Control of tree-destroying insect sought

The emerald ash borer, known for its metallic green color, is only about one-third of an inch long.

UNION COUNTY, NJ — Local authorities are partnering with JCP&L in an attempt to control the spread of an invasive insect by removing adult ash trees in northern Union County.

Summit is joining with JCP&L to remove 80 ash trees — one on Constantine Place and others on private properties — and treat others with pesticides during the next few months, according to a recent press release from the city of Summit.
The county will also be removing dozens of trees along county roads in Berkeley Heights, New Providence and Summit with JCP&L due to the infestation.

“As of now, there is minimal damage to our parks system,” Union County spokesman Sebastian Delia said in a Feb. 27 email, adding that there are no current plans to remove ash trees from the parks, even Watchung Reservation which borders Summit.

The target of the program is the emerald ash borer beetle, which has destroyed tens of millions of ash trees since its arrival in the United States in 2002, according to the state Department of Agriculture. The bright metallic green insect, which is only about one-third of a inch long, has recently been identified in Union County for the second year in a row.

The female beetle lays its eggs under the crevices of ash trees, and its larvae feed underneath the bark. It was first detected in New Jersey in the spring of 2014, and has since been discovered in 15 counties throughout the state, including Union County, according to the NJDA.

There are about 350 ash trees in Summit, according to city forester John Linson, and the first infected tree was identified in early February on Canoe Brook Parkway.

“There was one tree that was infested and that is an indication that others will be compromised as well,” Linson said in a Feb. 28 email to LocalSource.

The trees being treated with insecticides are located in the downtown area in planting pits, so they are able to be closely monitored.

“Summit loves its trees and we always try everything we can to preserve them. Removal is the last resort,” Linson added.
The city will also plant up to 70 trees this spring in the public right-of-way, according to Summit spokesperson Amy Cairns, but residents will need to request that a tree be planted in the right-of-way adjacent to their property.
Officials from Berkeley Heights and New Providence did not respond to requests for comment, so it is unclear whether more trees will be removed from those municipalities.

Infested ash trees have not been identified in the neighboring borough of Mountainside, according to Ronald Romak, the municipality’s director of public works.

“Most of our town shade trees along rights of way tend to be sycamore, pear and maple,” he said in an email on Feb. 26.
The beetle only infests ash trees, so other tree species will not be affected. There are approximately 24.7 million ash trees in New Jersey, according to the NJDA. Ash trees, which are native to the Garden State, have leaves composed of five to 11 leaflets and a distinct, diamond-shaped bark pattern in mature trees. There are 16 species of ash trees found throughout the state.

The emerald ash borer was first reported in the U.S. in 2002, and was believed to come from Asia tucked away in wooden shipping pallets, according to local arborist Bob O’Rouke. He said that one of the earliest signs of an infestation is increased woodpecker activity around a tree, as the beetle’s larva are a source of food for the bird.

“An ash tree has a darker-type bark but when the woodpeckers come to try and get the larva that were laid in the tree, the outer layer will fall off and it’ll have a tanner appearance,” O’Rouke said.

Other signs of infestation include yellow, thin or wilted foliage especially in the upper canopy of a tree, D-shaped beetle exit holes and shoots growing from roots or a tree’s trunk, he added.

It can take anywhere from six to 18 months for the beetles to completely infest and ultimately kill a tree by severing its vascular tissue, according to Linson.

Both Linson and O’Rouke said it is important to choose a proper replacement tree — such as white oak or sugar maple — for the ash.

“You really need to pick something that has very little insect or disease problems or structural problems,” O’Rouke said.