• Journal of Sericultural and Entomological Science
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• v.14 no.1
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• pp.25-35
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• 1972

This investigation was carried out to find the effects of silkworm rearing technique on the harvesting amounts. In spring and autumn of 1971, 14 silkworm rearing farmers at Botong Ri and Youngsoo Ri, Chongnam Myun, Hwaseung Kun, Kyunggi Do in Korea were selected as sample farmers. They were devided into two groups, high productivity group and low productivity group according to their harvesting amounts per box of silkworm eggs in 1970. The high productivity group represents the farmer who produced above average harvesting amounts per box, and the low group represents below average group. In this investigation, all farmers were adjusted to share uniform rearing condition with even mulberry leaves. Under this uniform condition, the effects of rearing techniques on the harvesting amounts per box of silkworm eggs and the effects of rearing condition on the harvesting amounts were inferred. Results obtained are as fellows; (1) Measuring from the 14 sample farmers, the effect of rearing technique on the harvesting amounts per box covers 15% of farmers in spring rearing season but 33% in autumn season. (2) Measuring from these sample farmers, the effects of the nutrition condition is less than 56% in spring rearing season but less than 69% in autumn, and it can be concluded that these effects include the effect of climate factor. (3) In the low productivity group. the most important facto. affecting the low productivity is non-disinfection of rearing environment.

• International Journal of Industrial Entomology and Biomaterials
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• v.12 no.1
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• pp.7-14
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• 2006

Silkworm diseases are better prevented than cured. Disinfection and hygiene are the two important aspects in silkworm rearing to prevent the diseases. Suitable disinfectant is the primary need to disinfect the rearing house, its surroundings and appliances to eliminate the persistent pathogens from the rearing environment. In this direction, Serichlor, a new disinfectant in Indian Sericulture marketed as Serichlor-60 (contains 60,000 ppm of chlorine dioxide) and Serichlor-20 (contains 20,000 ppm of chlorine dioxide) has been evaluated for its germicidal effect against the pathogens of silkworm, viz., spores of Nosema bombycis, Bacillus thuringiensis, polyhedra of BmNPV and conidia of Beauveria bassiana both in vitro and in vivo. Results indicated that high concentration (2,500 ppm of chlorine dioxide) is required to kill all the pathogens at 100% level. The efficacy of the Serichlor was greatly enhanced by the addition of 0.5% slaked lime solution. 500 ppm of chlorine dioxide in 0.5% slaked lime solution was found effective against all the pathogens tested. This concentration of disinfectant was also found effective for disinfection of rearing house, rearing appliances and silkworm egg surface. The disinfectant is stable, non hazardous, least corrosive and most suitable for Indian Sericulture.

• 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.30 no.1
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• pp.26-30
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• 2015

Tropical Tasar culture is forest and agro-based activity that covers agricultural and industrial activity. Tasar silk is produced by the silkworm, Antheraea mylitta which is polyphagous in nature. A large number of pests are reported to attack both the host plant as well as silkworm. As the rearing is conducted outdoor silkworms are exposed to attack of various pests during their life cycle. Eocanthecona furcellata (Hemiptera: Pentatomidae) is the major predator of tasar silkworm during young age rearing. Both nymphs and adults of the stink bug suck the heamolymph of silkworm leading to death. The present work was undertaken to study the life cycle of E. furcellata on larvae of vapourer tussock moth which is a major pest of tasar host plants. The incubation period, nymphal duration and total developmental period from egg to adult was $8.0{\pm}0.45d$, $16.0{\pm}3.24$ and $22.0{\pm}4.20d$, respectively. Pre-oviposition, oviposition and longevity of male and female stink bug was $3.20{\pm}0.38$, $17.60{\pm}1.86$, $42.40{\pm}1.94$, $37.00{\pm}3.18d$, respectively. Analysis of the data revealed no significant difference in life cycle of the predator when provided silkworm and vapourer tussock moth larvae as hosts. Which clearly indicates that E. furcellata can multiply on vapourer tussock moth larvae during non rearing periods. Adoption of recommended pest control measures for defoliators of tasar host plants during non-rearing periods will help in reducing the incidence of host plant pests and also in reducing the incidence of stink bug during rearing season. During the study it was also observed that larvae semilooper, boll headed caterpillar and nymphs of leaf hopper serve as alternate/secondary hosts to E. furcellata during non rearing seasons.

