City Enters Third Year of Emerald Ash Borer Battle

Three years since its discovery, the emerald ash borer -- an invasive beetle almost 100 percent lethal to native ash trees -- is still very much around Oak Creek.

The death of ash trees has been slow, however, and that may have lulled residents into a sense of complacency, according to City Forester Rebecca Lane.

But Lane said as the borer continues to plague trees, the city continues its efforts to treat ash trees. Oak Creek is entering its third year of participation in the Legacy Tree Project, designed to protect ash trees, raise public awareness and motivate homeowners to take action before their ash trees become affected.

Through Legacy Tree Project-associated funds, Oak Creek receives five years of treatment for about 125 ash trees.

"It is essential for Oak Creek residents to understand the beetle population has been more than doubling annually, bringing the region to a tipping point," Lane said. "Ash trees are under mass attack, and most untreated trees in the area are likely to die in the next five years."

EAB was first discovered in Oak Creek, which has thousands of ash trees, in 2009. Now, it should be assumed that all untreated ash trees in the city have some level of infestation and damage, Lane said.

"Many ash trees will look fine one year and barely leaf out the next, leaving no other option but chainsaw management," Lane said.

"Dead or dying ash trees and forests can be seen throughout the city. A drive through Oak Creek on I-94 is telling of the EAB invasion."

About 2,000 ash trees have been removed since 2009, and another 700 are under city-funded treatment. The city is working to install replacement trees in a timely fashion, according to a news release.

Residents who own ash trees should act now, Lane said. Arborists certified by the International Society of Arboriculture can help guide decisions about treatment, removal or an integrated plan using both approaches.

“If you own ash trees, there is no getting around the fact that EAB will cost you money," Lane said. "Skilled, thoughtful planning can prevent the high, safety-related costs associated with dead tree removal."