author(s)
Mona Joshi, Neeta Gaur, Renu Pandey and Rukesh Pramod KN

abstract
The aim of the present study is to test the pathogenicity of different entomopathogenic fungal isolates against Bihar Hairy Caterpillar (Spilosoma obliqua). On the basis of preliminary bio efficacy trials on all local isolates, two most virulent isolates of each Beauveria bassiana, Metarrhizium anisopliae and Nomuraea rileyi were selected for bio efficacy studies against S. obliqua. The results on dose mortality response of S. obliqua to two isolates of B. bassiana indicated that the LC₅₀ values of first isolate were lower than the second isolate indicating that isolate 1 as more virulent. Similarly the first isolate of M. anisopliae was found to be more virulent to S. obliqua with a lower LC₅₀ value, Relative LC₅₀ values between two isolates showed that second isolate was 17.8, 50 and 4.1 times more virulent than the first isolate for 4-5, 10-11 and 15-16 days old larvae. Isolate 1 of N. rileyi was more effective with lower LC₅₀ values. S. obliqua was found to be most susceptible to B. bassiana followed by M. anisopliae and N. rileyi respectively.