Rearing Performance of Multivoltine Pure Mysore and Nistari Races of Bombyx mori L.

The present investigation was conducted at the Sericulture laboratory, Entomology Section, College of Agriculture, Pune (Maharashtra) during April 2024 to June 2024 to study morphometric parameters of multivoltine Pure Mysore and Nistari Races under controlled laboratory conditions. Morphometric data of Pure Mysore and Nistari races were recorded from 25 samples at each stage. Egg size was measured under a microscope; larval length, breadth, and weight with calliper and balance, pupal size and weight after three days of cocooning; and adult body size and wingspan using a vernier calliper. Nistari consistently showed better morphometric traits than Pure Mysore across all stages. Egg size was nearly the same, with Pure Mysore having a slightly higher maximum length. Nistari larvae were longer, broader, and heavier in all instars, reaching 59.04 mm in length and 2.14 g in weight at the fifth instar compared to 56.02 mm and 1.89 g in Pure Mysore. Pupal size and weight were higher in Nistari with 1.97 cm length, 0.78 cm breadth and 0.98 g weight than in Pure Mysore with 1.78 cm length, 0.64 cm breadth and 0.84 g weight. Adult Nistari moths, especially males, also showed greater body length, breadth and wingspan, indicating superior growth and development throughout the life cycle. Nistari outperformed Pure Mysore at all stages, with larvae showing greater length, breadth and weight across instars, pupae exhibiting larger size and higher weight, and males displaying bigger body size and wider wingspan, indicating superior growth, physiological development and better potential for cocoon quality and silk yield.