Text Size:   A+ A- A   •   Text Only
Site Image
Asian Longhorned Beetle
Order: Coleoptera
Family: Cerambycidae
Scientific name: Anoplophora glabripennis Motschulsky
Common name: Asian longhorned beetle (ALB)

Adults: Adult ALB, although unlikely to be seen, are large (about 3/4-1 1/4 inches long), black with white spots and very glossy (see photo below). It is called the "starry night" beetle in China due to its coloration. The antennae are longer than the beetle's body and are banded black-and-white. Adults may be crawling over the trunks and branches of host trees, or possibly flying. There are several native beetles which are roughly the same size and color as ALB, so any suspicious beetles should be captured if at all possible and placed in a jar or film canister (NOT plastic bags - they'll chew through!). Place a label that includes the address and date inside the container and notify the Oregon Department of Agriculture.
  1. Large 3/8" diameter (9.5 mm) ROUND emergence holes where adult ALB have emerged from the tree. A good quick-and-dirty way to tell whether holes are the right size is whether a pencil fits into a hole. If not, the hole is too small to have been caused by ALB.
  2. Oval-to-round wounds or scars on the bark where female ALB have chewed out a place to lay eggs. The wounds are pale when fresh but darken with age. Sap flows and stains are often associated with oviposition scars. These oviposition scars are about 3/8" long (9.5 mm) and may occur in a row with about 3 - 5" between scars.
  3. Piles of coarse "sawdust" (caused by adult beetles chewing their way out from inside the tree) around the base of trees or where branches meet the main stem.
  4. Heavy sap flows running down trunks and branches, from egg-laying sites as the larvae feed inside the tree.
  5. Wilting or browning leaves at branch tips or dead twigs/branches
There are several types of non-ALB damage frequently reported. Some native carpenterworms and wood-boring beetles prefer the dead wood of tree scars and wounds. This type of damage is virtually confined to the exposed dead wood. Holes made by woodpeckers searching for grubs under bark are also frequently reported. These holes are often in neat rows and are too small for ALB. They also do not extend very deep into the wood, unlike ALB or wood-boring beetle galleries. Native wood-boring beetles also use many of the same trees preferred by ALB, but their emergence holes are generally smaller and are often confined to dead or rotting wood. ALB prefer healthy trees and sound wood. However, REMEMBER: we´d much rather you report damage caused by non-ALB than to omit reporting true ALB damage!
Asian longhorned beetle larva
Asian longhorned beetle pupa
Asian longhorned beetle adult

Damage: ALB larvae are wood borers and feed in both the sapwood and heartwood. Unlike most longhorned beetles, ALB is a serious pest of hardwoods because it can attack and kill healthy, as well as stressed, trees.

Impacts: ALB has the potential to become a serious pest of hardwoods in urban, rural, and forest environments throughout the U.S.

Host plants: Maples, willows, elm, and horsechestnut are the trees most commonly attacked, but birch, poplar, silk tree, sycamore, ash, and mountain ash are also hosts.
Distribution: Currently, there are infestations in New York, New Jersey, Worcester and Boston MA. There was an infestation in Illinois, but it has been successfully eradicated and the quarantine removed.
distribution maps

Biology and Life Cycle: ALB has a one-year life cycle in regions with a temperate climate similar to Oregon’s. The insect overwinters in host trees as full-grown larvae. Pupation takes place in spring with adult beetles emerging from 3/8- inch (9.5 mm) circular exit holes in June or July. Adults feed on the bark of small host twigs and mate from July into early autumn. Females excavate 1- inch diameter roundish oviposition depressions on the bark surface and deposit one egg in each prepared site. Eggs hatch about 11 days later into larvae that grow and feed on living vascular tissue and tunnel into heartwood tissue.

How you can help:
If you see this beetle or find trees with signs of damage, please:

  • Note the date and location where you found the beetle or damaged tree.
  • Capture the beetle and place it in a jar in the freezer to kill it and store the dead beetle.
  • Immediately report the information by calling the Oregon Department of Agriculture at: (503) 986-4636 or 1-800-525-0137.

What ODA is doing: Each year ODA surveys thousands of trees across the state. Inspecting trees allows ODA to detect any ALB infestations when they are relatively small and when they are more easily eliminated. 
USDA APHIS Asian longhorned beetle information

Photo credits:
ALB larva:Thomas B. Denholm, New Jersey Department of Agriculture,www.forestryimages.org
ALB pupa:Kenneth R. Law, USDA APHIS PPQ, www.forestryimages.org