Asian Longhorned Beetle

Much has been written about the emerald ash borer (EAB) but there is another forest pest that is threatening the hardwood forests in the U.S. that has the potential to be even more devastating than EAB.
 
The Asian longhorned beetle (ALB), Anoplophora glabripennis, was first discovered in New York City in 1996 and has also been found in Chicago, three counties in New Jersey, six cities in Massachusetts, and most recently in Bethel, Ohio which is 30 miles south east of Cincinnati.   It has not been found in Pennsylvania but it is a pest landowners should be aware of and on the lookout for.

ALB is native to Japan, Korea, and southern China and is believed to have arrived in the U.S. in wood packaging material in the early 1990’s from China.  ALB is considered a serious pest to hardwoods in its native range because it has few natural enemies.  In the U.S. it is considered an even more serious threat because there are no natural enemies known at this time. 

What makes this pest so destructive is that the list of host trees is large.  ALB are known to attack all species of maple, horsechestnut, buckeye, poplar, willow, elm, birch, London plane tree, sycamore, mimosa, hackberry, ash, and mountain ash.   They will attack trees of any size but trees over 4” in diameter are preferred.   ALB will attack healthy trees as well as trees that are stresses which makes it an even greater threat to our forests.

The beetles are very large ranging in size from .75 to 1.5 inches in length, not including the antennae.  They are shiny black with bright white spots and the legs have a bluish tint to them.  The adults have a pair of curved, black-and-white striped antennae that are even longer than the length of the body.  The adults emerge from trees from May through July and can live up to 66 days.  The adults feed on plant shoots for a few days then mate.  After mating occurs, the females chew rough, oval niches in the bark of the tree where the eggs are laid.

Once the eggs hatch, the larvae bore into the wood and feed between the xylem and phloem of the tree early on.  During the later stages, the larvae feed on the xylem only.  The mature larvae can reach 2” in length.  After the larvae pupate the adults begin to bore their way out of the tree and leave large round exit holes that are about ½” in diameter.  The feeding done by the larvae can girdle the tree and is what ultimately kills the tree. 

There is a native insect called the white spotted pine sawyer that greatly resembles ALB.  It is a native insect and is associated with dying, stressed, or dead conifers and it is not considered a pest.  The white bands on the antennae have faded white striping and the color of the body is not as glossy as ALB.

The good news is that ALB is a weak flyer due to its large size.  They can fly up to 400 yards but will usually re-infest their host tree or trees that are close nearby.    The bad news is that main control measure at this time is to remove all infected trees and then chip and burn them.  The goal when an infestation is found is to eradicate the beetle through tree removal.  So far experts feel that eradication efforts have been successful in some of the locations.  Of course preventing the further spread of the beetle is of the utmost importance.

Phytosanitation rules have been put into place that requires all wood packaging materials be treated before it is shipped to the U.S.  Not only does this help to protect against ALB but other exotic pests as well.  These new rules have made a significant impact on pests entering the country.  Of course the general public also has a very important role to play by not moving infected wood.  Moving firewood is one of leading causes of spreading these exotic pests.  The general public may not have been responsible for the introduction of these pests but it has unknowingly played a role in spreading them.  Remember to not transport untreated firewood.  Obtain it locally and burn it all or leave behind what is not used. 

For more information visit the U.S. forest webpage at http://www.na.fs.fed.us/fhp/alb/