'ASTRA' a user friendly compound to destroy the pathogenic microbes causing diseases to silkworm (Bombyx mori, L) in the rearing house and its impact on the rearing performance of new multi and bivolotine hybrids.

摘要

Silkworm Bombyx mori is domesticated for silk production and reared in colonial forms. All the major pathogenic microbes cause disease in silkworm and the most common among them are nuclear polyhedrosis, bacterial and viral flacherie, muscardine and pebrine. Nuclear polyhedrois is caused by Bm NPV (Baculoviridae). The viral flacherie is caused by Bm IFV (Picarnaviridae), Bm DNV (Parvovoridae) and Bm CPV (Reoviridae). bacterial flacherie are caused primarily by Serretia marcescens, Streptococcous sp. and Staphylococcus sp. of bacteria. Muscardine is caused normally by Beauvria bassiana. Pebrine, a dreaded uncommon disease is caused by Nosema bombycis. Survey on the prevalence of diseases in silkworm in different sericulture areas have been conducted during different seasons of the past couple of decades. An estimated cocoon loss of 12-15 kg/100 dfls has been reported. Many disinfectants formalin, Bleaching powder, Chlorine dioxide, Decol are available in the market. The concentration of these chemicals ranges 2-2.5% for destroying the pathogenic microbes in the rearing house. To overcome these, a new user friendly disinfectant called 'ASTRA' a product of CSR&TI, Mysore introduced very recently. It is a chlorine based spray disinfectant, which is effective against all silkworm pathogens at low concentration (0.05%). Astra is tested upon the crop performance of new multi and bivoltine hybrids during October-November, 2010 and November-December, 2010 at this Research Station. The rearing house was disinfected with Astra as per recommend dosage. The rearing performance of new multivoltine and bivoltine hybrids and incidence of silkworm diseases recorded during 5th instar of rearing. There is no crop loss due to incidence of silkworm diseases. The total disease incidence recorded is very minimal i.e., 0.3-0.8% which indicates that Astra disinfectant is very effective in destroying the pathogenic microbes in the rearing house which can be used safely at lower concentration for disinfection of rearing house and successful crop harvest. The economics and other aspects are discussed in the paper.