Asian Longhorned Beetle Identification Guide
Spot the invasive Asian longhorned beetle by its glossy black body, white spots, and bold black-and-white banded antennae.
Read the full Asian Longhorned Beetle encyclopedia entry →
Key Visual Features
The Asian longhorned beetle (Anoplophora glabripennis) is a large, striking longhorn beetle, typically 3/4 to 1.5 inches long, with a glossy, jet-black body scattered with distinct irregular white spots across the wing covers — a pattern that makes it fairly easy to recognize once seen. Its antennae are extremely long, often exceeding the length of the body (especially in males), and are boldly banded in alternating black and white segments. The legs are mostly black but may show a bluish-white tinge near the feet. The body is smooth and shiny overall, without the hairy or mottled texture seen in some other longhorn beetles.
Where and When You'll See Them
This beetle targets living hardwood trees, especially maple, birch, willow, elm, and horse chestnut, where females chew distinctive round exit and oviposition holes about 3/8 inch in diameter (roughly the size of a pencil eraser or a dime) into the trunk and branches. Adults are typically seen from late spring through fall, roughly June through October, resting on tree bark or branches, or occasionally found on the ground after falling from trees. Sap flow or sawdust-like frass at the base of a tree near these round holes can also indicate their presence.
Similar-Looking Bugs
- Whitespotted sawyer beetle — a native lookalike, but it has a single white spot at the base of the thorax and a duller, more mottled wing pattern rather than clean glossy black with scattered white spots.
- Old house borer — mottled grayish-brown rather than glossy black, and associated with structural softwood rather than living hardwood trees.
- Locust borer — has yellow zigzag bands rather than white spots and a different overall color scheme.
Quick ID Checklist
- Glossy black body with scattered irregular white spots, 3/4 to 1.5 inches
- Antennae longer than the body, banded black and white
- Legs may show a bluish-white tint near the feet
- Round exit holes about 3/8 inch (dime-sized) in hardwood trunks/branches
- Found on living hardwood trees like maple, birch, and willow, June through October
Frequently asked questions
How do I tell an Asian longhorned beetle from a whitespotted sawyer beetle?
The whitespotted sawyer has just one white spot at the base of the thorax and a duller, mottled wing pattern, while the Asian longhorned beetle has multiple scattered white spots on a clean, glossy black background.
What trees does the Asian longhorned beetle prefer?
It targets living hardwood trees, especially maple, birch, willow, and elm, where it bores into the trunk and branches.
What do Asian longhorned beetle exit holes look like?
They are round, roughly 3/8 inch across (about the size of a dime), found in the trunk or branches of infested hardwood trees.
When is the Asian longhorned beetle most commonly seen?
Adults are typically active from late spring through fall, roughly June through October.