Oviposition preference and development of rice weevil, Sitophilus oryzae (Lin.) (Coleoptera: Curculionidae) in different stored grains

Oviposition preference and development of rice weevil, Sitophilus oryzae (Coleoptera: Curculionidae) were observed in three varieties of stored grains i.e. parboiled rice ( Oryza sativa ), wheat ( Triticum aestivum ) and pulse ( Cicer arietinum ). In no choice tests, the mean number of eggs laid were 360.3 ±2.60 in rice, 382 ±2.49 in wheat and 394± 2.06 in pulse. In case of choice tests, the mean number of eggs laid were 13.6±0.4 in rice, 14.2 ±0.37 in wheat and 15.6 ±0.4 in pulse. The differences between the number of eggs laid in rice, wheat and pulse varied significantly in both no-choice and choice tests. The respective incubation period, larval and pupal period of the weevil reared on rice, wheat and pulse were 5.7 ±0.27, 5 ±0.47 and 5.4 ±0.27 days, respectively, 21 ±0.47, 20.3 ± 0.27, 19 ±0.47 days, respectively and 10.3 ±0.27, 10.7 ±0.27, 11.3 ±0.27 days, respectively. The total development time from egg to adult recorded in rice, wheat and pulse was 37 ±0.47, 36 ±0.47 and 35.6 ±0.72 days, respectively. The difference between the larval periods was significant (p < 0.05) when they reared in wheat and pulse. The larval and pupal period varied significantly (p < 0.05) between the individuals reared in rice and pulse. The developmental period was shorter in pulse than in rice and wheat. Bangladesh J. Zool. 45 (2): 131-138, 2017