Emerald Ash Borer

The Emerald Ash Borer, Agrilus planipennis, is a destructive beetle that feeds only on ash trees. The beetle is a splendid metallic green in color although it is as destructive as it is beautiful, so much so that scientists believe that ash trees throughout North America could be extinct within the next few years. The adult Emerald Ash Borer is not destructive to the ash tree itself. It eats the foliage of mature ash trees but does little damage during feeding. The destruction of the tree occurs when an adult female Emerald Ash Borer bores a hole in the trunk of an ash tree and lays up to 75 eggs deep within its bark. Trees infested with beetle larvae can be spotted by a unique “D” shape that a female bores into a tree before depositing her eggs.

Once eggs hatch and larvae emerge they are voracious eaters tunneling their way through the inner bark of an ash tree leaving distinct “S” shaped patterns, scaring the wood. This process stops an ash tree’s ability to transport water and other nutrients throughout its root system thus killing most infected trees within two years. It is hard to diagnosis an ash tree as infected until dieback starts occurring. One half of an infected tree’s branches will die off first. The remaining canopy will often die off the second year after infestation. So far scientists do not have a cure or a treatment for the disease. If they do not come up with something to stop the destruction of the Emerald Ash Borer in the next few years, the future for the ash tree in North America looks grim.

Until scientists can stop the beetles’ massive destruction they have resorted to unusual measures to stop further destruction. When a tree is found to be infested with beetle larvae they often destroy all ash trees within mile of the infested tree hoping to eliminate the Emerald Ash Borer from the area. While many healthy trees are destroyed it might be the only way to save the entire species of ash trees.

The Emerald Ash Borer wasn’t found in the United States until it was discovered in Michigan in the summer of 2002. It has since spread to 10 other Midwestern and Northeastern states and two provinces in Canada. Scientists aren’t quite sure how the Emerald Ash Borer arrived in North America but they think that the insect arrived on a commercial freighter ship or a cargo airplane inside of a wooden cargo crate or some sort of wooden packing material. Since its arrival in North America the Emerald Ash Borer has destroyed over 25 million ash trees. Ten million ash trees have been destroyed in Michigan alone. All varieties of ash trees such as white ash, black ash and green ash are the only species of trees to be effected so far.

Scientists are educating the public, teaching people what to be on the lookout for if they have ash trees on their properties, encouraging them to be vigilant if they suspect the presence of the Emerald Ash Borer, by calling their local agricultural extensions. Scientists have also quarantined infected regions by banning the cutting of firewood and banning the removal of ash wood from those regions. Hikers and outdoorsmen need to be extra vigilant in recognizing the Emerald Ash Borer to prevent spreading the insect to new regions.