Raffaelea lauricola, laurel wilt is a disease of redbay (Persea borbonia) and other plant species in the family Lauraceae. The disease is caused by a fungus. It is introduced into trees by a nonnative insect, the redbay ambrosia beetle (Xyleborus glabratus), which is native to Asia.
Once infection occurs, the fungus spreads quickly throughout the tree's vascular system, preventing the movement of water within the tree. Choked of water, trees wilt and die within a few weeks or months of becoming infected. Trees infected wilt and leaves turn reddish to purplish brown. Affected leaves may stay on the tree for over a year. A dark staining occurs in wilted branches and the main stem of dead trees under the bark. Redbay ambrosia beetles excavate tiny holes in the tree that may be difficult to see without peeling off the bark. Frass, made up of sawdust and beetle excrement are extruded from the beetle entrance holes.
Raffaelea lauricola is causing widespread mortality of species in the Laurel family in some counties of Alabama, Georgia, Florida, Louisiana, Mississippi, North Carolina and South Carolina. It is found predominately in coastal counties.
Raffaelea lauricola provide food and shelter for wildlife including songbirds, turkeys, quail, deer, and bears. Two species of swallowtail butterflies use redbay and spicebush as host plants and rely on thses species to complete their life cycles. Raffaelea lauricola also infects two rare plant species, pondspice and pondberry.
There are no proven management strategies for preventing the development of laurel wilt disease. Early sanitation of newly infested trees and limiting movement of infested wood may help slow the spread. Keep infected trees where they are. Never move dead host material, even moving chips or tree debris. Infected trees can be disposed of by cutting the tree and leaving it on the site, or burying or burning dead trees on the site following all state and local regulations. Saws and equipment used in this process should be cleaned of debris and disinfected before leaving the site.