Expression of the economic traits in different bivoltine silkworm (Bombyx mori L.) races reared on mulberry variety V₁

Significantly lowest disease incidence (1.93 per cent) and highest effective rate of rearing (97.77 per cent), larval weight of ten matured larvae (32.83 g), cocoon yield per 10000 larvae brushed (15.39 kg), single cocoon weight (1.56 g), single shell weight (0.280 g), cocoon filament length (758.75 m), cocoon filament weight (0.213 g) and denier (2.53) were recorded in bivoltine race NP₂ when reared on mulberry variety V₁. While the lowest effective rate of rearing (92.20 per cent), larval weight (28.90 g), cocoon yield per 10, 000 larvae brushed (12.21 kg), single cocoon weight (1.21 g), single shell weight (0.233 g), cocoon filament length (697 m), cocoon filament weight (0.149 g) and denier (1.92) and highest disease incidence (3.05 per cent) and cocoon shell ratio (19.24 per cent) were recorded in bivoltine silkworm race APS₄.