How to Check Trees for Asian Longhorned Beetles

The Asian longhorned beetle (Anoplophora glabripennis), native to Korea, China and Japan, is an invasive insect with no natural predators and a voracious appetite for a wide range of trees including maple, willow, poplar, ash, birch and elm, among others. 

Since its arrival to the U.S. in 1996 (likely a stowaway in wooden cargo crates from China), the destructive pest has destroyed over 130,000 trees across New York, New Jersey, Massachusetts, Ohio and Illinois. Threatening the timber and maple syrup industries and devastating forests as well as suburban and park landscapes, the Asian longhorned beetle (ALB) burrows deep into the tissue of hardwoods, causing trees to weaken and die. Once a tree is infested by this invader, it must be destroyed.

Although infestations of the Asian longhorned beetle have been successfully eradicated in some regions, spread of the incredibly destructive pest is still of national concern. To help combat ALB, the USDA has declared August “Tree Check Month.”

August is the peak month for ALB emergence. A shiny black beetle with white spots and long, banded antennae, the winged insect is 1-1.5 inches in length and seeks out hardwood trees in which to burrow. Early detection is key in preventing widespread infestation. Left unchecked, the USDA believes up to 70 percent of tree canopies can be lost in infected communities. 

Here’s how you can help:

Look Up

Scan the canopies of trees in your yard, in parks or any forested areas. Check for dead or dying branches or significant scarring of larger branches.

Look it Over

Examine tree trunks. An ALB presence can be detected by the presence of dime-sized exit holes, shallow scars in the bark, weeping sap from damaged trees or oval depressions where eggs have been laid.

Look Down

Check the ground around trees for evidence of frass (the excreta of insects), a sawdust-like material indicative of an ALB infestation.

If you think you’ve detected signs of an Asian longhorned beetle presence, contact the USDA by calling 1-866-702-9938 or report findings online at  www.AsianLonghornedBeetle.com. Digital photos may be submitted to help confirm findings. If spotted, the USDA suggests capturing and freezing the beetles for identification.