• International Journal of Industrial Entomology and Biomaterials
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• 제3권2호
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• pp.117-120
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• 2001

In India, mulberry (Morus spp.), the sole food plant of the silkworm, Bombyx mori (Linn.), is prone to infestation by the pink mealybug, Maconellicoccus hirsutus (Green). Infestation by this pest causes apical shoot malformation, popularly known as 'tukra'. Occurrence of tukra causes an appreciable reduction in leaf yield and quality, leading to low silkworm cocoon productivity. For management of M. hirsutus (Tukra), an IPM package comprising mechanical, chemical and biological measures was demonstrated in the mulberry gardens of five Government Silk Farms in Mysore District (Karnataka, India) during 1995-96. A suppression of 76.0% in tukra incidence and 90.19% in mealybug population was recorded by employ the IPM package which led to an estimated 4,000 kg recovery in leaf yield/ha/year. The impact of IPM package in the management of M. hirsutus, the role of biocontrol agent (Cryptolaemus montrouzieri Muls.) in pest suppression and the cost-benefit analysis of the IPM package are discussed.

• 한국잠사곤충학회지
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• 제32권1호
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• pp.38-43
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• 1990

Effects of topical application of 100, 200 and 300ng/$m\ell$ of 3-indole butyric acid (3IBA) on larval parameters were studied in polyvoltine Pure Mysore breed of B. mori. Each concentration was administered independently, at 36h to III, IV ＆ V instars, at 48h to IV ＆ V instars, and at 72h to V instar larvae. Of the various dosages used, the repeated applications of loons of 3-IBA at 36h to III, IV ＆ V instars resulted in a significant increase in larval weight, silk gland weight, cocoon shell weight and fecundity and a significant decrease in larval duration and cocooning percentage when compared with the corresponding parameters of the untreated controls.

• 한국잠사곤충학회지
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• 제29권1호
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• pp.31-38
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• 1987

누에 이면교잡에 의해 F1세대의 견층 연감율, sericin량 및 fibroin량을 유전 분석한 결과는 다음과 같다. 1. Vr-Wr graph에서 자웅간의 견층 연감율은 모두 초우성이고, 자웅간의 sericin량과 fibroin량은 모두 불완전 우성이었다. 2. 각 형질에 대한 분산성분의 추정에서 자웅간의 sericin 량과 fibroin량 및 자의 연감율에서는 유전자의 상가적효과가 우성효과보다 큰 경향이었고, 웅의 연감율에서만 반응이 양상이었다. 3. 우성의 방향에 있어서는 자웅간의 sericin량과 fibroin량에서 모두 높은 방향으로, 자웅간의 연감율에서는 낮은 쪽이 우성이었다. 4. 조합능력은 3개 형질의 자웅 모두 유의적으로 작용하였고, 특정조합능력보다 일반조합능력이 크게 평가되었다.

• 한국잠사곤충학회지
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• 제20권2호
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• pp.20-25
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• 1978

Research on the hormones of insect has followed by the special opportunities and problems arising from pollution. Since then, the main frame of it has been energetically exploited by ligation, decapitation and so on. In the meanwhile, knowledge of the biochemistry of hormone action as well as other aspects of biochemistry in insects has been gradually disclosed. Since 1966, practical use of active analogs of the hormones has been also worked out as an insecticide and brought the features of it to the light. On the other hand, it is expected to afford the increase of silk productivity resulted from control of the fifth larval period by delaying normal development. With these regards, some of analogs have been tried to apply practically to the silkworm. One of them is "Manta" produced by Zoecon Chemical Company and it is presently used for the increase of silk productivity in Japan. Another one is "R-20458", not registered one, issued by Stuffer Chemical Company. It is still pending for the silkworm growth regulator For the possibility of practical use, two chemicals are tested on the increase of silk productivity by topical application and the obtained results are summarized as follows. 1. It is evident that the fifth larval period was extended by topical application of the tested chemicals "Manta"and "R-20458"at the fifth instar after 51 hours of the last ecdysis, ranging from 12 hours to one day, as compared to. the control 2. In survival rates, there is no significance at 5% level between control and treatments. It proved that there was no toxity to silkworm by topical aprication. 3. There is an increase of cocoon yield in both chemical treatments. It was resulted from increase of weight of single cocoon. "Manta"2.5ppm produced 22.2kg of cocoon. It is equal to 9% increase in index, as compared to that of control. In case of R-20458, the increasing rates were varied at the different concentration; 21.4kg of cocoon production with 5% increase at 5ppm, 20.9kg of it with 2% increase at 2.5ppm and 20.6kg of it with 1% increase at 1. 25ppm in index, respectively, as compared with that of control. 4. Percentage of cocoon shell was increased by topical application. In case of "Manta" 2.5ppm, it is 25.6% which is equal to 6% increase in index, as compared with that of control. For "R-20458", the increasing rates of percentage of cocoon shell were varied with the different level of chemical concentration. They are 25.0% of 4% increase at 2.5ppm, 24.9% of 3% increase at 1.25ppm and 24.7% of 3% increase at 5ppm. 15% increase was attained at "Manta" 2.5ppm in the weight of cocoon layer based on cocoon yield and percentage of cocoon shell in index, as compared with that of control. The rates for "R-20458"are 5% increase at 2.5ppm and 4% increase at 1. 25ppm in index.

