The effectiveness of malathion and spinetoram alone and in binary combinations was investigated against the adults of Sitophilus oryzae (L.), Rhizopertha dominica F. and Tribolium castaneum (Herbst.). The obtained results showed that, the toxicity of each insecticide to the adults of the three insect species was concentration and exposure period - dependent. Adultsof  S. oryzae were highly susceptible to malathion alone but, R. dominica and T. castaneum adults were the least susceptible to the insecticide .While  R. dominica adults were higher susceptible to spinetoram alone than the two other species . Co-toxicity values resulted from adding  LC₁₀ of spinetoram to various malathion concentrations  showed a potentiation effects on the adults of  T. castaneum at all concentrations of malathion, on R. dominica at the three lowest concentrations and at the lowest concentration(0.25ppm) only on the adults of  S. oryzae.  Meanwhile an additive effect was achieved with other concentrations of malathion and LC₁₀ of spinetoram against the three tested insect species.A complete protection for stored wheat seeds was achieved with the Six tested mixtures(Mix₁ - Mix₆ ) against adults of S. oryzae  and R. dominica up to 6 months. Also, the same effect extended against T. castaneum adults to 5, 4 and 2 months with Mix₁, each of (Mix₂ and Mix₃) and Mix₄ ,resp. Contrarily, Mix₅, Mix₆ failed to give a complete mortality for T. castaneum adults at all various intervals( months). Data concluded that, stored wheat seeds treated with Mix₃ (4ppmM+5ppmSm)or Mix₄ (4ppm M+4ppm Sm) were protected against the three insects infestation for 3months.