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Oak Wilt

Oak wilt has been detected in Central Islip, Long Island. A tree care professional noticed the wilting leaves on pin oaks and contacted state officials. Four small trees tested positive in June for the fungus. View the Order (PDF, 540 KB) that establishes a protective zone around the infestation and prohibits the movement of oak out of this infected neighborhood.

Oak wilt is an aggressive disease that affects many species of oak (Quercus spp.) It is a very serious tree disease in the eastern United States, killing thousands of oaks each year in forests, woodlots, and home landscapes.

a graphic comparing the oak wilt symptoms of white oak and red oak
Symptoms of oak wilt in
A. white oak and
B. red oak.

Oak wilt was confirmed for the first time in New York State, September 2008, in Glenville, Schenectady County. In 2009, 73 infested or likely to become infested trees were destroyed. Additional infected trees were found in September, 2013. View the November 2013 Emergency Order (PDF, 217 KB) outlining the protective zone for this infestation.

Oak wilt is caused by a fungus, Ceratocystis fagacearum. The fungus grows in the water-conducting vessels of host trees and as it does, it causes the vessels to produce gummy plugs that prevent water transport. As water movement within the tree is slowed, the leaves wilt and drop off, and eventually the tree dies.

Oak wilt is known to attack all species of oak but kills red oaks quickly; it has been known to kill trees within a few weeks following infection. White oaks on the other hand may survive many years following infection.

To report oak wilt, email the DEC Forest Health office or call 1-866-640-0652.

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