Amorphous silica dust (Oryacide) was used to control adults of Sitophilous
granarius at concentrations of 200, 400, 600, 800 and 1 000 ~g silica dust/g wheat.
Adults of S. granarius were placed in the three classes of wheat grains (hard, soft &
durum)and incubated at 20°C and 28 ± 1 °C and 65 ± 5 % R.H. Mortality counts were
estimated after 48 and 168 hrs. Toxicity increased with increase lower concentration and temperature. Percent reduction of progeny reached
66.66 - 75.0 % in some wheat classes. Silica dust gave high percentages of mortality
after long-term storage at the four periods (1, 8, 16, and 24 weeks) at 500 and 1000
~g/g w. Seed germination was not affected by treatment by silica dust.