Dartmouth Bark Beetle Study (1 of 2) (IMAGE) Dartmouth College Caption Pine trees secrete resin to resist initial attacks by southern pine beetles, but the trees almost always die as they are overwhelmed by thousands of attacking beetles. Credit Dartmouth College Usage Restrictions Credit Dartmouth College License Licensed content 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.