Spores of blister rust on pine (IMAGE) University of California - Davis Caption Spores from white pine blister rust disease infect a pine tree in Sequoia and Kings Canyon National Parks. Credit Clayton Boyd Usage Restrictions Credit must be given to the creator. Only noncommercial uses of the work are permitted. License CC BY-NC 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.