Unsanitary storage bins can harbor grain-infesting insects, including the red flour beetle, Tribolium castaneum (Herbst). In a previous study involving heat treatment of empty bins, temperatures in the range of 50-55C for 2-4 h were effective in completely killing storedproduct insects. Previous research in flour mills showed improved efficacy in killing storedproduct insects by using diatomaceous earth (DE) dusts at temperatures below 50°C. In the current study, the efficacy of a diatomaceous earth formulation (DiaFil® 610) applied to concrete arenas, to simulate floor of empty bins, was examined at three application rates (0, 2.5 and 5.0 g/m 2) to control T. castaneum adults at five constant temperatures (28, 36, 42, 44, and 46°C). Ten adults of T. castaneum were placed on individual untreated and DE-treated concrete arenas for 4, 8, 12, and 24 h at each of the five temperatures. The efficacy of DE against T. castaneum adults increased with an increase in temperature and exposure time. Generally more adults died at 5.0 g/m 2 when compared with 2.5 g/m 2. In 2.5 and 5.0 g/m 2 DE treatments, exposure for 12 h at a temperature of 42°C resulted in 73-77% mortality of adults with 100% mortality observed after 24 h. At 44 and 46C, 100% mortality of adults was observed after 24 h of exposure at both DE rates. At these two temperatures, the high mortality in untreated arenas (controls) at 8, 12, and 24 h exposures ranged from 27-100% confounding the true effects of DE. Our results suggest that combined use of DE and temperatures below 50C can be used as an integrated approach for controlling insects in empty bins prior to storage of newly-harvested grain.