Influence of host plants on susceptibility of Helicoverpa armigera, Spodoptera litura and Spilarctia (Spilosoma) Obliqua to Beauveria bassiana

Investigations revealed that the mortality attributed to Beauveria bassiana was significantly associated with host plant species on which the insect larvae were fed. Differential susceptibility was recorded in larvae of all the three species when compared on the basis of percentage mortality and LT50 values. In case of Helicoverpa armigera, significantly higher mortality was recorded on 8th day when larvae were fed on gram and pea with lower LT50 values as compared to larvae reared on pigeon pea and tomato while Spodoptera obliqua was found significantly more susceptible when larvae were fed on cabbage as compared to other host plants, i.e., castor, japanese mint and soybean. In case of Spodoptera litura larvae reared on cabbage and castor were significantly more susceptible to the infection of B. bassiana in terms of percentage mortality as compared to groundnut and cauliflower while lower LT50 values were recorded for cabbage and cauliflower.