• International Journal of Industrial Entomology and Biomaterials
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• v.4 no.2
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• pp.143-147
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• 2002

Studies on the interrelationship between biological yield and harvest index, and their association with shoot rearing were carried out in 9 promising mulberry genotypes, which indicated significant variations among genotypes. Biological yield had close association with leaf yield components indicating that they are inter-related for higher productivity in mulberry, Biological yield revealed highly significant positive correlation with important leaf yield components. However height of the longest branch showed negative correlation with biological yield. Genotypes with higher biological yield associated with low ratio of stem weight to leaf weight and high Harvest index on dry weight basis are to be selected for shoot rearing. Biological yield recorded on fresh weight basis had less impact on the present study in comparison to dry weight basis.

• Proceedings of the Korean Society of Sericultural Science Conference
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• 1997.06a
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• pp.103-117
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• 1997

Decrease in the cocoon production of Japan is drastic because of low price of cocoon, scarcity of successors and so on. To tide over the difficulty, the automation system in the sericulture was discussed and some trials have been conducted by the Ministry of Agriculture, Forestry and Fisheries of Japan. The attempts are based on a low cost artificial diet which does not rely on mulberry leaves. Automatic machines developed until now are a rearing machine constituted with repeated belt conveyor, an reformation type of former rearing machine "Bombyx" and a mounting machine. Running parallel with them, utilization of 20-hydroxyecdysone extracted from a plant to the mounting was also studied to use their machines efficiently in the fields. In conclusion, 10 tons of law cocoon will come to be produced by two persons labor. At present, an automatic rearing system on low cost artificial diet has been developing for the future sericulture.

• International Journal of Industrial Entomology and Biomaterials
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• v.20 no.1
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• pp.13-17
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• 2010

Ten numbers of plants, based on their medicinal value, were used to test their efficacy against virosis (caused by cytoplassmic polyhedrosis virus) in tasar silkworm, Antheraea mylitta Drury. in indoor rearing conditions. The aqueous extracts of leaf of Azadirichita indica (neem), Acharanthus aspera, Psoralea corylifolia, Asparagus racemosus, Adhatoda zelanica (Basak), Andrographis paniculata (Kalmegh), Moringa oilephera (sahjan), whole plant of Phyllanthus urinaria (Bhuiamla), Centella asiatica (Veng sag) and Curcuma longa (Haldi powder) in different concentrations were used for containment of virosis in silkworm larvae. The tasar silkworm larvae were orally inoculated with PIBs ($1\times10^6$) of AmCPV in $2^{nd}$ instar and treated with plant extracts in each instar ($2^{rd}$ instar onwards). The mortality due to virosis was recorded during larval period. The plant extracts, irrespective of their concentrations, were found effective in suppressing the virosis where P. urinaria reduced the virosis to 56.90% followed by A. paniculata (53.82%) and least in C. asiatica (5.15%). The lowest pooled larva mortality 36.99% was recorded in the treatment of P. urinaria. Comparatively higher larva mortality 39.91% was observed with the treatment of A. paniculata. The highest larva mortality in treatment was with C. asiatica (81.99%). In treated control larva mortality was 86.50%.

• Journal of Sericultural and Entomological Science
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• v.21 no.1
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• pp.36-44
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• 1979

Those studies were examined rearing two varieties on Japanese descent and two varieties of Chinese descent by feeding polluted mulberry leaves, non-polluted ones and water-cleaned ones respectively to find effects of air-pollution on the economic characters of silkworms and analysis of contents of Sulphur and Cadmium in the mulberry leaves and silkworms as followings; 1) Japanese descent of polluted part was delayed about 2.5 days than non-polluted part, Chinese descent was delayed about 4 days or inequal and water-cleaned part was medium in the silkworm larval duration. 2) Results of maximum weight of 5th instal, cocoon layer weight and cocoon weight were decreased in due order non-polluted, water-cleaned and polluted in the factors of mulberry 3) Pupal ratio of Japanese descent was not shown statistical significance, but Chinese descent was revealed it obviously in the factors of mulberry leaves. 4) In the resistance of polluted mulberry leaves, Chinese descent was feeble obviously than Japanese and there were some difference even through among the same varieties. 5) The content of S and Cd of polluted area mulberry leaves was increased about 30% respectively than non-polluted area. 6) The fed part of non-polluted mulberry leaves was S 0.41% and Cd 0.013 ppm water-cleaned part was S 0.47% and Cd 0.024 ppm and polluted part was S 0.52% and Cd 0.042 ppm in the contents of S and Cd of silkworm larvae. 7) The contents of S and Cd didn't make visible injury in mulberry leaves but made it seriously in silkworm larvae. 8) The injury of dust on mulberry leaves was more serious than that of quality of mulberry leaves by air-pollution in the economic characters of silkworm. 9) As above results, Chinese descent should avoid contaminated area and it rearing by water-cleaned mulberry leaves can get noticable results in inevitable case on selection of parents silkworm rearingzone.

