The Asian longhorned beetle (Anoplophora glabripennis), the latest threat to North America’s hardwood forests, was first detected in trees in Brooklyn and Amityville, New York, in 1996. Its introduction to the United States has been covered by CNN and NBC Nightly News.

Experts are concerned about infestations of Asian longhorned beetles and other Chinese wood-boring insects in the coming years. Authorities enacted tough new measures to exclude new introductions of the beetle. They require that all solid wood-packaging materials entering the U.S. from China to be heat treated (kiln-dried), fumigated, or treated with preservatives.

The ALB is native to China, Japan, Korea and the Isle of Hainan. It is believed to have been introduced from China in untreated solid wood packing materials (crates, pallets, dunnage). As the volume of Chinese imports to the United States increased from $5 billion in 1985 to $72.8 billion in 1997, so did the volume of solid wood packing materials accompanying these shipments.

Although foreign shipments are inspected for insects by the USDA’sAnimal and Plant Health Inspection Service (APHIS), the ALB spends its pupal and larval stages buried inside the wood, making it difficult to detect.

The ALB has a long and growing list of hardwood host species in North America. While it seems to prefer maples and horsechestnut, it will readily attack yellow-poplar, willow, elm, mulberry, black locust, and several commercial fruit trees including pear and plum. ALBs species preference leaves a majority of northern hardwood forests, western hardwood forests and most North American urban forests at risk. It also finds southern hardwood species equally palatable. In addition, new hardwood species are continually being added to the susceptibility list.

Adult females lay their eggs in an opening in the bark of trees and often the exit hole left by an emerging adult. The larvae then bore large galleries deep into the wood. By the time the adults bore out of the tree, the tunnels they leave behind are 3/8-inch in diameter or larger. These tunnels disrupt the vascular functioning of the tree and eventually weaken the tree to the point that the tree literally falls apart and dies.

While they are inside the wood, the larvae are protected from pesticide applications. After the ALB has infested a tree, the only ‘treatment’ is to cut down, chip and burn the infested tree. Because of the beetle’s long life cycle, however, the difficulty is in knowing which trees are infested.