Hatchability and Survival of silkworm Bombyx mori and Eri Worms under Controlled Environmental Conditions in Uasin Gishu County
Eri worm (Samia Cynthia racini), a domesticated non-mulberry silkworm is polyphagous and multivoltine, while mulberry silkworm (Bombyx mori) is bivoltine and feeds on mulberry leaves. Domesticated silkworms are highly sensitive to environmental fluctuations, making the adaptability to environmental conditions different from wild silkworm. In Uasin Gishu temperatures range between 8.40C and 270C which are not suitable for the hatching and rearing of silkworm. The experimental treatments were done in pre-constructed structures with the dimensions of equal dimensions (4mx4m and 3m height). Iron roofing with enclosed concrete walls (L0), iron roofing with enclosed timber walls (L1), iron roofing with mud walls (L2) and greenhouses with flaps designated L3 (green house with all flaps open,) 3 flaps open (L4), 2 flaps open (L5), 1 flap open (L6) and one completely enclosed (L7) were used to test hatchability, survival and durations. The green house flaps were fitted with a net gauze to protect entry of predators. The control condition was in a thermo scientific incubator (L8) at the laboratory, with 3 replicas under constant temperature and humidity. The temperature and relative humidity were recorded using hygrometer/thermometer, while the duration to every instar and survival was recorded. The mean room temperature ranged between 30.310C±1.7 in L6 to 23.850C±1.86 in L0, and mean relative humidity of 75%±0.00 (L7) and 29.93%±3.85 (L4) was statistically significant. The time to hatching was 3 days (L0) to 6 days (L1, L2). Percent hatching was 88.8% and 91.83% for B. mori and Eri respectively in L1 but lowest in L4. Larval duration (34 days) was longest for B. mori and 26 days for Eri. Larval survival percentage was highest in L2 (76.73±4.81) for B. mori and 77.40±3.67 for Eri (L0). Greenhouse with all flaps open and mud walled structure could provide suitable conditions for sericulture production in Uasin Gishu County.
Datta, R. K. (1992). Guidelines for bivoltine rearing. Central Silk Board, Bangalore, India, 18.
Donia W. (2001). As smooth as silk. S & T Post Feature, XIX (5).
Gong, J., Zheng, X., Zhao, S., Yang, L., Xue, Z., Fan, Z., & Tang, M. (2020). Early molecular events during onset of diapause in silkworm eggs revealed by transcriptome analysis. International journal of molecular sciences, 21(17), 6180.
Lertsatitthanakorn, C., Rerngwongwitaya, S., & Soponronnarit, S. (2006). Field experiments and economic evaluation of an evaporative cooling system in a silkworm rearing house. Biosystems Engineering, 93(2), 213-219.
Oduor, E. O., Ciera, L., Pido, O., & Vijay, A. (2016). Eri silkworm rearing practices in Kenya. Journal of Entomology and Zoology Studies, 4(5), 197-201.
Pakhale, S. G., Bothikar, P. A., Lande, U. L., & Shendage, S. A. (2014). Evaluation of Some Mulberry Varieties for Rearing Performance and Economic Traits of Silkworm (Bombyx Mori L). In IOSR Journal of Environmental Science (Vol. 8). www.iosrjournals.org
Rahmathulla, V. K. (2012). Management of climatic factors for successful silkworm (Bombyx mori L.) crop and higher silk production: a review. Psyche.
Rahmathulla, V. K., Kumar, C. M. K., Angadi, B. S., & Divaprasad, V. (2012). Influence of weather factors on incidence and intensity of microsporidiosis in silkworm (Bombyx mori L.). Journal of Entomology, 9(5), 266-273.
Shanthan, B. M. A. (2014). Expression of mixed-age characteristics in the developmental marker events of the silkworm, Bombyx mori L., [Ph.D. thesis, ]. Sri Krishnadevaraya University.
Sharma, P., & Kalita, J. C. (2017). A Comparative Study on the Rearing Performance of Six Strains of Eri Silk Worm Samia Ricini, Donovan in Four Different Seasons. IOSR Journal of Pharmacy and Biological Sciences, 12(03), 13–18. https://doi.org/10.9790/3008-1203051318
Singh KK, Dhepe VS, Jadhav DV, Dusane SE, Gokhale SB (2002). A new technique of summer season chawki rearing of silkworm Bombyx mori (L). BAIF Dev Res Found 2002.
Srinath, B. (2014). Studies on the mixed-age population characteristics in the developmental marker events of certain bivoltine silkworm (Bombyx mori L.). Sri Krishnadevaraya University.
Tazima Y. (1978). The Silkworm an important laboratory tool. Kodansha Ltd: Tokyo, Japan.
Thapa, R. B., & Ghimire, N. P. (2005). Performance of mulberry silkworm (Bombyx mori L.) under leaf and shoot feeding methods. Journal of the Institute of Agriculture and Animal Science, 26, 83-86.
Wankhade, L. N., Rai, M. M., & Rathod, M. K. (2014). Influence of mulberry varieties on economic parameters in PM× CSR2 race of silkworm, Bombyx mori in Vidarbha climate. Bulletin of Indian Academy of Sericulture, 18(1/2), 73–76.
Xiang, H., Liu, X., Li, M., Zhu, Y. N., Wang, L., Cui, Y., ... & Zhan, S. (2018). The evolutionary road from wild moth to domestic silkworm. Nature Ecology & Evolution, 2(8), 1268-1279.