• International Journal of Industrial Entomology and Biomaterials
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• 제4권2호
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• pp.169-173
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• 2002

A practical technology for silkworm disease management at farmer\\`s level was suggested and test verified for its efficacy and adaptability. The technology consisted of disinfection of rearing house and appliances, early disease diagnosis, personal and rearing hygiene and silkworm body and rearing seat disinfection. Besides, the supportive techniques associated in disease management are cited. The validation trials of the technology involving 845 farmers crops with 147,530 disease free layings (dfls) of CSR bivoltine hybrids confirmed the effectiveness of the technology which resulted an average yield of 68.98 kg cocoons/100 dfls.

• International Journal of Industrial Entomology and Biomaterials
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• 제14권1호
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• pp.15-21
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• 2007

Three newly authorized bivoltine silkworm hybrids namely, $CSR2{\times}CSR4$ (productive single hybrid), $(CSR6{\times}CSR26){\times}(CSR2{\times}CSR27)$ (productive double hybrid) and $CSR18{\times}CSR19$ (robust single hybrid) were chosen for the present study. These hybrids were subjected to different temperature and humidity treatments i.e., $25{\pm}$1^{\circ}C and RH $65{\pm}5%$ (control), $30{\pm}1^{\circ}C$, with combinations of low relative humidity (RH $65{\pm}5%$) and high RH ($85{\pm}5%$) at different stages during rearing and spinning of silkworm larvae. The larvae of after 3rd moult were subjected to different thermal and humidity stress till the assessment of cocoon traits. The comparative rearing and reeling performance clearly indicated that the deleterious effect of high temperature and high RH was more pronounced for the majority of traits such as cocoon uniformity, cocoon weight, shell weight, shell percentage, reelability, filament length, raw silk percentage raw silk recovery denier and waste percentage on silk weight than other temperature and RH treatments and this effect was almost similar for all three silkworm hybrids studied. The present investigation clearly indicate that the deleterious effect of high temperature and high RH was more pronounced on rearing and spinning of silkworm larvae than other temperature and RH treatments and similar effect was noticed for all the three silkworm hybrids studied. The cocoon characters can be improved by providing ideal environmental conditions even during spinning stage of larvae affected with high temperature and RH. The study also suggest that high temperature and low humidity has greater effect during rearing stage than spinning stage.

• 한국잠사곤충학회지
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• 제49권2호
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• pp.51-55
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• 2007

기온, 강수량 등 기상요인이 누에에 미치는 영향을 조사하기 위해 뽕나무 재배조건, 토양, 기후조건이 다른 누에 우량교배조 지역적응시험 수행지인 전국 8개소를 대상으로 2006년 춘추잠기 양잠기상과 작황 영향 조사를 실시하였다. 2006년 춘추잠기 기상요소의 특징은 전국 평균 애누에때, 큰누에때, 섶중때의 기온은 각각 $17.7^{\circ}C$, $19.8^{\circ}C$, $21.5^{\circ}C$로 예년대비 평균 $1^{\circ}C$ 높았으며, 강수량은 각각 15.1mm, 6.9 mm, 7.0mm로 큰누에때와 설중때는 예년대비 평균 22.9 mm 적었다. 일조시수는 유충기간동안은 예년보다 1.7시간 짧았으나 설중때는 예년과 큰 차이 없었다. 즉, 예년대비 기온이 높고 강수량이 적어 가뭄현상을 보였던 2006년 춘잠기 작황은 예년에 비해 화용비율이 낮고, 수 견량이 약 1 kg 적었으며 전견중이나 견층비율은 다소 높았다. 추잠기 기상요소의 특징은 애누에때, 큰누에때, 설중때의 기온은 각각 $25.1^{\circ}C$, $20.5^{\circ}C$, $19.9^{\circ}C$로 예년대비 애누에때의 기온은 약 $1^{\circ}C$ 높았으며 큰누에때는 $1.3^{\circ}C$낮았다. 설중때는 거의 같은 수준을 보였다. 강수량은 각각 10.2mm, 4.6 mm, 3.7mm로 예년과 대비하여 큰 차이가 없었다. 즉, 예년과 비슷한 양상을 보였던 추잠기 기상은 2006년 추잠기 작황에도 별다른 영향을 주지 않았다. 즉, 전견중과 견층중은 예년과 큰 차이 없어 견층비율의 변화도 없었던 평작 수준이었다.

