Officials say that discovery of tree-killing insect in village shows that infestation is continuing throughout county
The emerald ash borer, a small green beetle that has killed numerous ash trees in the area since it was first detected in Wisconsin in 2008, has now been found in the Village of Fredonia.
It’s the fourth community in the county in which the insect has been found — and evidence the borer is continuing its relentless march across the area, officials said.
“It’s very likely the emerald ash borer is widespread over most of Ozaukee County,” said Bill McNee, a forest health specialist with the Department of Natural Resources. “The population has exploded over the last year.
“I’ll bet it’s in Saukville, and probably in Grafton, Cedarburg and Mequon, too. They’re surrounded by places that are infested.”
The borer previously was found in the towns of Saukville and Fredonia, Village of Newburg and City of Port Washington, and on Friday, McNee confirmed its presence in a dead tree near the Oakwood Forest lift station on Ridgeway Circle in the Village of Fredonia.
“I’ve been driving around today looking at ash trees,” Public Works Director Roger Strohm said Tuesday.
Strohm said the borer had likely been in the tree for some time, noting the insect had created galleries — tunnel-like passages under the bark — from the top of the tree to the ground.
At least one larvae was found in the tree as well, he said.
“We had expected to find it sooner or later,” Strohm said, noting the borer was discovered in the Town of Fredonia about a mile south of the village last year.
“I was crossing my fingers not to find it yet, but I was expecting that, if not this year, we would find it in the next year or two.”
Strohm said he and McNee drove through the village looking at ash trees after an Arbor Day presentation Friday.
They saw several suspicious trees on private property on the north end of the village, then headed to the lift station site so they could check trees on public property.
When they peeled back the bark on the dead ash, they discovered the tell-tale galleries underneath, Strohm said.
McNee said Tuesday that a number of trees on nearby properties also show signs of the borer.
“It’s pretty likely the bug is all over the village,” he said.
Ozaukee County Agricultural Agent Dan O’Neil agreed, saying Tuesday that the announcement that the borer has been discovered in yet another community is one that’s likely to be repeated.
“It’s no big surprise. It’s not a question of if we find it, it’s when we find it,” he said. “I fear this will not be the last time we hear this. This is going to be a story we repeat. I’m assuming it’s in a lot more sites than have been confirmed.”
The borer is a native of China that’s believed to have hitched a ride to this country on wooden pallets and crates. Since it was first detected in Michigan in 2002, the borer has relentlessly marched across the country, killing tens of millions of ash trees along the way.
Strohm said the Village of Fredonia will start treating significant ash trees in its parks this spring.
“We’ll remove some public ash trees,” he said. “The real nice ash trees, we’ll treat.”
The village will also likely start an adopt-an-ash program similar to those run in other communities, where people can pay to treat trees they are fond of, Strohm said.
The village is fortunate, he added, because there are only 70 to 80 publicly owned ash trees along the streets and in the parks.
“They only make up about 10% to 15% of the village’s trees,” Strohm said.
Last year, the village received a $21,500 Urban Forestry Grant from the DNR to initiate an action plan against the borer and update the community’s forest management plan, he said — a process that’s under way.
The Fredonia Public Works Board will likely discuss the borer and the village’s response when it meets next week, Strohm said.
The village is also expected to set up a public informational meeting to update residents on the situation, ways to detect the insect and potential treatments for the borer, he said.
Tell-tale signs of the borer include dead branches near the top of a tree or wild, leafy shoots growing out of the lower trunk, as well as D-shaped exit holes and bark splits that expose S-shaped tunnels.
Serious woodpecker damage is another sign.
While the tree where the borer was found didn’t have the D-shaped exit holes that are considered a hallmark of the insect, McNee said he’s seen that happen before.
The tree was probably only lightly infested last year, when the drought left the host tree stressed and less resistant. When the eggs laid by the borers last year hatched, they were able to decimate the tree easily.
“Because the trees can’t fight them, the population just exploded,” McNee said. “The trees seem to be covered, head to toe, in one season.”
But the cool weather this spring means the young generally haven’t left the tree yet, so there are few to no exit holes, he said.
One of the best ways to detect the borer now is the presence of woodpeckers and woodpecker flecking, McNee said.
“The woodpeckers have turned out to be good detection devices,” he said.
As a general rule, McNee said, if trees are less than 50% declining, they can still be treated with insecticide to fight the borer.
“If the trees were healthy last year and you’re not seeing woodpecker flecking on the branches, you can probably successfully treat the trees,” he said.
“They (insecticides) will do a very good job of protecting the trees even as neighboring trees die.”
People can treat trees themselves or hire an arborist to do the work, he said, although he recommended property owners consult an arborist to determine just how infested their ash trees are before starting treatment.
A good resource for people is the website www.emeraldashborer.info, McNee added.
Image Information: THE DISTINCTIVE GALLERIES left behind by emerald ash borer larvae were revealed by officials from the Department of Natural Resources in a tree in the Village of Fredonia last week, proof the invasive beetle is infesting ash trees there.