Pathogenicity and histopathological studies for local isolates of entomopathogenic fungi, Nomuraea rileyi (Farlow) Samson against Thysanoplusia orichalcea (Fab.) and Spodoptera litura (Fab.) (Lepidoptera: Noctuidae) infesting soybean, Uttarakhand, India

Among different biocontrol agents, entomopathogenic fungi Nomuraea rileyi (Farlow) Samson, was found as a predominant organism in the soybean ecosystem of Uttarakhand, India. So, two most virulent local isolates of the entomopathogenic fungus N. rileyi were isolated, multiplied and studied for pathogenicity and Histopathology against T. orichalcea (Fab.) and S. litura. Quantitative evaluation of the dose and time mortality response has been observed on different age group larvae (4-5, 10-11 and 15-16 days) of test insects. Histopathological study also confirms that the most virulent isolate of N. rileyi found from Bioassay studies, took less time to complete pathogenesis cycle (120 h) and it proves that, the rate of conidial germination and penetration of insect integument has been found to be related to the virulence of the fungi and the susceptibility of insect host.