From the Minnesota Department of Agriculture:
Minnesotans should be on the lookout for the insect and report any findings
St. Paul, MN: The European chafer beetle (Amphimallon majale), an insect that can cause major damage to turf grass, has been found for the first time in Minnesota.
A resident of south Minneapolis first noticed large swarms of beetles in their yard at dusk and reported the find to a University of Minnesota Extension entomologist who suspected the beetles were European chafers and reported them to the Minnesota Department of Agriculture (MDA). The MDA worked with the United States Department of Agriculture to confirm the identity of the insect since it had never been found in Minnesota before.
The European chafer beetle was discovered in the United States in 1940 in New York state and is currently found in the northeastern U. S., as well as Michigan and Wisconsin.
The grub of the European chafer can cause more damage to turf than Japanese beetles because it spends a longer portion of the summer feeding on turf. However, adults do not eat at all, so they do not defoliate other plants like Japanese beetles are known to do. Home lawns, golf courses, and turf growers could be significantly impacted if the European chafer beetle becomes established in Minnesota.
The adult insects are about a half-inch long and tannish in color. They are similar to the “June bugs” commonly found in Minnesota in early summer but are generally a bit smaller and lighter in color. The beetles emerge from the soil between mid-June and early July and are active on warm evenings for several hours just before and after sunset. The white grubs can range from ¼-inch to 1-inch long with a dark brown head and noticeable legs.
Since this is the first reported discovery of the European chafer beetle in Minnesota, the MDA would like to better understand where this insect may be in the state and how big of an issue this is to homeowners, golf courses, and turf growers. Minnesotans can report suspected European chafer to the MDA’s Arrest the Pest line at firstname.lastname@example.org or 1-888-545-6684. Before making a report, please capture the insect, take a picture, and put the insect in a container or plastic bag and place it in the freezer. The MDA will contact you if the specimen is needed for confirmation.
More information on the European chafer can be found here.