Greenhouse evaluation of Beauveria bassiana (Balsamo) Vuillemin against Aphis craccivora (Das) on Fenugreek

The bioassay studies were carried out to determine the LC50 and LT50 of Beauveria bassiana against Aphis craccivora on fenugreek under greenhouse conditions. The results revealed that, the cumulative corrected mortality (CCM) was 43.50% at higher concentration (1×1010 spores/ml) and it was 20.85% at lowest concentration (1×104 spores/ml) at one day after treatment (DAT). The CCM decreased with decreasing conidial spore concentration. Likewise, at 2, 3, 4, 5, 6 and 7 DAT, almost same trend was observed. At 7 DAT, the CCM was 85.04% and 55.21% at 1×1010 spores/ml and 1×104 spores/ml, respectively. The LC50 value of B. bassiana against A. craccivora was 1.2×108 spores/ml. Mean lethal time (LT50) values were worked out 73, 89, 97, 112, 126, 138 and 157 hours for 1010, 109, 108, 107, 106, 105 and 104 spores/ml, respectively. By testing the field efficacy of B. bassiana against A. craccivora, this insect pathogenic fungus can be used as potential biocontrol agent for the sustainable management of aphid in fenugreek crop