Laurel wilt is a disease of woody plants in the laurel family (Lauraceae). Hundreds of millions of redbay (Persea borbonia) trees have been killed by laurel wilt in the southeastern Atlantic Coastal Plain region of the United States (US). The disease has also killed large numbers of sassafras (Sassafras albidum) trees in forests and landscapes, and avocado (Persea americana) trees in commercial production. As of October 2019, laurel wilt was known to occur from Texas to North Carolina, south through Florida and north to Kentucky. Laurel wilt is expected to continue spreading through sassafras in the eastern US, and is a potential threat to California bay laurel (Umbellularia californica) in the western US and to lauraceous species elsewhere in the world. See Region 8 - Forest & Grassland Health for more information.
USDA. FS. Southern Region. State and Private Forestry.
USDA. FS. Southern Research Station. CompassLive.
Laurel wilt has devastated plants in the Lauraceae family – redbay, sassafras, pondberry, avocado, and others – since it was first detected in the southeastern U.S. around 2002. There is no widespread, effective treatment for laurel wilt. Genetics research is focused on learning more about the pathogen's genetic structure in order to improve detection methods and screening for possible resistance in Lauraceae host species. "We have developed genetic markers to describe the population of the pathogen in the U.S.," says USDA Forest Service plant pathologist Tyler Dreaden. "Knowing which genotypes to use contributes to a quicker, more cost-effective resistance screening process." Dreaden led a new study to shed light on the genetic structure of the pathogen and its reproductive strategy. The research team included Marc Hughes at the University of Hawaii at Manoa, Randy Ploetz and Jason Smith at the University of Florida, and Adam Black, horticulture director of the Peckerwood Garden Conservation Foundation in Texas. Their findings were published in Forests.
Distribution of Counties with Laurel Wilt Disease by Year of Initial Detection (Nov 2019) (PDF | 612 KB)
USDA. FS. Forest Health Protection. Southern Region.
View the updated regional infestation map for Laurel Wilt Disease (for initial detection in May 2002. Map is updated periodically (USDA,FS - Forest & Grassland Health).
USDA. FS. Northern Research Station.Select the non-indigenous forest pest to view maps depicting state and county distribution. Produced by: USDA, FS, Forest Health Protection, and its partners.
University of Georgia. Center for Invasive Species and Ecosystem Health.Provides state, county, point and GIS data. Maps can be downloaded and shared.
The section below contains highly relevant resources for this species, organized by source. Or, to display all related content view all resources for Laurel Wilt.
USDA. Forest Service; Southern Regional Extension Forestry. Forest Health Program.
See also: Laurel Wilt for more resources
European and Mediterranean Plant Protection Organization.
National Plant Diagnostic Network.
North American Plant Protection Organization.
State and Local Government
Florida Department of Agriculture and Consumer Services.
Alabama Forestry Commission.
Mississippi Forestry Commission.
Georgia Forestry Commission.
University of California - Riverside. Center for Invasive Species Research.
University of Kentucky. College of Agriculturel, Food, and Environment. Department of Forestry and Natural Resources.
- Fraedrich, S.W., T.C. Harrington, and R.J. Rabaglia. 2007. Laurel wilt: a new and devastating disease of redbay caused by a fungal symbiont of the exotic redbay ambrosia beetle. Newsletter of the Michigan Entomological Society 52(1-2):14-15.
- Harrington, T.C., S.W. Fraedrich, and D.N. Aghayeva. 2008. Raffaelea lauricola, a new ambrosia beetle symbiont and pathogen on the Lauraceae. Mycotaxon 104:399-404.