Identification and Toxicity Evaluation of Beauveria sp. Associated with White Muscardine Disease in Muga Silkworm Antheraea assamensis Helfer

The present study is an effort to isolate and identify the Beauveria sp. from white muscardine infected Antheraea assamensis Helfer (muga silkworm) larvae collected from rearing fields. The isolate was subjected to morphological identification followed by DNA barcoding analysis by sequencing the ITS1-5.8S-ITS2 region. The isolate was identified morphologically up to genus level. For molecular identification, the DNA was first isolated, amplified by using PCR followed by sequencing the ITS region. A phylogenetic tree was also constructed based on the data obtained from sequencing to trace the evolutionary history of the isolated fungus. The fungal species was identified as Beauveria bassiana with 98.6% sequence similarity with already documented B. bassiana strains. The toxicity of the isolated fungus was also evaluated against A. assamensis larvae. The LC50 value was determined at 96 hr and recorded at 1.1x108 spore/ ml concentration.