A Comparative Study on Host Range of Tribolium castaneum (Herbst) and Rhyzopertha dominica (Fabricius) to Cassava (Manihot esculenta Crantz) and Selected Stored Grains

Host range of Tribolium castaneum and Rhyzopertha dominica to cassava chips were compared with stored grains such as wheat, black gram and rice. Test insects (20 Nos., 1M: 1F) were reared in splintered and flour forms of host samples under laboratory conditions. The parental adults were removed after 10th day of exposure and emergence of grub was noticed. Flour forms of wheat, black gram, rice and cassava were found more suitable for the adult emergence of T. castaneum whereas R. dominica preferred whole and broken forms of selected food except cassava. The number of adult emergence of T. castaneum and R. dominica was higher in wheat flour (67.4±6.2) and whole form of black gram (164.2±4.7) respectively. In the case of T. castaneum, the number of adult emergence was 51.8±5.8 and 57.6±2.0 in flours of black gram and rice respectively, whereas it decreased to 5.4±1.5 and 5.0±1.5 in whole forms of black gram and rice respectively. In the case of R. dominica, the number of adult emergence was 147.0±6.1 and 67.0±3.5 in whole forms of wheat and rice whereas it was only 11.6±2.0 and 12.8±2.7 when reared in flour forms of wheat and rice respectively. Among all the selected forms of cassava, only the flour forms supports the adult emergence of T. castaneum and R. dominica .