Michigan warns residents to report invasive Asian longhorned beetle

• Asian longhorned beetles are known for attacking hardwood trees 
• They create tunnels inside of tree trunks during their larval stage and chew their way out as adults 
• Residents are advised to report the invasive bugs by calling the U.S. Department of Agriculture’s Asian longhorned beetle hotline

Michigan state officials are warning residents to be on the lookout for an invasive, non-native beetle that is known for attacking 12 types of hardwood trees, some of which are found in the state. 

The U.S. Department of Agriculture’s Animal and Plant Health Inspection Service is advising residents to check their trees for the Asian longhorned beetle —  a black, shiny insect with white spots and black and white antennae — especially in August, which the USDA had designated Tree Check Month. 

The invasive insect is known for attacking 12 different types of hardwood trees including willows, birches and its favorite, maples, according to the Department of Environment, Great Lakes, and Energy. In Michigan, there are over 1 billion maple trees.

During their larval state, Asian longhorned beetles create tunnels in tree trunks and branches and then chew their way out of them when the insects reach adulthood during the summer. 

Related:

• Michigan officials ask for federal disaster declaration for cherry industry
• Moose bone study in Michigan offers insight into aging: Turns out, it stinks
• Federal money to help Michigan begin slow work of rare turtle counts

While Asian longhorn beetles have not been spotted in Michigan yet, state and federal agencies are urging residents to check for signs of an infestation, which can prevent damage to urban landscapes and maple syrup production. 

“It doesn't have predators,” said Nathaniel Walton, consumer horticulture educator at Michigan State University. “Birds that are used to it know how to eat it and so these kinds of organisms that we consider invasive … take over an area more quickly. They can kill trees more quickly because the trees don't have natural defenses.”

Signs of an infestation could be exit holes, about the diameter of a pencil, near tree trunks, shallow round scars in tree bark, dead branches and wood-like shavings found near trees or branches. 

“The biggest risk is that it comes through … wood that's been harvested and turned into something else and then brought into Michigan without being checked for this beetle,” Walton said.

If you spot an Asian longhorned beetle or tree damage caused by the insect, you can report it by calling the USDA hotline at 866-702-9938 or submitting a report online. 

If you can, take a photo of the beetle or capture and freeze it for better identification.