Vol. 10, Issue 10, Part C (2024)

Abstract
The experiment was conducted in the Entomology Laboratory of Research Station, Govt. P.G.D.C. Campierganj, Gorakhpur, during September-October, in Completely Randomized Design with six treatments and three replications. Larvae of Silkworm hybrid MYX × CSR2 were fed on mulberry varieties like Morus alba (white mulberry), Morus rubra (Red mulberry), Morus nigra (Black mulberry) & Morus macroura (Himalayan mulberry), S-1635 and mixture of all varieties leaf like observations on the dimensions of different instars of silkworm Bombyx mori L. were recorded. Mulberry variety mixed different Morus leaf was recorded as best variety for growth and development of silkworm during final instars with maximum larval length (68.88 mm), larvae breadth (9.71 mm) and larval weight (3.24 gm) and economic trait of larval character like pupal weight (1.54 gm), Cocoon weight (2.10 gm), shell weight (0.63 g), cocoon shell ratio (31) and silk filament length (1198 m). Variety was also observed promising so far growth and development of silkworm larvae is concerned, while minimum larval length, breadth, weight and economic trait was observed when larvae fed on mixture of all varieties. The mean weight of larvae, pupae, cocoon economic character and shell as well as cocoon shell ratio and larval fibroin and sericin protein content of Bombyx mori were increased when fed with mixed varietal Morus. In addition, the filament length of secretion of salivary gland produced by this silkworm in response to mixed Morus showed significant increase with respect to the other five varieties of mulberry leaf. Positive correlation was observed in filament length against fibroin and sericin protein content. The overall performance of Bombyx mori in terms of growth and economic parameters was significantly improved with mixed Morus and this variety has the potential to enhance the commercial qualities of silk production. Therefore, it is suggested to be used in sericulture for higher yield of silk thread production to rearers.