News Neighborhoods

Clash With the Ash: Tree-Killing Ash Borer Finally Reaches Eau Claire County

Lauren Fisher |

Eau Claire County residents can no longer transport firewood in or out of the area upon the discovery of emerald ash borers in a local tree. The ash borer is a species of iridescent green beetle that kills ash trees. The beetles themselves eat foliage, causing little harm. The larvae, however, feed on the inner bark of the trees, which damages the plant’s ability to transport water and nutrients throughout its system. Infestations are generally difficult to detect until the tree is beyond saving. In recent years, the insect has gradually spread across most of Wisconsin’s counties, including Chippewa, Buffalo, Trempealeau, and Jackson.

Arborist Lucas Stelter recently discovered the infested tree on the UW-Eau Clare campus just south of Water Street. He noticed extensive woodpecker damage caused by the birds eating the larvae.  Other signs of infestation include drying or thinning of tree crowns, D-shaped exit holes on the trunk, splitting bark, and tunneling marks under bark.

The City of Eau Claire has been preparing for the arrival of the emerald ash borer for the past five seasons. The city has made efforts to plant a diverse range of tree species in public spaces, and developed a plan to selectively treat and remove affected trees.

“Ash trees will die due to this insect, unless they are chemically treated with insecticides,” a Dec. 4 press release from the City of Eau Claire said. Residents with ash trees may consider treating them with pesticides in order to stave off infestation. Products are available for homeowners to handle the issue themselves, although larger trees might merit the attention of a professional.

Affected trees may pose risk of injury as their branches weaken and potentially fall off.  Proper disposal methods of infested trees include chipping to pieces ½ inch or smaller, burning, or covering cut wood to dry for two years.

More information on the emerald ash borer can be found at

Image: Howard Russell/Michigan State University