Emerald ash borer's destructive path claims 10 Aspinwall trees
Bright green tags mark a row of 10 ash trees along Freeport Road in Aspinwall for removal by early fall, but a shiny green beetle marked them as goners.
These trees and millions of others across Western Pennsylvania are infested with emerald ash borers, a beetle-like bug from Asia that can kill ash trees by feeding just below their bark.
“I didn't realize those green signs all meant ‘destined for death.' Those poor things,” said Kimberly Petrikovic, an office manager at Bradford Capital Partners, across from the trees that helped anchor a flower bed and buffer the sight and sound of trains rumbling past. “I just don't know what they're doing to stop this.”
More than five years after the beetle's discovery in Butler and Allegheny counties, the insect continues its destructive spread in the state, killing swaths of Pennsylvania's 300 million ash trees. Preventive insecticide treatment is so expensive that it's usually reserved for trees that have historic, aesthetic or personal significance.
Officials are trying to clean up dead and dying trees before they become a hazard to roads, trails and structures.
“Every month it seems like there's another county added to the list” of infested areas, said Terry Brady, spokesman for the Department of Conservation and Natural Resources. In 2013, infestations have reached Warren, Forest, Elk, Clearfield, Cambria, Blair and Fayette counties.
Nearly every county in the Pittsburgh region except Greene has been affected since 2007, according to the DCNR. The Department of Agriculture confirmed the latest infestation on Thursday in Cameron County.
The bugs hit Pittsburgh's parks hard. Workers removed 175 ash trees from Frick Park alone during the past two years, said Bryan Dolney, field ecologist for Pittsburgh Parks Conservancy.
Dead trees deeper in the woods, away from trails or parking areas where brittle branches could fall, were left alone for insect and animal habitat. Formerly shaded areas such as the park's Tranquil Trail are more open.
About 155 trees in parks citywide were “injected” with an insecticide that costs up to $435 a pint.
“We've saved what we can save, and we still have a list of a few candidates for injection,” Dolney said.
Statewide, signs and ad campaigns exhort Pennsylvanians not to move firewood, because the beetles or their larvae can hitchhike in firewood to uninfested areas faster and farther than they normally fly. The state remains under a federal ban on exporting firewood.
In state parks, staff took inventory of trees and found ash borers affected tens of thousands, said Rachel Wagoner, a DCNR resource manager. Including trees not surveyed and those on private property could raise the number into the millions, she said.
Staff treated some trees but others were too far gone. “It was more of a manage-as-things-decline situation,” Wagoner said.
Officials released natural predators of the beetle, including varieties of parasitic wasps, to buy time — with the hope that “hardier, maybe more resistant, trees to take over.”
Penn State University researchers are working on ways to trap the insects, said entomology professor Thomas Baker. One projects, funded by the USDA, was designing a lure that looks like a female ash borer to trap curious males on a sticky sheet.
Matthew Santoni is a Trib Total Media staff writer. Reach him at 412-380-5625 or email@example.com.