ALLEGAN COUNTY, MI -- West Michigan foresters are investigating the discovery of an invasive insect that helps cause the death of hardwood American beech trees.

The Gun Lake Tribe says that beech scale, an exotic pest that has helped kill millions of Michigan beech trees, was recently found on tribal land in Hopkins Township. The tribe issued a notice about the discovery on Monday, Feb. 9.

Environmental staff "may have identified this problem early enough to prevent further infestation," said D.K. Sprague, Gun Lake Tribe chairman.

Together, beech scale and an exotic fungus called Neonectria faginata infest stands of beech trees, leading to the fatal Beech Bark Disease (BBD).

The disease itself has not been confirmed on the tribal land, but where the scale is found, BBD usually follows, said Allegan Conservation District forester Shawn Kelly.

Allegan is the southernmost Michigan county where the scale insect or disease has been found, said Kelly. Last year, infected trees were discovered in Kent County.

The tribal land samples were sent to Michigan State University and the Michigan Department of Natural Resources for analysis.

The disease has been around Canada and parts of the U.S. for more than a century. It was discovered in Michigan in 2000 and is most prevalent in the Upper Peninsula.

There are 32 million American beech trees in Michigan, according to the DNR. About 2.5 million have died from the disease and that number is expected to climb.

Infestation occurs when scale insects colonize and eat into beech bark, wounding the tree with feeding holes by which fungus enters the trunk. Infected trees appear "whitewashed" as the insect population grows.

Infected trees eventually die within three to six years. Brittle trees will break in heavy winds before dying, a condition known as "beech snap." Infected trees are removed from state parks and campgrounds to prevent them from falling.

"BBD is in a lot of places across the state," said Ron Murray, DNR forest health unit manager. "We're finding it more along the Lakeshore as it goes further south."

The disease can spread by several vectors. The insects can be wind-dispersed, or carried around by animals. Moving beech firewood in spring and early summer is discouraged due to the greater potential for spread at that time.

"Wildlife spread it. Birds spread it," said Murray. "We haven't found anything yet to stop it."

Michigan has 7 million acres of beech-containing forests. The DNR began experimenting a few years ago with planting naturally disease-resistant trees in seedling orchards in an effort to develop genetically resistant trees.

It's a "very long term" solution for saving the American beech species, said Murray.

The genetic research happening in an Ohio lab is promising, he said. However, "there will be a lot of trees killed in the meantime, I'm afraid."

Landowners who find beech scale are highly encouraged to contact their local conservation district or DNR office. Telltale signs includes a whitewashed appearance of the tree trunk, beech snap, black secretion from lemon shaped sores, other discolorations, or wilting of branches or the trunk.

The DNR says that infested beech wood retains some value if harvested early.

"While beech bark disease can be a very damaging agent, it is a relatively slow-moving complex," wrote DNR forest health specialist Roger Mech. "This provides land managers options that are not available in dealing with other, more aggressive organisms like oak wilt and emerald ash borer."

The Allegan Conservation District will do on-site exams free-of-charge.

Garret Ellison covers business, government and environment for MLive/The Grand Rapids Press. Email him at gellison@mlive.com or follow on Twitter & Instagram