가잠(家蠶) Virus에 관(關)한 연구(硏究) -저항성(抵抗性)에 관(關)한 기초조사(基礎調査)-

박광의 ( K. E. Park ),강석권 ( S. K. Kang ) 한국잠사학회 1969 한국잠사곤충학회지 Vol.9 No.-

1. 본 조사는 현재 우리나라에 보존되어 있는 계통을 전부 수집하여 Virus병에 대한 저항성을 계통 별로 조사함으로써 잠견생산에 막대한 피해를 주는 Virus병에 대하여 저항성이 강한 계통을 선발하는 동시에 선발된 결과는 앞으로 저항성품종 육성자료로 삼고저 하였다. 2. 가잠의 핵형다각체 Virus병에 대하여 저항성이 강한 계통은 N4, N6, N48, E111로써 log ED 50의 값이 0.799~1.611 범위 내에 있으며 강한 계통으로서는 N10, C62, N70, C108이고 log ED 50의 값은 5.159~7.258 범위 내에 있다(표 4참조) 그리고 일본계통이 가장 강하여 log ED이 3.770이 3.770이고 중국계통의 log ED 50은 3.564로서 다음이고 가주계통의 log ED 50이 3.381로서 가장 강한 계통으로 나타났다. 감염율의 회귀방정식의 방향계수는 0.1~0.6범위로서 우리나라 보존계통의 저항성의 균일성이 비교적 작을 경향을 나타냈다. 계통별 저항성의 유전현상에 대한 해명과 품질육성을 위한 구체적인 응용방법에 관한 구명은 차후의 숙제로 남게 되었다. 3. 잠체의 수분 및 회분과 Virus병에 대한 저항성과는 상관관계가 없었고(표 8참조) 다만 감잠비율(보통 사 육법에 의하여 조사된 것)과는 고도의 상관관계가 있다. 즉 4면 기잠에서는 수분 및 회분과는 관계가 없었고 3면 기잠에서는 수분은 +0.326 회분은 +0.326으로서 고도의 유의성을 나타냈고 1면과 2면의 회분에서는 각각 +0.520과 +386으로서 고도의 유의성을 나타냈으나 수분에서는 유의성이 없었다(표7 참조). 4. 교배조간에 있어서는 기호 205가 모든 형질에 있어서 가장 우수하였다. 특히 204는 강건성이 매우 좋았으나 견질에 있어서 대조구보다 약간 떨어진다. 기호 212는 견질을 약간 떨어지고 감잠비율은 보통이나 수견량이 공시품종 중 가장 많았다(표 11). 5. 종합적으로 기술하면 Virus에 대한 저항성이 강한 상기 몇 계통은 강건성 품종육성을 위한 기초자료가 될 것이며 계속 여러 계통 외 특성을 조사하여 특성 보존을 위한 품종보존의 완벽을 기하여야겠다. 1. Objectives and Importance. Many silkworms have been damaged by nuclear polyhedrosis virus diseases thoughout the country every year causing a decease in cocoon production by approximately ten per cent per year. The damage caused by the infections virus has occured in spite of complete disinfection. In this respect, it is well known it is impossible, at the present time, to protect the silkworm from these virus infections through chemical and physical control methods. Therefore, this author has attempted to solve this urgent problem from the view point of heredity and breeding, discovering the different resistances and heritabilities among 120 stains collected from throughout the country, and selecting the ones with highest resistance for the basic materials in the silkworm breeding. 2. Results of work 1) The strains with strong resistance to the nuclear polyhedrosis virus diseases are N4, N15, N48, C55/ and E111, the log ED50 values of them vary between 0.799 and 1.611. The susceptible strains are N20/, C62/, N76/, N79/ and C108/, the log ED50 values of them vary between 5.159 and 7.258. (Reference Table 4) The Japanese strain with a log ED50, value of 3.770 is the strongest, followed by the Chinese strain with a log ED50 value of 3.564. The weakest is the European strain with a log ED50 value of 3.3381. The direction coefficient of the regression equation of the susceptibility varies between 0.1 and 0.6, the uniformness of the resistance of the preserved strains of this country is comparatively low. The hereditary henomena of the resistance of each strain and the conerete method of its application for silkworm breeding main the subjects for later studies. 2) The content of water and ash in silkworm has not been correlated with the capability for resistance to the virus diseases(Reference. Table 8), but it is very significantly correlated with mortality rate (in common reaning). In the case of the silkworms which have just completed the fourth moulting the content of water and ash is not related to the mortality rate. In the case of the silkworms which have just completed the third moulting, however, the water(+0.326) and ash (+0.362) registered a high significance. The ash content in the first (÷0.520) and second (÷0.386) moults is highly significant but water content in both cases is not significant (Reference Table 7). 3) The No. 205 strain proved to be the best in character among the various F1 hybrids. No. 204 was very good in strength but a little lower in cocoon character than the control. No. 212 was a little low in cocoon character and mortality was average, but the cocoon harvest was the best among all the varieties offered for (Reference Table 9). 4), In short, the above mentioned strains which are known to have strong resistance to the virus disease are expected to provide basic data for breeding strong varieties. It is proposed that continued research should be conducted on the characteristics of various strains for a satisfactory preservation of various characteristics research should be conducted on the characteristics of various strains for a satisfactory preservation of various characteristics.

