Weather Forecast


Keep ash borer plans in spite of cold weather

DNR Division of Forestry

A forest health expert says the ongoing frigid air hugging the state is not enough to wipe out the tree-killing pest known as emerald ash borer.

It seems these guys have figured out how to take winter’s cold shoulder.

Bill McNee of the Department of Natural Resources says experts predict that many EAB larvae will die, but the ash tree pest isn’t going away. Their native habitat in eastern Asia experiences cold winters and the pest is adapted to them.

“They are somewhat protected beneath the tree bark and many of them will survive the recent cold temperatures,” McNee says. “It will be a little warmer beneath the bark than the outdoor air temperature, and the wind chills do not affect them because they are sheltered.”

McNee says experts predict that populations of the pest are likely to rebound this summer, since each female beetle that emerges this summer will lay 50-100 eggs.

At this point, it is not known if larval mortality will have any significant impact on Wisconsin’s ash trees or significantly delay ash tree mortality. Forestry experts do not recommend changing EAB management plans because of the cold weather.

Continue to look for EAB in ash trees. Woodpecker damage is a good sign that an ash tree is infested with EAB or other pests.

Insecticide treatment of high-value ash trees near known infestations should continue this spring.

Don’t delay tree removals or timber harvests that are already scheduled. Giving non-ash tree species more time to grow means that the future impacts of EAB will be reduced.

Continue planting non-ash tree species.

Douglas County falls under special quarantine rules after the beetle was discovered in Superior last summer.

To help slow the spread of the beetle, buy firewood in the local area where you plan to burn it, or buy Wisconsin-certified firewood that has been treated to eliminate pests.

Additional information about Emerald Ash Borer, insecticide treatments and forest management can be found online at