Effect of feeding mulberry variety V₁ on the biology of different bivoltine silkworm (Bombyx mori L.) races

The shortest larval duration (27.45 days), pupal duration (10.39 days) and highest moth emergence (90.75 per cent), fecundity (472.00 eggs) and hatching per cent (97.25) were noticed in NP₂ bivoltine race feeding on mulberry variety V₁ (Victory). The longest larval duration (31.00 days), pupal duration (12.50 days) and lowest moth emergence (78.75 per cent) and fecundity (406.50 eggs) were noticed in APS₄ bivoltine race, while lowest hatching per cent (91.50) was recorded in APS₅ bivoltine race.