A tree-killing fungus has been on New Jersey's radar for years, given its presence in neighboring states. But now it's too close for comfort, and state officials are keeping an eye out for signs that it's made its way to the Garden State.

Last week, officials in New York confirmed a breakout of oak wilt disease on Long Island.

"Long Island, being so much closer than other detections, definitely heightens our awareness," said Rosa Yoo of the New Jersey Forest Service within the state Department of Environmental Protection.

Oak wilt has never been detected in New Jersey. But it can be spread by insects, as well as the transport of wood from one location to another, as the fungus can stay alive in dead wood for several months.

It can also spread from tree to tree through the network of roots underground. Oaks' roots, Yoo explained, intertwine with one another and these "root grafts" make it easier for the disease to travel from one tree to the next.

NJ Department of Environmental Protection

Making matters worse, an oak tree's root system has the potential to spread hundreds of feet.

If spotted in New Jersey, the best chance of stopping its spread is by cutting the roots of the infected tree(s), according to Yoo, But the fungus can stay viable in soil for several years, so the replacement of oaks in the affected area would not be recommended for some time.

The fungus attacks all oaks, but the most susceptible are red oaks, New Jersey's official state tree.

"They can die within weeks of infection," Yoo said. Trees of the white oak family can take up to a year to succumb to infection, which leads to leaf discoloration, wilt and then death.

The state does not conduct aerial surveillance specially for oak wilt, but it's on the list of "damage-causing agents" the state looks for each year from the sky.

"If anything looks suspicious, we go on the ground and try to determine what's causing it," Yoo said.

More from New Jersey 101.5: