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Asian Longhorned Beetle

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Common name: Asian Longhorned Beetle

Scientific name: Anoplophora glabriplennis

Hosts:  Host trees of Asian longhorned beetle include:

  • ash (Fraxinus spp.)
  • birch (Betula spp.)
  • elm (Ulmus spp.)
  • golden raintree (Koelreuteria spp.),
  • horse chestnut / buckeye (Aesculus spp.)
  • katsura (Cercidiphyllum spp.)
  • London planetree / sycamore (Platanus spp.)
  • maples (Acer spp.) including boxelder, red, silver, and sugar maple,
  • poplar (Populus spp.)
  • willow (Salix spp.)

The Asian longhorned beetle is an insect that can do very serious damage and even kill trees while in its larval stage. It is native to parts of Asia. It is believed that the beetle, while in the larval or pupal stage, was transported here in the wood of shipping crates from Asia.

It was first discovered in the Ravenswood area of Chicago in 1998. In 2008, the Illinois Department of Agriculture announced that it had eradicated the pest in Chicago. Asian longhorned beetle occurs in other states and could return to Illinois in the future.

The adult Asian longhorned beetle is about 1 ¼ inches in length; glossy jet black with small white spots on its wing coverings. It has long antennae that are distinctly banded black and white. The antennae of the males are 2 1/2 times their body length, while the female antennae are 1 3/4 times their body length. Because they are heavy-bodied insects, they cannot fly great distances.


External signs of damage include large holes (⅜ inch to 1 ¼ inch) where the adults exit the tree, as well as chewed areas where the female lays her eggs. Sap may flow from exit holes and egg-laying sites and sawdust may sometimes be seen at the base of infected trees.

The main damage is done by the larvae as they tunnel, first through the tree’s vascular (food and water conducting) tissue, then into the heartwood. Tunneling in the vascular tissue reduces the ability to move food and water through the tree and can lead to dieback of branches.  Damage to the heartwood can reduce the structural soundness of the tree. Symptoms of decline can often be seen in the first three to four years of infestation. It may take 10 to 15 years for the tree to die.

Life Cycle

Asian longhorned beetle can overwinter as eggs, larvae or pupae. This diversity of overwintering stages allows adult beetles to emerge from the trees over an extended period of time, from May to October.

The adults chew their way out of the trunks, leaving exit holes between ⅜ and 1 ¼ inches in diameter, round and very deep.

After mating, female beetles chew depressions in trees to lay eggs. These depressions can be oval to round in shape.

When the eggs hatch, the larvae begin feeding under the bark.

The first three larval stages feed in the tree’s phloem (food-conducting vessels), then late third and early fourth larval stages feed on xylem (water-conducting vessels). Mature larvae burrow winding galleries in the heartwood of the tree.


Cultural Management

Because most of the Asian longhorned beetle’s life cycle is spent deep inside the tree, they are difficult to control. The beetles have a few natural enemies in their native Asia, including nematodes, woodpeckers, and parasites, but their natural enemies are unable to keep them from being a serious problem even there.

Early detection of infestations is important to limit the spread of this insect because it may become a significant tree pest in this country. Management includes destroying infested trees. Insecticides do not give control of this pest.

If you believe you have seen the Asian longhorned beetle, please collect an adult beetle in a jar, place the jar in the freezer, and notify the U.S. Department of Agriculture in your state.

In northern Illinois, contact the Illinois Department of Agriculture:

Scott Schirmer, Nursery & Northern Field Office Section Manager
DeKalb Field Office, 2280 Bethany Rd. Suit B, DeKalb, IL 60115

For more information, contact The Morton Arboretum Plant Clinic (630-719-2424 or