Despite winter’s might, ash borer treatment urged
By Amy Lavalley Post-Tribune correspondent April 6, 2014 7:28PM
The emerald ash borer. | File photo
Updated: May 8, 2014 9:34AM
Sure, it was a long, cold, miserable winter, but there’s at least one creature that didn’t care the invasive emerald ash borer, which is munching its way through ash trees throughout the region and the state.
An assortment of tree experts point out that the insect migrated to Indiana by way of Michigan, a state hardly known for its warm winters. But they also note that early April is a good time to apply a preventative pesticide, or apply the chemicals to ash trees in the early stages of infestation. It might be enough to save the tree, experts said.
“The cold weather will knock out the population some, but not enough to think we’re safe,” said Nikky Witkowski, horticultural educator with the Lake County extension service.
The emerald ash borer arrived in the United States by way of Detroit in the early 1990s in a shipping container full of wood products, said Philip Marshall, state entomologist and forest health specialist with the Indiana Department of Natural Resources.
It crept its way south and was first spotted in Indiana at a campground in Steuben County, just south of the Michigan state line, in June 2004, he said. The pest was first found in Porter County in 2006, in the town of Porter. Lake County followed later, with the bug popping up in Merrillville in 2011. In this area, the infestation is worse closer to Lake Michigan.
Statewide, 84 counties are on quarantine for the ash borer, though in 15 of those counties, the insect has yet to be found. The quarantine covers the insect itself, hardwood species firewood, and any part of the ash tree, according to the DNR website. Eight counties in the southwestern part of the state have been completely spared so far.
The insect can travel hundreds of miles over a few days, with a little help.
“That’s the easy part. You did it. You moved it 200, 300, 400 miles, and you probably did it in two or three days,” Marshall said, adding firewood has been one of the main ways the insect has spread, making campgrounds one of the hotspots for the ash borer.
As spring slowly warms the region, homeowners can look for early signs of whether their ash trees have fallen victim to the emerald ash borer. Those include sections of the tree not leafing out, or parts with stumped leaves, Witkowski said.
Woodpeckers also may flick off small sections of bark to get at ash borer larvae, though that may be difficult to spot, she said. Another sign experts noted: Capital “D” shaped holes in the bark, where the ash borer has burrowed in.
If the ash borer infestation is severe, Witkowski said, the bark will fall off the trees; at that stage, trees may need professional care, or to be cut down.
Homeowners who notice early signs of the ash borer may be able to save their trees with annual application of products containing the pesticide imidacloprid, which also can be used as a preventative treatment.
“The bottom line is, you can’t assume your ash is safe,” Witkowski said. “You have to treat it. If you don’t treat it, it will eventually get it.”
At Alsip Home and Nursery in S. John, lawn and garden manager Sharisa Eatinger said a growing number of customers have been coming in each spring to get what they need to treat or pre-treat their ash trees.
“If you do it now before leafing, you have a better chance of saving the tree,” she said.
Communities, meanwhile, are doing what they can to manage their trees.
When Valparaiso inventoried its trees about six years ago, 7 percent of those on public land, including streets, cemeteries and parks, were ash trees. That included more than 600 trees, said Ann Brugos, executive assistant with the public works department and a member of the board of directors for the Indiana Urban Forest Council.
The city’s current inventory is 383 ash trees, and the city will be removing 82 of those in the Essex Park subdivision alone. Later this month, the city’s “Shade Brigade” tree planting volunteers will plant 107 native tree species in that subdivision, thanks to federal grant money.
The city is removing ash trees because ongoing treatment for the ash borer is too costly, Brugos said, though the city picked some ash trees in Essex Park to try to save.
“We’d hate to lose every single ash in our inventory, which is what would happen if they weren’t treated,” she said. “There’s just no way we could treat every ash tree.”