author(s)
Bireshwar Kundu, Supriya Okram, Tapan Kumar Hath and Debanjan Chakraborty

abstract
The research was conducted at the Laboratory of Department of Agricultural Entomology, UBKV, Pundibari. Objectives of the research work were to determine the bio-efficacy of different inert materials viz., kaolinite, bentonite, cow dung ash, saw dust and sand against Sitophilus oryzae on wheat under laboratory conditions based on adult mortality, percent grain damage and percent weight loss. The results showed that kaolinite was found to be the best treatment causing 90% of adult mortality at 35 days followed by bentonite (79.55%), cow dung ash (72.53%) and saw dust (45.95%). In terms of grain damage and percent weight loss, kaolinite was noted to be the most effective grain protectant with the corresponding values of 0.613% and 0.437% respectively which was followed by the bentonite (1.060% and 0.728% respectively). Sand was recorded to be the least effective one with 2.218% of grain damage and 1.842% of weight loss due to the attack of the rice weevil. It was found that kaolinite was found consistently and significantly superior over the remaining treatments followed by bentonite which was at par with cow dung ash.