家蠶育種의 最近의 進步

K. E. Park(朴光義) 한국육종학회 1978 한국육종학회지 Vol.10 No.3

There are far less breeders and research institutes in our country than those in Japan. In the field of sericultural industry, well developed country, Japan has not made a reasonable development in silkworm breeding science due to no exchange of new breeding technique and new idea. Therefore it is quite natural that most Korean breeders have experienced in the difficulty of silkworm breeding because of no information from other countries. However the silkworm variety belongs to well improved organism like other animals and plants. 1. On the basis of productivity in 1960 the amount of cocoon production per 10 a increased by 2.3 times, the amount of raw silk per 10 a by 2.7 times, and the amount of cocoon production per box by 1.9 times in 1976. These increases seem to result from newly improved silkworm varieties and stability of silkworm rearing. As shown in table 2, the length of a cocoon filament has increased by 46 per cent and the percentage of raw silk by 23 per cent. These characters are closely related to the hereditary phenomena of a variety. 2. At present time, twenty-two silkworm varieties almost equal to the productivity of Japanese varieties are authorized and being extended to the farmers. Of those varieties, 12varieties were improved at Sericultural Experiment Station and 10 varieties at Private Research Institutes. 3. In general the resistance of male and F₁ hybrid to the diseases is stronger than that of female and original parent respectively. In order to remove the week point of original parent the double cross or three way cross is being used. 4. The hereditary phenomena of a few virus resistances disclosed recently will be applied to the silkworm breeding. 5. Complete resistance to Ina-virus was inherited by a recessive major-gene and possibility of its application to the breeding is broadly discussed. 6. The silkworms fed on the artificial diet are known to be susceptible to virus and Streptococcuss faecalis. 7. The resistant strains to high temperature, humidity and nutritive deficiency have been required up to the present time. Optimum conditions were able to be set up for resistance test of a variety and selection of a new silkworm strain. There are still problems, such as the resistance to low temperature and sudden change of temperature. 8. In our country the young silkworms are being fed on the artificial diet in large scale. Simultaniously with this application of artificial diet, new variety suitable to the artificia1 diet is urgently required. 9. Newly hatched silkworms have no close relation to the component change of improving artificial diet in their feeding response and growth. This finding suggests that the breeding for a suitable strain to the artificial diet can be started at any time. 10. Feeding responses to the artificial diet become better gradually every generation. Maximum feeding responses are usually found in 4th generation. 11. Individual selection for Bombyx mori can be carried out as using l% chromic oxide for test of digestibility of a larva. Thus the productivity of soil may be incerased. 12. Male and female can be easily discriminated by the difference of larval marking, egg color and cocoon color which were obtained in a complex translocation between Z(autosome) and W chromosmes.

5령일수별급상량(齡日數別給桑量)의 증감(增減)이 가잠실용형질(家蠶實用形質)에 미치는 영향(影響)

박광의 ( K. E. Park ),문재유 ( J. Y. Moon ),김주읍 ( C. U. Kim ) 한국잠사학회 1969 한국잠사곤충학회지 Vol.9 No.-

