The lethal concentration 99% (LC99) value of profenofos against C. pavonana larvae standard was 0.0442% in dry film method and 0.0179 in feeding assay method (Table1). The LC99 value in feeding assay method was lower than that in dry film method. This indicates that synthetic insecticide with profenofos as active ingredient had higher toxicity through oral application. Profenofos was active as a stomach and contact poison and has a wide spectrum against insect pests (Worthing,1991).