H.P. MEGHWAL1 AND N.K. BAJPAI

The effect of different temperatures and humidity levels was studied on bio–ecology of Sitophilus oryzae (Linn.) in stored maize 26°C, 28°C, 30°C and 32 ±1°C with variable humidity levels i.e., 65, 70, 75 and 80±5 per cent under laboratory condition in different BOD incubators in the Department of Entomology, Rajasthan College of Agriculture, Udaipur during 2007 and 2008. The longest ovipositional period (42.55 days), maximum fecundity (155.73 eggs/female) and shortest developmental period from egg to adult (28.58 days) of S. oryzae was recorded at 30°C temperature. The combination of 30°C temperature and 75 per cent relative humidity was preferred by S. oryzae where longest ovipositional period (48.80 days), maximum fecundity (170.70 eggs/female), minimum duration of larval and pupal period (23.70 days) and shortest developmental period from egg to adult (27.40 days) was recorded. At 26°C temperature and 65 per cent humidity growth and development of S. oryzae was retarded as evinced by ovipositional period (25.00 days), longest incubation period (7.00 days), maximum larval and pupal period (38.60 days) and longest developmental period from egg to adult (45.60 days).