Emerald ash borer: More information
Detroit in 2005 was a sobering sight. Ash tree skeletons were everywhere. The Inquirer had sent me there to write about the emerald ash borer, an insect that was killing every ash it got to, and was spreading fast. Officials figured it would make its way to Pennsylvania at some point, and the paper wanted me to find out what lay ahead.
Emerald ash borer: More information
Detroit in 2005 was a sobering sight. Ash tree skeletons were everywhere.
The Inquirer had sent me there to write about the emerald ash borer, an insect that was killing every ash it got to, and was spreading fast. Officials figured it would make its way to Pennsylvania at some point, and the paper wanted me to find out what lay ahead.
As this morning's story detailed, the ash borer as now arrived in our midst in southeastern Pennsylvania. It was discovered in a condominium complex in Warrington, Bucks County, by an astute arborist who noticed woodpecker damage -- a telltale sign because the birds love the larvae that are killing the tree.
Alas, the paper was tight on space this morning, so the story had to be cut. Here are some of the points I thought people who were really interested in the topic might want:
The reason the Bucks County detection is scary for many tree folks is that it comes late in the game, as is usually the case.
The usual progression is that the borers are in a tree for three to five years before they’re detected. Then, for maybe another three to five years, tree mortality proceeds more or less linearly.
After that, “mortality can best be described as being exponential,” said Greg Hoover, a Penn State entomologist. “The curve will become quite steep.”
Likewise, although the insect was first discovered in this country in Detroit in 2002, officials determined from examining damage to tree rings of infected ashes that it had likely been around since the mid-1990s.
Like so many other invasive species, it was thought to have hitchiked on wooden packing crates.
The borer spread through the city and its suburbs. The insect also chewed through municipal budgets. In Westland, a small city of 86,000 people west of Detroit, officials spent $1 million in two years to clear thousands of dead and dying ash trees along streets and in parks.
Homeowners paid out of pocket, too, and mourned the lost shade and landscape value for their homes.
I met a woman whose neighbor spent summer days under the huge ash in front of his house. With the giant gone, he sat in a small motor cart and followed the shade cast by smaller trees. She has lost the tree outside her window, and now the sun was streaming in. So she needed new curtains and a bedspread, she said, because they had faded so badly. Her sole consolation: A formerly reluctant rose bush bloomed in her formerly sunny yard.
Oh, the ways, large and small, that trees impact our lives. On the grander scale, in cities, they provide cooling shade and they filter the air and they up the value of properties and neighborhoods.
By now, fifteen states plus Ontario and Quebec are part of a multinational effort to fight the borer.
And still, it spreads.
Mark Biresch came to the Hampton Greens condominium complex to prune some trees, and he immediately noticed damage from woodpeckers on an ash.
He called Scott Guiser, the educator at Penn State’s Extension Service in Bucks County, who came to have a look, as did a state Department of Agriculture entomologist, Sven Spichiger.
The diagnosis seemed clear.
When they looked in a wooded area around the complex, they found about 20 more infested ashes.
Officials had already planned to hang purple traps in parks and campgrounds throughout eastern Pennsylvania, hoping to nab a few insects if they were in the area. But those are iffy. And the idea is only to detect the insects, not to control them.
For control, a few species of parasitic wasps look promising. As well as some heavy-duty insecticides.
What to do?
Donald Eggen, chief of the division of forest pest management in the state’s Bureau of Forestry, said that municipalities and homeowners should do inventories to figure out where ash trees are located.
Then, “let’s picture all those trees dead. Let’s make a plan.”
Municipalities may try to save a few prime specimens. Eggen lives near West Chester, and Hoopes Park, where he sometimes gives talks about trees — and the borer — has “at least 30 beautiful, huge ash trees.”
A first-line treatment is a soil drench containing imidacloprid, and although it is only about 60 to 70 percent effective, Eggen said, people who have trees within 20 miles of the Warrington site might want to consider starting treatments.
An arborist can do this, but if you go for a version available at stores, “read the label,” Eggen said. Read the entire label.”
If and when an actual infestation is confirmed by an expert, it might be time for a substance such as Tree-age, which is injected into the tree and can be administered only by an arborist.
After the recent discovery, arborists are watchful, and perhaps a tad fearful.
“This is a big surprise,” said arborist Ken LeRoy, who has already been contacting clients to discuss strategy.
“I really expected for it to knock on the door a little more. This is like a Trojan horse. It came right into the center of Bucks County.”
And here's the Penn State site.
Here's a link to Scott Guiser's blog, where he describes the Warrington find and offers more informational websites.