• International Journal of Industrial Entomology and Biomaterials
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• v.33 no.2
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• pp.121-131
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• 2016

Ten microsporidian isolates from Samia cynthia ricini, and Antheraea assamensis in India along with a Nosema reference strain (NIK-1s_mys) from B. mori India were characterised morphologically and molecular based tools. The test isolates observed elongated oval in shape while reference strain was oval and ranging from 3.80 to 4.90 m in length and 2.60 to 3.05 m in width. The ribosomal DNA region 'IGS' of test isolates assessed by PCR amplification, followed by cloning and sequencing. IGS sequence and phylogenetic analysis of test microsporidian isolates showed very close relationship with three Nosema references species: N. philosamia, N. antheraea isolated from Philosamia cynthia ricini and Antheraea perny in China respectively and N. disstriae from Malacosma disstriae in Canada. The clustering pattern of dendogram reveals all test isolates appear distinct from Nosema std. (NIK-1s_mys) India used as reference strain in the study. The result suggests IGS indeed a suitable and highly applicable molecular tool for identifying and characterise the microsporidian isolates in similar population.

• International Journal of Industrial Entomology and Biomaterials
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• v.28 no.2
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• pp.32-38
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• 2014

Food consumption and conversion efficiency of eri silkworm Samia ricini Donovan were studied during $4^{th}$ and $5^{th}$ larval instars by feeding castor leaves fortified with 100, 200, 300, 400 and 500 ppm concentrations of aqueous extracts of cyanobacteria Anabaena variabilis. The nutritional indices viz., ingesta, digesta, approximate digestibility (%), reference ratio and efficiency parameters like ECI and ECD were recorded which were significantly high at 400 ppm concentration treated batches of $4^{th}$ instar larvae over control batches. The decline in nutritional efficiency parameters of $5^{th}$ instar treated larvae might be due to higher utilization of the digested food for metabolic activities. Significant difference of ECI to cocoon % and non-significant difference of ECD to cocoon% and shell were observed between the treatments and control. Cyanabacteria feed supplement contains antibiotic and nutritions factors which has reflective effect on the biological parameters in eri silkworm and therefore has greater application in commercial eri silkworm rearing.

• Journal of Sericultural and Entomological Science
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• v.33 no.2
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• pp.93-96
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• 1991

The "Manta"(Juvenile hormone analogue-Methoprene) was topically applied at 36.48 and 72 hrs after the fourth ecdysis to eri silkworm, Samia cynthia ricini with doses of 2.75$\mu\textrm{g}$/$m\ell$, 4/0$\mu\textrm{g}$/$m\ell$ and 8.0$\mu\textrm{g}$/$m\ell$. The eri silkworm responded to 2.75$\mu\textrm{g}$/$m\ell$ of "Manta" applied at 72 hrs after the fourth ecdysis, resulting in improvement of larval, cocoon, pupal and cocoon shell weigths.ocoon shell weigths.

• International Journal of Industrial Entomology and Biomaterials
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• v.30 no.1
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• pp.6-16
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• 2015

This study established the genetic characterisation of 10 microsporidian isolates infecting non-mulberry silkworms (Antheraea assamensis and Samia cynthia ricini) collected from biogeographical forest locations in the State of Assam, India, using PCR-based markers assays: inter simple sequence repeat (ISSR) and random amplified polymorphic DNA (RAPD). A Nosema type species (NIK-1s_mys) was used as control for comparison. The shape of mature microsporidian spores were observed oval to elongated, measuring 3.80 to $4.90{\mu}m$ in length and 2.60 to $3.05{\mu}m$ in width. Fourteen ISSR primers generated reproducible profiles and yielded 178 fragments, of which 175 were polymorphic (98%), while 16 RAPD primers generated reproducible profiles with 198 amplified fragments displaying 95% of polymorphism. Estimation of genetic distance coefficients based on dice coefficients method and clustering with un-weighted pair group method using arithmetic average (UPGMA) analysis was done to unravel the genetic diversity of microsporidians infecting Indian muga and eri silkworm. The similarity coefficients varied from 0.385 to 0.941 in ISSR and 0.083 to 0.938 in RAPD data. UPGMA analysis generated dendrograms with two microsporidian groups, which appear to be different from each other. Based on Euclidean distance matrix method, 2-dimensional distribution also revealed considerable variability among different identified microsporidians. Clustering of these microsporidian isolates was in accordance with their host and biogeographic origin. Both techniques represent a useful and efficient tool for taxonomical grouping as well as for phylogenetic classification of different microsporidians in general and genotyping of these pathogens in particular.

