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The Michigan departments of Natural Resources and Agriculture and Rural Development today announced the addition of beech leaf disease to the state's invasive species watch list. Invasive species on the watch list have been identified as posing an immediate or potential threat to Michigan's economy, environment or human health. These species either have never been confirmed in the wild in Michigan or have a limited known distribution. Beech leaf disease is associated with the microscopic worm Litylenchus crenatae, a nematode that enters and spends the winter in leaf buds, causing damage to leaf tissue on American beech and European and Asian beech species. Infestations result in darkened, thick tissue bands between leaf veins, creating a striped effect on the leaves, leaf distortion and bud mortality. Trees weakened by leaf damage become susceptible to other diseases and can die within six years. Beech leaf disease has not been found in Michigan. The disease was first discovered in Ohio in 2012. Since then, it has been identified in seven eastern states and Ontario.
Beech leaf disease has now been confirmed in Prince William County – the first detection in Virginia. The disease affects American beech (Fagus grandifolia) trees and is associated with a foliar nematode. Symptoms include dark stripes between leaf veins, thickening and curling of leaves, and canopy thinning. Contact VDOF's forest health program if you see these symptoms. For more information, view this Beech Leaf Disease Pest Alert (Jan 2021) [PDF, 312 KB] publication.
This concise publication gives useful information for homeowners, master gardeners, and professional landscapers about the boxwood blight disease: its symptoms, sanitation measures when it is discovered on a property, and preventive measures.
California Department of Health Services; California Department of Food and Agriculture; Mosquito and Vector Control Association of California; California Vectorborne Disease Surveillance System.
Louisiana State University. AgCenter Research and Extension.
Citrus canker, a serious disease of citrus, was recently found on trees in East Baton Rouge and Livingston parishes, according to LSU AgCenter plant doctor Raj Singh. Citrus canker is a highly contagious bacterial disease that was first detected around 1914 in Louisiana and declared eradicated by 1940. The disease is known to cause defoliation, premature fruit drop, blemished fruit and tree decline. Severely infected trees ultimately may stop producing fruit. If you believe your citrus trees have citrus canker, contact the U.S. Department of Agriculture at 225-298-5410 or the LDAF Horticulture and Quarantine Division at 225-952-8100.