5령일수별급상량의 증감이 가잠 실용형질에 미치는 영향은 다음과 같다. 1. 5령 전기간 표준급상량을 급여한 것보다 5령일수별로 30%증가 급여한 것은 실용형질 중 1과수에만 영향하고 화용비율, 전견중, 견증량, 견증비율, 상견비율에는 영향하지 않는다. 즉, 급상량증가는 강건성과 사량증가에는 효과가 없다. 2. 5령 전기간 표준급상량을 급여한 것보다 5령일수별로 30% 감량 급여하는 것은 실용형질 중 가장 중요한 전견기, 견증중에 크게 영향하며 화용비율, 견증비율, 상견비율 1계수에는 영향하지 않는다. 즉, 5령 전기간 표준급상량을 급여한 것에 비하여 5령 전기간 감량급여 한 것은 전상량이 12%, 상증중이 17% 가벼운 것으로 가장 불량하며 5령일수별로 감량 급여한 것 중에 특히 5령 7일째 감량한 것은 전상중, 상증중이 각각 5% 가벼운 것으로 불량하였다. This study was carried ont to investigate the effect of feeding amount on the metric characters of silkworm at each day of 5th instar. The results obtained from the study are summarized as follows: 1. The increased amount of feeding did not affect on the metric characters except the character, number of cocoon per litre, by each day of 5th instar. 2. The decreased amount of feeding did affect the weight of cocoon, weight of cocoon layer and did not affect the pupation, best cocoon rate, cocoon layer rate and number of cocoon per litre by each day of 5th instar. Namely, the weight of cocoon or weight of cocoon layer was decreased by 12 to 17 per cent in decreasing amount of feeding through 5th instar. Weight of cocoon or cocoon layer decreased by 5 per cent in the decreasing amount of feeding at just 7th day of 5th instar.

잠란(蠶卵)의 반문수(斑紋數)와 타계량형질(他計量形質)과의 유전상관(遺傳相關)과 환경상관(環境相關)에 관(關)한 연구(硏究)

박광의 ( K. E. Park ) 한국잠사학회 1962 한국잠사곤충학회지 Vol.2 No.-

1961年 春期에 卵紋數와 各種 實用形質과의 表現, 遺傳 및 環境相關과 各形質의 遺傳力을 농촌진흥청 蠶業試驗場에서 蠶品種 各道 連絡試驗에 供試하는 8 品種에 對하여 調査하였으며 該 試驗場에 保存되어 있는 蠶品種中 2(5) 品種에 對하여는 相關, 系統別 卵紋數 또는 變異를 調査하여 다음과 같은 結果를 얻었다. (1) 卵紋數와 全繭重, 繭層重 및 纖度와는 高度의 貧表現相關과 貧遺傳相關을 나타냈으며 環境相關은 나타나지 않았다. (2) 卵紋數는 中國系統이 가장 많고 日本系統이 中間이고 歐洲系統이 最小였다. (3) 減蠶比率과 卵紋數와의 關係는 一定한 경향이 없다. (4) 繭層重과 系長의 遺傳力은 全繭重, 纖度 및 卵紋數의 것에 比해서 적었다. (5) 卵紋集團의 小多角形 斑紋數가 많은 品種일수록 卵紋의 絶對數가 많았다. (6) 卵紋數의 變異는 歐洲系統이 가장 크고 中國系統, 日本系統의 順으로 적은 것 같다. 全繭重, 繭層重 및 纖度는 卵紋數를 基準으로 하여 그것들을 선발하면 間接的으로 選拔 效果를 높일 수 있을 것이며 特히 卵時代에 選拔함으로서 飼育의 經費를 節約할 수 있을 것이다. This work was carried out to investigate the phenotypic, genotypic, and environmental correlations between the number of the egg markings and other metric characters, and their heritability, with eight varieties in Bombyx mori L. Five European varieties, ten Chinese varieties and ten Japanese varieties were used to know the average number of the egg markings and their variabilities for each strains. The results may be summarized as follows: 1) there were highly negatively phenotypic and genotypic correlations between the number of the egg markings and total cocoon weight, weight of cocoon layer, or denier, but not an environmental correlation. 2) The average number of the egg markings in Chinese strain was more than that in other strains. 3) The correlation between the motality and the number of egg markings seemed not to be found. 4) The heritability of the weight of cocoon layer and the bave length was less than that of total cocoon weight, denier and number of egg markings. 5) The more the number of the polyhedral particles in an egg marking group became, the more the total number of egg markings increased. 6) The variation of the number of the egg markings in European strain was larger than that in any other strains. 7) It is expected that the selection for the number of the egg markings may have genetic advances of total cocoon weight, weight of cocoon layer, or denier. Especially the selection for the number of the egg markings before rearing will save the silkworm rearing cost.

