Studies on the Effect of Differential Feeding on the Commercial Characteristics of Mulberry Silkworm (Bombyx mori L) in Wet Summer in West Bengal, India

The study evaluated the effect of feeding of different maturity level of mulberry leaves i.e. tender, medium, mix, mature, over mature leaves and feeding of shoot during late stages on the commercial characteristics of crossbreed (N×M12 (W)) during wet summer in West Bengal for sustainable development in Sericulture Industry. The data was compared with control where conventional leaf feeding method was followed. The most of the larval and cocoon characters were recorded significantly higher in shoot feeding fed batch and Medium leaves fed batches. Significantly higher post cocoon parameters viz. average filament length, nonbreakable filament length; renditta and raw silk recovery percentage etc. were recorded in medium leaf fed batches and shoot rearing batch. Though qualitative analysis of leaf suggested that tender leaf is more nutritious than other maturity level of leaves but due to prevailing of high moisture in the rearing room as well as in rearing bed during wet summer, it becomes difficult for silkworm larvae to release water during late stage and particularly during spinning if silkworms are fed with high moisture containing tender leaves. More important thing is that whatever water released by silkworm larvae particularly during the end of Vth instar and initiation of spinning, fifty percent of it goes for silk spinning. Present investigation indicates that it is better to feed silkworm larvae with shoot and medium leaf during late instar in wet summer. Mature and over mature leaves fed batch showed inferior performance in terms of all the characters due to their poor nutritional composition.