Studies on the mode of transmission of Bombyx mori nuclear polyhedrosis virus in silkworm, Bombyx mori l

Disease free layings of silkworm breed, DUN22 were procured, incubated, brushed and reared upto 3rd instar enmass following the standard rearing method. Just after 3rd moult, the experiment was laid down into four treatments (T1-T4) as per the experimental design. Five replications of 100 larvae in each treatment were maintained and data with regard to 5th instar and total larval duration, diseases incidence, yield and pupation rate were recorded and analysed statistically. Perusal of data revealed significant difference in afore mentioned economic traits and therefore concluded that Bombyx mori Nuclear Polyhedrosis Virus (BmNPV) spreads infection secondarily and also had negative impact on the silkworm, B. mori.