Infected Tree (IMAGE) University of California - Riverside Caption An orange tree that is infected with huanglongbing. Leaf symptoms begin on one or a few branches and slowly spread to the rest of the tree. Credit Georgios Vidalakis, UC Riverside Usage Restrictions None 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.