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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Journal of Sericultural and Entomological Science
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Journal DOI :
Korean Society of Sericultural Science
Editor in Chief :
Volume & Issues
Volume 16, Issue 2 - Dec 1974
Volume 16, Issue 1 - Jun 1974
Selecting the target year
Studies on the Environmental Factors Affecting the Cocoon Crops in Summer and Autumn in Korea
Journal of Sericultural and Entomological Science, volume 16, issue 2, 1974, Pages 1~34
These experiments pertain to various factors influencing the quantitative characters of cocoon crops in summer and early autumn seasons. Initially, in order to establish the possible ways of the silkworm rearing more than three times a year in Korea, the author attempted to get further information about the various factors affecting the cocoon crop in every silkworm rearing season. The trials were conducted eleven times a year at four places for three years. The field trial was conducted with 19 typical sericultural farmers who had been surveyed. At the same time the author statistically analyzed the various factors in close relation to tile cocoon crop in autumn season. The effect of guidance on 40 sericultural farmers was analyzed, comparing higher level farmers with lower level farmers ; and the author surveyed 758 non-guided farmers near the guided farmers during both spring and autumn seasons. In addition, another trial on the seasonal change of leaf quality was attempted with artificial diets prepared with leaves grown in each season. It was found that related factors to cocoon crops in summer and early autumn seasons appeared to be leaf quality, and temperature for young and grown larvae. A 2
factorial experiment was designed in summer season, and another design with one more level of varied temperature or hard leaf added to a 24 factorial experiment was conducted in early autumn. The experimental results can be summarized： 1. Study on the cocoon crops in the different rearing seasons 1) It was shown that earlier brushing of silkworm generally produced the most abundant cocoon crop in spring season, and earlier or later than the conventional brushing season, especially earlier brushing was unfavorable for the abundant cocoon crop in autumn season. 2) The cocoon crop was affected by the rearing season, and decreases in order of sire with spring, autumn, late autumn, summer and early autumn seasons. 3) It was Proved that ordinary rearing and branch rearing were possibles 4 times a year ; in the 1st, 3rd, 8th, and 10th brushing season. But the 11th brushing season was more favorable for the most abundant cocoon crop of branch rearing, instead of the 10th brushing season with ordinary rearing. 2. Study on the main factors affecting the cocoon crop in autumn season 1) Accumulated pathogens were a lethal factor leading to a bad cocoon crop through neglect of disinfection of rearing room and instruments. 2) Additional factors leading to a poor cocoon crop were unfavorable for rearing temperature and humidity, dense population, poor choice of moderately ripened leaf, and poor feeding techniques. However, it seemed that there was no relationship between the cocoon crop and management of farm. 3) The percentage of cocoon shell seemed to be mostly affected by leaf quality, and secondarily affected by the accumulation of pathogens. 3. Study on the effect of guidance on rearing techniques 1) The guided farms produced an average yearly yield of 29.0kg of cocoons, which varied from 32.3kg to 25.817g of cocoon yield per box in spring versus autumn, respectively. Those figures indicated an annual average increase of 26% of cocoon yield over yields of non-guided farmers. An increase of 20% of cocoon yield in spring and 35% of cocoon yield in autumn were responsible. 2) On guided farms 77.1 and 83.7% of total cocoon yields in the spring and autumn seasons, respectively, exceeded 3rd grade. This amounted to increases of 14.1 and 11.3% in cocoon yield and quality over those of non-guided farms. 3) The average annual cocoon yield on guided farms was 28.9kg per box, based on a range of 31.2kg to 26.9kg per box in spring and autumn seasons, respectively. This represented an 8% increase in cocoon yield on farms one year after guidance, as opposed to non-guided farms. This yield increase was due to 3 and 16% cocoon yield increases in spring and autumn crops. 4) Guidance had no effect on higher level farms, but was responsible for 19% of the increases in production on lower level farms. 4. Study on the seasonal change of leaf quality 1) In tests with grown larvae, leaves of tile spring crop incorporated in artificial diets produced the best cocoon crop; followed by leaves of the late autumn, summer, autumn, and early autumn crops. 2) The cocoon crop for young larvae as well as for grown larvae varied with the season of leaf used. 5. Study on factors affecting the cocoon crops in summer and early autumn A. Early autumn season 1) Survival rate and cocoon yield were significantly decreased at high rearing temperatures for young larvae 2) Survival rate, cocoon yield, and cocoon quality were adversely affected by high rearing temperatures for grown larvae. Therefore increases of cocoon quantity and improvement of cocoon quality are dependent on maintaining optimum temperatures. 3) Decreases in individual cocoon weight and longer larval periods resulted with feeding of soft leaf and hard leaf to young larvae, but the survival rate, cocoon yield and weight of cocoon shell were not influenced. 4) Cocoon yield and cocoon quality were influenced by feeding of hard leaf to grown larvae, but survival rate was not influenced by the feeding of soft leaf and hard leaf. 5) When grown larvae were inevitably raised at varied temperatures, application of varied temperature in the raising of both young and grown larvae was desirable. Further research concerning this matter must be considered. B. Summer season 1) Cocoon yield and single cocoon weight were decreased at high temperatures for young larvae and survival rate was also affected. 2) Cocoon yield, survival rate. and cocoon quality were considerably decreased at high rearing temperatures for grown larval stages.
