Efficacy of fungicide ‘Kavach’ against Beauveria bassiana L. in silkworm Bombyx mori L.

Silkworm Bombyx mori L. is prone to be attacked by pathogen and more notably Beauveria bassiana L. Bed disinfectant Kavach was inoculated in different dosages (0.2%-1.6%) to IV and V instar silkworms of both bivoltine and cross breeds. Potency of disinfectant was assessed for the parameters such as survivability, larval duration, physiological, chemo and bio-assay tests. It was revealed that, bivoltine (NB4D2) silkworms were highly susceptible to diseases compared to cross breeds (PMxNB4D2). In bivoltine silkworms, survivability was found to be 61.15% at 1.6% of Kavach, when dusted twice during IV and V instar and crossbreed silkworms exhibited better resistance of 63.10% with the same treatments. Kavach treated silkworms showed decreased larval duration compared to control worms. Crossbreed silkworms were capable of maintaining high level of soluble proteins in spite of infection on 3rd day (17.40%), 4th day (20.50%) and 5th day (21.55%) whereas in bivoltine silkworms soluble protein level was brought down on 3rd day (19.30%), 4th day (22.40%) and 5th day (23.40%). Total soluble sugarsvaried from third day till fifth day in both the races. Kavach dusted twice at 1% proved to be very useful in the improvement of various commercial cocoons characters