Effect of nucleopolyhedrosis virus on silkworm bombyx mori linn and its transmission from further generation

Sericulture is one of the most agro-based industries in World. From time, sericulture practices have undergone changes to improve productivity. Disease development and mortality are ever present phenomena in the silkworms as in other living organism. Among silkworm disease, Grasseric, a viral disease of silkworm, Bombyx mori L. has been causing great economic loss to sericulturist. Perhaps a good understanding of this disease, its mode of transmission and recent developments are of great relevance for combating the disease. The present study review deals with a detailed account of the LC50 for larval mortality during fifth instar was 0.096 X 106. Nucleopolyherosis virus inclusion bodies ml-1 in Pure Mysore and 0.218 X 106 PIBs ml4 in NB4D2 silkworms. Besides mortality of silkworms, there was a significant reduction in the cocoon weight, shell weight and shell ratio in the surviving silkworms. The F1 progeny obtained by selfing the moths emerged from the silkworms inoculated with BmNPV exhibited interiority in fecundity, hatchability, larval weight, cocoon yield, cocoon weight shell weight, shell ratio, filament length, denier and effective rate of rearing when compared to control batches