Firewood Restrictions Remain In Effect To Prevent Spread Of Invasive Insect

Firewood restrictions remain in effect in many Wisconsin counties to prevent the spread of an invasive insect that can kill ash trees.

The emerald ash borer can be found in most southern Wisconsin counties, and north of Highway 29 in parts of Douglas, Sawyer, Oneida and Door Counties.

The small, metallic green beetle came to the United States accidentally in wooden shipping crates from China. It was first discovered near Detroit in 2002.

The emerald ash borer turned up this year for the first time in Ashwaubenon in Brown County, and last year in Stevens Point and Wisconsin Rapids in Portage and Wood counties.

Most of the northern part of the state is free of the bug, except for parts of Oneida, Sawyer and Douglas counties.

Portage County master gardener Nick Schultz said people from southern Wisconsin who own cabins or camp in the north woods could accidentally carry the insect with them.

“There is a restriction on moving firewood, for just this reason,” Schultz said.

It is illegal in Wisconsin to move hardwood firewood from counties infested with emerald ash borers to other parts of the state, unless it is from a firewood vendor certified by the Wisconsin Department of Agriculture Trade and Consumer Protection.

Schultz said the ash borers do most of their damage at the larval stage.

“It’s a small worm that burrows in, so it gets under the bark and it basically sucks out the juice of the tree,” Schultz said.

Lynn Caine, vice president of the Wisconsin Master Gardeners Association, said there are telltale signs when ash trees are infected.

“You’ll find D-shaped bore holes going into your ash tree,” Caine said. “Also, if you start looking at your ash tree and you have woodpeckers in the top, they’re up there because the larvae are already in there.”

Emerald ash borers are tiny, so people usually don’t notice them until it’s too late for the tree.