• Journal of Sericultural and Entomological Science
• /
• v.44 no.1
• /
• pp.22-27
• /
• 2002

The Yongcheonppong was cultured in the form of a dense mulberry field coverd with polyethylene film and was tested in Suwon and Chunchon. The agronomic characteristic and some consideration on the result of the silkworm rearing were as follows. The Yongcheonppong was the medium budding variety and was longer in length of young shoots than the Kaeryangppong. The Yongcheonppong was higher in leaf yield in spring than the Kaeryangppong and was lower in leaf yield in autumn than the Kaeryangppong to the contrary. The Yongcheonppong was a little higher in the number of branches and was longer in the length of the branch than the Kaeryangppong and so was appropriate for rearing with mulberry shoots. Yongcheonppong was more resistant to twig blight and die-back and was a little susceptible to dwarf disease. As the Yongcheonppong was most resistant to the freezing injury, it was appropriate for the cold region and enabled the farmers to rear some amount of silkworms every year. In Chunchon, The Yongcheonppong increased by 11% in cocoon yield than the Kaeryangppong when the freezing injury occurred 1 year out of 2 years and produced about the same as the Kaeryangppong in cocoon yield when the freezing injury occurred 1 year out of 3 years.

• Journal of Sericultural and Entomological Science
• /
• v.18 no.2
• /
• pp.1-60
• /
• 1976

In present study, radioautography and electron-microscopy were applied by the author to the elucidation of the mechanism of diapause in Bombyx mori L. (1). Patterns of nucleic acid and protein syntheses during embryonic development of silkworms, incubated at high and at low temperatures, were demonstrated by means of radioautography with labelled precursors of nucleic acid and protein. On the third day after blastokinesis the embryo incubated at high temperature generally incorporated much of the $^3$H-glycine into the brain and the suboesophageal ganglion, and some into other regions. When incubated at low temperature, no difference in the pattern between the brain, the suboesophageal ganglion and other parts was observed. Radioautography with $^3$H-thymidine revealed no significant difference in DNA synthesis in embryos incubated at high and low temperatures. In diapausing eggs twenty days after deposition, only a few cells of the mesoderm incorporated the labelled material into their nuclei, but in the hibernated eggs all the nuclei of the mesoderm had thymidine incorporation. After blastokinesis only the anterior portion of the embryo around the brain and the suboesophageal ganglion had thymidine incorporation; this was not observed in the posterior portion.

• Journal of Sericultural and Entomological Science
• /
• v.38 no.1
• /
• pp.7-12
• /
• 1996

Reproducible the random amplified polymorphic DNAs(RAPDs) patterns were obtained in the two silkworm strains(J111, Galwon) by adjusting concentration optimized of Taq DNA polymerase(one unit), dNTP(200$\mu$M), MgCl2(1.5mM) and template DNA(30ng). In addition, anealing temperature ranging 35$^{\circ}C$ to 42$^{\circ}C$ by the adjusted condition was investigated and fixed at 35$^{\circ}C$ in this study. Variation among individuals and between male and female of Jam 113 strain was not authorized. DNA polymorhpisms among silkworms were authorized by five RAPD markers using OPM04 random primer. Using the primer showing polymorhpims between parents(J111, Galwon) in thirty three individuals, RAPD-PCR for F2 analysis was performed and segregated 3 : 1 in the F2 population. Consequently, RAPDs detected in the parents were obtained as genetic markers, which can be used for construction of genetic map for this industrially particular insect, silkworm Bombyx mori

• Journal of Microbiology and Biotechnology
• /
• v.17 no.4
• /
• pp.547-559
• /
• 2007

