State inspectors are on watch in Houston County to see if the emerald ash borer has invaded Minnesota.
Inspectors from three states are converging near the border where Iowa, Wisconsin and Minnesota meet to look for a tiny, metallic-green beetle that could devastate millions of ash trees. Wisconsin officials confirmed Tuesday that the invasive emerald ash-borer has infested trees in Victory, Wis., about 20 miles south of La Crosse.
The Minnesota Department of Agriculture immediately implemented an action plan and began investigating whether the insect has leapt the border into Houston County, and whether a quarantine may be necessary to contain it.
"It's so close that we really don't want to take chances," said Mike Schommer, MDA spokesman.
Minnesota has about 900 million ash trees, second highest number in the nation after Maine.
Two workers are already looking for damaged ash trees along 5 miles of state Hwy. 26 in the extreme southeastern corner of the state, said MDA entomologist Mark Abrahamson. A half-dozen others from the U.S. Department of Agriculture and Minnesota Department of Natural Resources are expected to join them in the next day or two.
The Wisconsin discovery came after a businessman noticed a half-dozen dying ash trees in Victory and called a state hot line, said Mick Skwarok, plant pest specialist with the Wisconsin Department of Agriculture, Trade and Consumer Protection. A forester from the Wisconsin Department of Natural Resources sent samples to a federal lab in Michigan for analysis and confirmation over the weekend.
"The trees that we've seen appear to be pretty heavily infested, if not standing dead, which means an infestation has been there for a while," Skwarok said.
The poor condition of the trees is similar to those in other states where borers have been living for five years or more, he said.
That's potentially bad news for Minnesota and Iowa, because the beetles could have spread to border areas or even farther.
The beetle was brought to the United States in packing crates from China and discovered near Detroit in 2002.
It has killed more than 20 million ash trees in southeastern Michigan and millions more in several nearby states and Ontario. It first appeared in Wisconsin near Lake Michigan last summer.
The risk is both rural and urban. Ash trees were commonly planted to replace diseased elm trees, and city foresters estimate there are 200,000 ash trees in Minneapolis and 90,000 in St. Paul on public and private land.
To reduce the risk of spreading, Minnesota officials have encouraged citizens to use only local firewood. States with infestations have also established quarantines, which prohibits taking ash firewood, timber, mulch, pallets or nursery stock that might contain beetles out of the county.
Quarantine is a possibility in southeastern Minnesota, depending on whether the beetle turns up, Abrahamson said. It is not active until May, so inspectors are looking for such evidence as dead branches, loose bark and serpentine tunnels packed with sawdust under the bark. Abrahamson and others from Iowa and Wisconsin will tour the infested area this week and coordinate a wider investigation.
The head of a Minnesota House environmental oversight committee brought up the topic on Tuesday during a discussion to consider a measure aimed at protecting forests.
"Once you know that the emerald ash borer is in your neighborhood, you have to move [on it] immediately," said Rep. Jean Wagenius, DFL-Minneapolis.
Staff writer Dave Shaffer contributed to this report. Tom Meersman • 612-673-7388