Effects of Level of Dietary Protein or Carbohydrate on the Economic Characters and Amylase Activity of the Silkworm, Bombyx mori
Journal of Sericultural and Entomological Science, volume 16, issue 2, 1974, Pages 35~53
A series of experiment was conducted to investigate the effects of the level of dietary Protein (soybean meal) and carbohydrate (sucrose) on the growth rate, feed efficiency, nutrients digestibility and amylase activity of larvae at 5th instar. The results obtained from the experimentation are summarized as follow： (1) It was found that the body weight gain, cocoon quality and feed efficiency of the 5th instar larvae were significantly affected by the level of protein and carbohydrate in the artificial diet. Present data revealed that the proper level of dietary protein and carbohydrate would be the most important factor for the optimum growth of larvae. (2) In the amount of diet consumption, the group of larvae gained more body weight consumed more diet than the group gained less amount of body weight. (3) Digestibility of nutrients was improved as the level of protein in the diet increased, although the level of dietary carbohydrate did not exert any positive results. (4) It was observed that the amylase activity in digestive juice was stimulated by the increasement of dietary carbohydrate. However, no correlation between the level of dietary protein and carbohydrate was detected in the amylase activity. (5) Analytical data indicated that the amount of protein or carbohydrate excreted through feces and urine was proportional to the content of protein or carbohydrate in artificial diet. The group o( larvae consumed the diet contained high protein excreted more protein and less nitrogen free extract than did the group received low protein diet. Likewise, the group of larvae fed high dietary carbohydrate excreted more nitrogen free extract and less protein through excreta than the group consumed low carbohydrate diet group. (6) Although the amylase activity of the larvae received the artificial diet was higher than the larvae received natural diet (mulberry leaf), the rate of body weight gam and the quality of cocoon produced from the natural diet group was better than the artificial diet group. It is, thus, concluded that feeding the larvae by the artificial diet may net be recommendable. (7) It was determined that the best level of protein (soybean meal) and carbohydrate (sucrose) in artificial diet was found to be 40g and 0g, respectively when it was fed to the 5th instar larvae. (8) It may be concluded from the results obtained that the artificial diet that could stimulate the activity of amylase nay not be recommendable for the practical larvae feeding Purpose due simply to the Poor economic return from this diet than natural diet.
