August is tree check month

Follow these five steps to spot the Asian longhorn beetle before it spots your trees!

The Asian long-horn beetle has not yet been identified in Michigan, and you can help keep it that way by being vigilant. Photo credit: USDA Animal and Plant Health Inspection Service
The Asian long-horn beetle has not yet been identified in Michigan, and you can help keep it that way by being vigilant. Photo credit: USDA Animal and Plant Health Inspection Service

The Asian Long-horn Beetle (ALB), Anoplophora glabripennis, is a non-native insect that was first discovered in North America in 1996, in New York State. The beetle, which is native to China, Japan and Korea, likely found its way to North America via solid wood packing material, similar to other non-native wood boring insects like the Emerald Ash Borer. Since 1996, the insect has been spotted in New Jersey, Toronto, Ontario, Massachusetts, Chicago area and the Cincinnati area. Some places have declared it eradicated (Chicago area, New Jersey, Boston and several locations in New York); however, it continues to live on in other areas, prompting federal quarantines on nursery stock, logs and wood products. Firewood is also included in the quarantine, providing another reason Michigan State University Extension supports not moving firewood, and to “buy it where you burn it.”  

Why is it an issue?

The ALB is a large, boring type of insect, with feeding and life cycles similar to the Emerald Ash Borer. What is different and threatening about the ALB is that it prefers to feed on maple trees, and maple trees make up about 18 percent of our Michigan forests. Even worse, is that the ALB is known to also use a variety of other trees as a host, meaning that if it finds a foothold in Michigan, many of our forest resources may be at risk.

What can you do?

The ALB has not yet been identified in Michigan, and you can help keep it that way by being vigilant. Spend a few minutes inspecting your trees for signs of the ALB. August is tree check month because evidence of the beetle will be most easily seen. Follow these steps to check the trees in your yard, woodlot or forest.

  1. Look for slightly smaller than dime-sized exit holes. The holes are perfectly round and should be big enough for a pencil to easily be inserted.
  2. Look for shallow scars in the bark. These scars indicate that the ALB has chewed through the bark to deposit eggs, likely in the same tree from which it hatched.
  3. Look for sawdust-like material on the ground or on tree branches. This material is produced as the larva bore, or chew through the interior of the tree before emerging.
  4. Look for branch breakage. The ALB larva may initially only inhabit a portion of an infected tree, cutting off water and nutrients to that portion, or branch, killing it without noticeably affecting the rest of the tree.
  5. Look for the beetle. The ALB is black in color with white spots and can be an inch long. It closely resembles a few species of our native boring insects (white spotted pine sawyer), but has distinctive long, black and blue stripped antennae.

What to do if you spot evidence or a beetle?

Tell someone! And take a picture. You can call or submit a picture to your local Michigan State University Extension office, or the Michigan Department of Agriculture and Rural Development (MDARD) (MDA-Info@michigan.gov or 1-800-292-3939) Michigan State University as well as MDARD have experts that are trained to identify the beetle and the evidence it leaves behind. If it is found, a quick response may be the only way to save our Michigan forests.

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