견사량(繭絲量)과 관계(關係)있는 몇 가지 요인(要因)에 대(對)하여 -보존잠품종별잠견(保存蠶品種別蠶繭)의 견층비율(繭層比率)과 연감율조사(練減率調査)-

박광의 ( K. E. Park ),신원집 ( W. J. Shin ),남중희 ( J. H. Nam ) 한국잠사학회 1968 한국잠사곤충학회지 Vol.8 No.-

견사량과 관계가 있는 견층비율과 견층연감율을 우리나라 보존잠품종별로 조사한 바 다음과 같은 결과를 얻었다. (1) 견층비율과 견층연감율간에는 상관이 없었으며, 전견중과는 중국계통에서만 정(+)의 상관이 있었다. (2) 계통별로는 연감율의 차이가 없으나 품종간에는 차이가 있었다. (3) 숫컷의 연감율보다 암컷의 연감율이 높았다. The aim of this treatise was to find out the factors related to the weight of a have in the original silkworm. The results obtained are as follows: 1. There is no relationship between the degumming rate and cocoon layer rate, but there is related with the weight of cocoon only in chinese strain. 2. There is no difference among the strains, but considerably differente in degumming rate among the species. 3. The degumming rate of female is higher than that of male.

작잠(작蠶)에 관(關)한 연구(硏究)

박병희 ( B. H. Park ),송기언 ( K. E. Song ),이상풍 ( S. P. Lee ),박광의 ( K. E. Park ) 한국잠사학회 1965 한국잠사곤충학회지 Vol.5 No.-

本 實驗은 中性子 및 γ-Ray를 작蠶 踊體 및 蠶卵에 照射하여 突然變異體를 얻고저 行하였든 바 그 結果는 다음과 같다. 1) 踊體에 對한 中性子 處理區는 모두 羽化 하였으나 交尾不能이였으며 4000γ 區만은 産卵은 하였지마는 全部 不受精卵이였고 卵內容物도 없었으며 一部는 卵殼에 구멍이 뚫려있었다. 2) 秋期 二化期에 卵에 對한 中性子處理區에서는 50~60%의 乳化率을 보였으나 卵에 對한 γ-Ray 處理區는 全然 孵化하지 못하였다. 3) 中性子에 對한 踊體의 減受性은 卵보다 弱하다. 4) 孵化率은 γ-線量에 反比例한다. 5) γ-4000區에 繭質이 多少 優秀한 突然變異體를 얻었는데 來年度에 次代檢定을 行할 豫定이다. I. Breeding of tussah silkworm(preliminary report). The preliminary examination for bleeding has been carried out since 1963 in tussah silkworms. 1) The strain(l-MG-B) of the heaviest silk quantity was the green silkworm and brown cocoon in univoltine, and the strains(2-G-B, 2-MG-B) of the heaviest silk quantity were also the green silkwom and brown cocoon in bivoltine in both spring and fall in 1965. 2) It looks like the voltinism, the body color and the cocoon color have reached to pure line up to 1965. II. Best place for the winter of tussah pupa. This work was aimed to find out good ways for the winter of tussah pupa. 1) The hatch of bivoltine was better than that of univoltine. 2) The cocoons covered with the leaves were good in the emergence of moth. 3) The cocoons which were kept at natural temperature till the first emergence of moths would show bad in both hatch and emergence. 4) If some of the pupae kept under natural condition were controled at proper temperature for a few days, hatch and laying eggs were best. 5) The best places for the winter were the egg storage and the rearing room. III. Relation between incubation temperature and voltinism. 1) When the tussah pupa are kept at natural temperature during winter, the moths do not come out of the pupa. 2) There is no difference between about 18℃ and about 25℃ during incubation in hatching ratio. 3) The tussah silkworms of univoltine in mortality are stronger than that of bivoltine. 4) There is not any relation between voltinism and high or low temperature for pupa and eggs. IV. Induced mutation by gamma-ray and neutron in tussah silkworm. This work was carried out in order to induce the mutation by treating the pupa or the eggs of tussah silkworm with gamma my and neutron. The results obtained are as follows. 1. Though the whole pupa treated with neutron become moths, the moths have no ability to copulate each other. The only moths emerged from pupa treated with neutron, 4000γ are able to lay all un-fertilized eggs, some of which have a hole on the surface and nothing of contents. 2. The non-diapause eggs are treated with neutron in spring, but the hatching ratio is 50∼60 percent, but the whole eggs treated with gamma ray are never hatched. 3. The sensitivity of the pupa to neutron is weaker than that of the eggs. 4. The hatching ratio is in direct proportion to the gamma ray dose. 5. Author find out a new mutant which is excellent in the cocoon quality, so he will do the progeny test next hear.

