Vol. 3, Issue 6, Part C (2017)

Abstract
The silkworm, Bombyx mori L. is a monophagous insect and consumes only mulberry leaves during larval stage of its life cycle. The performance of silkworm such as growth, reproductive potentiality and quantum and quality of cocoon production depends on nutrient composition of food, which includes both absolute and relative amounts of proteins, amino acids, lipids, carbohydrates, sterols, water, minerals, vitamins, etc., besides its genetic endowment. The silkworm requires several vitamins for their growth and survival. The pyridoxine is necessary for the proper functioning of over 60 enzymes that participate in amino acid metabolism. In the present investigation, the silkworm bivoltine hybrids namely FC1 and FC2 were taken and mulberry leaf supplemented with pyridoxine at varied concentrations viz., 100, 500 and 1000 ppm. Both hybrids performed well for the most of the economic traits except denier at 1000 ppm. Further, the succinate dehydrogenase activity level was more in FC2 when compared to FC1 at 1000 ppm in fifth instar fifth day followed by fifth instar third day and fifth instar first day larvae.