Pest of the Month -- February

Sudden Oak Death

Sudden Oak Death is caused by a funguslike pathogen Phytophthora ramorum. Since 1995, Sudden Oak Death has killed tens of thousands of coastal oaks in northern California. Kentucky trees and shrubs that may be at risk include rhododendron (see inset), buckeye, bigleaf maple, bay laurel, and evergreen huckleberry. Northern red oak and pin oak also may be susceptible.

Joseph O'Brien, USDA Forest Service, www.invasive.org

Bleeding or oozing of a dark reddish-brown thick sap is the first symptom to appear on true oaks. It typically occurs on the lower portion of tree trunks (less than 10 feet). Secondary pests, such as beetles and wood decaying fungi, attack weakened trees so identifying Phytophthora ramorum on the currently recognized hosts is not clear cut; confirmation in a laboratory is required.

–some information taken from July 25, 2001 field guide prepared by Susan Frankel, USDA-FS