Impact of Seasonal Variations on Cocoon Yield and its Attributed Traits of Eri Silkworm (Samia ricini, Donovan)

Author: Wahengbam Sapana, Subadas Singh, Y Surjalata, Anowar Hossain, Debaraj Yumnam, Somdip Majumdar and Somorjit Singh

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Abstract

Eri silkworm, Samia ricini (Donovan), is a domesticated multivoltine non-mulberry silk insect. The silkworm has been exploited commercially for its silk since time immemorial. Therefore, ericulture is an ideal subsidiary occupation in a country like India, providing supplementary income to a large number of rural hilly and tribal populations. Investigations had been conducted to learn the influence of seasonal variation on the growth, survival, and reproductive performance of eri silkworm (Samia ricini) eco-races to optimize sericulture productivity. Six eri silkworm eco-races (Borduar, Dhanubhanga, Genang, Khanapara, Nongpoh, and Titabar) were evaluated across four seasons (March-April, April-May, June-July and August-September) for key traits including larval weight, single cocoon weight (SCW), single shell weight (SSW), shell percentage, effective rate of rearing (ERR), pupation rate, fecundity and hatching percentage. The results demonstrated significant seasonal variations, with April-May and August-September being the most favourable for larval growth, while June-July provided optimal conditions for cocoon production. Genang and Titabar emerged as the most productive eco-races in terms of cocoon traits, while Khanapara and Nongpoh displayed the highest pupation and survival rates. Reproductive parameters such as fecundity and hatching percentage were also influenced by seasonal fluctuations, with peak values recorded in March-April and August-September. This study underscores the importance of season-specific eco-race selection and adaptive rearing strategies, including controlled environmental conditions, to enhance silk productivity. These findings provide valuable insights for sustainable eri silkworm farming and suggest future research directions for genetic and environmental optimization

Keywords

Eri silkworm, seasonal variation, eco-race, effective rate of rearing, non-mulberry, domesticated

Conclusion

This study highlights the significant impact of seasonal variation on the growth, survival, and reproductive performance of eri silkworm ecoraces, emphasizing the importance of selecting the right ecoraces for the right season to maximize productivity. The findings indicate that April-May and August-September are the most favourable seasons for larval growth, while June-July provides optimal conditions for cocoon formation. Among the studied ecoraces, Genang and Titabar were identified as the best performers in terms of cocoon traits, whereas Khanapara and Nongpoh demonstrated the highest pupation and survival rates. Overall, the results emphasize the potential of season-specific ecoraces selection and environmental control strategies to enhance the economic viability and sustainability of eri sericulture. These findings provide a valuable framework for improving silkworm breeding programs and large-scale eri silk production, ensuring year-round productivity and economic gains for farmers

References

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How to cite this article

Wahengbam Sapana, Subadas Singh, Y Surjalata, Anowar Hossain, Debaraj Yumnam, Somdip Majumdar and Somorjit Singh (2024). Impact of Seasonal Variations on Cocoon Yield and its Attributed Traits of Eri Silkworm (Samia ricini, Donovan). Biological Forum – An International Journal, 16(7): 336-340