The Michigan Department of Agriculture says it's focusing attention related to the tree-killing emerald ash borer on preventing it from spreading further in the Upper Peninsula.
The state, on Monday, revised its quarantine related to the exotic beetle to consolidate Lower Peninsula counties into one level from two.
The change allows people to move firewood in the Lower Peninsula, but the state asks people not to do so to help prevent the spread of other exotic pests. A ban remains on moving firewood across the Mackinac Bridge.
Ken Rauscher, director of the Plant Pest Management Division, says the department is committed to protecting the Upper Peninsula from the ash borer's spread.
The beetle has devastated tens of millions of ash trees in eight states.