Three experiments were conducted to evaluate the use of solar radiation for reducing survival of mountain pine beetle populations in infested logs. Ponderosa pine logs were used in experiments 1 and 2 and lodgepole pine logs were used in experiment 3. Experiment 1 comprised three treatments: (1) one-layer solar treatment without plastic sheeting and logs rotated one-third of a turn once a week; (2) two-layer solar treatment with plastic sheeting; and (3) two-layer solar treatment without plastic sheeting. For experiment 2, two additional one-layer treatments were added: one-layer treatment with plastic sheeting and no rotation and a one-layer with no plastic sheeting and no rotation. Experiment 3 included all the above-mentioned onelayer treatments only. For all experiments, brood density per 0.05 m 2 (0.5 ft 2 ) was estimated before and after treatment and analyzed using repeated measures analysis of variance. Subcortical temperatures were monitored in one replicate of all treatments in all experiments. In experiment 2, phloem moisture was monitored before and after treatment in uninfested logs. All treatments in all experiments caused drastic reductions in brood survival. In experiment 1, the one-layer treatment with the logs rotated once a week significantly reduced brood survival compared to the two-layer without plastic sheeting treatment but was not different from the two-layer with plastic sheeting treatment. There were no differences in brood survival after treatment associated with any treatments in experiments 2 and 3. In all experiments brood survival was consistently reduced in the aspects of the logs exposed to the sun. Maximum temperatures were consistently higher in the treatments with plastic sheeting, the exposed surfaces of the logs to the sun, and the upper layer of logs in the two-layer treatments. No differences were detected in phloem moisture content in uninfested logs before and after treatment in experiment 2, suggesting that heat is directly responsible for the observed reductions in survival. We conclude that solar treatments are an effective alternative for reducing mountain pine beetle survival in infested ponderosa and lodgepole pine logs.