Technical Abstract: The effect of short exposures to spinosad-treated wheat and maize was evaluated against adults of four stored-product insects: the lesser grain borer, Rhyzopertha dominica (F.), the rice weevil, Sitophilus oryzae (L.), the red flour beetle, Tribolium castaneum (Herbst), and the psocid Lepinotus reticulatus (Enderlein). Adult mortality was recorded after 0, 2, 4, 8, 16, and 40 h on commodities treated with 1 ppm of spinosad (immediate mortality). Surviving individuals were removed and placed on untreated wheat or maize, and mortality was recorded again 7 d later (delayed mortality). Progeny production was determined 65 and 35 d later for the beetles and psocids, respectively. Rhyzopertha dominica was most susceptible, and immediate mortality after 40 h reached 78 and 72% on wheat and maize, respectively. Seven days later, all adults that had been exposed for >2 h were dead on both commodities. Progeny production was reduced, and no progeny were found when parental adults had been exposed for >8 or >4 h on wheat and maize, respectively. For S. oryzae, 40-h exposures increased delayed mortality on both wheat and maize, but progeny production still was high. Generally, no effect of short exposures was observed for T. castaneum. Lepinotus reticulatus progeny production was not avoided despite increased parental mortality on maize. More progeny were found on wheat than on maize, except for T. castaneum. The results indicate that R. dominica is very susceptible after short exposures to spinosad-treated substrate, but the other species can survive and reproduce at the exposure range examined.