Effect of Restricted Feeding of Parent on the Larval and Cocoon Characters of the First Generation Silkworm (Bombyx mori)


Abstract: This study was conducted to determine the effect of nutritional stress due to reduction in the number of feeding days during the fifth instar of parental larva on the parental and following genaration for larval and cocoon traits. Mulbery leaves were provided during the fifth instar for different durations of 1, 2, 3, 4, 5, 6 and 7 days, which were regarded as treatment. The normal span of feeding of these larvae were 8 days which was considered as control. A lot of larvae mortality occured due to feeding for 1 and 2 days therefore, these treatments were not considered. According to the result of experiment there were some negative effects of nutritional restriction on the cocoon characters of parental genaration only. Cocoon and cocoon shell weight and number of eggs and egg weight decreased parellel to reduction of feeding days. 4 to 6 day feeding resulted in reduced weight of newly larvae of following generation, the weight differed significantly (P<0. 05 ). From that of control. Adlibitum feeding in the following genaration did not show significant difference between the control and any of the treatments. with respect to single full grown larval weight, larval duration, single cocoon weight, shell weight. filament weight, filament lenght. The result indicated that larval and cocoon characters are genetically determined and the feeding stress of different duration imposed on the parent can not influence the larval and cocoon characters in the following generation.

Keywords: Silkworm, duration of feeding, egg, larva and cocoon characteres, generation

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