Bacillus thuringiensis (Bt) was first described by Berliner [10] when he isolated a Bacillus species from the Mediterranean flour moth, Anagasta kuehniella, and named it after the province Thuringia in Germany where the infected moth was found. Although this was the first description under the name B. thuringiensis, it was not the first isolation. In 1901, a Japanese biologist, Ishiwata Shigetane, discovered a previously undescribed bacterium as the causative agent of a disease afflicting silkworms. Bt was originally considered a risk for silkworm rearing but it has become the heart of microbial insect control. The earliest commercial production began in France in 1938, under the name Sporeine [72]. A resurgence of interest in Bt has been attributed to Edward Steinhaus [105], who obtained a culture in 1942 and attracted attention to the potential of Bt through his subsequent studies. In 1956, T. Angus [3] demonstrated that the crystalline protein inclusions formed in the course of sporulation were responsible for the insecticidal action of Bt. By the early 1980's, Gonzalez et al. [48] revealed that the genes coding for crystal proteins were localized on transmissible plasmids, using a plasmid curing technique, and Schnepf and Whiteley [103] first cloned and characterized the genes coding for crystal proteins that had toxicity to larvae of the tobacco hornworm, from plasmid DNA of Bt subsp. kurstaki HD-1. This first cloning was followed quickly by the cloning of many other cry genes and eventually led to the development of Bt transgenic plants. In the 1980s, several scientists successively demonstrated that plants can be genetically engineered, and finally, Bt cotton reached the market in 1996 [104].

• Journal of Sericultural and Entomological Science
• /
• v.8
• /
• pp.51-62
• /
• 1968

This study was carried out to investigate the life cycle and the damage of Tricholyga sorbillans Wiedmann to silkworms(Bombyx mori L.). The results are summarized as follows. 1. This insect has 5 or 6 generations per year in Suwon area. 2. The egg, larval, and pupal stage are about 2, 8 and 18 days respectively. 3. The weather conditions considerably affect the life cycle, that is, the 3 rd generation is the shortest of all, lasting for 21 days and l4 hours, and the 5th generation is the longest for about 40 days. 4. The larvae come out of silkworm bodies, burrowing into the ground 3.5cm to 10.5cm in depth before changing into the pupae. 5. This insect does not overwinter as pupa, but seems to do as larva, parasiting on the field insects. 6. The damage of Tricholyga sorbillans Wiedmann to silkworm was 27.9％, it is so high that the silk worms could not be reared outside without a reasonable control method. 7. When the full-grown silkworm is parasited by one egg of these insects, there is not only enough possibility of spinning. but also without any effects of their larvae on the cocoon quality. 8. The damage of Tricholyga sorbillans Wiedmann throughout the country covers 6.36％ in spring, 4.09％ in fall, and 5.25％ yearly mean.

• Journal of Sericultural and Entomological Science
• /
• v.13 no.1
• /
• pp.35-47
• /
• 1971

Current overseas research reveals that among the pathogens causing flacherie of silkworm, damage by infectious flacherie virus is the most serious, but little research in this fold has been reported in Korea. This experiment was undertaken to observe the occurrence of infectious flacherie virus by means of biological environmental conditions associated with occurrence of virus discase and interaction of the virus of flacherie and Bacillus spp. isolated from flacherie silkworm, and to determine ways to check infection by the virus during the rearing of silkworms. The results obtained are as follows: 1. The pathogen, infectious flacherie virus observed in Korea, is proved to be round in shape and 26-30m$\mu$ in diameter under observation with electron microscope, 2. The infectious flacherie virus-disease occurred apparently in conditions of nutritional disturbance such as shortage of diet or rearing in high temperature and humidity during the 3-4th instar. 3. The percentage of disease-occurrence was increased remarkably, and the latent period was shortened in the case of simple inoculation of virus suspension as compared with the suspension added with bacteria. 4. The application of calcium hydroxide in the silkworm-rearing bed is able to check infection of virus disease.

• Journal of the Korean Home Economics Association
• /
• v.43 no.12 s.214
• /
• pp.79-96
• /
• 2005

The purpose of this study is to explore the conceptions of children and their activities in everyday lives during the late period of the Goryo Dynasty. The historical method was used and the materials for analysis were the literatures written from the late thirteenth century to the fourteenth century in the Goryo Dynasty, such as 'the Ikjaijip'(익재집), 'Mokeunjip'(목은집), 'Yangchonjip'(양촌집). According to the results, the perspective on the nature of a chad was that children were inherently good with the true character which was given from natural laws and that each child was born with different natural endowment. Also, the notions on child development were that the infancy was a pure and perfect period which us not contaminated by temperament and worldly desires, instead of the developmental model that childhood is as a stage and the child must develop from the state of incompetence to the state of maturity. In addition, there were the principles for development that were keeping the innate ideal state and fostering it from the earliest time as infants were born with innate ideal state or ability. The concepts of children's characteristics were considered that they were inclined to make much noise and movement, but to have the plain and straightforward expressions and consistency in their feelings and everyday activities. And intelligent abilities for learning were often considered as desirable traits. In everyday lives, children did the household chores such as caring for livestock and silkworms or embroidering. Among their games were exploring activities, free plays using natural materials, pretend-plays, bamboo-stilts riding, and Yutnori.

