Effect of different nutritional conditions of Silkworm Bombyx mori (Lepidoptera: Bombycidae) on its susceptibility to Beauveria bassiana (Hyphomycetes: Moniliales)Abstract : Effect of nutritional conditions of silkworm Bombyx mori on the susceptibility to Beauveria bassiana was studied and discussed in this paper. There was significant difference in the susceptibility of silkworm to B. bassiana when the nutritional conditions of silkworm were changed. Feeding with V1 variety mulberry leaves increased the susceptibility of silkworm to the fungus. Feeding silkworm with tender leaves also increased the susceptibility of silkworm to B. bassiana. The LT50 value was 6.18 days when tender leaves were provided and it was 6.34, 6.62 and 6.59 days with medium, matured and normal leaves, respectively. Feeding with tree mulberry leaves resulted in less mortality when compared to the others.