Earlier this year, in the town on Central Islip, the Cornell University Plant Disease Diagnostic Clinic (CU-PDDC) used a new rapid test they developed to identify a small number of oak trees with oak wilt disease on Long Island.

Director of CU-PDDC, Karen Snover-Clift said, this is a significant find and only the second location and third time that oak wilt has been identified in New York state, as it was confirmed in Schenectady County in 2008 and again in 2013. By providing diagnoses and research on plant diseases, he is collaborates closely with the New York State Department of Environmental Conservation (DEC) and the Department of Agriculture and Markets (NYSDAM).

Snover-Clift said “We’ve been fortunate that we’ve caught this infection early. Oak wilt is a huge threat. It is similar to other diseases that people have heard of like Dutch elm disease and chestnut blight, which came in and wiped out all those trees.”

Oak samples were submitted to the Cornell diagnostic clinic by an arborist who was working on a client’s trees on private land this year. So in it he noticed a few oaks were having problems.

He had ruled out a number of other common problems on these oaks and then found CU-PDDC oak wilt identification materials available online, funded through the Specialty Crop Block Grant Program through NYSDAM. NYSDAM also alerted him to send in oak samples to the Cornell clinic for diagnosis.

In April, for the oak fungus, the DEC removed the four trees from the new site that tested positive, chipped them and disposed of the chips.

The DEC has issued an emergency order that establishes a protective zone prohibiting the removal of living and dead oaks, unless the wood has been chipped to less than one inch in two dimensions. Also, the DEC order creates a 150-foot “red oak free zone” surrounding the area where the infected trees were discovered.

The DEC will remove all red oaks in these zones to protect remaining oaks in the area in coming months. Residents have been encouraged to report any sudden losses of oak tree leaves they observe.

There is no known cure for oak wilt, which is caused by a fungus, Ceratocystis fagacearum that gums up and plugs water-conducting vessels in the tree, causing leaves to wilt and fall, leading to the tree’s death.

Snover-Clift said that to educate the public is the best way to prevent the spread of oak wilt.