Vol. 8, Issue 8, Part Q (2024)

Abstract: A study was conducted to know the rearing performance of the thermotolerant bivoltine silkworm breeds and hybrids under Beauveria bassiana infection at the Department of Sericulture, UAS, GKVK, Bengaluru during 2021-22. Thermotolerant bivoltine breeds viz., B1, B4 and B8 and their hybrids with CSR4 i.e., B1×CSR4, B4×CSR4 and B8×CSR4 along with Pure Mysore as a muscardine resistant and CSR4 as a muscardine susceptible breeds were used in this study. A batch of silkworms of all the breeds and hybrids were inoculated with 9.04 × 10⁴ spores/ml of B. bassiana @ 0.5 ml per silkworm immediately after 4^th moult and another batch was reared under normal condition. The rearing performance revealed that B1 breed and B1×CSR4 hybrid had performed better under control conditions, where as Pure Mysore breed for the survival characters, while B4 breed and B4×CSR4 hybrid for economic characters performed better under infected conditions. Hence, we can say that B4 breed and B4×CSR4 hybrid are exhibiting good disease resistance.