Changes in qualitative and quantitative traits in the bivoltine silkworm hybrid of bombyx mori L. due to changing environmental conditions

The authorized commercial bivoltine silkworm hybrid namely, CSR2 x CSR4 was chosen for the present study. The hybrid was subjected to different temperature and humidity treatments i.e., 25±1°C and RH 65±5% (control), 30?1?C, with combinations of low relative humidity (RH 65±5%) and high RH ( 85±5%) at different stages during rearing and spinning of silkworm larvae. The larvae of after 3rd moult were subjected to different thermal and humidity stress till the assessment of cocoon traits. The comparative rearing performance clearly indicated that the deleterious effect of high temperature and high RH was more pronounced for the majority of traits such as survival, cocoon yield, shell weight, and shell percentage, reelability, filament length, raw silk percentage and filament size than other temperature and RH treatments. The characters can be improved by providing ideal environmental conditions even during spinning stage of larvae affected with high temperature and RH.