Keywords: Mulberry variety, silkworm race, cocoon production

An experiment was conducted in factorial Completely Randomized Design to study the interaction of selected mulberry varieties (Kanva-2, Khopasi-1, Ichinose and Husan) and silkworm races (J_12,C_12,J₁₂^♀× C₁₂^♂, and C₁₂^♀× J₁₂^♂) for qualitative and quantitative aspects of cocoon production under mid hill condition of Nepal during August-September 2005. Immediately after hatching, silkworm larvae of each race were brushed on leaves of each mulberry variety consisting of 16 treatments in combinations replicated four times. Mature worms from each treatment were mounted in individual bottlebrush type mountage. After seven days of mounting, cocoons were harvested separately from each treatment. Pre-cocoon and post-cocoon characteristics were recorded and data analyzed using MSTATC. In general, silkworm race J₁₂ × C₁₂ had the highest hatchability (98.5%) and maximum body weight (46.13 gm/10 larvae) in the fifth instar when fed on Kanva-2 mulberry variety. The highest fresh and dry cocoons weight (17.85 gm and 7.34 gm / 10 cocoons) obtained in silkworm race J₁₂× C₁₂ fed on Ichinose and Kanva-2 mulberry varieties, respectively. The silkworm race C₁₂× J₁₂ fed on Husan mulberry variety gave the highest shell ratio (23.10%) and market price (Rs.174.63/kg fresh cocoons). Higher shell ratio is preferred for higher market price thus rearing of double hybrids silkworm races (J₁₂× C₁₂ and C₁₂× J₁₂) and single hybrid silkworm race C₁₂ with Ichinose and Husan can be suggested under farmer’s field conditions.