Threats to Maple Trees

Threats to Maple Trees

Threats to Maple Trees

Threats to Maple TreesThe Asian Longhorned Beetle is a native of China and Korea, but has recently arrived in the United States and Canada. This large beetle attacks and kills maple trees and other hard woods. If allowed to spread, it could potentially devastate our hardwood forests and upset the balance of our forest ecosystem. Lumber & firewood harvesting, maple production and our beautiful fall foliage would all be adversely affected. How did it get here?
It is possible this insect began arriving in the United States in the 1980s, but was not discovered and identified until 1996. It is believed to have arrived as larvae within wooden pallets, crates and packing material from the Orient. As the larvae ate its way through the wood and matured, it found that our hardwood trees were good hosts, with the sugar maple being the tree of choice. There is no known predator of the Asian Longhorned Beetle in the U. S., so it could rapidly increase in population if left undisturbed.

How does it damage the trees?

The adult beetle chews through the bark down to the cambium interface and lays her eggs into the tree. As the larvae grow, they tunnel into the tree.

It takes about 12-18 months for the larvae to reach adulthood, and during this time, they continue to tunnel through the tree. These tunnels interrupt the flow of sap and soon kill the tree. When the adult beetle emerges from the tree in the spring, it creates a ? inch hole on the tree trunk, branch or exposed root. Sawdust can be found beneath these holes.

Where has it been found?

The Asian Longhorned Beetle has been found in Toronto, Canada, and in 1996 it was discovered in Brooklyn, NY. Later it was discovered in other parts of New York, New Jersey and Illinois. Government agencies converged on the infected areas and removed thousands of trees in an attempt to keep the beetle from spreading. In the summer of 2008, the ALB was discovered in Worcester, Massachusetts. It is believed to have arrived about ten years earlier, so it had spread significantly during those years and is the largest infestation found in the U.S. Thousands of trees had to be removed, finely chipped and burned. During the spring of 2009, the beetle was discovered in W. Boylston and Holden, Massachusetts. Currently, foresters are working to identify infected trees and plan for eradication during the beetle?s winter dormancy. The ALB has also been found in warehouses and ports all over North America, but halted before infestation could occur.

What is being done to stop its spread?

Fortunately, the ALB does not fly far, so infestations tend to be localized. There is no insecticide known to kill the ALB, therefore, infected trees must be destroyed. Infected areas are quarantined, and firewood is not allowed to be removed from those areas. New Hampshire is asking people not to transport firewood into the state, because it could contain ALB larvae. Pallets and crates are now supposed to be heat treated to kill insects before exporting from China. A baited trap is being developed to catch the beetle and hopefully prevent the cutting of trees. Persistent efforts are being made to alert and educate the public about the Asian Longhorned Beetle, so everyone will be on the lookout for it. In July, 2006, the quarantine in Illinois was lifted because no more ALB were found.

What does the Asian Longhorned Beetle look like?

Threats to Maple TreesThreats to Maple TreesAdult beetles are large, (3/4 – 1 1/2 in. long) with very long black and white banded antennae. The shiny body is black with white spots. The adult ALB can be seen from June to November. A picture of the Asian Longhorned Beetle is located at the top of this page. The White Spotted Pine Sawyer, a similarly looking beetle is a native to NH, and can easily be mistaken for the Asian Longhorned beetle.

Threats to Maple Trees

White Spotted Pine Sawyer

What should I do if I see one?

If you see what you believe is the Asian Longhorned beetle, capture it, put it into a plastic jar and freeze it to keep it from deteriorating. Check this website for a photo comparison, and if you still think it is the ALB, contact your county forester at UNH Cooperative Extension for verification. More information about the ALB can be found on: The University of Vermont Website

How can I help?

Do not transport any firewood into NH from another state. Examine any wooden pallets you may have to learn where they originated. If any read China, inspect them carefully for larvae tunnels and 1/2 inch adult exit holes. Do not transport pallets that may be carriers, but check nearby trees for signs of infestation. Be alert for signs of the Asian Longhorned Beetle, and notify your state forestry department if you should see one.