- The ash borer is native to China, Korea, Japan and eastern Russia. Prior to June 2002, the pest was never found in the United States. Researchers believe that the ash borers were accidentally brought to North America in ash wood used for crating and shipping cargo.
- Ash borers belong to a family of insects called metallic wood-boring beetles and affect all types of North American ash trees including black, white and green varieties. The ash borer can affect trees in landscaped areas or natural woods and has been found in branches with diameters as narrow as 1 inch. Emerald ash borer infestations have been found in Michigan, Illinois, Indiana, Pennsylvania, Kentucky, Missouri, Virginia, West Virginia, Maryland, New York, Minnesota, Ohio, South Dakota and Wisconsin.
Ash Borer Lifecycle and the Role of the Affected Tree
- The invasive insects are present from May through the end of July. Adult ash borers emerge from the bark of infected trees in late May and within a short span of time begin laying eggs. The eggs hatch in the bark of the affected ash tree; newly hatched ash borers spend the winter months in larval form. The beetles appear to prefer laying their eggs on ash trees that are already stressed; however, they can infect healthy trees as well as those that are already stressed, diseased or dying.
- Symptoms of ash borer infestations including a thinning tree canopy followed by death in as much as half of the tree's foliage and branches. Within two years, most of the tree's foliage and canopy will be dead. Adult ash borers leave markings in the bark of affected ash trees -- the markings are shaped similar to the letter "D" and mark the area from which adult beetles emerge from the bark.
Preventing the Spread
- Human activities are the primary way in which ash borers are spread over long distances. Three prime examples include bringing infested firewood into unaffected areas, moving infested ash tree or moving infested logs. In an effort to try to control the infestation, many states have instituted a quarantine, making it illegal to bring ash trees or products containing ash wood into the state or county. Additionally, many state agencies and universities in the affected states have instituted educational programs to teach the public about the problem in an effort to stop the spread of the destructive ash borer.