Biological control of a cosmopolitan pest Helicoverpa armigera through baculoviruses is emerging as safe and best viable alternative control measures over the chemical methods. But there use in the field is very limited, due to their short persistence, reduced viability and slow killing of pest. The virulence of the virus is significantly influenced by the host plant chemicals against the insect pest. The infectivity of the nuclear polyhedrosis virus, HearNPV to H. armigera was significantly reduced when viral occlusion bodies were exposed to the plant phenolic compounds. The degree of inactivation of HearNPV was greater on chickpea than that reported on pigeonpea, fieldbean, soybean, blackgram and greengram host plants.