The white muscardine fungus,Beauveria bassiana (Bals.) Vuill., was recorded for the first time on sugarcane internode borer,Chilo sacchariphagus indicus (Kapur) in a field survey conducted at Coimbatore, Tamil Nadu. In laboratory tests, the fungus caused 10.0 to 93.3% mortality in third instar larvae and 3.3 to 100.0% mortality in fourth instar larvae when treated at 104–109 spores/ml. The incubation period varied from 6.2 to 13.0 days in third instar and 5.8 to 10.0 days in fourth instar. The mean spore production/larva varied from 0.04 × 109 to 0.72 × 109 in third instar and 0.11 × 109 to 3.44 × 109 spores/larva in fourth instar.