The emerald ash borers are heading west, leaving town – and tens of thousands of dead ash trees in their wake in northeast Indiana.
But don’t breathe a sigh of relief just yet.
Other invasive pests are lying in wait, only a few miles from the state’s eastern border, ready to pounce on various species of trees, according to Phil Marshall, forest health specialist and state entomologist with the Indiana Department of Natural Resources.
Many of the state’s 150 million ash trees have died or are dying, costing Hoosiers millions and marring the landscape and altering the environment, Marshall said in a statement announcing this week as Emerald Ash Borer Awareness Week in Indiana.
Years ago, many cities, towns and private citizens planted ash trees because they were known to be fast-growing, strong and tolerant. Other benefits of trees include cleaner air, lower utility bills, higher property values and reduced flooding.
The state continues to monitor the spread of the emerald ash borer and much of Indiana remains under a federal quarantine, which bars or limits the transfer of ash wood – living or dead, Marshall said.
Right now his department is setting traps in the state’s southwest counties.
They no longer monitor northeast Indiana, because the ash borer has pretty much run its course and already destroyed many of the ash trees, he said.
The pest kills the tree by tunneling into the sapwood as a grub and emerging as an adult.
The best indicator of whether an ash tree is infested is to watch the woodpeckers in February and March when they bore holes in ash trees to eat the ash borer larvae.
After the woodpeckers bore the holes, the bark changes color and we can tell by looking if the ash borer is present, Marshall said.
The emerald ash borer came to the United States in 2002 and 2003 from Asia, China and parts of Russia on shipments loaded on ash pallets.
It’s particularly important that people heed the quarantine and not transport ash wood unless it is seasoned or certified as clean, Marshall said.
No shortage of pests
Many times it takes one or even two years for larvae in the wood to die, he said.
Larvae in the wood could come out as adults this summer, in 2015 or even in 2016, he said.
As the ash borer moves west in search of more ash trees, two new invasive pests – the walnut twig beetle, which kills black walnut trees, and the Asian long-horned beetle, which can kill eight different species of hardwood trees, particularly maple trees – are just a few miles from the state line near Cincinnati and moving west, Marshall said.
In Fort Wayne, the city has removed 13,000 dead ash trees in addition to 4,000 other species of dead trees in the last six years, Parks Director Al Moll said.
In 2008, the city had 55,000 street trees and by the end of this year there will be about 48,000, he said.
That doesn’t sound good, but the positive thing is that we are down only about 7,000 trees because we have continued to replant each year, Moll said.
The Parks Department will plant 2,200 new trees this year – both in the parks and on city streets – and should be completely done with removing dead ash trees by June, he said.
More than 1,000 of the ash trees that are left are being treated with direct injections into the trunks, he said.
Many of those are in Freimann Square and along Clinton Street near Headwaters Park – the gateway to the city, he said.
The city always loses about 500 trees a year from natural causes, but this year’s harsh winter added another 250 trees to the death toll, Moll said.
By mid-August, the city had spent nearly $3 million removing the dead trees.
New Haven’s experience
In nearby New Haven, city crews just finished removing seven ash trees along the Rivergreenway that had become public safety concerns, Parks Superintendent Mike Clendenen said.
The city has spent $10,000 to $15,000 in the last few years to remove dead ash trees in eight parks, mostly the ones in open spaces or the ones that posed safety concerns, Clendenen said.
We don’t bother with the ones in undeveloped areas, because we can’t afford to take them all down, he said. We are replanting about 20 trees a year with the help of the Friends of the Park and the Great Tree Canopy program.
New Haven received a Tree City USA designation in 2012, 2013 and 2014 for tree management, planting and maintenance, something the city is very proud of, Dave Jones, superintendent of Utilities said.
There are 770 city trees on city property and currently, 45 infested ash trees to be removed, Jones said. The city normally removes about 10 trees a year, he said.
Fifty-one diseased ash trees have been removed over the last three years and 66 other trees had to be removed for construction projects, Jones said.
During that same time, we planted 175 trees.
Thirty trees – ash and others that are in the way of a sidewalk project – are scheduled to be removed this year, he said.
The city has spent $110,000 for contractual tree removal in the last three years, Jones said. The city budgets about $5,000 a year for tree removal.
All it takes is one windstorm to go over budget, Jones said. We always end up spending more.
Nearly 30 miles to the north, in Churubusco’s 68-acre town park, Park Superintendent Rick Krider noticed in 2010 that some of the park’s ash trees seemed to be thinning.
Our main woods where most park activities take place had 82 ash trees and they were dying fast, Krider said.
In 2011 the town contacted a contractor who began trunk injections on some of the trees the town thought could be saved.
I decided to try and save 14 of the most important trees – ones that were around concession stands and a splash pad that provided shade, Krider said.
The town council agreed to pay for about $2,000 to treat the trees in 2011 and again in 2013, he said.
It turned out to be a wise decision.
Twelve out of the 14 made it, Krider said.
It cost another $10,000 to remove 30 trees and that cost was covered by anonymous donors, he said.
Rick Wilson, a tree care manager at Signature Lawn and Tree Care Service in Fort Wayne believes the emerald ash borer infestation has reached a threshold.
They are still around, but it’s a much easier population to deal with, Wilson said.
Wilson spent much of the past week treating infested ash trees around the city with trunk injections – which must be reapplied every two years – and with topical soil treatments.
We can’t guarantee that we can save them, he said. We have some that look great, but we have also lost some in the process.
The harsh winter had little effect on the emerald ash borer since it takes seven or more days of continuous 30- degree-below-zero weather to kill the larvae, Wilson said.
He advises homeowners to look at their ash trees’ canopies this spring to tell whether the tree is healthy.
If the tree is missing 20 to 25 percent of its canopy, it’s the customer’s decision on whether or not to treat it, but we cannot guarantee it will be saved, Wilson said.
If it is missing only 10 percent of its canopy, there’s a good chance it can be saved.