Jon Brown found something in Forkston Township, Wyoming County, this spring that will likely change the makeup of Pennsylvania’s forests in the near future.
And not in a good way.
Brown, who is an arborist and owner of Brown Hill Tree Company, noticed the ash trees near the Forkston baseball fields and up through Windy Valley looked odd. The color was a little off, he said, and woodpeckers were peeling the bark away to feast on something inside the wood.
Turns out it was the emerald ash borer, an invasive insect that has virtually wiped out ash trees where it was first found in Michigan years ago and now appears on track to doing the same thing in Pennsylvania.
The emerald ash borer is actually a beetle. Adults feed on leaves and cause little damage, but their larvae feed on the inner bark of ash trees, eventually preventing the tree from being able to transport water and nutrients and ultimately killing it. Monitoring conducted by the state first detected the insect in western Pennsylvania in 2007 and a few years ago in Luzerne County along the Wyoming County border.
It’s believed the insect has been spread through states and counties by the transportation of infested wood, such as firewood. It’s now found in 22 states and 47 of Pennsylvania’s 67 counties.
“It’s sickening knowing all these trees are going to die,” Brown said. “We’ve been watching for it pretty intently and now it’s pretty bad here.”
Brown predicts the emerald ash borer will do to ash trees what blight did to chestnut trees decades ago when it wiped them out of Pennsylvania’s forests.
It’s a dire prediction, but one that Sven Spichiger, the state entomologist with the Pennsylvania Department of Agriculture, agrees with.
“It kills at a 99.9 percent rate. We’re looking at the loss of an entire genus of trees,” Spichiger said.
When told of the infestation in Wyoming County, Spichiger wasn’t surprised. He said the insect is now found in more counties than not and it doesn’t take that long to spread.
Initially there were several quarantines in place to stop the movement of firewood with the hope it would slow down the spread of emerald ash borer, but since it is relatively widespread today the county-to-county quarantine has been lifted, Spichiger said. There is still a quarantine on firewood coming into the state - it must be bark-free, and another federal quarantine on moving firewood out of the state.
But Spichiger said the best approach is simply don’t take firewood anywhere.
“Even though it’s not technically illegal to move firewood, you really need to think about it,” he said. “If an infested tree is cut for firewood, the emerald ash borer can still live inside that bark for two years. If you cut it down and drive it to your cabin to burn, the larvae will hatch out and you’ve basically killed all the ash trees in that area.”
Because ash trees are prevalent in the northern half of the state, the insect threatens to wipe out a species that is valuable to the timber industry. Brown said the ash borer has a flat head and drills D-shaped holes into the wood before it kills the tree.
His advice for landowners who have ash trees in an infested area: cut them down while they still have value as timber.
If you have an a few ash trees in your yard, however, there is hope.
For the last three years, Brown’s company has been treating ash trees for customers. There are two ways, he said, and both methods are best performed from now until mid-June.
One method involves spraying the lower 5 feet of the tree with an insecticide, which the tree eventually takes up through its trunk and branches. The treatment costs about $3 per circumference inch and has been done yearly, Brown said.
Another treatment method involves drilling holes in the base of the tree and inserting plugs with pressurized bottles that injects the insecticide into the tree over time. This method costs between $7 and $12 per inch, Brown said.
“People need to be aware that this is a real issue,” he said. “The treated trees could be the only ones that survive.”
Other methods are also being explored, according to Spichiger. Researchers are looking into the viability of parasites and even a predatory wasp that could kill the emerald ash borer. The state Department of Conservation and Natural Resources is collecting ash tree seeds so if the insect is stopped, seeds can be planted to replace what was lost.
Still, the work into a biological control is a very long-term project, Spichiger said, and could take a decade or more before there are any results.
“This is a very devastating insect, but it doesn’t mean we’ve stopped fighting or have given up hope,” Spichiger said. “We do have successes when it comes to utilizing a fungus to control gypsy moths and stopping the oak-borer. People are working on it.”