Survey for Determining Predisposing Factors of Major Diseases of Mulberry Silkworm, Bombyx mori L.

摘要

Extensive surveys were conducted in major silkworm growing regions of Tamil Nadu to assess the disease incidence level, losses due to major diseases and prioritize the factors that predispose the larvae to diseases. The results of the survey revealedthat the incidence of grasserie, flacherie, muscardine diseases and cocoon melting was the highest in Salem district (4.5 %, 7.5 %, 1.0 % and 4.0 %) followed by Erode (3.2 %, 6.0 %, 1.0 % and 2.4 %) and Coimbatore district (2.4 %, 3.0 %, 1.2 % and 2.0 %). Garrett's ranking of etiological agents responsible for diseases showed that leaf quality was the most important factor with mean score of 71.60 (rank 1) followed by rearing condition (69.46, rank 2) and disinfection practice (54.90, rank 3).