The insecticidal pyrrol chlorfenapyr was applied to concrete, tile, and wood surfaces, at an application rate of 0.11mgAI/cm2. Adult Tribolium castaneum (Herbst), the red flour beetle, and adult T. confusum (DuVal), the confused flour beetle, were exposed for 2 and 4 hours, removed, and held without food for 7 d post-exposure. All beetles survived the initial exposures, but survival of both species decreased during the 7-d holding period, with T. confusum being the more susceptible species. Survival was generally lower on concrete than on tile or plywood, and was greatly reduced on all three surfaces after 4 h of exposure compared to 2 h. Survival of T. castaneum after 2 h of exposure on concrete, tile, and plywood was 2.5 ± 2.5%, 25.5 ± 15.4% and 40.0 ± 7.1% respectively, after seven days. In contrast, all T. confusum exposed on concrete and tile were dead after 4 and 5 d, respectively, while survival on wood after 7 days was 20.0 ± 16.8%. After 4 h of exposure, all T. casteneum and T. confusum exposed on concrete and tile were dead after 2-4 d post-exposure, while survival on wood after 7 days was 41.5 ± 6.4 % and 0 for each species, respectively. Non-linear and linear regressions were fit to the data for both species.