• Journal of Sericultural and Entomological Science
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• v.36 no.2
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• pp.115-118
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• 1994

Differences of feeding response of 280 silkworm genetic stocks and 71 breeding lines to MP-O artificial diet and the mode of the inheritance were investigated. Feeding response to MP-O diet varied markedly between the silkworm varieties, and the non-normally distributed curve for the response was observed. From the genetic analysis, the high feeding response to MP-O diet was recessive to the low feeding response. Therefore it is considered that the high feeding response of the newly hatched silkwrom larvae to MP-O diet is controlled by a recessive gene.

• International Journal of Industrial Entomology and Biomaterials
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• v.6 no.1
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• pp.103-106
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• 2003

Among silkworm diseases, white muscardine is the most virulent and contagious disease caused by Beauveria bassiana and common during winter and rainy seasons. The disease is managed at present by practicing the silkworm body and rearing seat disinfection to prevent the spread of white muscardine during silkworm rearing as the available methods do not cure the silkworms against white muscardine. The use of systemic fungicide was suggested recently to control white muscardine. The present study investigated the practicability of application aspect of systemic fungicide as spray, It is observed that 3 times feeding of systemic fungicide through mulberry leaf, fed immediately after third, fourth moult and on $4^{th}$ day of final instar as most effective in suppressing the multiplication of the fungus in silkworm. Spraying of the systemic fungicide on mulberry in the rearing house, air-dried and feeding was suggested as suitable application method. Alternately the spraying of the systemic fungicide on mulberry in mulberry garden 6 hrs prior to feeding was also suggested as a method for the control of white muscardine in silkworm rearing.

• Journal of Sericultural and Entomological Science
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• v.36 no.2
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• pp.130-137
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• 1994

This experiment was conducted to evaluate the reasonable rearing technique of Japanese oak silkworm under the different rearing condition as environment, feeding materials and rearing methods. The results are summerized as follows. The optimum temperature for the indoor rearing of Japanese oak silkworm was 25~26$^{\circ}C$ a in young silkworm and 22~23$^{\circ}C$ in grown silkworm, and generally in the condition of variable day/night temperature the growth of silkworm was faster than in that of constant temperature. The optimum relative humidity for it's growth was 80~90% at young silkworm stage and 60~70% at grown silkworm stage. The photoperiod was not affected to the growth of Japanese oak silkworm. The earlier brushing, the shorter the young silkworm stage, and the cocoon quality improved compared to the later brushing time. As a feeding materials aok (Auercus acutissima Crruthers) leaves were better than those of chestnut tree (Castanea Crenata Siebold & Zuccarini) and feeding value of cultivated oak tree leaves was better than that of natural oak tree leaves. The moving time when revealed the better cocoon production of Japanese oak silkworm from indoor condition to outdoor was 15 days after hatched, and the cocoon production was decreased by the earlier moving to outdoor.

• International Journal of Industrial Entomology and Biomaterials
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• v.47 no.2
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• pp.79-89
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• 2023

This paper is about the development results of an automatic silkworm breeding system to reduce labor and time by automatically performing the works for silkworm droppings changing and feed its food. It consists of an automatic guided vehicle and a processing unit. The automatic guided vehicle transports a silkworm dropping changing frame mounted on a silkworm tray stand, and the processing unit takes over the dropping changing frame on it, removes excrement contained the droppings changing frame and feeds silkworm food. In the case of the current silkworm farming, because the breeding period for large silkworms (4 to 5 stage) is short to 14 days and the supply of mulberry leaves takes 98% of the total amount of mulberry leaves needed for breeding silkworms at this time, labor concentration is intensive, and all breeding works depends on manpower. Therefore, it was difficult to breed large silkworms on a large scale. Moreover, silkworms are bred by adding Silkworm bed (Seop) and mulberry in the silkworm tray, and their droppings changing is to separate silkworms and excrement by moving silkworm trays one by one, and the production cost increases due to the high-cost manpower for silkworm breeding. To solve this problem, technology for automating silkworm breeding has also been developed. However, there is still a limitation that silkworm feeding and droppings changing works are not suitable for mass breeding because a lot of labor and time are spent depending on manual work. Therefore, a new silkworm breeding system for breeding silkworm automatically is needed and so we developed an Automatic Silkworm Breeding System applying the droppings change frame, the inverting unit, the feeding silkworm food device and automatic guided vehicle.