다화성잠저승(多化性蠶저蠅)(Tricholyga sorbillans Wiedmann)에 관(關)한 연구(硏究)

김낙정 ( N. J. Kim ),박광의 ( K. E. Park ),강석권 ( S. K. Kang ) 한국잠사학회 1968 한국잠사곤충학회지 Vol.8 No.-

1. 수원지방에서 다화성잠저승의 세대회수는 5~6회이다. 2. 다화성잠저승의 란, 유충, 용, 기간은 대체적으로 2일, 8일, 18일 간이다. 3. 기상조건 특히 온도에 대하여 본충의 세대기간은 큰 영향을 받는다. 각세대중에서 가장 짧은 세대는 제3세대로서 21일 14시간이고 가장 긴 세대는 제5세대로서 약 40일 간이다. 4. 가잠에 기생한 본충의 유충은 탈출 후 3.5cm~10.5cm 토중으로 들어가 화용한다. 5. 다화성잠저승은 용태월동을 하지 않고 유충태월동을 한다고 생각된다. 6. 실외사육에 있어서 본충에 대한 피해는 27.9%였다. 7. 견잠에 있어서 다화성잠저승의 피해를 받을지라도 영견가능하고 견질에 대하여 큰 영향이 없다. 8. 수견 후 본충의 전국 피해조사에 있어서 춘잠기가 6.36%, 추잠기가 4.09%, 년간 5.25%였다. 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 3rd 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.

家蠶 人工飼料에 對한 系統別 攝食性에 關한 硏究

J.U. KIM(金周浥,),K.E. PARK(朴光義) 한국육종학회 1979 한국육종학회지 Vol.11 No.1

This experiment was carried out to find out the feeding response of 82 varieties being preserved to artificial diet, and its relation to the moulting and growth of the young larvae. The results obtained are as follows. 1. There are differences of the feeding response among varieties and strains. The feeding response to the artificial diet becomes better in order of Japanese, European and Chinese strains. 2. Highly positive correlations were found between the feeding response, and moulting ratio and growth at 1st, 2nd instars. Excellent feeding response to the artificial diet made the larvae moulting well and growing uniformly. On the other hand, there was no correlation between the weights of lst moulted larvae and 1st moulting ratio. 3. Groupings could be attempted by the differences of the feeding response to the artificial diet. These groupings can be applied for the silkworm breeding.

잠종(蠶種)의 질(質)이 잠작(蠶作)에 미치는 영향에 관한 연구(硏究)

김윤식 ( Y. S. Kim ),김문협 ( M. H. Kim ),박광의 ( K. E. Park ),이상풍 ( S. P. Lee ),강석권 ( S. K. Kang ),성수일 ( S. I. Seong ) 한국잠사학회 1972 한국잠사곤충학회지 Vol.14 No.2

춘추잠기를 통하여 잠기별로 성적이 좋은 항목과 여타항목 성적간의 관계를 보면 일정한 경향을 발견할 수가 없으므로 종합적인 고찰을 하기가 지극히 곤란하나 대략 다음과 같이 요약할 수 있겠다. (1) 월년잠종 냉장입고시의 배자 발육계제와 부화율 및 실용부화율간에는 어떠한 경향을 발견할 수가 없다. 그러나 부화율이 좋지 못한 잠종은 실용부화율이 낮을 뿐만 아니라 상견수견량이 적고 또한 화용률도 낮다. 실용부화율이 좋지 못한 잠종은 유화율이 약간 낮은 경향이 있으나 상견수견량과 부화율은 평균치 이상이거나 평균치에 근사하다. 따라서 실용부화율은 누에의 건강과는 관계가 적다고 할 수 있겠다. (2) 오교율은 상견수견량과 화용율에 영향을 미치리라고 생각되며 오교율이 높아지면 원잠이나 원잠견의 혼입률이 높아지는 것이다. 그리고 오교율은 잠견제조에 속하는 문제이며 양잠의 양적 및 질적 생산에 영향을 미치는 요인이라고 하겠으나 여건에 따라서는 원종과 교잡종간에 현격한 차가 나타나지 않는 것이라고 생각된다. 또한 월년잠종과 불월년잠종간의 평균오교율차는 교잡원종의 순도에 기인한 것이라 생각된다. (3) 상견수견량이 적은 잠종은 화용율이 낮은 경향이 있으니 상견수견량과 화용율간에다 관계가 있다고 생각된다. (4) 견층비율이 낮은 잠종은 화용율이 낮아지는 경향이 있다고 하겠다. 따라서 견층비율은 잠품종적인 문제 이외에 잠작과도 유관하다고 생각된다. The authors studied on the effect of silkworm eggs collected from the whole silkworm egg producers in Korea to know the cocoon crops, and the results are as follows. There was no remarkable correlation on the effect of silkworm eggs quality for the cocoon crops but can be concluded as follows. 1) There was a weak correlation between the hatching ratio and economical hatching ratio but no correlation between economical hatching ratio and cocoon crops. In other word, hatching ratio couldn`t be influenced for the silkworm health. 2) Non-hybrid ratio (miss-crossing ratio) influenced to the amount of reelable cocoons and pupation ratio but on this experiment, there was a little influence for the cocoon crops. The authors found that there is no difference between origin and its F1 crops under the more suitable conditions. Non-hybrid ratio can be determined the silkworm eggs quality, but notice that the ratio decrease only when used pure origin. 3) There is some correlation between harvesting amounts of reelable cocoon and pupation ratio. In general, the eggs which harvest small amounts of reelable cocoon are lower on the pupation ratio. 4) The influence of cocoon layer ratio is based on the variety absolutely but cocoon crops also has a little influence on the cocoon layer ratio.

