DULUTH, Minn. (AP) -

The discovery of the emerald ash borer in northwestern Wisconsin has led to a quarantine on transporting wood that could become an issue for Minnesota mills.

A Minnesota Public Radio report says the quarantine prohibited moving firewood from outside of Wisconsin's Douglas County. But it's also kept the region's timber industry from transporting unprocessed ash trees.

Jon Harris of the county's forestry department says loggers and mills alike will feel a level of pain from the quarantine.

The Sappi mill in Cloquet, Minn., has stopped buying Douglas County ash for now. Mill manager Gary Erickson says a limited quarantine is manageable, but there could be challenges if the quarantine area expands.

Duluth officials say it's only a matter of time before the invasive insect crosses into Minnesota.