Emerald Ash Borer Discovered On The East End

Even though an adult emerald ash borer is only a half-inch long, it can wreak havoc on a thicket of ash trees. The larvae of the small green beetle feeds on the living tissue between the bark and the wood, causing the trees to collapse.

Earlier this month, Cornell Cooperative Extension of Suffolk County found larva in an infested tree in Southold. Alongside the research cooperative, the New York State Department of Environmental Conservation is sounding the alarm for residents to keep an eye out for the devastating pest.

The invasive beetle is native to Asia and was first discovered in the United States in 2002 in Michigan. It has since spread to other regions of the country. In New York, the state has devoted $13.3 million in the 2018-2019 budget under the Environmental Protection Fund targeted specifically for mitigating invasive species.

The pest consumes and kills green, white, black and blue ash species, as well as fringe trees. The tree is a common feature of residential landscapes and along roadsides on Long Island. Robert Carpenter, the executive director of Long Island Farm Bureau, said farmers with tree nurseries will likely be the most affected if infestations persist.

“It has been a big concern on Long Island for many, many years,” Mr. Carpenter said. “Up further west, there are a number of ash trees. It is a major pest for us.”

Heavily damaged trees may not be able to recover once the pest is established in an area, according to a DEC release last week. Extension officials say trees within a 15-mile radius are potentially in danger of infestation.

Identifying the emerald ash borer may be difficult in the winter, said Dan Gilrein, an entomologist at Cornell Cooperative Extension of Suffolk County. The insect is usually found from late May to July as the outer tree bark is removed or after woodpecker activity. Larvae attack the upper branches and limbs and then work their way down to the lower trunk year after year. After larvae feed on the water and nutrients inside of the tree, they emerge as adults—with metallic green wings and coppery red or purple abdomens—through 1/8-inch D-shaped holes.

“While this insect will attack young trees in nurseries, I suspect most nurseries had stopped growing ash a few years ago when it was clear planting ash was an unwise choice, seeing how this insect was spreading,” Mr. Gilrein said. “Nurseries that do have ash should certainly consider protections now or in the near future.”

“There is some good news,” he continued. “There are effective treatments for ash trees that generally work well to protect them before they are infested. They may also work on early-stage infested trees if the damage is not severe. … I would strongly suggest homeowners contact a [landscaping] professional to discuss their individual situation.”

The DEC regulates the movement of untreated firewood to prevent the spread of invasive tree pests, and recommends that wood from ash trees that have been infested with the emerald ash borer “be left or utilized on site, or chipped to less than one inch in at least two dimensions to prevent further spread,” according to a statement.

Anyone who suspects a possible infestation is encouraged to reach out to the Cooperative Extension Diagnostic Lab in Riverhead at 631-727-7850. Photographs can be sent to the DEC’s Forest Health Diagnostic Laboratory at foresthealth@dec.ny.gov.