• 한국잠사곤충학회지
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• 제26권2호
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• pp.32-36
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• 1984

전국 621개 양잠시범부락의 84가을 누에병 발생율과 그 원인을 조사한 결과는 다음과 같다. 1. 누에 사육 기간중 누에병 발생율은 약 17%이었다. 2. 누에병 종류별 발생율은 농병(38.5%), 경화병 (20.3%), 연화병(17.9%) 및 쉬파리병 (9.4%)의 순이었다. 3. 누에병은 종잠기보다 장잠기 이후에 주로 발생하였다. 4. 누에병 발생의 주원인은 기상환경불량, 농약피해 및 소독불량이었고, 엽질불량, 사육기술부족 및 공해는 큰 문제가 되지 않았다.

• International Journal of Industrial Entomology and Biomaterials
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• 제14권1호
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• pp.45-50
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• 2007

Ethanol extract of 20 botanicals in 3 concentrations i.e., 2.5%, 5% and 10% were evaluated for their efficacy to improve reproductive performance of mulberry silkworm (Bombyx mod L.) through feeding botanical enriched mulberry leaves during $2^{nd}$ day of $4^{th}$ age as well as $1^{st}$ and $3^{rd}$ day of $5^{th}$ age larvae. The preliminary screening was done by ranking the botanicals based on influence in most important reproductive contributing parameters such as single cocoon weight, effective rate of rearing, pupation rate, fecundity and recovery of eggs/kg cocoon. Five botanicals viz., Asparagus recemosus, Achyranthes aspera, Tribulus terrestris, Withania somnifera, Parthenium histerophorus ranked first were further evaluated at 8% 5% and 3% concentrations to confirm their effectiveness and standardize effective concentration. Among the rearing parameters, mature larval weight, shell ratio and number of cocoons/kg were not significantly influenced by the treatments. However, reproductive parameters such as effective rate of rearing (wt), pupation rate (%), fecundity (No.) and egg recovery (g)/kg cocoon were significantly (P<0.05) influenced by the botanicals. Higher fecundity and egg recovery were obtained on treatment with Withania somnifera irrespective of concentrations. However at 5% concentration, pupation rate, fecundity as well as egg recovery were found significantly higher than that of other concentrations, confirming its effectiveness for improving reproductive efficiency.

• International Journal of Industrial Entomology and Biomaterials
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• 제47권1호
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• pp.1-11
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• 2023

The Indian golden muga silkworm, Antheraea assamensis Helfer is an economically important wild silkworm endemic to Northeastern part of India. In recent years, climate change has posed a threat to muga silk production due to the requirement that larvae be reared outdoors. Since the muga silkworm larvae are exposed to the vagaries of nature, the changing climate has increased the incidence of microbial diseases in the rearing fields. Accurate diagnosis of the disease causing pathogens and its associated epidemiology are prerequisites to manage the diseases in the rearing field. Although conventional microbial culturing methods are widely used to identify pathogenic bacteria, they would not provide meaningful information on a wide variety of silkworm pathogens. The information on use of molecular diagnostic tools in detection of microbial pathogens of wild silk moths is very limited. A wide range of molecular and immunodiagnostic techniques including denaturing gradient gel electrophoresis (DGGE), random amplified polymorphism (RAPD), 16S rRNA/ITSA gene sequencing, multiplex polymerase chain reaction (M-PCR), fluorescence in situ hybridization (FISH), immunofluorescence, and repetitive-element PCR (Rep-PCR), have been used for detecting and characterizing the pathogens of insects with economic significance. Nevertheless, the application of these molecular tools for detecting and typing entomopathogens in surveillance studies of muga silkworm rearing is very limited. Here, we discuss the possible application of these molecular techniques, their advantages and major limitations. These methods show promise in better management of diseases in muga ecosystem.

• International Journal of Industrial Entomology and Biomaterials
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• 제32권1호
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• pp.1-11
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• 2016

Tropical tasar silkworm, Antheraea mylitta is a commercial forest silkworm in India that produces tasar silk, but never experimented in Uttarakhand, a Himalayan state of India. A. mylitta express divergent phenotypic characters under different ecological conditions; so, we studied the effect of seven forest tree species in two rearing seasons on variability in silk gland weight of Daba (bivoltine) ecorace of A. mylitta at Forest Research Institute in Dehra Dun, Uttarakhand during 2012 and 2013. We used two-way completely randomized block factorial design and Post HOC Tukey's HSD test to analyse the collected data and there after carried out multiple regression analysis. Results indicated that silk gland weight differed significantly between rearing seasons (DF=1, F=2333.98, p <0.05), host plants (DF 6, F= 1516.25, p <0.05) and their interactions (DF=6, F=7.10, p <0.05). Higher silk gland weight was found in second rearing season than the first on all the host tree species. Terminalia alata fed A. mylitta larvae showed the highest silk gland weight of 8.03 and 9.47 g in first and second rearing seasons, followed by T. tomentosa (7.19 & 9.01g), T. arjuna (6.8 & 8.08 g) and L. speciosa (6.57 & 7.83 g) fed larvae, respectively. Post HOC Tukey's HSD test indicated that silk gland weight of L. speciosa and T. arjuna fed larvae in both the rearing seasons did not differ significantly. E.I. analysis also confirmed that T. alata, T. tomentosa, T. arjuna and L. speciosa are better in their order of merit than T. bellirica , T. chebula and L. tomentosa. Multiple regression analysis indicates that larval weight gain is a strong predictor (β=1.002, t=346.777, p = <0.05) for the silk gland weight of A. mylitta ; however, larval duration had significant negative regression weight (β=-0.270, t=-8.436, p = <0.05) on mean weight of silk gland.

