The Asian longhorned beetle, (Anoplophora glabripennis) or ALB, is an invasive wood-boring insect that feeds on a variety of hardwoods including maple, birch, elm, ash, poplar, horsechestnut, and willow. ALB threatens the health of New York's hardwood forests and negatively impacts agriculture and tourism.
ALB beetles are approximately 1.5 inches long and shiny black, with white spots on their wing cases. They have black and white antennae that can be up to twice as long as their body.
Signs Of An Infestation
Trees being attacked by ALB often have wilted foliage and canopy dieback, but the main signs to look for include:
- Round, ⅜ to ½ inch exit holes from adults emerging from trees beginning in late July.
- Round, ½ inch depressions (egg-laying sites) in the outer bark.
- Sap oozing from egg-laying sites and exit holes.
- Deep exit holes, insert a pencil to determine if the hole is at least an inch deep.
- Sawdust, or frass, collecting at the base of the tree or on branches. ALB Compared to the Native Whitespotted Pine Sawyer
Trees being attacked by ALB often have wilted foliage and canopy dieback, but this can be caused by a number of different factors and should not be used on its own as a sign of ALB infestation.
Females often chew depressions in the bark where they deposit one to two eggs at a time, laying up to 60 eggs on average. After they hatch, the larvae bore into the tree and begin feeding on the living tissue just underneath the bark which disrupts the nutrient and water flow within the tree. The larvae then continue deep into the heartwood where they continue to feed until they are ready to pupate. Repeated attacks from scores of larvae, generation after generation, eventually girdles the tree and kills it. Tree death usually occurs 7-9 years after the initial infestation, depending on site conditions and the tree's overall health.ALB has a native look-alike that you may encounter in New York State, the whitespotted pine sawyer (Monochamus scutellatus). Upon first glance, it can be easily mistaken for ALB. However, the whitespotted pine sawyer has a distinctive white spot at the top of where its wing covers ("elytra") meet, while the ALB has none. This comparison of both species shows the location of that white spot on both the male and female whitespotted pine sawyers. Also, note that the white markings on the wing covers and antennae are much more visible on the Asian longhorned beetle.