Many of you who camp in Virginia State Parks may have noticed our alert to leave your firewood at home. Although you may find this a nuisance, there is a very good reason. The reason is the emerald ash borer (Agrilus planipennis).
The emerald ash borer is an insect that is native to Asia, and like the Japanese beetle, has become a problem in the United States. Despite their tiny legs, the have scaled the globe to cause devastation in areas that do not have sufficient predators to counteract them. Many efforts are under way to try and quarantine as many of the affected areas as possible to prevent their spread. This is why Virginia State Parks ask that you do not bring firewood into the parks. One piece of firewood with emerald ash borers could cause a park-wide problem that can quickly spread to surrounding areas.
There are certain signs to look for that can point to an emerald ash borer problem. Usually you will notice that the tree will begin to lose its upper leaves. This can progress until the tree is completely bare. You may also notice that the tree begins to send out shoots, called epicormic shoots, from its trunk and roots. If you investigate the problem further, you may notice that the new shoots have leaves that are larger than normal, and there may be increased woodpecker activity in the area.
The direct signs of emerald ash borer are vertical fissures on the bark which is due to callous tissue formation. You may also see tunneling in the exposed bark which is a sign borer activity. There are often serpentine shaped larval feeding galleries in the bark. The weaves will go back and forth across the wood grain. They will be packed with a mixture of sawdust and excrement called frass. Adults will form D-shaped holes when they emerge from the tree.
The insects themselves are bright metallic green and are about a half an inch long. They have a flattened back and purple abdominal segments beneath their wing covers. The larvae are found in the trees and are creamy white with flattened, bell-shaped body segments. Their terminal segment has a pair of small appendages. (pictures can be seen here)
Currently, the emerald ash borer has infested its way into Illinois, Indiana, Maryland, Michigan, Minnesota, Missouri, Ohio, Pennsylvania, Virginia, West Virginia and Wisconsin. All these states are taking steps to prevent the spread of these insects. Millions of ash trees have already been lost, so please help us do all we can to prevent this problem from spreading further.