Susceptibility of Wheat and Rice grains in Storage to Rice weevil, Sitophilus oryzae (L.)

An experiment on susceptibility of wheat (Triticum aestivum L.) and rice (Oryza sativa L.) grains to rice weevil (Sitophilus oryzae L. Coleoptera: Curculionidae) was carried out at Palli Siksha Bhavana (Institute of Agriculture), Visva-Bharati, Sriniketan, West Bengal. The study revealed considerable differences in adult emergence, grain damage percentage and weight loss percentage between wheat and rice grains. Wheat experienced higher grain damage (0.95%) and weight loss (0.48%) despite fewer adult emergences (66), while rice supported a greater adult population (132) but lower damage rates (0.53% grain damage, 0.23% weight loss). When tested for susceptibility to S. oryzae, in wheat and rice, as per the parameters, the number of adults emerged (66 & 132) and average developmental days (31.167 & 39.05), the susceptibility index obtained was 13.442 & 12.498 for wheat and rice. Thus, the results showed that wheat is comparatively more susceptible than rice.