With 12 international ports of entry and a favorable climate, Florida provides an ideal new home for invading plant pests, diseases and noxious weeds.

Laurel Wilt is a disease of avocado and the native redbay-laurel tree family. Laurel wilt is caused by a fungus that stops the flow of water going up the tree which causes the tree leaves to wilt. The fungus is carried into the tree by the redbay ambrosia beetle. The redbay ambrosia beetle was first detected in the United States in 2002 and in Florida in 2005.

 Currently the redbay ambrosia beetle-laurel wilt disease infestation has spread west and south in Florida. Avocado trees have been reported as infested in Duval and Brevard Counties. As of this writing the redbay ambrosia beetle has not been detected in Miami-Dade or Palm Beach County. More sampling and testing is in progress. The Florida avocado industry is the state's second-largest fruit industry (behind citrus) and is worth $30 million at the wholesale level. In addition to commercial production, many homeowners in South Florida have backyard avocado trees. These trees form an important part of the urban canopy and contribute economic, aesthetic, and environmental benefits, adding as much as 10 percent to residential property values. They provide shade and wildlife habitat, and improve air quality.

There are at least 30 species of ambrosia beetle in Florida. Unlike most other ambrosia beetles in Florida, the redbay ambrosia beetle attacks healthy trees. The redbay ambrosia beetle is very small (about 2mm long) dark brown to black, and is cylinder-shaped. The redbay ambrosia beetle is native to India, Japan, Myanmar and Taiwan. The beetle was first detected in a survey trap in Port Wentworth, Georgia in 2002 probably arriving in infested solid wood packing materials (such as pallets or crates) used to ship commercial goods.

Symptoms of an ambrosia beetle infestation include leaf and young stem wilting, dead leaves hanging onto stems and stem and limb dieback. Inspection of the trunk and major limbs may show dried sap from the bore holes and/or small strings of compacted sawdust (ejected wood fiber) protrude from the small bore holes along the trunk of the tree. These symptoms are suspicious for the redbay ambrosia beetle and laurel wilt disease and the tree should be sampled to determine if the beetle and the laurel wilt disease are the cause of the symptoms.

Currently we recommend homeowners:

1.      Report any suspicious redbay or avocado trees to the Division of Plant Industry at 1-888-397-1517.

2.      Redbay and avocado trees should not be moved or sold as firewood, tree trimmings, BBQ smoke wood, mulch or wood-turning material.

3.      Extreme caution should be used in moving live redbay and avocado trees and wood products into counties where the pest is not yet found. Insect and disease free containerized host trees should only be purchased from registered nurseries, and host trees showing any signs of wilt or dieback should be destroyed immediately.

4.      Current recommendations for urban and rural residents with redbay or avocado that are confirmed to be positive for the laurel wilt disease include: cutting the tree down and placing the wood into the urban debris stream, that is, taken to the local landfill and destroyed or buried or composting the tree by cutting the tree to the ground, placing all wood or chips on top of the stump, and covering with a tarp all the way to the ground. For more information on how to build compost piles stop by the Palm Beach County Cooperative Extension Service 531 North Military Trail WPB Master Gardener Volunteer Help Desk M-F 9-4