Laurel Wilt

Pathogen

A species of Raffaelea has been shown to be the cause of a vascular wilt disease known as laurel wilt, a severe disease on redbay ( Persea borbonia ) and other members of the Lauraceae in the Atlantic coastal plains of the southeastern USA . The pathogen is likely native to Asia and probably was introduced to the USA in the mycangia of the exotic redbay ambrosia beetle, Xyleborus glabratus . Analyses of rDNA sequences indicate that the pathogen is most closely related to other ambrosia beetle symbionts in the monophyletic genus Raffaelea in the Ophiostomatales . The asexual genus Raffaelea includes Ophiostoma-like symbionts of xylem-feeding ambrosia beetles, and the laurel wilt pathogen has been named Raffaelea lauricola sp. nov. (Harrington et al. 2008).

Colonies of Raffaelea lauricola growing from diseased wood chips in culture (A), and conidia and conidiophores under magnification (B). Photos by T.S. Schubert , Florida DACS Division of Plant Industry (A) and S.W. Freadrich, USDA Forest Service (B).

 

 

 

Additional Information

• Raffaelea species Associated with Xyleborus glabratus and Other Ambrosia Beetles- T. Harringtion, Iowa State University, and S. Fraedrich, US Forest Service, Southern Research Station, Laurel Wilt Conference 27-Feb-09 (Slideshow 1.2 MB).

• Population Genetic Studies of the Laurel Wilt Pathogen, Raffaelea lauricola – M. Hughes, C. Anderson, and J. A. Smith, University of Florida, Gainesville, FL., Laurel Wilt Conference 27-Feb-09 [338 KB].

• Development of a Quantitative, Real-time PCR Assay for Raffaelea lauricola – T. J. Dreaden, and J. A. Smith, University of Florida, Gainesville, FL., Laurel Wilt Conference 27-Feb-09 [97 KB].

• 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. [PDF 419 KB]

• Fraedrich, S.W., T.C. Harrington, R.J. Rabaglia, M.D. Ulyshen, A.E. Mayfield, III, J.L. Hanula, J.M. Eickwort, and D.R. Miller. 2008. A fungal symbiont of the redbay ambrosia beetle causes a lethal wilt in redbay and other Lauraceae in the southeastern United States. Plant Disease 92(2): 215-224.

• Laurel Wilt: Causal Agent - a Fungal Pathogen, Stephen Fraedrich, USDA Forest Service. 1/19/2007. (PDF 99 KB)

• The Laurel Wilt and Other Ambrosia Fungi, Similarities to the Dutch Elm Disease Cycle, and Management Implications - Thomas C. Harrington, ISU, 1/19/2007 (Slideshow, 1.9 MB)

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USDA Forest Service - Forest Health Protection, Southern Region
Last Modified: Wednesday, 16 February 2011 at 15:54:22 EST