Ecologists Take On Tiny Green Beetles That Infest Ash Trees

Transcript

DAVID GREENE, HOST:

We are reporting this morning on a colorful, little bug causing a whole lot of trouble. The emerald ash borer is a tiny, green beetle that's been spreading across the United States and decimating ash trees. Now a majority of U.S. states have infestations and 38 million trees could be at risk. Ohio is on its way to losing 1 in 10 of all its trees. And as Lewis Wallace reports from member station WYSO in Yellow Springs, an Ohio scientist has made a troubling discovery.

LEWIS WALLACE, BYLINE: Macy Reynolds is on the Yellow Springs Tree Committee. She has helped plant native trees, called white fringetrees, along the bypass here. Awesome trees, she says.

MACY REYNOLDS: In the spring they have these kind of like icicles coming off all white flowers, and they have a wonderful smell. Someone should make a perfume out of it. It's beautiful.

WALLACE: Over the summer, Reynolds was riding along here when she saw a guy hacking at a fringe tree with a saw.

REYNOLDS: I saw him cutting down the tree, and I thought, oh, somebody's cutting down a tree on the bike path. And I thought, oh, no.

WALLACE: Turned out the culprit was Don Cipollini, an ecologist at nearby Wright State University. He explained he had the Tree Committee's permission to cut it down for study. She believed him, but...

REYNOLDS: That's when the police car drove up. And he was sure we were doing something we shouldn't be. And we said, oh, we're taking this to see what the emerald ash borer has done.

WALLACE: The officer backed off, but they were left looking at a much bigger problem. Signs that the emerald ash borer is living under the bark of this tree.

DON CIPOLLINI: The green menace. There you go.

WALLACE: That's Don Cipollini. He says after years of study, he had a hunch about fringetrees and decided to inspect.

CIPOLLINI: And I just went from tree to tree.

WALLACE: And lo and behold, he found signs of ash borer larvae right here in these trees along the path.

CIPOLLINI: It's been like detective work, really. I've followed leads. I've had tips provided to me about where these trees can be found.

WALLACE: A few things still aren't clear, though, like whether the hungry bug will eventually kill fringetrees or whether some trees are more susceptible than others. Still, it's a game changer. Before now, scientists have only had to worry about monitoring the ash trees.

DAN HERMS: When I first heard that white fringetree was infested, I was demoralized.

WALLACE: That's Dan Herms, an entomologist at Ohio State University. He explains the pests showed up in southeast Michigan in the '90s, probably brought over from Asia, and they've been fanning out from there, helped by people unwittingly moving them in firewood across state lines. Just removing all the infested trees could cost billions.

HERMS: It's an example of an invasive insect eliminating some of the biodiversity from our forests. And so it's one species. But this is just one species in a big list.

WALLACE: And right now, there's no good way to stop the emerald ash borer. Pesticide treatments are available after the fact, but they are expensive and not guaranteed to work. The next big area of study involves releasing wasps into the environment that like to lay their eggs inside the eggs of ash borers. But wasp releases are definitely a don't-try-this-at-home type thing. Macy Reynolds has been watching the ash trees here die from the borer. In some places, it looks like a tornado came through. And it's all coming from these tiny creatures.

REYNOLDS: They're no bigger than, like, a ladybug. And they're bright green. And you look at it, and you go how can this thing take down a whole tree?

WALLACE: The U.S. Department of Agricultural is studying how widespread the white fringetree problem is before it puts out any recommendations. For NPR News, I'm Lewis Wallace in Yellow Springs, Ohio. Transcript provided by NPR, Copyright NPR.