The state Department of Agriculture has confirmed small infestations of a tree-killing bug called the hemlock woolly adelgid at sites in Emmet, Macomb and Ottawa counties.
The infestations announced Friday are the first in Michigan since one four years ago in the Petoskey area.
The invasive insects have decimated hemlock forests along the East Coast.
The tiny bugs suck sap from young twigs on hemlocks. That causes the needles to dry out and die. The insects have the capability of taking over and killing an entire tree in a matter of years.
Michigan has more than 100 million hemlock trees.
The Holland Sentinel reports workers were combing the forests of Ottawa County's Park Township this week for signs of the bug.