GRAND RAPIDS, Mich. (WOOD) — The Michigan Department of Natural Resources has added two new invasive species to the state’s watch list and removed another.
One of the new threats is the mountain pine beetle, described as an aggressive and destructive bark beetle commonly found across the western United States and Canada. Hot and dry summers, along with mild winters, have helped the insect expand its range, creeping closer to Michigan.
“It’s a very, very aggressive beetle that attacks all types of pine,” said Joanne Foreman, Invasive Species Communications Coordinator for the DNR. “The pine beetle bores into the bark of pine trees, and once there is a good colony of those beetles that are investing the tree, the tree will eventually die. There is currently nothing we can do to save a tree from Mountain Pine Beetle.”
Susie Iott, an invasive species program specialist with the Michigan Department of Agriculture and Rural Development, says the beetle attacks several pine species, including one that serves as key habitat for a threatened bird.
“White and red pines are primary species in our forest ecosystems, and jack pine serves as critical habitat for the Kirtland’s warbler,” Iott said in a statement. “If the mountain pine beetle were to become widely established in Michigan, it would cause severe losses across multiple industries, including timber products, plant nurseries and tourism.”
Mountain pine beetles typically move by being transported on logs and firewood. MDARD issued a quarantine on any firewood or bark-lined pine products from the western U.S. and Canada in 2020.
“We are very concerned this time, because of our pine forest,” said Foreman. “Obviously in Michigan, we have lots of pine, across the state, really in our Northern and UP areas especially, but we also have a very large forest industry that relies on things like our different pine species.”
The other threat is water-primrose. It’s an aquatic plant native to the southeastern United States and was first used in ornamental landscapes. Now, they have spread to wetlands, establishing dense mats along shorelines, stealing resources from native species.
“The problem is that these can spread very rapidly,” said Foreman. “They’re one of those plants that grows across the surface of the water near the shoreline. And that means they’re crowding native plans. They’re also getting in the way of boating and fishing, and a lot of other reasons we use the water.”
There are established populations in four counties across Michigan, three in metro Detroit and Ottawa County.
“(Those populations) indicate the species can survive and thrive in Michigan’s climate,” the DNR said in a statement. “Once established, water-primrose can be very difficult to remove, making early detection critical.”
The DNR says herbicides can be effective against water-primrose, but only if detected in an early stage.
Another invasive plant has been removed from the state’s watch list — not because it has been eradicated but because it is now established widely across Michigan.
European frog-bit now has established populations across six states, plus Quebec and Ontario. It is now commonly found along the coasts of Lake Erie and Lake Huron and inland lakes and ponds across the state — including stretches of the Grand River in Ottawa County.
Like water-primrose, European frog-bit grows in dense mats along the surface. It can slow down boat traffic and cut down the amount of oxygen and light in the water column, which impacts the food chain for waterfowl and fish.
Despite being removed from the invasive species watch list, the European frog-bit remains a prohibited plant, making it illegal to possess, introduce, import or sell in Michigan. State and local management groups will continue efforts to remove known populations of the plant.
“It’s just been critically essential to what we do, to make sure people are aware and can report easily to us,” explained Foreman.
— News 8’s Taylor Morris contributed to this report.