Threat to the Ash Spreads in Midwest

The Emerald Ash Borer, an insect already responsible for the destruction of 15 million trees in Michigan, has been spotted near Chicago, in a leafy subdivision called Windings of Ferson Creek, in exburban Kane County. Believed to have come from China in wooden packing crates, the ash borer was first discovered in the Detroit suburbs in 2002. Illinois is the fourth Midwestern state to report a sighting, along with Ontario province in Canada.

The loss of trees in Michigan already puts the ash borer ahead of last decade's scourge, the Asian longhorned beetle. Arborists fear the bright green borer's destruction will outpace Dutch Elm disease, which all but eradicated that species beginning in the 1950s. Ashes are thought to make up at least six percent of the Midwest's tree population.

The adult borer nibbles only leaves, doing relatively little harm. The bug's larvae, however, eat their way through the bark, killing the tree over two to three years. Leaving smaller holes higher up the tree than Asian beetles, borers are harder to detect. The adult found in Kane County this week was trapped in a spider web.

Drenching the soil at an infested tree's base with Bayer Advanced Garden Tree and Shrub Insect Control can stop the borer, as can implanting insecticide "bullets" below a tree's bark. But arborists are preparing for the worst, gathering healthy seeds of the four main varieties of ash to replant in case grown trees vanish from our woods and streets.