What are they?
Citrus (Anoplophora chinensis) and Asian (Anoplophora glabripennis) long-horned beetles are large beetles whose larvae feed on the wood of trees. When the beetles mature to adulthood, they emerge through holes that weaken the trees further. They are extremely destructive to hardwood trees.
Are they here yet?
No. The citrus long-horned beetle is native to southeast Asia and was first detected in a Washington nursery in 2001. An eradication program was implemented immediately with no new infestations reported since. However, with the increase of global trade and movement of plant materials via the Internet, the state still is at risk for new introductions.
For more information on where surveys have been conducted for wood-boring insects in the Puget Sound Basin, see maps.
Why should I care?
Unlike our native long-horned beetles that feed on dying trees, Asian and citrus long-horned beetles feed, and even kill, healthy trees. The beetles have a range of more than 40 host trees that they can damage. Letting these tree-killing beetles establish would be devastating to forests, parks, and yards. The Asian long-horned beetle killed thousands of trees in New York and Chicago, and according to some estimates, cost more than $369 million for the inspection, treatment, and removal of the infested trees.
What should I do if I find one?
How can we stop them?
Do not purchase or trade this species. Early detection is critical for avoiding serious problems. Learn how to recognize Asian long-horned beetles. Contact your local Washington State University Extension office for more information.
What are their characteristics?
Asian Long-horned Beetle
- Anoplorophera glabripennis is a large, robust beetle. Its wings are a shining black with irregular splotches of white.
- The antennae are quite striking with bands of black and gray.
- The feet and legs are decorated with a slate blue pubescence.
Citrus Long-horned Beetle
- Anoplorophera chinensis is very similar in appearance to the Asian long-horned beetle because it is closely related. It is large, stout, and about 1-1.5 inches long with shiny black wings marked with
10-12 white round dots.
- Males generally are smaller than females, and have their abdomen tip entirely covered by the wings. The females’ abdomens are partially exposed.
- The males’ antennae are longer than the females’ in comparison to their body size.
How do I distinguish them from native species?
The Asian and citrus long-horned beetles have a few native lookalikes, including the banded alder borer and the spotted pine sawyer. Please visit these links to help with identification:
- Iowa State University’s BugGuide
- Washington State University Whatcom County Extension
- University of Vermont – Asian Long-horned Beetle
Where can I get more information?
- U.S. Department of Agriculture
- Washington State Department of Agriculture
- Washington State University Whatcom County Extension, Garden Friends and Foes