ALB signs and symptoms
Adult Asian longhorned beetles (Anoplophora glabripennis) are 3/4 to 1-1/2 inches long, shiny black with white spots. The antennae are long and have alternating bands of black and white. The antennae are usually 1 to 2 times greater than the length of the body. The upper sections of the legs are whitish to blue. Adults are active from summer to mid-fall.
Females chew crater-shaped pits 1/2 inch in diameter into bark to deposit their eggs. The hole may appear orange.
The wormlike larvae can be up to two inches long, are yellowish-white, cylindrical and fleshy, with a varied texture on the underside. Larval feeding galleries or tunneling may be visible on severely impacted trees.
The pupae are generally 1 to 1-1/4 inches long and ½-inch wide, are off-white to light brown and appear like an immature version of the adult with legs and antennae compressed against the body. It takes three years for the ALB to mature.
When the adult beetles emerge, they leave behind a hole 3/8 inch in diameter.
Wood shavings may be found extruding from holes in the bark and around the base of infested trees.
Do not confuse ALB with the cottonwood borer
The Asian longhorned beetle (left) should not be confused with the cottonwood borer (right), a native longhorned beetle. The adult cottonwood borer has a more even mix of black and white patterns on its body and has solid black antennae.