• Journal of Microbiology and Biotechnology
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• v.30 no.9
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• pp.1367-1378
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• 2020

The polyphagous eri silk moth, Samia ricini, is associated with various symbiotic gut bacteria believed to provide several benefits to the host. The larvae of S. ricini were subjected to isolation of gut bacteria using culture-dependent 16S rRNA generic characterization, metagenomics analysis and qualitative enzymatic assays. Sixty culturable aerobic gut bacterial isolates comprising Firmicutes (54%) and Proteobacteria (46%); and twelve culturable facultative anaerobic bacteria comprising Proteobacteria (92%) and Firmicutes (8%) were identified inhabiting the gut of S. ricini. The results of metagenomics analysis revealed the presence of a diverse community of both culturable and un-culturable gut bacteria belonging to Proteobacteria (60%) and Firmicutes (20%) associated with seven orders. An analysis of the results of culturable isolation indicates that these bacterial isolates inhabited all the three compartments of the gut. Investigation on persistence of bacteria coupled with metagenomics analysis of the fifth instar suggested that bacteria persist in the gut across the different instar stages. In addition, enzymatic assays indicated that 48 and 75% of culturable aerobic, and 75% of anaerobic gut bacterial isolates had cellulolytic, lipolytic and nitrate reductase activities, thus suggesting that they may be involved in food digestion and nutritional provision to the host. These bacterial isolates may be good sources for profiling novel genes and biomolecules for biotechnological application.

• Proceedings of the Korean Society of Sericultural Science Conference
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• 2005.04a
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• pp.51-51
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• 2005

• Proceedings of the Korean Society of Sericultural Science Conference
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• 2005.04a
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• pp.50-50
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• 2005

• Proceedings of the Korean Society of Applied Entomolohy Conference
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• 2005.05a
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• pp.130-130
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• 2005

• Proceedings of the Korean Society of Applied Entomolohy Conference
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• 2005.05a
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• pp.131-131
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• 2005

• Animal Bioscience
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• v.35 no.5
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• pp.711-720
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• 2022

Objective: The objective of this study was to determine the appropriate amount of eri silkworm pupae meal (Samia ricini) to add to the broiler diet. Methods: Two hundred 1-day-old male chicks with initial weight at 50.03±0.56 g/chick were divided into four groups (five replicates per group and ten chicks per replicate): a control group fed a corn-soybean diet and experimental groups supplemented with 5%, 10%, or 15% eri silkworm pupae meal. All experimental diets were isocaloric and isonitrogenous and formulated respecting nutrient requirements. Growth performances were collected during the experimental period and other parameters were collected at the end of experiment when broilers reached thirty-eight days old. Results: A higher cold carcass weight and skin yellowness in the broilers fed 10% eri silkworm pupae meal compared with the other groups (p<0.05). Therefore, supplementation with 10% eri silkworm pupae meal is suggested for the broiler diet formulation because it did not cause any serious negative consequences on growth performance, health status, carcass characteristics and meat quality. However, the usage of eri silkworm pupae meal at 15% is not recommend because it led to negative outcomes Conclusion: The addition of eri silkworm pupae at 10% can be used as an alternative protein sources for broiler chickens which provided benefits on cold carcass weight and skin yellowness without adverse effects.