Studies on the Transovarial Transmission of Cytoplasmic Polyhedrosis Virus with Reference to the Phenomena of Induction, Interference and Virulence Enhancement in the Silkworm, Bombyx mori
Journal of Sericultural and Entomological Science, volume 16, issue 2, 1974, Pages 55~75
Transovarial transmission of cytoplamic polyhedrosis virus in the silkworm was studied by observing the phenomena of induction, interference and virulence enhancement in the larvae from moths inoculated with hexagonal Polyhedra of cytoplasmic polythedrosis virus. The experimental results obtained are as followings. 1. The effect of inoculation with tetragonal polyhedra of cytoplasmic polyhedrosis virus on the rate of infective induction with hexagonal polyhedron virus and with hexagonal plus tetragonal polyhedron viruses in the larvae from moths infected with hexagonal polyhedron virus was studied. Infection rate was higher by 40 to 60 percent in the larvae from infected female group than in tile larvae from noninfected female group. 2. In the studies of the effect of formalin-feeding on the induction of infection with hexagonal polyhedron virus, infection rate was higher by 40 percent in the larvae from infected female group than in the larvae from noninfected female group. However, there was no significant difference in the infection rates between the two formalin-concentration groups. 3. The effect of cold treatment on the induction of infection with hexagonal polyhedron virus was studied. Infection rate was higher by 50 percent in the larvae from infected female group than ill the larvae from noninfected female group. No difference was found in the infection rates of the two treatment groups of 12 and 48 hours. 4. The phenomena of induction and interference were studied by observing rate of infection with hexagonal polyhedron virus induced by the inoculation with tetragonal polyhedron virus. The degree of interference of primary hexagonal polyhedron virus by secondary tetragonal Ployhedron virus was increased as the dosage of secondary virus was increased. At the concentration of 1
8/m1 of the secondary virus, the degree of interference was similar to. that of control group. On the other hand, infection with tetragonal polyhedron virus at low concentration was interfered by the primary virus. At the concentration of 1N10f/m1 of tetragonal polyhedron virus, however, the rate of infection with tetragonal polyhedron virus was increased sharply, which is still lower by 30 percent than that of control group. 5. In the studies of induction and virulence enhancement, based on the 1ate of mixed infection with hexagonal and tetragonal polyhedron viruses, the highest difference of infection rate between experimental group and control group exceeded 40 percent when the concentration of tetragonal polyhedron virus was 1
7/m1. However, the infection rate of control group was not affected by concentrations of tetragonal polyhedron virus.
Studies on the Solubility Phenomenon and Activities of Silk Cocoon Sericin through the Filature Water Conditions.
Journal of Sericultural and Entomological Science, volume 16, issue 2, 1974, Pages 77~98
This study was carried out ill an attempt to investigate the properties and activities of sericin obtained from silk cocoon shells in silk reeling water through various instrumental analyses. In addition, the effects of the characteristics in sericin solubility on the reeling process and silk qualities were also studied on the basis of tile above conditions. The results obtained are as follows： I. The sericin properties and activities through various analytical instruments. 1. The water solubility of each amino acid such as serine, glycine. glutamic and aspartic acids against the pH modified water by using automatic amino acid analyzer, showed the lowest solubility at PH 5, but it increased according to drifting toward the alkalinity. 2. When the obtained sericin particles by water pH variation were observed with the electronic microscope, it was found for the sericin Particles to expand in the alkaline regions. 3. The IR spectrum results showed the differences among the pH modified sericin solutions at the range of 2,100cm-1 and 1.890cm-1 of wave number. 4. The existence of sericin with in silk fabrics made differences in the X-ray interference intencity, that is, the non-degummed fabrics had the interference peak at 2
, and the degummed ones had it at 2
. II. The results of sericin solubility for silk reeling process. 1. The sericin solubility and swelling had a tendency to increase up with high M-alkalinity and pH value of water. But in case of acidity. water hardness and concentration of ethylene glycol were high, the sericin solubility and swelling were decreased. 2. With the filature experiments, the best conditions of filature orator are summarized as fellows ; a. pH; 6.9
0.2 d. acidity; below10ppm b. total hardness; 55：5ppm e. Fe ion; none c. M-alkalinity; 40
Studies on the Control of Bud Bright of Mulberry Tree when Intermediate-Cutting Harvest in Autumn
Journal of Sericultural and Entomological Science, volume 16, issue 2, 1974, Pages 99~109
These studies aimed to establishment of controlling measure of the bud blight of mulberry tree when intermediate cutting harvest in autumn. The results obtained as following. 1. Effect of chemicals a) Results of 1972 (1) Of the seventeen chemicals tested. according to in vitro, the mycelial growth of Gibberella lateritium f. sp. mori was highly inhibited by PTAB and Benlate. PTAB and Benlate were also highly effective under the conditions of pathogen inoculated to the piece of mulberry tree and fungicidal action of these chemicals were stronger than the others. (2) Topsin-M. organic fungicide and plant growth regulator were not effective to inhibition of mycelial growth. (3) The effectiveness of fungicides were reduced gradually as the time after treatment increased. PTAB and Benlate retained approximately 50 percent of the original activity even after 15 days. (t) Of the twelve chemicals tested in fold, Benlate combination of PTAB with Apion, Apion and PTAB were the most effective fungicides for the control of bud blight of mulberry tree. (5) There is a sigificant difference between the timing on spraying, but it is not greatly effective for the control of bud blight of mulberry tree. b) Results of 1975 (1) Of the ten chemicals tested, according to in vitro RH 893, combination of Benlate with TMTD and TMTD were the most effective to inhibition of mycelial growth, followed by Benlate and combination of Benlate with Topsin M. (2) Of the eleven chemicals tested, Benlate, combination of Benlate with Kinondu, combination of Benlate with Topsin-M and Topsin M were highly effective under the renditions of pathogen inoculated to the piece of mulberry tree. (3) Of the eleven chemical evaluation tests were conducted in 3 experiment fold of Seoul, Chuncheun and Pusan, Benlate, Topsin-M, Apion, TMTD. combination of Benlate with Topsin-M, combination of Benlate with TMTD, combination of Benlate with Apion were highly effective chemicals for the control of bud blight of mulberry tree. (4) There is no difference between the timing on the chemical spraying after intermediate cutting harvest mulberry tree in autumn. 2. Ecological Control. When the mulberry shoot were cut off one to two buds from the top of intermediate cutting from 15th to 30th on October, bud blight of mulberry tree was greatly reduced in next spring compared with the effective chemical spraying. 3. Economical analysis on the results of chemical and ecological tests. When the expenses of ecological control for bud blight of mulberry tree per one ha was 100. thats of chemical control was from 159 to 254 according to spraying machines.
