Laurel Wilt on Swampbay (Persea palustris) in Miami-Dade County Dr. Jonathan H. Crane, Tropical Fruit Crop Specialist University of Florida, IFAS Tropical Research and Education Center Homestead, Florida Feb., 2011
Laurel Wilt on Swampbay (Persea palustris) inMiami-Dade County
Dr. Jonathan H. Crane, Tropical Fruit Crop Specialist
University of Florida, IFASTropical Research and Education Center
Homestead, Florida
Feb., 2011
Location of the LW positive trees
• Three swampbay (Perseapalustris) trees were sampled February 1, 2011.
• Between mile marker ~20 and 21 on east side of Krome Avenue.
• Samples were sent to 3 laboratories– DPI, Gainesville – J. Smith, UF-SFRC– R. Ploetz, UF-TREC
• Confirmed by:– Visual – CSMA selective
augur - symptoms– Molecular testing
• PCR amplification of diagnostic small subunit (rDNA)
• PCR amplification of diagnostic microsatellite DNA loci
– Koch’s postulates• Inoculate container-grown
‘Simmonds’ avocado trees with isolates from suspect trees
General location of LW positive swamp bay trees
N. Kendall Dr./SW 88 St.
Krome Avenue/SW 177 Ave./997N
Tamiami Trail/SW 8th St.
Bird Rd./976
LW positive swampbay trees Area of suspect swampbay trees
Canal
Symptoms of laurel wilt (Raffaelea lauricola)
• Leaf and young stem wilting
• Leaf color change from green to dark green, bluish-green, to greenish brown to brown.
• Dead leaves hanging on the tree.
• Stem and limb dieback.
• Commonly sections of the tree show symptoms and other sections do not. Eventually the whole tree shows symptoms.
• Dark black or bluish black streaks in sap wood.
Symptoms of ambrosia beetle (Xyloborus glabratus) infestation
• Look along limbs and/or trunk
• Dried sap
• Sawdust (toothpicks)
• Beetle entrance wholes
Swampbay – just south of mi. marker 20 and between mi. marker 20-21 along SW 177 Ave. (Krome Ave.)
= dying tree
Why is it important to destroy infested swampbay trees
• Infested native trees are a significant reservoir for reproduction of the redbay ambrosia beetle (RAB).
• Evidence suggests the number of RAB that emerge from native trees is hundreds of times greater than from non-native hosts (e.g., avocado).
• The current infestation is very close to Florida’s second largest fruit crop industry, avocado.
• Reducing the RAB population now will provide time to further develop strategies to mitigate and/or control laurel wilt and RAB.