This disease was first found in South Florida in 2011 and is spread by tiny insects called ambrosia beetles. Laurel wilt infects only avocado and related trees such as swamp bay and red bay. Your other fruit and landscape plants will not get infected with laurel wilt.
The symptoms of this disease include: the avocado leaves quickly turn dark purplish green or greenish brown but stay on the tree giving it a wilted look. Other symptoms include sawdust tubes on the trunk and branches. Don’t confuse it with natural leaf fall, which is normal. When avocados bloom, such as now, most or all of the leaves will yellow and drop off. Trees infected with laurel wilt typically do not shed their dead leaves.
If your avocado is infected, there are unfortunately no treatments available to save it. Keep in mind that a dying or dead tree is a source of the beetles that spread the laurel wilt disease.
You are asked to do the following since your avocado tree is dying: Hire a qualified professional to have your tree and stump removed as soon as possible. Cutting down trees yourself can be dangerous and risky. Preferably have the tree chipped on-site. The chips can be used as mulch in your landscape. Or the chips can be hauled away to a trash transfer station.
Do not leave dead trees in your yard or on the right-of-way since beetles will continue to emerge from the wood and spread the disease.
Once your tree is suspected to be infected with laurel wilt, please call the Laurel Wilt Hotline 888-397-1517. The Florida Department of Agriculture may want to test your tree to see if it is positive for the laurel wilt fungus. They are monitoring the spread of this disease in Florida and in Miami-Dade County, but they will NOT remove your tree.
To find out more about this disease, there are fact sheets on the UF/Miami-Dade County Extension web site on the “Insect and Diseases” page at http://miami-dade.ifas.ufl.edu/.