• International Journal of Industrial Entomology and Biomaterials
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• v.3 no.1
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• pp.105-108
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• 2001

The wild entomopathogenic fungi, Cordyceps militaris, were collected at the Whawang mountain, Korea. The pupae of the silkworm, Bombyx mori, were used as infecting hosts for the production of the silkworm-mili-taris dongchunhacho, silkworm vegetable wasps and plant worms with C. militaris. Three inoculation methods in terms of injection, spray and immersion were tested against the silkworm pupae. The three inocu1ation methods revealed 100% infectivity to the silkworm pupae tested. Of the three inoculation methods, the injection method was highly effective in the reduction of the period required for the endosclerotium and the completion of fruiting body formation. These results indicate that the silkworm pupae are very effective host insects for the production of C. militaris.

• International Journal of Industrial Entomology and Biomaterials
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• v.5 no.2
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• pp.189-194
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• 2002

Silkworm diseases are major constraint in silk cocoon production. Among silkworm diseases, white muscar-dine is highly contagious and most common in winter and rainy seasons. It is suggested that hemocytes involve in defense against invasion of Beauveria bassi-ana and systemic fungicide/chemicals prevent the proliferation of fungi in the hemolymph or preventing the growth of the fungi in the body cavity through enhancing the hemocyte mediated defense response. In the present study the influence of systemic fungicide on hematological changes in silkworms infected with Beauveria bassiana was reported. It is observed that the total hemocyte counts increased in the hemolymph up to 5 days post inoculation in systemic fungicide treated batches while in the inoculated control the increase was up to 3 days indicating the positive hemocyte mediated response in silkworm treated with systemic fungicide. After 2 days in the inoculated control as the multiplication and growth of mycelia increased, defense capacity of the silkworm was decreased. The biochemical changes were also observed in the hemolymph of silkworm infected with B. bassiana. In silkworm infected with Beauveria bassi-ana, the total protein content increased whereas total carbohydrate and total lipids decreased as the infection progresses. In the case of systemic fungicide treated batches the increase in total protein content was comparatively higher and decrease in total carbohydrate and lipids were comparatively lower than the inoculated control.

• International Journal of Industrial Entomology and Biomaterials
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• v.11 no.2
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• pp.119-124
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• 2005

To determine the level of heterosis, higher cocoon shell weight multivoltine congenic lines (Con. L) and bivoltine syngenic lines (Syn. L) of silkworm were used for crosses. First filial generations $(F_1s)$ expressed heterobeltiotic genetic interaction at significant magnitude (p < 0.01) for single cocoon shell weight (SCSW). The other linked characters viz., single cocoon weight (SCW) and yield by weight per 10, 000 larvae were also significantly higher (p < 0.01) than the better parental lines. All the hybrids showed significant improvement for these aforesaid characters over standard heterosis (Standard check). The reeling parameters viz., filament length, raw silk, neatness, cohesionstrokes etc, also showed improvement among the hybrids than check in congenial environment. Overall results suggested that the cross between congenic and syngenic lines provide better heterosis with good quality silk than conventional hybrids and may be used for commercial exploitation.

• International Journal of Industrial Entomology and Biomaterials
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• v.4 no.1
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• pp.5-11
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• 2002

Seven fungicides viz., salcylic acid, bacistin (Carbandazim 50% WP), bayleton (Triadimefon 25% WP), Dithane M-45 (Mancozeb 75% WP), captan (Captaf 50% WP) formaldehyde and benzoic acid at three concentrations (0.50,0.75 and 1.0%) and ten plant products viz., Hena leaf, garlic bulb, tomato leaf, mango bark, cotton leaf, turmeric powder, onion, tulsi leaf, neem leaf and ginger at 1.0,2.0 and 3.0% concentrations were screened against Aspergillus flavus and A. tamarii in vitro. Among fungicides, salcylic acid and bavistin and among plants Hena and Mango bark powder were found to be very effective at all concentrations tested. Based on in vitro screening, only selected six fungicides at 1.0, 1.5 and 2.(0% and six plants at 2.0,4.0 and 6.0% concentrations were tested in vivo for controlling Aspergillosis in silkworm. Salcylic acid and bavistin fungicides and Hena leaf powder and Mango bark powder have shown considerable effect in controlling Aspergillus infection in silkworm at all concentrations tested.

• Journal of Sericultural and Entomological Science
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• v.39 no.1
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• pp.22-29
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• 1997

Ultraviolet weavelength (UV) of 366 nm produced clearer fluorescent dolor than that of 254 nm for the inspection of silkworm cocoons. Fluorescent color of silkworm cocoons varied in color, appears no relationship with the natural color under the normal light. Uniformity of fluorescent color was improved by selection of blue or yellow line from wild types. Blue and yellow, located at the opposite poles on the color solid and L*a*b* color system, confirmed as pure standard of fluorescent color in the silkworm races for commercial white cocoons. the cocoons with blue fluorescence occupied as high as 1.7 to 8.6 times than those with yellow in the Japanese silkworm races. Fluorescence of silkworm cocoon was not affected by forced flow dry at 70$^{\circ}C$ for 6 hrs. While the Japanese races revealed no sexual difference in fluorescent color, sex-dependence of the color was common in the Chinese races for commercial white cocoon. The fluorescence of cocoon shell of Chinese races showed clear separation of blue of median color. Silkworm strain of Dc20 and Fc24 were sexualy segregated 98.8${\pm}$1.20%, 99.0${\pm}$1.00% by cocoon fluorescence, as that of 99.3${\pm}$0.44% by typical larval marking of sex-limited inheritance. Specific expression of cocoon fluorescence, applicable to breeding of simple discrimination of sex for Chinese races, inspected thoroughly on the surface and inner layer of cocoon shell.