• International Journal of Industrial Entomology and Biomaterials
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• 제7권2호
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• pp.221-229
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• 2003

Ten multivoltine female parental lines were crossed with popular bivoltine male silkworm breed NB$_4$D$_2$. Three types of heterosis parameters viz., heterosis over mid-parental value (hybrid vigour), heterobeltiosis (useful heterosis) and standard heterosis (standard check) were estimated for 15 economically important quantitative traits. The interaction among the hybrids and parents indicated significant effect for maximum characters. The heterotic effect of new hybrid combination was compared with popular hybrids viz., Pure Mysore${\times}$NB$_4$D$_2$ and Nistari${\times}$NB$_4$D$_2$. Varied heterotic effect was observed for different traits for different hybrid combination. The results inferred that the crosses viz., BL$_{23}$${\times}$NB$_4$D$_2$ ranked top for 14 traits followed by Hosa Mysore${\times}$NB$_4$D$_2$ for 11 traits; PA$_{12}$${\times}$NB$_4$D$_2$ for 9 traits; BL$_{24}$${\times}$NB$_4$D$_2$ for 8 traits; Kolar Gold${\times}$NB$_4$D$_2$ for 7 traits; WAI$_1$${\times}$NB$_4$D$_2$ for 6 traits and MU$_{11}$${\times}$NB$_4$D$_2$ for 5 traits. Among these, the best hybrids Kolar Gold${\times}$NB$_4$D$_2$ and MU$_{11}$${\times}$NB$_4$D$_2$ were identified for longer filament length and fine denier. Similarly for higher cocoon yield and silk productivity BL$_{223}$${\times}$NB$_4$D$_2$ and BL$_{24}$${\times}$NB$_4$D$_2$ were found to be superior. These hybrid combinations are suitable for commercial exploitation at large scale.e.e.e.

• International Journal of Industrial Entomology and Biomaterials
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• 제19권1호
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• pp.205-213
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• 2009

In order for further systematic maintenance of silkworm stocks kept in Korea we analyzed character quality of a diverse array of silkworm strains originated from several sericulture-practicing countries. The analysis of about ten qualitative characters from 67 strains (13 of Japanese strains, 15 of Chinese strains, 14 of European strains, 6 of Korean and Tropical strains, and 19 of unknown origin) revealed a significant difference in the ten different qualitative characters among silkworm strains. In the analysis of quantitative characters, Japanese and European strains were highest in hatchability, the Korean and Tropical strains were highest in pupation rate, and unknown origin and Chinese strains were highest in cocoon yield and number of egg laid. With the connection of molecular genetic analysis the current data may provide the advanced ground for further systematic maintenance of valuable genetic resources of silkworms, although more breeds should be investigated for further complete pictures.

• International Journal of Industrial Entomology and Biomaterials
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• 제13권2호
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• pp.109-112
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• 2006

The use of commercial silkworm hybrids resistant to important silkworm diseases is economical and better option particularly in tropical areas. This necessitated the evolution of productive bivoltine silkworm breeds non-susceptible to $BmDNV_1$. Non-susceptibility to $BmDNV_1$, infection was found to be controlled by a single recessive gene, nsd-l or a dominant gene, Nid-l. A major dominant/recessive gene confers resistance to $BmDNV_1$, from potent donor parents have been transferred to 10 productive but susceptible bivoltine silkworm strains through conventional breeding methods. By utilizing these breeds prepared 25 hybrids $(5{\times}5)$ and hybrid evaluation was carried out to identify most promising hybrids resistant to $BmDNV_1$. All these hybrids are inoculated with $BmDNV_1$ inoculum along with productive control hybrid $CSR2{\times}CSR4$ and reared under standard rearing procedure. Based on inoculated rearing and test reeling results, two most promising hybrids $(CSR18DR{\times}CSR29DR\;and\;CSR21DR{\times}CSR50DR)$ were selected for commercial exploitation. The selected hybrids have shown a survival rate of >85% with productive traits, where as control hybrid have shown 11.1% survival with inferior cocoon traits. The methodologies adopted were discussed.

