Adult beetles are most active during the summer and early fall. Throughout the summer, they can be seen on tree branches, walls, outdoor furniture, cars and sidewalks. If you see the beetle or any signs of infestation, you need to report it immediately.

You won’t see the beetle after the first frost until it emerges again in the summer. During the winter months, the beetle’s larvae tunnel deep into the trees they infest. Although you can’t spot it, you can still be a beetle buster by not moving firewood. Moving firewood can spread the beetle, its larvae and its eggs to healthy trees. So buy it locally and burn it locally, and don’t move firewood off of your property.

The Signs

Throughout its life cycle, the ALB leaves obvious signs of its presence in and around host trees. The adult female chews 35-90 oval depressions, called oviposition sites, into the bark of the host tree. She lays a single egg beneath the bark at each site.

The beetle then hatches into a white caterpillar-like larva that tunnels deeper into the tree, where it feeds and develops over the winter.

In the spring, beetle larvae inside the host tree build a hard case for themselves called a pupa and develop within it. In the summer, the adult beetles chew their way out, leaving dime-sized (1/4" or greater), perfectly round exit holes.

As the beetle tunnels, the ALB often pushes sawdust-like material, called frass, out onto the ground or tree branches.
 
 
 

Infested tree.

Looks Like ALB, But It’s Not.
The Whitespotted pine sawyer beetle is often mistaken for the ALB. Here are the telltale differences:

• The Whitespotted sawyer has one white dot between the top of its wings. ALB does not have this dot.
• The Whitespotted sawyer’s wings are rough and bronzish-black as opposed to the ALB’s shiny smooth black wings.

Click image to enlarge

For more photos of the Whitespotted pine sawyer, and other insects similar in appearance to the ALB, go to:
The University of Vermont’s Asian Longhorned Beetle Public Identification