잠병(蠶病)이 잠작(蠶作)에 미치는 영향(影響)에 관(關)한 조사연구(調査硏究)

김문협 ( M. H. Kim ),김윤식 ( Y. S. Kim ),박광의 ( K. E. Park ),이상풍 ( S. P. Lee ),강석권 ( S. K. Kang ),성수일 ( S. I. Seong ) 한국잠사학회 1972 한국잠사곤충학회지 Vol.14 No.1

잠병이 잠작에 미치는 영향을 조사하기 위하여 경기도 용인군 남사면 방아리, 경북 칠곡군 약목면 그리고 경북 칠곡군 북삼면의 양잠농가를 대상으로 잠병에 대한 피해율을 조사한 결과는 다음과 같다. 1) 잠병에 의한 감수율은 춘잠기에는 5.5%, 추잠기에는 8.9%이었고 년간 평균 7.2%였으며 하견을 병해견으로 환산한다면 8.3%였다. 2) Virus 다각체병과 연화병에 의한 병해율은 전발병의 치잠기에는 17.8%, 장잠기에는 82.2%로서 높은 비율을 나타내었다. 3) 평균산견량은 상자당 27.74kg이었는데 추정산견량에 대하여 잠병에 의한 감수량은 2.411kg이었다. 4) 원인불명의 감수량이 3.611kg으로서 잠병에 의한 감수량의 약 1.5배였다. 이 원인불명의 감수량은 주로 유실잠과 하견이 많았기 때문이다. 5) 잠작이 비교적 안정된 농가수는 춘기에는 54.7%, 추기에는 21.9%였다. 6) 잠병 이외의 피해율은 10.70%였고 전감잠비율은 17.87%였다. This investigation was conducted to measure the effects of silkworm diseases on the cocoon crepe. The sample farmers were selected at three areas in Korea. a. Banga Ri, Namsa Myoen, Yongin Kun, Kyoenggi Do b. Moorim Ri, Yakmok Myeon, Chilkok Kun, Kyeongsangbuk Do c. Oero Ri, Buksam Myeon, Chilko Kun, Kyeongsangbuk Do 1. Reduction ratio of crops by the silkworm disease was 5.5% in spring season, and 8.9% in the autumn but 7.2% in a year. Including disease damaged cocoons being spoiled cocoons, it was 8.3%. 2. The ratio of disease-damage by the polyhedrosis virus and flacherie was 17.8% of whole disease at young instar and was 82.2% at advanced instar which showed highest ratio. 3. Average production amount of the cocoon was 27.74kg. The reduction amount by the silkworm disease against the estimated production aomunt was 2.411kg. 4. Reduction of amounts by unknown factors was 3.611 kg. This was 1.5 times of reduction amount by the disease. This nay be chiefly due to the missing silkworms and spoiled cocoons. 5. Ratio of farmers harvesting stable cocoon crops was 54.7% in spring rearing season but 21.9% in autumn. 6. Damage ratio of factors other than the silkworm disease was 10.70% and it was 17.87% of total mortality.