Region's Trees Vulnerable to Emerald Ash Borer: UConn Experts

STORRS, CT — A cute little bug named the emerald ash borer has staked a claim to trees in north central and eastern Connecticut and it could change the landscape over the next few years, University of Connecticut forestry experts are saying.

To illustrate that point, one university official took a break from watching the eclipse on Horsebarn Hill to point toward the treeline at the far end of the hill, looking away from the UConn Dairy Bar.

"That could all be gone," the professor said.

Tree experts at the university said changes are already "evident."

The borer belongs to a family known as jewel beetles and are actually nice to look at, professors said. But after hatching from inconspicuous eggs laid on the tree’s trunk, Borer larvae chew their way through a tree’s actively growing outer layer just beneath the bark, an area called the cambium, which promotes annual growth rings, a vital area for the transportation of water and nutrients throughout the tree, UConn experts said.

The tunneling cuts circulation to areas of the tree both above and below the damaged tissues and if enough larvae feed on a tree at once, the tree can die in as little as two years, UConn experts said.

The adult Borers are only three-eighths-of-an-inch to to a half-inch long, a sixteenth-of-an-inch wide, and live for just three to six weeks and are rarely seen, according to UConn experts. The larvae are 1.5 to 2 inches long, and feed on ash bark for one to two years, UConn experts said.

The Emerald Ash Borer is native to northeastern Asia. Since it was first detected in North America in 2002, it has left millions of dead trees in its wake as it spread across the country, finally arriving in Connecticut in 2012.

“The Ash Borer has devastated the ash population,” said UConn arborist John Kehoe. “Until recently, the Borer hadn’t been reported in Mansfield, but it’s making an impact now. We especially need to watch out in the UConn Forest.”

Forests are more susceptible and some thinning is OK in the long run, experts said. UConn arborists said they have been keeping a close eye on the situation and have administered annual preventive treatments to protect the many notable specimen ash trees, including the beautiful, old tree beside the UConn sign on Route 195, across from Moulton Road, on the approach to campus from the north.

Homeowners should also keep an eye on any ash trees they may have. Bill Bates, another University arborist, recommends looking for wilted leaves and woodpecker damage on the tree limbs or trunk, as both are possible signs of Emerald Ash Borer activity. If an infestation is suspected, it’s best to call an arborist who can treat the tree appropriately. In addition, the UConn Center for Land Use Education and Research encourages anyone who finds the insect or evidence of an infestation to inform the state entomologist.

The outlook for individual ash trees is more hopeful than for those that are clustered in a forest.

“Treating individual trees on campus is fairly inexpensive, but in the case of thousands of trees, like in the UConn Forest, it simply isn’t feasible,” Kehoe said. “We’ll have to see what happens. Hopefully a biological control will come along, like we saw with the fungus for the gyspy moths.”

Photo Credit: U.S. Department of Agriculture