• 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.1 no.2
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• pp.155-159
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• 2000

In the spring silkworm rearing period of year 1998, some nutritional aspects were studied in the Agricultural Research Station of the Komotini town in Greece, to investigate the feeding behaviour of some Bulgarian silkworm hybrids, suitable for spring rearing, during the fourth and fifth instal under the local climatic conditions. The silkworms were fed by locally cultivated Japanese Kinriu mulberry (Morus alba L.) variety leaves. Eight Bulgarian hybrids had been used, namely Vratza-53xVratza-52, Ukraine-20xVratza-53, Super 1xHessa 2, Merefa 2xVratza 35, as well as their reciprocal crosses. The studies showed out a remarkably higher feed intake and feed utilization by the hybrids Hessa 2xSuper-1, Merefa 2xVratza 35 and Vratza-52xVratza-53. The same hybrids showed an efficient food utilization by means of daily growths cocoon shell ratio and raw silk output. In terms of food to silk conversion efficiency Hessa 2xSuper-1 hybrid gave the best results. Larval stage duration for fourth and fifth instar was not affected by feed intake and utilization. All hybrids showed a good adaptation to the local environment and their feeding performance was equal to the international existing standards. All calculated parameters were found to be around the mean values of other up to date presented results and thus considered as acceptable for the needs of the local production.

• Journal of Sericultural and Entomological Science
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• v.37 no.2
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• pp.114-120
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• 1995

The effect of juvenile hormone analogue(JHA, Manina) on larval feeding duration, pupation ratio, cocoon weight, and cocoon shell weight in the present commercial parent and hybrid silkworm stocks were investigated. Topical applications of JHA on parent silkworm stocks were to prolong larval duration, but results of response on those stocks were not consistent. Especially the JHA on Jam 121, Jam 123 and Jam 138 did not play a role in larval duration, whereas that on Jam 114 was most effective in prolongation more than two days, compared with the controls. subsequent prolongation of feeding duration resulted in increase of cocoon weight and cocoon shell weight of most parent silkworm stocks, while Jam 114 showed decrease in cocoon weight and cocoon shell weight in spite of prolonged feeding duration of two days. Unlike the parent silkworm stocks, durations of feeding period in all hybrid silkworm stocks were prolonged about one day. Treatments of JHA on the hybrid stocks gave rise to increase of cocoon weight and cocoon shell weight, and especially were most effective in Sasung-jam, Eunbaek-jam and Samgwang-jam. Although treatments of JHA seemed to have no harmful effect on physiology of parent silkworm stocks as well as that of hybrid stocks, the JHA retarded pupation ratio of some parent silkworm stocks such as Jam 122, 131, 135 and 138 by about 10%.

• 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.

• Journal of Sericultural and Entomological Science
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• v.28 no.2
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• pp.38-47
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• 1986

Silkworm(Bombix mori) were reared with modified artificial diets which were mixed with, as additives, leaf powders of Erigeron canadensis L., Cassia tora L., Cyperus anuricus Var.Laxus and Vigna Sinensis NEDL. The effects of additives on silkworm characteristisc of tested plants were summarized as follows ; 1. About 2-5% addition on dry weight base of leaf powders of E. canadensis, C. tora, C. anuricus or V.sinensis to the basic artificial diet promoted feeding response and digestion and resulted in good practical silkworm characteristics. The addition of V.sinensis and C.anuricus showed especially good effects. 2. The syneristic effect between different plant species was not recognized based on the feeding response and digestion of silkworm reared with various combinations of 2-4 different plant additives. 3. Electrophoretic zymograms of estrase, protease and phosphatase on haemolymph, intestine and silkgland were significantly different among treatments. In general, 1 or 2 more electrophoretic bands were detected when feeding response and digestion were promoted. 4. Contents of starch, crude fat, crude protein and inorganic base were apparently higher in the tested plants than in mulberry leaves. However, no volatile ingredent which is directly realted with feeding response was identified.

• Applied Microscopy
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• v.26 no.1
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• pp.59-65
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• 1996

The silkworm feeding behaviour reveals two types of feeding response i. e., energetic and inert feeding response to diet. These two new technical terms are being introduced in the present study. The structures of functional organs of mouthpart and antenna of energetic and inert feeding response to diet were examined by scanning electron microscope. There is a big variations in the ultrastructures of different sensilla. The maxillary palpi or sensilla basiconica at the top of maxillary palpus of maxilla are well developed in the energetic larva while in the inert larva, these organs on the right side are extremely deformed. Similarly, these sensilla on the third segment of antenna are well developed in the larva energetic to diet has only two deformed sensilla basiconica, that is why silkworm can not show a proper form. This is related to abnormality and it is due to the fact that behaviour is too strong to select the food but fails and finally dies of the starvation.