Author : Mahesh Kumar, Magdeswar Sharma and Pradeep Kumar Sharma

Four larval instars viz. IInd,III rd,IVth & Vth were fed on diet treated with four different concentrations i.e. 1×108, 1×107, 1×106, 1×105 POB/ml to evaluate highest mortality and maximum viral yield. Findings suggest that Ha-NPV should be applied to IIIrd instar larvae in vitro to achieve high larval mortality (78.33 %) and maximum viral yield (4.319 x109 POB/g of cadavar) at 1x107ml dose inoculum. Mortality percentage reduced with a corresponding reduction in virus dosages in all studied instars.

Keywords: Helicoverpa armigera, POB, Mortality, Inoculum–dose, viral yield.