Characterizing and Testing Biocontrol Potential of Two Bacillus Strains Isolated from the Tea Defoliating Pest, Arctornis submarginata(Walker) (Lepidoptera: Lymantriidae) Khewa Sangita (Subba)*, Mukhopadhyay Ananda** Entomology Research Unit, Department of Zoology, University of North Bengal, Darjeeling, 734 013 *E-mail: sangita.khewa@yahoo.com
**E-mail: am_nbu@yahoo.co.in
Online published on 16 February, 2013. Abstract Two strains of Bacillus were isolated from the diseased caterpillars of Arctornis submarginata (Walker) (Lepidoptera: Lymantriidae), a defoliator of tea crop from Darjeeling Terai region. Biochemical characteristics of Bacillus strain Arc02 showed positive reaction in lysine utilization, ornithin utilization, Citrate utilization, malonate utilization, esculin hydrolysis, rhamnose, cellobiose, raffinose and glucose utilization while Arc03 strain showed positive reaction in nitrate reduction, H2S production, V-P test, esculin hydrolysis and utilization of citrate, saccharose, trehalose and glucose. Studies on SDS-PAGE of crystal protein of of Arc 02 showed four major protein bands with the molecular weights 117.32 kDa, 75.14 kDa,55.97 kDa and 39.15 kDa, while the profile of four protein bands of Arc03 showed 122.7 kDa, 85.8 kDa, 50.3 kDa and 46.84 kDa bands. The LC50 value was of Arc02 was found to be 796.22 μg/ml compared to 342 μg/ml as the LC50 value of Arc03. Based on LC50 value the latter strain (Arc03) apprears to be more toxic with a higher biocontrol potential as a microbial pesticide against A. submarginata. Top Keywords Bacillus strain Arc02 and Arc03, Arctornis submarginata, Defoliating pest, Tea, Darjeeling. Top |