FIELD STUDIES ON THE USE OF HIGH-TEMPERATURES TO CONTROL CRYPTOTERMESBREVIS (ISOPTERA, KALOTERMITIDAE)

Nine separate commercial high temperature treatments were observed thr oughout the State of Hawaii. Both ambient temperatures and structural wood core temperatures were monitored in the areas most prone to slow rates of temperature increase, i.e., the largest, lowest structural lu mber and timbers next to potential heat-sinks. Data were analyzed to d etermine the range of temperature increase rates under various conditi ons as well as to test the impact of those conditions on heating rates . The mean maximum wood core and ambient temperatures were 55.1 degree s C and 68.1 degrees C, respectively. The longest time that it took to achieve the target wood core temperature of 49 degrees C was 5h. The mean rate of temperature increase was 0.28 degrees C/min, the minimum was 0.04 degrees C/min and the maximum was 1.41 degrees C/min. Minor a nd repairable property damage was observed during two high temperature treatments when ambient treatment temperatures exceeded 70 degrees C. The rates of temperature increase observed in field applications were generally considerably lower than those used in laboratory studies of the effects of rate on the thermal tolerance of C. brevis. Degree of surface exposure to heated air had a significant effect on the rate of temperature increase in lumber.