From University of Illinois Extension. Forest Health - Tree health. Detailed description on diseases, insects and control. Includes forum, search engines, and polls. Gypsy Moth - The gypsy moth is a serious threat to trees including maples, oaks and elms.
Caterpillars feed on leaves, weakening the tree.
Oak Wilt - Oak wilt is a devastating fungal disease that attacks red oaks, white oaks and live oaks of North America. Learn how you can identify and control this oak tree disease. Powdery Mildew - Powdery mildew is a fungus that attacks the leaves of various plants including poplar and willow trees and roses. Wired Digital Inc., a Lycos Network site. All rights reserved.