The biological activity of the botanical insecticide neemazal (con‌tains 10% azadirachtin) and the inert dust Katelsous (84% rock-phosphate and 16% sulphur) was studied agaist the adults of Trogoder‌ma granarium Everts, infesting cereal grains and their products especial‌ly in hot and sub-hot countries. Neemazal powder and katelsous dust were applied to wheat grains as surface treatment, at rates of 4000, 1000. 500, 250 and 125 ppm for neemazal and at rate of 1% for katelsous dust. The high dosage (4000 ppm) of neemazal showed high significant effect on adults mor‌talities (90%), compared with 25% in katelsous and 3.33% in control. After 4 days post exposure, all dosages of neemazal as well as katel‌sous, proved high toxic effect on adults (93.33-96.67% mortalities) in comparison with 23.33% in control. Males were more sensitive to all rates of neemazal used as well as katelsous than females that is obvi‌ously indicated 1 day post exposure. Both the high dose of neemazal (4000 ppm) and katelsous 1% were significantly highly active in reducing the Fl progeny. Reductions of 92.62% and 92.08% in Fl progeny were obtained for both, respec‌tively , after one month. Dosages 1000, 500, 250 ppm also proved high protective value to wheat grains (86.07-81.14%). After a storage peri‌od of two months for the treated grains with all dosages of neemazal and katelsous, no offspring was produced at any treatment compared with average no. of 61.63 insect produced in control. All treatments of nemazal powder and katelsous dust, showed no hazards effect on seed germination of treated wheat grains, with exception of the high dosages (4000 and 1000 ppm) of neemazal which reduced the percentage of seed germination to 88% and 92%, respectively.