The New York State Departments of Environmental Conservation (DEC) and Agriculture and Markets (AGM), Cornell Cooperative Extension (CCE) of Suffolk County, and the Cornell University Plant Disease Diagnostic Clinic (CU-PDDC) confirmed the presence of the invasive plant disease laurel wilt on Long Island, marking the first discovery of the plant disease in New York State. Originating in Asia and first identified in the U.S. in Georgia in 2002, the disease is deadly to plants in the Laurel family and present in multiple southeastern states, with the northernmost cases prior to New York’s detection in Kentucky and Virginia.
“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 kills trees and shrubs in the laurel family. Laurel wilt 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 the fungal spores. 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.
The Suffolk County case originated when a private landowner in the village of Northport observed a dying sassafras on their property this summer and sent a sample to the Suffolk County CCE to diagnose the problem. Cornell University’s Long Island Horticultural Research and Extension Center then isolated the fungus and CU-PDDC confirmed the identification, followed by confirmation by the U.S. Department of Agriculture’s Animal and Plant Health Inspection Service.
State Agriculture Commissioner Richard A. Ball said, “We’re collaborating closely with our partners to respond to this detection of laurel wilt on Long Island. 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.”
Cornell University Plant Disease Diagnostic Clinic Director Karen Snover-Clift said, “Cornell’s Plant Disease Diagnostic Clinic has been building molecular testing capacity for years and is well-prepared to respond to emerging threats like laurel wilt. The CU-PDDC is proud to serve as the state’s primary laboratory for confirming future samples.”
The loss of sassafras and spicebush could have wide-ranging impacts on southern New York’s forests and wildlife. Both species provide food and shelter for birds, pollinators, and mammals. Spicebush berries are 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. Their decline would reduce forest diversity, weaken natural food webs, and increase native forest susceptibility to invasive plants.
Laurel wilt causes rapid decline in sassafras and spicebush. Signs and symptoms to look for 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.
For members of the public who encounter symptomatic sassafras and spicebush:
- 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.
People often use wood from trees that have died on their property as firewood when they go camping, which can allow invasive pests and diseases to spread long distance in a short period of time. To help stop the spread of laurel wilt and other invasives, follow DEC’s firewood regulations and use local or heat-treated firewood.
Cornell University is hosting an information session on Sept. 10 about the laurel wilt detection. The public is encouraged to attend. To learn more, visit the DEC Laurel Wilt webpage.
