Oak Wilt Update for Southold Newsletter

Oak wilt, a deadly fungal disease for oak trees was discovered in six new locations in New York last year including Southold.  All oaks are susceptible to the disease, but oaks in the red oak family (leaves with pointed lobes) may die from the disease within weeks.  White oaks (leaves with rounded lobes) will likely also die of the disease, but can take years to die of the disease. The disease blocks the flow of water and nutrients from the roots to the crown causing leaves to wilt and fall off during the growing season. 

The first way the disease spreads is through specific types of beetles.  Fungal spore mats form just under the bark of infected red oaks after they have died from the disease. During the warmer months, these spore mats emit a sweet odor that attracts sap-feeding beetles and bark beetles, which can pick up fungal spores as they crawl around. The beetles are also highly attracted to fresh wounds in other trees—often caused by pruning. In this way, they spread the fungus from infected trees to healthy trees sometimes miles away. Infected firewood and other wood materials also pose a threat because they can harbor the fungus and/or beetles that can spread the disease.  The disease can also spread through root connections between oaks that occur underground.

In Southold, NYS DEC has confirmed one tree infected with oak wilt.  This tree has been removed and sanitized properly by being chipped on site.  The department will continue to monitor this area through aerial and ground survey detection for the next 5 years.

Symptoms of oak wilt are best observed during the summer. Learn to identify the symptoms of oak wilt which include discoloration around the entire leaf edge and sudden loss of a substantial portion of leaves during the summer. For questions, contact the DEC Forest Health Forestry Technician, Jennifer Kotary at (518) 410- 6360, or email photos of tree symptoms to: foresthealth@dec.ny.gov.