• International Journal of Industrial Entomology and Biomaterials
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• v.45 no.1
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• pp.22-28
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• 2022

Silkworms are very sensitive to changes in temperature and humidity, and unless it is a suitable temperature and humidity to grow, the productivity and quality of silkworms are greatly reduced. Therefore, it is very important to manage temperature and humidity for silkworm feeding facilities. In particular, it is essential to install heating facilities in Asian countries with distinct seasonal changes. During the feeding period, many farms manage the temperature and humidity of feeding facilities by installing and using electric heaters inside the facilities. However, it is very difficult to manage the room temperature stably by the heaters. In addition, unlike the temperature inside the facility, silkworms could undergo severe temperature changes as the inside of the rearing tray could not be warm enough. In this study, in order to improve the previous heating method, the new rearing method that directly heats the bottom of the rearing tray was developed. Compared to the previous room-heating system, the novel heater-installed tray (HIT) system significantly reduced the change in temperature during the experimental period. In addition, the number of days of silkworm growth up to harvest was shortened, which was effective in growth performance, and it was also found that silkworms grew more uniformly in HIT system than in previous system. Moreover, as the heater tubes were installed directly under the rearing tray, it quickly dried mulberry leaves and silkworm feces after feeding, and as a result, the environment in the tray was greatly improved with decrease the labor of breeder. In conclusion, these results suggest that the heater-installed rearing tray method greatly improves silkworm quality, increases weight of silkworms, and final profits compared to the previous room heating system with electric heaters.

• International Journal of Industrial Entomology and Biomaterials
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• v.3 no.2
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• pp.135-139
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• 2001

Experiments were held in Egypt to test a new Package of practices for commercial cocoon production, including adding secondary macro and micronutrients to the mulberry garden, disease free rearing regime, low temperature rearing in young instars and natural mounting fur silkworms. This package for seed silkworm rearing lead to increase in fecundity by 67-121eggs (15.12-26.22%) and yield of standard boxes per 1 parent egg boxes by 57-58 egg boxes(48.33-51.66%) respectively in comparison th the traditional cocoon production technology.

• International Journal of Industrial Entomology and Biomaterials
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• v.46 no.1
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• pp.1-8
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• 2023

Mulberry (Morus spp.) production is a vital activity in sericulture along with rearing of silkworms (Bombyx mori L.) for silk production. The Sericulture Research and Development Institute (SRDI) conducted a study that evaluated 11 mulberry varieties, including nine newly-evolved mulberry hybrids and two check varieties. These mulberry varieties were fed to silkworm hybrid, DMMMSU 115 x 100. The rearing performance of DMMMSU 115 x 100 was determined based on the silkworm economic traits such as weight of 10 matured larvae, cocoon weight, shell weight, shell percentage, cocoon yield, reelability percentage, filament length and filament size. Six silkworm rearing trials were conducted with 50 silkworm larvae per treatment in three replicates. The data were analyzed in a one-way Analysis of Variance. Significant differences were tested further using Tukey's Honest Significant Difference. Mulberry varieties that garnered an evaluation index value of higher than 50 were identified and selected. Results of the study revealed significant variations among the mulberry varieties based on the parameters gathered except on the reelability of cocoons, filament length and size. Matured silkworm larvae fed with Alf 55 were significantly heavier and higher cocoon yield compared to those fed with Alfonso and S₅₄. Alf 32, Alf 55, Alf 58, Bat 37 and Bat 73 were identified as potential varieties and highly recommended as feed for the silkworm hybrid, DMMMSU 115 x DMMMSU 100.

