Potentiality of Beauveria bassiana strains against Helicoverpa armigera through laboratory bioassay

The susceptibility of second instar Helicoverpa armigera (L-2) to seven strains of Beauveria bassiana, was tested under laboratory conditions at ICAR-IIHR, Bengaluru during 2016-17 using the larval immersion method. The highest virulence (100%) was recorded in strain-4 with LC50 value (2.02 x 105spores ml-1) followed by strain-1(92.50%) with LC50 value (2.48 x 105 spores ml-1) at 120 hours after treatment. Corrected mortalities ranging from 59.50 to 100% at different hours after treatment were recorded in all the strains with more profound effects in strain- 4 and strain-1.