• International Journal of Industrial Entomology and Biomaterials
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• v.9 no.1
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• pp.79-87
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• 2004

The silkworm rearing and growth parameters of 63 multivoltine silkworm accessions under extended period of egg preservation at 5$^{\circ}C$ from 30 days to 45 days were studied. The results indicate that, nine accessions did not respond to extended period of egg preservation at low temperature and the remaining 54 accessions responded to the treatment and three rearings were conducted for comparision with the control; to estimate the effect of prolonged egg preservation at low temperature. The non-parametric tests statistics (Wilcoxon tests) was adopted for comparing the mean performance of treated batches (45 days) over the control (30 days). Highly significant variability was found among the accessions for all the parameters under study. The genetically controlled morphological characters were not altered in the treated batches, which were found to be on par with that of control. However, the total larval duration varied significantly over the control in 51 accessions. Similarly, the fifth age larval duration of 27 accessions showed decreasing trend compared to control. Altogether 41 accessions were found to be tolerant to long-term cold preservation upto 45 days, without showing any significant variation for morphological as well as essential quantitative traits. These accessions may be recommended for long-term egg preservation schedule up to 45 days, which will reduce the cost of conservation of these silkworm germplasm.

• International Journal of Industrial Entomology and Biomaterials
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• v.9 no.1
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• pp.35-40
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• 2004

Bombyx mori densonucleosis virus type 1 (BmDNV1)- a non occluded virus causes flacherie disease in the susceptible stocks of the silkworm, Bombyx mori. However, some stocks are non-susceptible. Non-susceptibility to BmDNV1 in B. mori is a unique case where the virus infection is completely inhibited by a single gene of the host. A survey conducted by this institute in some parts of Karnataka state has revealed that, 43.05% of the total incidence of flacherie disease caused by non-occluded viruses, are due to the synergistic infection of B. mori densonucleosis and infectious flacherie virus. Earlier study indicated that rearing of BmDNV1 resistant silkworm stock is effective in protecting silkworm against BmIFV also. In the present study the response of 78 silkworm stocks which include 42 of non-diapausing and 36 of diapausing groups, to BmDNV1 is investigated. Newly ecdysed third instar larvae were inoculated per-os with 10% inoculum of BmDNV1 extracted from the mid-gut of infected silkworm. One non-diapausing and three diapausing silkworm stocks were found to be resistant to BmDNV1. Eleven silkworm stocks were found to possess moderate resistance whereas rest sixty three were found to be susceptible to BmDNV1. Genetic analysis has shown that the resistance to BmDNV1 is autosomally inherited and controlled by a major dominant or a major recessive gene in different silkworm stocks. These resistant stocks can be utilized as the resource material to develop BmDNV1 resistant commercial hybrids. The selection strategies, depending upon the mode of inheritance of resistance in the resource material chosen, are discussed.

• International Journal of Industrial Entomology and Biomaterials
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• v.18 no.2
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• pp.57-61
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• 2009

Three years($2004{\sim}2007$) survey was conducted on the incidence of silkworm diseases namely, Grasserie, Flacherie, Muscardine and Uzi fly, a silkworm pest with 150 sericulture farmers in the districts of Chittoor and Anantapur in Andhra Pradesh. The data revealed that grasserie and flacherie incidence were maximum in summer season and minimum in winter season whereas muscardine was observed high in winter season in both the areas and rarely in rainy season in Chittoor and Anantapur districts. An improvement of 11.16 and 7.6 kg cocoons/100 dfls were recorded in the batches of PM xCSR2 Diseases free layings(Dfls) reared in rearing houses disinfected with 2% bleaching powder and Ankush, a plant based bed disinfectant applied as per schedule, respectively. The Uzi fly incidence was suppressed by 61.02% in batches where the integrated package was adopted for control of Uzi fly infestation.

• International Journal of Industrial Entomology and Biomaterials
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• v.7 no.1
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• pp.65-68
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• 2003

One of the biggest problems encountered during the last phase of silkworm rearing is non-uniform maturation of the silkworms especially during cooler months. Phytoecdysteroid (20-hydroxy ecdysone) was extracted in large-scale from a plant belongs to Caryophyllaceae and fed to silkworm larvae to test the effect of phytoecdysteroid. About 80％ of the silkworms were ready for mounting by 18 hrs after treatment (when the treatment is done for uniform spinning), whereas in control batch only 37％ worms were ready for mounting by the same time.

• International Journal of Industrial Entomology and Biomaterials
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• v.13 no.2
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• pp.113-117
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• 2006

Heterosis was studied involving two multivoltine silkworm breeds viz, APM1 and SLKSPM through rearing and isozyme analysis. A positive significant heterotic effect was observed in fecundity, hatching % and survivability. The heterobeltiosis was observed only in fecundity and hatching %. Isozyme analysis of ${\alpha}-esterase$ showed variation in loci and allelic expression. The allele with heterozygosity $(Est-2^{12})$ was observed at the Est-2 locus in $F_1$ progeny. Est-3 was observed in $F_1$ progeny, whereas it was completely absent in both parental lines. The present study suggests that the markers ($Est-2^{12}$ and Est-3) targeted for introgression may be useful for the improvement of fecundity and survivability as the phenomenon of heterosis was observed only in $F_1$ progeny.

• Journal of Sericultural and Entomological Science
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• v.14 no.2
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• pp.73-79
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• 1972

This study was carried out to investigate the effects of the mulberry leaves sprayed with filtered solutions and non-filtered solutions of ginseng, on the various practical characteristics of the silkworm (Bombyx mori) in spring, summer and late autumn in 1971, and spring and autumn in 1972. 1. There was no evidence that the various ginseng concentrations influence the practical characteristics in the silkworms, according to the different instars and rearing seasons. 2. Non-filtered solutions of ginseng have a bad effect upon the silkworm characteristics, especially in pupation ratio and reelable cocoon ratio.