• Journal of the Korean Society of Costume
• /
• v.5
• /
• pp.65-81
• /
• 1981

I referred to documents to study the origin and the progressing process of textiles. Cotton seeds were first imported from China by Mun, Ik Jem at the end of the era of Koryeo, and cotton had several different names such as mok-myen, cho-myen, gil-pae, baek-chep-za, tap-po, ban-ki-wha, dong-yep-po and so on. Since the era of the Three Kingdoms, people had heard of cloth of superior quality but it was not certain whether it was imported from China or made in our country. It seems that cotton was not made during that period, white silk, hemp cloth, and ramie fabric were produced. At that time, linen was called cotton by mistake. After importing cotton seeds from China, all the people began to plant them and made their clothes from them. At the beginning of the Yi Dynasty, the weaving technique was dependent on China. However, the government persuaded farmers to plant them. At that time cotton was used as a means of purchasing instead of money. Silkworms raising started during the era of the Three Kingdoms and it was widely spread at the beginning of the Yi Dynasty. In order to encourage sericulture' spinning and weaving instruments were installed in the royal palace and the queen with sher court maids demonstrated how to spin and weave. The activity was named "chin-jam-ye." Linen was the representative of all textiles and it was also very popular. The technique of weaving had already been highly developed at the era of Silla. During the era of the Three Kingdoms people used "bang-chu-cha" as a weaving instrument. They discovered several new hand machines in the period of the Yi Dynasty: they were instrument of removing seeds, spinning wheel, hemp cloth loom and so on, and we find the remains of them these days.

• Journal of Sericultural and Entomological Science
• /
• v.35 no.2
• /
• pp.86-88
• /
• 1993

The effect of short term duration(1, 2 and 3 days) after urea foliar spray on leaf quality was investigated by chemical analysis of leaves and silkworm rearing with leaves treated with urea in autumn. Foliar spray increased water content by 0.4~0.7% and total nitrogen by 0.19~0.51% in leaves compared to the conventional treatment. Foliar spray increased NO3-N concentration in leaf 503~1107 ppm more than the conventional treatment. NO3-N concentration in leaf decreased with days after foliar spray. Whole cocoon weight and cocoon shell weight increased by 0.02~0.14g and 0.5~3.1 cg, respectively in foliar spray than in the conventional treatment. Though foliar spray raised NO3-N concentration in leaf, leaves harvested one day after foliar spray were no harmful to silkworm.

• International Journal of Industrial Entomology and Biomaterials
• /
• v.29 no.2
• /
• pp.169-178
• /
• 2014

In this study, we investigated genetic diversity of 22 microsporidian isolates infecting tropical tasar silkworm, Antheraea mylitta collected from various geographical forest locations in the state of Jharkhand, India, using polymerase chain reaction (PCR)-based marker assay: random amplified polymorphic DNA (RAPD). A type species, NIK-1s_mys was used as control for comparison. The shape of mature microsporidians was found to be oval to elongate, measuring 3.80 to $5.10{\mu}m$ in length and 2.56 to $3.30{\mu}m$ in width. Of the 20 RAPD primers screened, 16 primers generated reproducible profiles with 298 polymorphic fragments displaying high degree of polymorphism (97%). A total of 14 RAPD primers produced 45 unique putative genetic markers, which were used to differentiate the microsporidians. Calculation of genetic distance coefficients based on dice coefficient method and clustering with un-weighted pair group method using arithmetic average (UPGMA) analysis was conducted to unravel the genetic diversity of microsporidians infecting tasar silkworm. The similarity coefficients varied from 0.059 to 0.980. UPGMA analysis generated a dendrogram with four microsporidian groups, which appear to be different from each other as well as from NIK-1s_mys. Two-dimensional distribution based on Euclidean distance matrix also revealed considerable variability among different microsporidians identified from the tasar silkworms. Clustering of few microsporidian isolates was in accordance with the geographic origin. The results indicate that the RAPD profiles and specific/unique genetic markers can be used for differentiating as well as to identify different microsporidians with considerable accuracy.