Effects of grain moisture and temperature on infestation of rice weevil, sitophuus oryzae (linn.) on unhusked-unparboiled rice

Abstract

Extent of grain damage, germination and viability caused by rice weevil, Sitophilus oryzae (L.) infestation at different grain moisture and temperature levels were studied under laboratory condition. The grain damage was higher at 37°C (0.873%-1.963%) followed by 30°C (1.083%-1.393%) and at room temperature (17-35°C) (0.219%-1.09%) at any of the four moisture levels (10, 12, 14 and 16%) tested. The results also indicated that 30°C and room temperatures with high moisture levels of 14 and 16% were conducive to rice weevil damage. Infestation of unhusked-unparboiled rice by rice weevil did not affect its germination and viability irrespective of temperature and moisture levels.