Ash borer's spread stopped - for now

Nov 5, 2009, 18:26 PM by User Not Found

Officials release Chinese wasp in hopes it can also contain beetle

Posted Nov 04, 2009 @ 09:53 PM


After several consecutive seasons of newly discovered emerald ash borer infestations, state agriculture officials recently found no new traces of the invasive pest outside previously quarantined areas.

Thousands of purple traps hung throughout the state over the peak summer travel months for the beetle, infestations of which ultimately decimate ash tree populations, found no insects beyond the boundaries where it already is believed to be.

"Our monitoring and surveillance did not find beetles outside the existing quarantine area," Illinois Department of Agriculture spokesman Jeff Squibb said Wednesday. "There have been new detections, but they've all been within the quarantine boundaries."

The department placed approximately 5,000 traps across the state to detect infestations of the beetle, though this year more traps were located farther south. Infestations in the northeastern part of the state have been documented.

The state ag department expanded its emerald ash borer quarantine area to include all or part of three central Illinois counties in November 2008 after traps placed in 2008 indicated a spread of the beetle.

The quarantine restricts the movement of cut firewood and some landscaping materials. Added to the list last year were Woodford and McLean counties and the eastern flank of Marshall County. Those areas brought to 21 the total number of counties that were fully or partly quarantined.

That quarantine area remains in effect, Squibb said.

But officials might have a new weapon to fight the continued spread of the insect. Researchers recently released hundreds of Chinese wasps in some infested areas around Chicago to test whether the insects, which are one of the few natural predators of the beetle in Asia, can prove to be an effective biological control against the borer.

The wasp's scientific name is Oobius agrili. Female wasps, which are smaller than a poppy seed and don't sting, lay eggs inside borer eggs. The young consume the borer egg as part of the reproduction process.


Matt Buedel can be reached at 686-3154 or