• 한국잠사곤충학회지
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• 제39권2호
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• pp.140-145
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• 1997

Silkworm fed on mulgerry leaves with 1000 times diluted Insegar(main component : Fenoxycarb, ethyl-2-(4-phenoxyphenoxy)ethylcarbmate) and its effects was investigated on increase of the 5th larval silkgland weight and silk quality. The oral application of fenoxycarb showed increase of the silkgland weight. The whole period of the silkgland weight falls on the 2nd instar treatment by 13%, the 3rd day of the 4th instar by 111%(3100 mg) and the whole period of the 5th instar treatment rather decreased it by 66%(497 mg), as compared to 1470mg of the control. Female and male both increased 15%(1779mg) and 12%(1554mg) of the silkgland weight with the 2nd instar treatment, as compared to 1548mg and 1391mg in control, respectively. 118%(3368mg) and 104%(2832mg) of increase in the silkgland weight were also showed with the 3rd day of the 4th instar treatment but 70%(463mg) and 61%(539mg) of decrease were shown with the 5th instar treatment. The maximum weight of the middle silkgland weight increased by 6%(1248mg) and 127%(2673mg) with the 2nd instar and with the 3rd day of the 4th instar, respectively but 67%(393mg) of decrease took place, as compared to 1175mg of the control. The maximum increase of the posterior silkgland weight with whole peried of the 2nd instar treatment increased 12%(419mg) and 75%(656mg) and 64%(135mg) of decrease was shown, as compared to 374mg of the control. The oral application of Insegar at the 2nd instar increased 26 m of cocoon length, 4.0 cg of the cocoon filament weight and 0.21d of the silk denier, as compared to 1147 m of the cocoon length, 38 cg of the cocoon filament, 2.99d of the silk denier, weight of cocoon filament and silk denier, respectively but denier variance narrowed to 0.33d, as compared to that of the control.

• 한국잠사곤충학회지
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• 제31권2호
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• pp.102-112
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• 1989

국내에서 보존중인 148개 누에 품종을 공시하여 화용비율, 상견화율, 수견량, 1l과수, 단견중, 견층중, 견층비율, 5령경과일수, 전령경과일수 등 9개 형질을 조사하여 주성분분석과 집락분석방법으로 품종분류를 하였으며 그 결과는 다음과 같다. 1. 상관분석결과, 수견량, 단견중, 견층중, 견층비율, 5령경과일수, 전령경과일수의 6개형질은 상호간에 고도의 정의 상관관계를 보였다. 2. 9개 조사형질의 상관계수에 대한 주성분분석 결과, 제일주성분-제삼주성분까지의 3주성분에 의하 전정보량의 약 805가 해소되었으며, 제1주성분은 견생산성인자, 제이주성분은 고치생산성인자로 특징지워졌으며 제삼주성분은 총합특성치의 특성을 정의하기 어려웠다. 3. 주성분 스코아를 이용하여 계산한 city block distance(품종간거리)에 의하여 148개 누에품종은 7개의 품종군으로 분류되었는데, I군은 견생산성이 낮고 고치생산성이 중 정도인 품종군으로 여러 지리적 품종들이 비교적 고루 분포되어 있었으며, II군은 견생산성은 높으나 고치생산성이 낮으며 일본종으로 구성되어 있었다. 제III군은 견 및 고치생산성이 공히 낮은 품종군이었고, 제IV군은 견생산성과 고치생산성이 다같이 가장 우수하였으며 주로 중국품종으로 구성되어 있었다. 제V군은 견생산성은 높으나 고치생산성이 낮았으며 대부분 유럽종으로 구성되어 있었다. 제VI군은 견 및 고치생산성이 낮은 일본종으로 구성되어 있었다. 3. 지리적 품종과 품종군과의 관계에서 중국품종들은 주로 제IV군에 분포되어 있었고 유럽종은 주로 제5군에 분류되었으며, 일본종은 7개의 품종군에 고루 분포되어 유전적으로 가장 다양한 것으로 나타났다.

• 한국잠사곤충학회지
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• 제34권1호
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• pp.21-29
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• 1992

누에 품종육성을 위한 기초자료를 얻기 위해 7개 품종을 이면교잡하여 얻은 F1 세대에 대한 유전자의 분포상태, 우성정도, 분산성분과 성분비 등을 분석한 결과를 요약하면 다음과 같다. 1. 8개 형질에서 정방향의 잡종강세를 나타낸 형질은 암견층비율을 제외한 7개 형질이었으며 이 중암전견중, 암용체중은 매우 높은 잡종강세를 나타내었고 부방향의 잡종강세는 암·수견층비율에서 볼 수 있었다. 2. 각 형질에 대한 분산분석의 결과는 세포질의 영향인 모체효과와 정·역간의 효과에서 암견층비율과 암용체중을 제외한 전 형질에서 유의성이 인정되었다. 3. Vr-Wr graph에서 암전견중과 암·수용체중은 초우성을 나타내고 수전견중, 암·수견충중, 암·수견층비율은 불완전우성으로 유전되었다. 4. 유전분산성분에서 수전견중, 암·수견층중, 암·수견층비율은 상가적 효과가 우성효과보다 크게 나타났고, 암전견중은 우성 효과가 상가적 효과보다 크게 표현되었다. 5. 협의의 유전력은 암·수전견중, 암·수견층중, 암·수견층비율에서 0.51 이상으로 높았고, 광의의 유전력은 암용체중을 제외한 전 형질에서 0.77 이상으로 높았다. 6. 우성의 방향은 암견층비율이 부이고, 암·수견층중이 5.22, 6.02로 다소 높았으나 암·수전견중, 수견층비율, 암·수용체중은 정으로 낮았다.