An invasive fungal disease that targets trees and shrubs in the laurel family was detected for the first time in New York in July, according to the state Department of Environmental Conservation.
The disease, called laurel wilt, was discovered in the village of Northport, Long Island, when a homeowner sent a sample of their dying sassafras tree for testing at Cornell University’s Plant Disease Diagnostic Clinic.
“The detection of laurel wilt on Long Island marks a troubling new chapter in the spread of this invasive plant disease,” DEC Commissioner Amanda Lefton said. “DEC is collaborating with our conservation partners to understand the extent of impacted trees, evaluate control options, and launch public outreach to increase awareness about laurel wilt and how to report it.”
Laurel wilt is a fungal pathogen that is spread by the invasive redbay ambrosia beetle, which introduces the fungus when it tunnels into the stems and branches of host plants, leaving behind spores, DEC said.
Originating in Asia and first identified in the U.S. in Georgia in 2002, laurel wilt is now widespread in many southeastern states. Prior to New York’s detection, the northernmost cases were in Kentucky and Virginia.
In New York, native species at risk are sassafras and spicebush. Despite its name, mountain laurel is not in this family and is not impacted by the disease.
However, the loss of sassafras and spicebush could have wide-ranging impacts on southern New York’s forests and wildlife, DEC said. Both species provide food and shelter for birds, pollinators, and mammals.
Spicebush berries are also a critical fall food source for migratory birds, while the leaves of both spicebush and sassafras support the larvae of native butterflies such as the spicebush swallowtail, DEC said.
The decline of either of these plant species would reduce forest diversity, weaken natural food webs, and increase native forest susceptibility to invasive plants, DEC said.
“We’re collaborating closely with our partners to respond to this detection of laurel wilt on Long Island,” state Agriculture Commissioner Richard A. Ball said. “As we continue to learn more about the spread of this harmful plant disease and how to control it, we’re also working to increase awareness of this find and encouraging the public to report any sightings.”
Signs and symptoms of laurel wilt include:
• Sudden wilting of leaves;
• Dark streaking of sapwood beneath the bark; and
• Small entry holes on the branches, trunk, or roots, which are sometimes surrounded by fine sawdust-like “toothpicks” pushed out from the bark.
If you encounter sassafras or spicebush showing these symptoms:
• Submit a report through nyimapinvasives.org; and
• Do not move or transport branches, trunks, or bark from symptomatic sassafras or spicebush, even for disposal. Chip dead wood and use it as mulch on-site.
To learn more, visit DEC’s laurel wilt webpage