The Effect of Four Mulberry Varieties on Performance of Bombyx mori L. (Lepidoptera, Bombycidae)

Silkworm larvae were reared on the leaves of four mulberry varieties i.e. Morusalba, M. rubra, M. latifoliaand M. nigra. The varieties were evaluated for nutritional potential on the growth and cocoon characters of silkworm. The results revealed that larval growth by weight, single cocoon weight, shell weight and shell percentage were greatly influenced by the nutritive value of different mulberry leaves. The maximum and minimum body weights were found (25.50 g) and (20.50 g) in M. alba respectively. The effect of mulberry species on larval and pupal mortality was non-significant. The percent defective cocoons (3.32%) and good cocoons (96.68%) were found in M. nigra. The maximum effective and good cocoon was found in M.alba (6.73%) and (96.68%), respectively. The maximum single cocoon weight of 1.34 g was recorded in M. nigra while minimum was 1.035 g in M. rubra. The larvae fed on M.nigra showed maximum single shell weight of 0.55 g. The minimum single shell weight of 0.242 g was recorded in M.rubra. Maximum shell ratio of 26.49% was recorded in M.nigra while minimum shell ratio 23.43% was recorded in M.alba. Protein and carbohydrates were found in mulberry leaves (17.25-21.06%) and (35.47-37.25%), respectively. The maximum carbohydrate (37.25%) and protein (21.06%) were found in M.nigra. Generally the larvae fed on M.nigra leaves gained more body weight and gave better cocoon characters. These variations could be attributed to the nature of nutritive value in tested species.