The Asian longhorned beetle (ALB) is an invasive insect that feeds on certain species of hardwood trees, eventually killing them. The ALB most likely came to the United States inside wood packing material from Asia. Since it was first discovered in Brooklyn, New York in 1996, the beetle has caused tens of thousands of trees to be destroyed in Illinois, Massachusetts, New Jersey and New York.

If the ALB were to become established here, it could become one of the most destructive and costly pests ever to enter the United States. If we don’t find and stop the ALB, we’ll lose more than trees. We’ll lose industries worth billions of dollars – and wildlife habitats too. Our yards and neighborhoods will take decades to recover.

Lifecycle of the ALB
The Asian longhorned beetle (ALB) spends most of its life as a larva inside a hardwood tree. The adult female ALB chews a depression or egg site into the bark and lays a single egg beneath the bark. Egg sites are visible on the bark of the tree. They can be oval or round in shape or small slits depending on the tree species and thickness of the bark. With a lifespan of 14-66 days, a female ALB can lay 30-60 eggs in her lifetime.

When the larva emerges from the egg, it initially feeds on the tree’s living tissue directly beneath the bark. The mature larva then moves deep into the tree and feeds on the woody tissue. This feeding and burrowing causes the tree to weaken and eventually die. The larva becomes a pupa inside the tree.

About one year after the egg was laid, the adult beetle breaks out of its pupal casing and chews its way out of the tree, creating perfectly round exit holes that are about 3/8” in diameter. Adult beetles emerge in July and August. They feed on leaves and small twigs and then mate, continuing the life cycle with the female beetles laying more eggs in the tree. Female beetles tend to lay eggs on the same tree every year until the tree dies.

Spot the Beetle. Stop the Beetle.
One of the most important ways you can help stop the ALB is to look for it and report it. Adult beetles are most active during the summer and early fall. They can be seen on trees, branches, walls, outdoor furniture, cars, and sidewalks. While the ALB may appear threatening, it is harmless to humans and pets. With these unique characteristics, it’s easy to identify the ALB:

• 1 to 1 ½ inches in length
• Long antennae banded in black and white (longer than the insect’s body)
• Shiny, jet black body with distinctive white spots
• Six legs
• May have blue color on feet

Signs of Infestation
While it can fly, the beetle tends to lay eggs in the same tree from which it emerged as an adult. The eggs hatch and the larvae burrow and feed just under the bark. By the late summer and fall, the caterpillar-like larva tunnels deep into the tree. The following summer, the ALB drills its way out of the tree as a mature beetle. It bores through the tissues that carry water and nutrients throughout the tree, eventually starving and killing it. In addition to looking for the beetle, you can search for signs of infestation, including:

• Shallow divits in the bark where the eggs are laid
• Sap seeping from wounds in the tree
• Dime-sized (1/4” or larger), perfectly round exit holes in the tree
• Sawdust-like materials, called frass, on the ground and the branches

Download an ALB Fact Sheet View our Photo Gallery Read the Frequently Asked Questions

Battling the Beetle
Due to the huge threat this beetle poses to America’s trees, Federal, State and local governments are taking steps to eradicate the beetle, including quarantining infested areas.

We need your help. Know all of the signs. Look for the beetle. Report it. And never move firewood – it may contain the beetle, its larvae or eggs. Humans can unknowingly transport it hundreds of miles in firewood. Cutting a tree into firewood does not kill all ALB developing inside it. Adult beetles can still emerge. The best approach is to burn firewood in the county where you get it. Learn more ways you can help.