Ohio now in danger of losing oak trees to imported disease

Name a tree and it likely has its nemesis. First there was Dutch elm, a fungus that destroyed American elm trees in the 20th century.

Then the early part of the 21st century brought the emerald ash borer, a native of China and Korea, to the United States. It proceeded to wipe out billions of ash trees that were once the second-most common shade tree in America after maples. A 2003 four-day Dispatch investigative series, Global Swarming, detailed the cause, effects and costs of the ash borer.

Nearly 4 billion ash trees in Ohio were virtually wiped out in the past decade and a half, and now new adversaries for oak and maple trees have been detected, according to stories earlier this month in The Dispatch and its suburban This Week newspapers.

Unfortunately, we have not learned from the devastation of the emerald ash borer how to halt the incidental importation of invasive species that like to hitch rides to the United States from ports in China, Korea, Japan and the like.

In Upper Arlington, Parks and Forestry Superintendent Steve Cothrel has alerted

residents to watch for another tree borer: the Asian longhorned beetle, which likes to leave its larva in maples but moves more slowly from tree to tree than did the highly destructive ash borers. Cothrel said the beetle has not been found in the northwest suburb though it was detected elsewhere in Ohio in 2011

Of greater concern is the more recent revelation that plants infected with Sudden Oak Death disease were brought into Ohio for sale in Walmart and Rural King stores between March and May.

That disease is attributed to a plant pathogen, Phytophthora ramorum, that turned up on an estimated 1,600 rhododendron and lilac plants that were shipped to stores throughout Ohio and 17 other states. Until now, the pathogen has been seen primarily in California, where it has killed millions of oak trees.

It will take vigilant consumers to help contain this infestation. The plant health division of the Ohio Department of Agriculture can provide instructions for destroying infected lilacs and rhododendrons at 614728-6400 or by emailing plantpest@agri.ohio.gov.