Fine Structure of Median Neurosecretory Cell in Diapause and Non-Diapause Brains in the Silkworm Bombyx mori
Park, Kwang E. ; Seong, Su-Il ;
Journal of Sericultural and Entomological Science, volume 16, issue 2, 1974, Pages 111~117
The electron micrographs of the larval brain of the silkworm. Bembyx mori. show that median neurosecretory cell of diapause-egg producer may participate in the production of lipo-granules and that of non-diapause egg producer may do in the production of electron-translucent vesicles. It was found that ribosome-like particles of diapause-egg producer gradually developed into highly dense particles and came into line along the smooth-surfaced endoplasmic reticulum. They finally became lipo-granules.
Histological Studies on the Exuvial Gland in a Non-moulting Silkworm, Bombyx mori L
Journal of Sericultural and Entomological Science, volume 16, issue 2, 1974, Pages 119~125
When the nomal silkworms reached active time of 3rd instar stage both non-moulting larva and normal silkworms from the same rearing tray were collected and fixed. The silkworms in 4th instar stage whose growth was as dwarfish as those in 1st and 2nd instar stages were also collected and fix with the normal silkworms. Non-moulting larva and normal silkworms were morphologically compared and the examined results from the tissue inspection are summarized as follows： 1. In spite of the fact that the normal silkworms reached the active eating time of 3rd instar stage non-moulting silkworms were dwarfish as if they had been reared for two days. Non-moulting silkworms which were observed at the time of 4th instar stage showed no much difference in their growth. 2. There was the tendency that the exuvial gland as was shown in Fig. 1 and 2 was flat cyslidium of ellipse and its size at thorax was small shile the gland at abdomen was big. 3. The exuvial gland at thorax has been reported to be bigger at thoracic base than at dorsal vessel but according to the present it was examined to be irregular. 4. The size of exuvial gland of silkworms in the active eating stage of 3rd instar was from 151.3
(major axis) to 94.5
(minor axis) at prothorax and from 568.6
(major axis) to 495.1
(minor axis) at 7th abdominal segment. The sire oe exuvial gland of non-moulting silkworm was 57.5
(major axis) to 51.3
(minor axis) at prothorax and from 91.5
(major axis) to 75.5
(minor axis) at 5th abdominal segment (see Fig. 1) 5. When the normal silkworms reached 4th instar active eating stage its exuvial gland was compared to that of dwarfish silkworm. The result was that the size of normal silkworm at prothorax was from 252.2
(major axis) to 131.6
(minor axis) and the size of exuvial gland at 7th abdominal segment was from 691.5
(major axis) to 493.4
(minor axis) while the sire of exuvial gland of non-moulting at prothorax was from 71.4
(major axis) to 61.5
(minor axis) and the size of the non-moulting silkworm's 8th abdominal segment was from 94.6
(major axis) to 71.5
(minor axis) (See Table 2) 6. There was a remarkable difference in the from of exuvial gland of non-moulting silkworm. The size of alveolar of the non-moulting silkworm was many times larger compared to that of normal silkworm 7. There was no great difference between secretory cells of normal and non-moulting silkworms but the granular type exuvial gland was small in sire compared to that of normal silkworm.
