Pathogenecity of a baculovirus isolated from Arctornis submarginata (Walker) (Lepidoptera:Lymantriidae), a potential pest of tea growing in the Darjeeling foothills of India

A granulosis virus (GV) was isolated from the diseased caterpillars of Arctornis submarginata (Walker) (Lymantriidae), a defoliating pest of tea from Darjeeling foothill region. The phase contrast and transmission electron microscopic studies identified the virus as granulosis virus. SDS–PAGE analysis of major protein of the occlusion bodies was found to be 31 kDa, characteristic for granulin. The total genomic DNA was isolated. The major band found was of molecular weight 16 kDa. Bioassay conducted with the occlusion bodies (OBs) of the virus showed LC50 value of 4.46 × 104 OBs/ml for the second instar caterpillars. Median lethal time (LT50) were 6.6 days for 1 × 104 OBs/ml, 5.09 days for 1 × 105 OBs/ml, 4.45 days for 1 × 106 OBs/ml and 3.87 days for 1 × 107OBs/ml concentrations. The results indicated the potential of the virus for its future application as microbial pesticide against A. submarginata in future.