A  field experiment was conducted for two years from 1996-98 to evaluate the bio-efficacy of Nomuraea  rlieyi on defoliator Spodoptera litura and pod borer Cydia ptychora in soybean and potato. Treatment effect due to N. releyi became visible at 7 DAS and its superiority was more evident at 14 DAS. In soybean, the pathogen lnflicted significantly higher reduction of spodoptera  larvae at higher concentration (1.2 x1012conidia/ 1) at 14 DAS, than in SINPV and Bt 'and performed at par in lowering percent leaflet damage. Pod and grain damage in soybean by lepidopteran pod borer at higher dose was on par with Bt.  Grain yield did not vary between NPV and N. rileyi treated plot but Bt.  treatment caused higher yield. In potato, the fungus was as effective as NPV and Bt at higher concentration at 14 DAS but inferior at 3 & 7 DAS in reducing larval number and leaflet damage. Tuber yield due to NPV and Bt was higher than the test fungus. Efficacy of N. rlieyi increased with increase dosage of fungus and all the doses of M . relieyi were significantly superior to untreated check in both the crops. Chlorpyrifos was superior to all the microbial agents. A comparison of the efficacy of N. rileyi between the crop ecosystems, soybean seemed to favour the fungal action far better than potato.