A experiment was conducted to study the percent damage caused by insect pest on oyster mushroom. The phorid fly, sciarid fly and staphylinid beetle recorded minimum (52.01%) and maximum (70.60%) per cent of damage in treatment T1 (Wheat straw + P. sajorcaju) and T6 (Paddy straw + P. florida) at 42 DABO. Same trend was also observed at 49 DABO in treatment T1 (94.97%) and T6 (100%).