Study Confirms Beetles Exploit Warm Winters to Expand Range (image) DOE/Los Alamos National Laboratory Share Print E-Mail Caption North American bark beetle outbreaks have killed millions of trees. A new study demonstrates how the Mountain Pine Beetle's range is expanding due to warming temperatures but reveals how overpopulation might decelerate growth. Credit LANL Usage Restrictions None Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.