Sampling Guidelines and Recommendations for Submitting Samples for Diagnosing Laurel Wilt in Avocado Trees (Persea americana L.)

Laurel wilt symptoms in avocado trees include green leaf wilting, desiccated (brown) leaves, and stem and limb dieback. Credits: J. H. Crane, UF/IFAS TREC

Laurel wilt (LW) is a vascular disease caused by a fungal pathogen transmitted to avocado trees by several ambrosia beetle species and through root grafts among adjacent avocado trees. A critical part of preventing and controlling plant diseases is determining the causal agent so that the appropriate management practices can be implemented to eradicate or contain the outbreak. Proper sampling is a critical step in disease diagnosis and in the determination of the causal agent of disease. This new 3-page publication of the UF/IFAS Horticultural Sciences Department was written by Jonathan Crane, Romina Gazis, Jeff Wasielewski, Daniel Carrillo, Bruce Schaffer, Fredy Ballen, and Edward Evans.

Assessing the Survival of the Redbay Ambrosia Beetle and Laurel Wilt Pathogen in Wood Chips (FOR289/FR351)

Figure 2. 1 m3 mulch bin with mesh bags on the surface containing woodchips from the infested redbay trees.What is the best way for homeowners to dispose of dead redbay trees to avoid spreading laurel wilt? This 4-page fact sheet summarizes a UF/IFAS study providing evidence that a simple technique — chipping the dead trees — can help contain the disease within a small area and that there is a low probability of long-distance movement of LW via wood chips. Written by Don Spence, Jason Smith, Albert Mayfield III, Jiri Huler, Randy Ploetz and Lukasz Stelinski, and published by the UF Department of School of Forest Resources and Conservation, November 2011.

Redbay Ambrosia Beetle Xyleborus glabratus Eichhoff (Insecta: Coleoptera: Curculionidae: Scolytinae) (EENY491/IN886)

Ambrosia beetles are wood-degrading insects that live in nutritional symbiosis with ambrosia fungi. Usually we consider ambrosia beetles beneficial because they accelerate the decay of dead trees, which is important for nutrient cycling in healthy forests. However, the redbay ambrosia beetle and its fungal symbiont transmit the causal pathogen of laurel wilt disease among plants in the Laurel family (Lauraceae). They are considered a “very high risk” invasive disease pest complex having potential equal to that of Dutch elm disease or chestnut blight. Laurel wilt is a relatively new disease and much is still unknown about how it will impact the flora of North America. This 7-page fact sheet highlights what we do know about this important new pest. Written by Rajinder Mann, Jiri Hulcr, Jorge Peña, and Lukasz Stelinski, and published by the UF Department of Entomology and Nematology, May 2011.

HS1179 Homeowner Detection of and Recommendations for Mitigating Redbay Ambrosia Beetle-Laurel Wilt Disease on Redbay and Avocado Trees in the Home Landscape

HS1179, a 4-page illustrated fact sheet by Jonathan H. Crane and Jason A. Smith, provides homeowners with an update on redbay ambrosia beetle-laurel wilt disease in Florida, how the beetle and pathogen are spread, symptoms of infestations, and recommendations for homeowners. Includes references. Published by the UF Department of Horticultural Sciences, May 2010.