Skip to content

Check Your Trees in August for Signs of the Asian Longhorned Beetle

By Robyn Rose

August is Tree Check Month for the Asian longhorned beetle (Anoplophora glabripennis) since this is the time of year when the majority of adults emerge from trees.

Robyn Rose

Experts believe the ALB’s introduction to the United States occurred through solid wood packaging material from China. ALB larvae bore into hardwood trees, damaging the tissues that carry nutrients and water, causing the trees to weaken. Once the ALB has infested a host, there is no practical way to save or cure the tree.

The spread of ALB into forested areas could severely affect several industries, including timber, maple syrup and nursery stock. The spread of ALB would also result in indirect losses, such as reducing a community’s aesthetic value, affecting tourism, or disrupting international trade.

The most effective way to eradicate ALB from an area with infested trees is to remove all infested and potential host trees from that area. Chemical treatments can also mitigate the risk of ALB spread.

Previous ALB infestations occurred in urban areas with relatively low tree density. Emerging rural infestations contain much denser tree canopies.

APHIS has fought the Asian longhorned beetle for more than 15 years, achieving eradication in Illinois, New Jersey, Staten Island, Manhattan and Boston.

Currently, there are populations of ALB in New York, Massachusetts and Ohio, and we don’t want it to spread any further. To date, private citizens have discovered all separate ALB outbreaks and reported their findings to either USDA or their state’s department of agriculture.

ALB has 12 host trees, with the five most preferred hosts being maple, horsechestnut, birch, willow and elm. These trees should be checked for signs of ALB damage.

Signs of ALB damage to look for include:

  • Round exit holes in the bark of the host tree
  • Oval or round exit sites that look like a wound in the tree
  • Accumulation of frass that looks like sawdust being pushed from a hole
  • Weeping sap
  • Tunneling
  • Pupal chambers

Report any signs of ALB to

Dr. Robyn Rose is national policy manager for the USDA-APHIS Asian Longhorned Beetle Eradication Program.

1 Comment »

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.