The first case of emerald ash borers emerging this spring was found the week of April 16 in Jefferson County. Since the borers do not emerge all at once, owners of ash trees need to watch for signs of the pest during the next three to four weeks, said Lee Townsend, extension entomology professor in the University of Kentucky College of Agriculture.

The borer’s emergence is almost three weeks ahead of normal due to the mild winter and a very warm March, Townsend said.

A small, dark-green metallic beetle, the emerald ash borer attacks all species of ash trees. The larvae burrow into the tree to feed beneath the bark, destroying the tree’s ability to transport water and nutrients to its canopy. This can cause die-back of the top of the canopy within a year or two and ultimately kill the tree.

Once adults emerge from the trees, they immediately fly up to the topmost leaves to get direct sunlight and feed on the foliage for about a week. Mating and egg-laying will begin about two weeks later. Adults will be active through June, Townsend said.

Owners of ash trees may find it difficult to spot the borers because of their size and preference for the topmost foliage, but they can find evidence of the insect by inspecting their ash trees for any D-shaped holes in the bark. The adult borers make these holes when exiting the tree in the spring. Owners of ash trees can also look for uneven notches on the edges of the tree’s leaves as a sign that the insect has been feeding on them.

Those who suspect they have an emerald ash borer infestation should contact the Kentucky Office of the State Entomologist at 859-257-5838.

Individuals can get more information on the emerald ash borer from the local office of the UK Cooperative Extension Service or on the UK emerald ash borer website http://pest.ca.uky.edu/EXT/EAB/welcome.html.