AUGUSTA — Many people travelling in Maine and beyond have taken note of strange purple objects strung in trees alongside the road, traps to help detect a small emerald-colored beetle, the emerald ash borer.

“Emerald ash borer is a grave threat to ash trees across the continent and in Maine,” Maine State Entomologist Dave Struble explained. “Our ash trees appear to have no native resistance, and the borer kills trees very quickly. This is why we need to know if the borer is here.”

The emerald ash borer is native to Asia and probably hitched a ride to our country on crates, pallets or other solid wood packing material. Initially detected around Detroit in 2002, emerald ash borer now has established infestations in 15 states from Minnesota to New York, and as far south as Tennessee, as well as in the Canadian provinces of Ontario and Quebec. Its rapid spread has been attributed to movement of infested firewood and nursery stock. Although the adult beetle does little direct damage to the host trees, the immature insects, small white larvae, chew meandering tunnels under the bark, cutting off the vital flow of water and nutrients. Trees die in as little as three years after attack.

This year, Maine has deployed 200 traps, up from 50 in 2010.

“We target areas with high risk of introduction of emerald ash borer and important ash resources with the traps.” said Karen Coluzzi, survey coordinator for the Maine Department of Agriculture. “These include campgrounds, nurseries, traffic corridors and high-value stands.”

The traps, triangular prisms about two feet long and one foot wide on each side, are coated with a non-toxic glue that will ensnare adult beetles. Lures that are attractive to the insect are attached inside the trap. Traps are then hoisted into the canopies of ash trees because this is where EAB adults prefer to spend most of their time.

“The traps do not pose a risk to humans, pets, or wildlife, however, they are extremely sticky,” explained USDA State Plant Health Director, Terry Bourgoin.

“The purple traps are one way we look for emerald ash borer,” said Struble. “We also use girdled ash trees and biosurveillance with a native wasp. Even with all these monitoring programs, we still rely on a concerned, aware public to cover the ground our monitoring efforts cannot reach.”

For more information on emerald ash borer, go to www.maineforestservice.gov/EAB_ID.htm. To report a damaged trap in Maine, contact USDA APHIS PPQ at 848-5199. To report suspected emerald ash borer or its damage, contact Maine Forest Service: 287-2431 or 800-367-0223, [email protected].