Ash borer difficult to detect
In the past few days, area residents have become aware that an invasive beetle known as the emerald ash borer has been found in Butler County.
A relative newcomer to the United States, detected in Michigan in 2002, the beetle is native to Asia. In addition to spreading by natural means, the borer can be transported in infested firewood, timber and nursery stock. In Michigan alone, the emerald ash borer is responsible for the loss of more than 7 million ash trees.
The beetle is known to infest all species of ash. Eggs are laid between layers of bark and in bark crevices. The larvae hatch in about a week and bore into the tree, feeding on the inner bark and phloem. They create distinctive "S"-shaped galleries in the inner bark. They overwinter and emerge as adults through "D"- shaped exit holes in May and June. Adults are active through the end of summer.
New infestations are difficult to detect. Damage to the tree may not be evident for three years. Signs of an older infestation can include branch dieback in the upper crown of the tree, excessive branching of the tree trunk, vertical slits in the bark and woodpecker damage.
Other factors such as drought may also cause stress to ash trees. A native insect pest, the redheaded ash borer, can also cause damage.
The emerald ash borer is distinctive in color and shape. If you think that you have found the beetle, report it by contacting the state Department of Agriculture or the state Department of Conservation and Natural Resources.
You may also contact the Butler County Extension Office at 724-287-4761 or e-mail ButlerExt@psu.edu. Copies of a color brochure showing pictures of the beetle and examples of damage to ash trees are available to help with identification.
This material is submitted by Donna Zang, Extension director, and the staff of the Penn State Extension office at the Sunnyview complex.