• 한국잠사곤충학회지
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• 제19권1호
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• pp.19-23
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• 1977

차아염소산 나트륨용액의 실험실내에서의 간이시험을 통하여 양잠소독 약제로써의 적용가능성을 얻고 경화병원균에 대한 생물학적 약효검정에 대한 시험결과 아래와 같은 성적을 얻었다. 1. 차아염소산 나트륨용액 1,3,5%를 누에에 처리하여 약제가 누에표피에 접착됨으로써 받은 피해를 조사하였으나 아무런 해가 없는 것으로 나타났다. 2. 차아염소산 나트륨용액 1,3,5%를 누에에 침식하여 약제가 누에의 생리에 미치는 영향을 조사하였으나 약해가 없는 것으로 나타났다. 3. 차아염소산 나트륨용액의 황강병원균에 대한 약효는 생물학적 검정을 통하여 조사한 결과 동약제의 3%의 경우는 춘추잠기에 각각 7.3, 11.4% 발병율을 보였고 5%의 경우는 춘추잠기에 각각 6.7, 10.0%의 발병율을 보임으로써 무처리구의 평균 97%의 발병율을 보인데 비하여 좋은 효과를 보였다.

• International Journal of Industrial Entomology and Biomaterials
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• 제5권2호
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• pp.175-182
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• 2002

A new high yielding mulberry genotype, Victory-1 (V-1) was recommended to the field for irrigated areas by Central Sericultural Research and Training Institute (CSRTI), Mysore during 1996-1997. As K-2 and S-36 mulberry genotypes are already in the field, a study on the comparative performance of V-1, 5-36 and K-2 varieties, in terms of leaf yield, yield attributes, leaf moisture and moisture retaining capacity and their impact on silkworm rearing was carried out under Telangana conditions of Andhra Pradesh during 1999-2001. Among the three genotypes the leaf yield was found to be significantly (P < 0.01) higher in V-1 (64,130 kg/ha/yr) followed by S-36 (44,064 kg/ha/yr) and K-2 (23,990 kg/ha/yr). The maximum leaf moisture was also observed in V-1 (71.84%) compared to S-36 (66.86%) and K-2 (64%). The moisture retaining ability was more in V-1 (70.17%) followed by S-36 (66.20%) and K-2 (60.08%). The yield attributes were found to be significantly (P < 0.01) enhanced in V-1 over S-36 and K-2. Silkworm rearing results (bioassay) indicated a significant (P < 0.01) reduction in larval duration and improvement in larval weight, effective rate of rearing by number and weight, single cocoon and shell weights and shell ratio in the silkworm lots fed on V-1 variety followed by S-36 and K-2. Hence, in this study, V-1 was found to be superior among the three varieties studied.

• 한국잠사곤충학회지
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• 제37권2호
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• pp.235-243
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• 1995

Recently, the cocoon production is reducing very steeply in Japan. The main reason for this cocoon reduction is due to high labor cost and the production expense is apt to rise year by year. Accordingly, the improvement of cocoon productivity by retrenchment of the production expense is intensively required in my country. Therefore, the silkworm rearing on the artificial diet is largely expected as the innovation techniques of sericulture. Since rearing of the silkworm on artificial diets has first been achieved in 1960, and the silkworm larvae were reared throughout all the instars on artificial diets(Fukuda et al., 1960, Ito & Tanaka, 1960). The artificial diets used at this time contained 50% or more of dried, pulverized mulberyy leaves as one of the main ingredients, and the composition was rather simple. When reared on these diets, larval growth and development were retarded, small cocoons appeared, and the adults laid only a small number of eggs. At first, we would like to study about nutritional requirement of the silkworm, using the chemically defined diet which prepared artificially. Subsequently, attempts were made to improve the diets by replacement of crude ingredients with possibly purer compounds, as mentioned later. Before giving the details on individual nutrient, I would like to summarize about the outline of utilization flow of various nutrients through the larval-pupal development and these daily quantitative requirements per body weight in the silkworm when they were reared on mulberry leaves.