The quality of food material and the status of health of stages of larval instars of silkworm reflect on the quality of the silk cocoon in sericulture. The prepupal stages of black soldier fly (BSF) are with significant quantity and quality of the proteins including the antimicrobial proteins (AMPs). The methanol solution of BSF-Meal with strength of 100 mg/L (100 ppm) was used in present attempt for the topical application to the fifth instar larval stages of silkworm, Bombyx mori (L) (Double Hybrid Race). The topical application of methanol solution of BSF-Meal was made at forty-eight hours after the fourth moult. The untreated group of larvae and solvent treated group of larvae were also maintained. Treating the fifth instar larvae with methanol solution of BSF-Meal was found reflected on the significant improvement in the economic char of the cocoons and silk fiber. The weight (grams) of cocoon (deflossed whole), weight (grams) of silk-shell, pupal weight (grams) and percentage of silk-shell or ratio in the group of larvae recipient of the topical application of methanol solution of BSF-Meal was recorded 3.189** (±0.715); 0.796**(±0.194); 2.393 and 24.960*** respectively. The silk fiber length (meter); silk fiber weight (gram) and denier-scale of silk-fiber gained through the reeling the cocoons of treated group were recorded 1494.61*(±169.55); 0.796** (±0.118) and 4.793*** respectively. Efficient use of methanol solution of BSF-Meal for topical application to the silkworm larvae serve to orchestrate the fortification of health through the preventing the infection of microbial pathogens and significant yield of silk product.

Keywords: Host defense proteins, BSF meal, Silk-cocoon and Cocoon shell-shell ratio