Studies on the Development of Mounting Accelerator for Silkworm, Bombyx mori
Journal of Sericultural and Entomological Science, volume 16, issue 2, 1974, Pages 127~131
Although several kinds of repellents or attractants have been used for mounting accelerators in the silkworm. Bembyx mori, more effective reagents still have not been developed. The authors developed a mounting accelerator with medical herb (Achyranthes bidentata Blume) and glutamic acid, an indispensable amino acid of silkworm, and experimented it's effects in both periods of spring and fall in 1972-1973. It was obtained that the mounting accelerator newly developed by authors shortened the economic periods by a half day, and did not have an bad effect on cocoon quality.
A Study on Utility of Raw Materials for Accelerating the Silkworm Mounting.
Journal of Sericultural and Entomological Science, volume 16, issue 2, 1974, Pages 133~139
The objective of this study is to compare the effects of raw materials as method of speeding up mounting of matured silkworm, for reducing concentrated labor during mounting periods. The results obtained from this study are summarized as fellows： (1) Quercus acutissima Carrs showed the most remarkable effect of repellent. Persicaria blumei Gross and Artemisia asiatica Nakai were followed in order. The rest repellents were also expected to be applicable. considering known material (silk-up) with lower mounting percentage. (2) The effective methods of preparation of repellent were to make distillate. Decocted solution type was considered to be the easiest way of preparation. (3) It seemed to be that there was little effect of repellent on the qualities of cocoon and silk. (4) When a repellent was applied to a silkworm bed, immatured silkworms were observed to mount. Thus it suggests that the repellent will give remarkable effects only when the degree of matured of silkworms is uniform.
A Study on the Improvement of Special Rearing of Young Silkworm for a Simple Cooperative Rearing
Journal of Sericultural and Entomological Science, volume 16, issue 2, 1974, Pages 141~146
This study was carried out to observe the possibility of special rearing of young silkworm for a simple cooperative rearing in the indoor vinyl house. The results of this study are as follows. 1. Temperature and humidity were regulated reasonably in the indoor vinyl house in comparison with general rearing and covered rearing with damp-proof and all workings in it were more convenient. 2. Duration of silkworm life was same in the covered rearing with damp-proof and indoor vinyl house, but general rearing was longer spring rearing silkworm period, 5 hours and autumn young silkworm period. 6 hours than indoor vinyl house. 3. In the mortality ratio, missing larvae of general rearing was more than any other treatments in spring and autumn. There was no difference between covered rearing with damp-proof and indoor vinyl house rearing, but missing larvae seemed to be a little indoor vinyl house. 4. In the individual cocoon ratio there was no significance in spring and autumn, but best cocoon ratio was high in the special rearing and good and low cocoon ratio was high in the general rearing. 5. In the cocoon weight of 10,000 3rd moulted silkworm. cocoon weight of general rearing was less than any other treatments in spring rearing season, and that of covered rearing with damp-proof and indoor vinyl house rearing It was same result. 6. There was no significance in the cocoon layer ratio in spring and autumn, but that of covered rearing with damp-proof and indoor vinyl house was high in comparison with general rearing. 7. As showed above, it is considered that the rearing of indoor vinyl house is worth as special rearing of young silkworm for simple cooperative rearing because it showed good records with three times feedings a day in comparison with general rearing and covered rearing with damp-proof.
Influences of Reeling Conditions on the Denier Control of Raw Silk for Automatic Silk Reeling with Fixed Size
Journal of Sericultural and Entomological Science, volume 16, issue 2, 1974, Pages 147~155
The purpose of this study is to find out influence of reeling conditions on the denier control of raw silk for automatic silk reeling machine. The results obtained are as follows： 1. Effect of groping end part temperature (X
) (1) Average size Y＝0.02945X
＋18.27 (2) Size range Y＝0.04224X
＋2.99 (3) Size deviation Y＝0.01667X
－0.13 (4) Maximum deviation of size Y＝0.04657X
－0.929 (5) Quality of raw silk Y＝－0.07055X
＋10.082. Effect of silk reeling bath temperature (X
) (1) Average size Y＝0.0334X
＋19.08 (2) Size range Y＝0.016X
＋5.24 (3) Size deviation Y＝0.0014X
＋1.05 (4) Maximum deviation of size Y＝0.0206X
＋1.59 3. Effect of silk reeling velocity(X
) (1) Size range Y＝0.01797X
＋3.95 (2) Size deviation Y＝0.00327X
＋0.845 (3) Maximum deviation of size Y＝0.00905X
＋1.50 (4) Quality of raw silk Y＝－0.03232X