Influence of food sources on developmental period of Rhyzopertha dominica, Tribolium castaneum and Sitophilus oryzae

Nutrient status of host has a profound influence on biology, colonization, rate of feeding and survival of an insect. To know the influence of different food sources on developmental period of three key pests of stored products viz., the lesser grain borer, Rhyzopertha dominica (F.), the rust red flour beetle, Tribolium castaneum (Herbst.) and the rice weevil, Sitophilus oryzae (L.), a laboratory study was conducted on their natural food sources at 28–30°C temperature and 65–70% relative humidity. When R. dominica was reared on whole wheat, paddy, sorghum and broken wheat, the egg period was lowest (4.73) in wheat and highest (6.38) in paddy, larval period was minimum (28.20) in wheat to maximum (33.40) in paddy, pupal period ranged from 5.00 to 7.00 in wheat and paddy, respectively and the total development period ranged from 37.93 days in wheat to 46.78 days on paddy and were significantly different at p=0.01%. Similarly, wheat, rice, sorghum flour and wheat flour were used for rearing T. castaneum which revealed that, egg, larval, pupal and total development period were significantly different and ranged from 3.40 to 5.10, 23.00 to 27.12, 5.40 to 8.60 and 31.80 to 40.82, respectively. The lowest overall development period was found on wheat flour and highest was on rice. S. oryzae, when reared on wheat, rice, sorghum and maize grains recorded egg period from 4.00 (sorghum) to 6.00 (maize) days, larval duration from 27.00 (sorghum) to 32.00 (maize) days, pupal period from 7.00 (sorghum) to 9.00 (maize) days and total development period ranged from 38.00 (sorghum) to 47.00 (maize) days, which showed significant difference at p=0.01%.