GREENFIELD — The emerald ash borer has arrived in Riley Park with a death threat – if not a death sentence – to dozens of mature trees that canopy the city’s staple family park.
The tiny green insect was first reported in Hancock County in 2011, but this is the first time it’s been found in Greenfield’s main park, where more than half of the trees are mature ashes that will likely have to be chopped down in the next few years.
“I knew it was going to hit eventually,” said Joe Whitfield, city naturalist. “The only thing we can do is, when they go just cut ’em down.”
The park’s first victim has already been felled: A 75-foot, 50-year-old ash came down Wednesday morning after much of its canopy had already died.
It was a disappointing day for parks employees, who two years ago marked each of the park’s 125 ash trees with red paint so they could watch for an infestation. Now, they say, it’s probably just a matter of time before other trees will have to be destroyed.
The emerald ash borer is an invasive insect native to Asia. It was first discovered in North America in 2002 in the Detroit area; it likely arrived in infected shipping pallets from Asia.
The larva of the insects is what kills the ash trees. They eat away at the vascular system of the tree.
Moving at a half mile a year on its own, the emerald ash borer has spread more rapidly thanks to people who move infested firewood, nursery stock or logs across state lines.
And it could have a big impact throughout Indiana. Out of an estimated 8 billion ash trees in American forests, according to the U.S. Forest Service, there are around 147 million in Indiana forests, according to Purdue University. At least 2 million more are in urban areas lining streets, yards and parks.
“We have done what we can from a preventive standpoint,” said Ellen Kuker, director of Greenfield parks. “We’ve identified all of them, we’ve marked them, we’ve treated the ones that we can.”
But unfortunately, the treatment – drenching the roots with insecticide twice a year – doesn’t seem to be enough. And there’s no saving an ash tree once it’s too far gone.
Kuker said the best bet for the future is to plant other types of trees in the park that won’t get infested.
“My first call now that I know the (the ash borer) is found in Riley Park will be to the (Department of Natural Resources) to let them know it has somewhat hit the center of town and also to ask them for guidance if there are any grants available to communities affected,” Kuker said.
It’s not just Greenfield city officials who are noticing the emerald ash borer. Roy Ballard, Purdue Extension educator for Hancock County, said he’s been getting calls from residents throughout the county this summer who have questions about the insect. They have shown him samples of bark from their trees, showing the tell-tale swirled pattern of the larvae feasting on the wood.
Another sign a tree has been affected, Ballard said, is D-shaped exit holes on the bark from the adult insects. The tree’s canopy will also start to die, and limbs won’t leaf out.
“Then also the tree responds to that by throwing out a bunch of new, little clumps of secondary growth from the trunk,” Ballard said. “So there’ll be clumps of new, wispy growth from the trunk. It’s a tree’s way of compensating for the damage; kind of like its last gasp.”
To prevent an infestation, Ballard said homeowners can soak the roots of the tree with insecticide or hire a professional landscaper to inject the trunk with a chemical. Injections can be expensive – at around $300 a shot – so Ballard said the homeowner will have to decide whether the tree is worth saving.
Kuker said the department has been soaking the roots of some of Riley Park’s ash trees, but several of the trees are too close to Brandywine Creek to use the chemical.
Riley Park is most affected because it has the oldest trees. Newer parks, like Beckenholdt, don’t have ash trees because city officials knew the emerald ash borer would eventually show up.
Last summer, the nonprofit group Regreening Greenfield planted 50 new trees of several species in Riley Park in anticipation of a loss of ash trees. Those trees are small and will take years to reach the size of the ash trees, but it’s the best that can be done for now, Kuker said.
Infested trees must come down, she added, for the safety of park visitors. Dying, falling limbs can be dangerous.
“(Riley Park) will have a different feel, a different look. But we’re doing everything we can to not take a tree down till absolutely necessary,” Kuker said. “We feel so helpless. There just isn’t a lot we can do.”
Those who see the ash borer or have possible tree damage should call the DNR at (866) NO-EXOTIC. Ballard said ash trees have a strong history in Indiana’s forests and parks, and it’s too bad the tiny killer has arrived.
“They’ve been a real piece of the infrastructure of our forests and our landscape,” Ballard said. “They’re a real strong tree…. It’s a real shame to lose them.”
If you see this beetle or notice trees with signs of damage, the Department of Natural Resources asks you to do the following:
Report the information by calling the Indiana DNR at (317) 232-4120.
Note the date and location where you found the beetle or damaged tree.
Capture the beetle in a plastic jar and place it in the freezer to preserve it.
Carefully wrap and send to the DNR.