• Journal of Sericultural and Entomological Science
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• v.14 no.1
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• pp.15-24
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• 1972

During the autumn-rearing season of 1971, at the silkworm rearing house at the college of agriculture, Seoul national university in Korea, the authors carried out a series of experiments (1) on the susceptibility of four important silkworm pathogens (Aspergillus flavus, Bacillus thuringiensis, Aspergillus oryzae, and Isaria farinosa) to Halamid (Tosylchloramide Sodium), (2) on the acute toxicity of Halamid to silkworm larvae at every instar, (3) on the inhibiting effect of Halamid to the attack of two silkworm infections, fungal muscardine and viral jundice, and the chronic toxicity of Halamid to silkworm larvae, and (4) on the yield and quality of the raw silk harvested from the Halamid treated silkworms. As the results of the experiments the authors found that Halamid could be applied usefully to silk worm rearing industry as an effective disinfectant for both silkworms themselves and their envir onmental articles, rearing houses and tools, also that Halamid exerts its disinfectant effect most efficiently as a disinfectant for silkworms when sprayed in 2% or 3% aqueous solution every second day throughout all tile instars of larval stage.

• Journal of Biosystems Engineering
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• v.16 no.1
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• pp.83-89
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• 1991

One of the most serious problems in Korean sericulture farms is to improve the adiabatic conditions for the simple silkworm rearing houses which has been widely adapted since early 1980'. Thus, this study is aimed to solve the problems by selecting the thermal screen material and by finding the method of its instalation. For the study, 4 kinds of materials which are (1) TE005,(2) NW60, (3) NW300 and (4) AL110 are selected and 4 different types of methods which are surrounding boundary of rearing bed(type A), surrounding inside of wall and ceiling (type B), installing on inside of wal ony (type C) and installing on ceiling Inly (type D) are installed. Decision criteria of the best combination of screen material and installation methods is made by calculating the heating load coefficients and by testing the application at the simple silkworm rearing houses. The obtained results are summarized as follows ; 1. The effect of thermal screen on reducing the thermal energy is remarkable. It saves energy more 50% than unscreened simple silkworm rearing houses. 2. From a stand point of a good screed material on thermal energy reduction, the NW300, AL110 and PE005 are recommanded materials. However, NW60 and PE005 are regarded as desirable materials from the practical point view. 3. Also, the effect on thermal energy reduction is largely affected by the method of thermal screen installation. The surrounding boundary of the silkworm rearing bed(type A) is the most desirable method to reduce the energy, which saves 56.6% of it. 4. In the practical application, NW60 and type A is considered to be the best combination of material and installation method. By this combination, the level of maximum heating load can be reduced at the rate of 43% for spring season and 40% for autumn season. 5. Another heating method, comparted heating, can be recommended to save the energy.

• Journal of Sericultural and Entomological Science
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• v.39 no.1
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• pp.30-35
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• 1997

A rapid and sensitive detection of BmNPV contamination in silkworm rearing room was carried by Plymerase chain reaction(PCR). Silkworm nuclear polyhedra were dissolved for the extraction of viral DNA within 30 minutes followed by the treatment of alkaline solution. The combination of primers of NP3 and NP2 was superior in PCR to the other 7 primers applied. Each primer was designed with 20 base in size and Newly designed NP3 of sense and the already reported NP2 for antisense were better in reaction than other primers. PCR products appeared 500bp in size. And annealing was confirmed proper at 55$^{\circ}C$ condition. Amplifiable template DNA amount was confirmed at least 100 ng to 0.1 ng and regarded as applicative for the assay of silkworm rearing environmental condition of sericultural farm. In case of the detection of BmNPV from the dust, sensitivity by PCR was as high as 1,000,000 times than that of microscopic observation.