Plant Industry - Asian Longhorned Beetle

Asian Longhorned Beetle

The Asian longhorned beetle (Anoplophora glabripennis; ALB) is an invasive insect that is native to Asia and was first detected in the United States in 1996 in Brooklyn, New York. This invasive insect has since been found in other parts of New York, Illinois, Massachusetts, New Jersey, Ohio, and South Carolina. This pest is not known to occur in North Carolina but early detection is critical for protecting North Carolina agriculture, businesses, and forests.

ALB is a known pest of many hardwood species. The female adults lay their eggs in niches chewed into the bark of trees. The larvae that emerge from the eggs will tunnel and chew into the bark creating tunnels under the surface. Over time these tunnels can disrupt the flow of nutrients into trees causing decline and eventual death. The preferred hosts for ALB include Acer (maple, boxelder), Aesculus (horsechestnut, buckeye), Betula (birch), Salix (willow), and Ulmus (elm). Less common hosts include Albizia (mimosa), Fraxinus (ash), and Populus (poplar).

How to identify Asian longhorned beetle:

Adult Asian longhorned beetles are about an inch long and are black with irregular white spots along their backs. Their antennae are quite long (typically longer than their bodies) and have alternating black and white segments.

Asian longhorned beetle adult  
(Photo credit to the Invasive Species Centre)

ALB are commonly mistaken for a native insect, the whitespotted pine sawyer (WPS). The easiest way to tell the two species is apart is that WPS has a white spot at the base of its wings while the invasive ALB does not (this feature is circled in red in the picture below; ALB on the left and WPS on the right).

Signs & Symptoms of Asian longhorned beetle:

One key sign of this pest is the presence of perfectly round exit holes in hardwood trees (see below). For size reference, a pencil fits perfectly in one of these exit holes. To differentiate from carpenter bees which make a similar hole in wood, ALB tunnels go straight through wood while carpenter bee tunnels go in and then angle down. Other signs include the presence of many small wounds with chew marks around the edges; these are the egg niches. As larvae tunnel and feed under the bark a buildup of frass (may look like sawdust) may appear. Evidence of tunneling in cut or broken branches is also common. You may also see weeping sap, early leaf color change and drop, and branches dropping or dying.

This pest is most commonly moved in solid wood packing material and in infested materials such as logs and firewood. Do not move firewood and remember to buy it where you burn it to help prevent the spread of invasive pests.

If you suspect you have found Asian longhorned beetle please take a photo and/or collect a specimen and report it to badbug@ncagr.gov. Include a size reference like a ruler or coin in any photos you submit and provide the location of the detection and contact information where you can be reached. We will assist you with specimen submission.

Helpful Links: 
Asian Longhorned Beetle Common Look-Alikes in North Carolina 
Asian Longhorned Beetle Pest Alert 
USDA Asian Longhorned Beetle Program