• The Korean Journal of Pesticide Science
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• v.13 no.3
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• pp.177-184
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• 2009

This study was carried out to investigate infection process, symptoms and main component of the domestic silkworm, Bombyx mori. larvae and pupa infected with the entomopathogenic fungus Cordyceps, Paecillomyces tenuipes. The Cordyceps, Paecillomyces tenuipes, was highly infectious to the silkworms. A pathogenicities of Cordyceps, Paecillomyces tenuipes, may be highly virulent because of the low resistance or high susceptibility of the silkworms. The silkworm larva infected with Cordyceps formed phialospores on the phialides at the imperfect stage of the genus Cordyceps, But silkworm pupa infected with Cordyceps formed ascospores in the asci at the perfection stage of the genus Cordyceps. The results of analysis of health silkworm pupa and silkworm pupa infected with Cordyceps were obtained that amino acid, fatty acid, and nucleoside were very different.

• International Journal of Industrial Entomology and Biomaterials
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• v.7 no.1
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• pp.75-78
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• 2003

This study was carried out to investigate the mineral content of the feces of the $5^th$ instar larvae in a few silkworm species such as a parent domestic silkworm (Jam134), a hybrid (Kumok-jam), the Japanese oak silkworm, and the Chinese oak silkworm. The major minerals of all silkworms throughout all $5^th$ instar larval period are K, P, Mg and Ca, and the result is consistent with the previous study of the mineral content in the mulberry leaves. Although the calcium content decreased sharply at $7^th$ day of the $5^th$ instar, the crude protein content significantly increased at the same age in both domestic silkworms, suggesting a direct relationship between feeding behavior of the silkworms at the larval period and mineral/protein contents. However, this trend was not observed in both oak silkworms. In the comparison of the mineral content among silkworm species, two domestic silkworms were significantly higher in the calcium content compared with two oak silkworms, and the hybrid Kumok-jam was further higher significantly than the feces of parental Jam 143. Excluding the calcium content, overall no significant content variation in other minerals was observed among four silkworm species studied in this study.

• Journal of Sericultural and Entomological Science
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• v.40 no.2
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• pp.117-125
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• 1998

Entomopathogenic nematodes, Heterorhabditidae and Steinernematidae, were isolated from the soil of mulberry field, and the high infectivity and invesiveness were confirmed in the silkworm, Bombyx mori. The cause of non-microbial and acute flacherie was found as an disease by infection with soil-born nematodes through the mulberry leaves contaminated with soil and rainwater. The causal nematodes were isolated by silkworm trap from all of the 5 soil samples collected on the 5 mulberry fields, and identified as 3 strains of Heterorhabditis sp. and 2 of Steinernema sp. Rainwater itself, however, wasn't engaged in the silkworm disease, mulberry leaves with rainwater was rather profitable for cocoon production when the leaf quality was too hard to feed silkworm. Feeding of wet mulberry leaves with rain might not so harm to silkworm when the condition of rearing room to be kept at suitable temperature and ventilated well. Nematode infection of silkworm could be occurred by harvesting and feeding of contaminated mulberry leaves on the weather condition of rainy and wind. For the prevention of nematode infection, silkworms should be fed the leaves harvested from the higher portion of the mulberry tree in rainy days. For an oppositional application of this susceptibility of silkworms to nematode, might be useful on the collection and amplification of nematode agents for biotic control of pest insects.

• International Journal of Industrial Entomology and Biomaterials
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• v.5 no.1
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• pp.123-126
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• 2002

More than three hundred million men in the world are suffering from erectile dysfunction. Korean ancient medical records say that the unmated male silkworm moth is effective in strengthening men's vitality, but no scientific examination has preyed its clinical efficacy. Currently, silkworm moths are not allowed for food-stuff. Thus, we selected silkworm of 14-days-after-metamorphosis, at which external morphology possesses that of pupae, but internal component is that of moths. To obtain the reliable source of unmated male silkworm moth, we used the sex-limited silkworm breed with larval marking. The body marker allows casual separation of sex during larval period, preventing mating right after emergence from cocoon. Using the extract prepared with the pupae of 14-days-after-metamorphosis, we investigated the tonic effect of the extract on the rat fed the extract for three weeks. The results showed that the testosterone levels in serum increased maximum by 19%, that of testicle increased maximum by 200%, and athletic endurance of the rats rose by 6%, suggesting positive tonic effect of the pupae prepared at the stage of 14 days after metamorphosis.