Jeffrey Hahn, Asst. Extension Entomologist
The Asian longhorned beetle (ALB), Anoplophora glabripennis, was recently found for the first time in Ohio, 30 miles southeast of Cincinnati. This exotic borer, originally from Asia from southern China, Korea, and Japan, was first found in North America in 1996 in New York. Two years later it was found in Chicago (but was eradicated there). Since then, it has also been discovered in New Jersey (2002), Toronto (2003), and Massachusetts (2008) before being found in Ohio.
This is a good reminder to be watching for ALB in Minnesota. Although it has not been discovered here yet, we have a lot of trees this borer loves to attack, including maple, American elm, and willow. It is important for people to be familiar with ALB so suspicious insects can be reported. In Ohio, a private citizen found insects in three maples that she thought could be ALB and reported it to entomologist at Ohio State University who then passed this on to USDA-APHIS for verification.
The best way to recognize ALB is from the adults. They are large insects, ranging in size from 1 - 1 ½ inches long (not counting the antennae). Like other long-horned beetles, ALB has antennae that as long or longer than its body, up to four inches in length. ALB particularly has distinctive black and white banded antennae. It's body is a glossy black with as many as 20 white distinct spots on it. Because of this, ALB is sometimes called the starry sky beetle. Adults are active throughout the summer and into the fall.
Don't confuse ALB with the whitespotted sawyer, a native long-horned borer in Minnesota. A whitespotted sawyer is about 3/4 - 1 1/4 inches long and has a dull black body with indistinct white spots or patches. Males lack any banding on their antennae while females possess only faint bands. Whitespotted sawyers are associated with conifers.
You may see ALB larvae in wood. They are legless and cylindrical in shape with a head that just sticks out of the body. They are large, growing up to two inches in size. These larvae create oval tunnels as they bore into the sapwood and heartwood. Although it is easy to identify ALB as a type of roundheaded borer (the larvae of long-horned beetle), it is difficult to identify roundheaded borers as ALB.
If you have maple, elm, or willow in your yard or other hardwoods like birch and poplar, watch for signs of infested trees. Because ALB is such a large insect, when it emerges as an adult, it creates a large, 3/8 - 3/4 inch wide round exit hole in the trunk or branches. This large enough to stick the eraser end of a pencil into the hole. Other potential signs of ALB include sawdust on the ground or the fork of branches, sap oozing from the exit holes, and the presence of small oval to round shallow pits chewed into the trunk or branches - the females chew these for a place to lay eggs.
If you think you have found ALB, contact the Minnesota Department of Agriculture's "Arrest the Pest" Hotline at 651-201-6684 (Metro Area) or 1-888-545-6684 (Greater Minnesota).