TERRE HAUTE —
It’s unofficially a fact.
The dreaded Emerald Ash Borer has been found in Vigo County.
On Monday, Purdue University entomology professor Cliff Sadof collected three EAB larvae from an ash tree growing at Indiana State University, where ash trees ring a parking lot at Seventh and Tippecanoe streets
“You are probably at four to five years until they’re (ash trees) all dead,” Sadof told Indiana State grounds manager Stephanie Krull as he shaved away sections of bark and wood to find the larvae’s feeding tunnels.
Krull and some of her landscaping team had brought a section of the infested tree to an EAB presentation at the Vigo County Public Library for examination by Sadof, who shared information on how property owners can protect their North American ash trees from certain death.
Krull told the Tribune-Star that her staff has suspected EAB in the ash trees on campus since noticing woodpecker holes high on the trees, and then noticing silvery spots high up in the branches. Woodpeckers love to eat the creamy-white larvae, which hatch from eggs laid by the emerald green bugs, high in the canopy of trees.
Though the EAB finding remains unofficial until it is certified by a specialist, neither Krull nor Terre Haute’s urban forester Sheryle Dell was surprised to see the devastating wood-boring beetle, which starves ash trees of nutrients and water by tunneling under bark.
“It’s in the surrounding counties,” Dell said. “It was just a matter of time before it was found here.”
Fortunately for the city of Terre Haute, a street tree inventory has been compiled. Of the 14,000 street trees located within city rights-of-way, about 1,300 are ash trees, Dell said. Those figures do not include city parks, cemeteries or redevelopment properties.
The adult emerald ash borer is dark metallic green in color, about a half-inch long and an one-eighth inch wide. It destroys the water- and nutrient-conducting tissues under the bark of an ash tree. An infected tree can die within two to five years of when symptoms begin. The leaf canopy on infected trees dies off, followed by the branches. Soon the tree is beyond saving.
The focus of Sadof’s presentation during Monday’s public meeting of TREES Inc. at the library was how property owners can reduce their loss of ash trees by taking preventative steps now. Chemical products do exist that can be applied to the ground around an ash tree.
Soil drench products containing imidacloprid, dinotefuran or emamectin benzoate provide protection by “poisoning” the trees’ leaves so that EAB nibbling on the leaves will die. The treatments should be applied at specific times of the year, usually in spring. Property owners can do some treatments themselves, Sadof said, but larger trees need to have an insecticide treatment applied by a professional.
In response to a question about how costly it is to treat an ash tree, Sadof explained that some of the pesticide costs about $20 per quart. A tree that needs two quarts, based on its size, will receive a $40 treatment each year for about six years to keep it alive. That is $240 spread out for six years. The one-time cost of cutting down and removing a dead ash tree can be more than five times that expense if the tree is large and near a house or power lines.
“It is a good investment to spend $30 to $40 to save a nice ash tree,” Sadof said.
An information guide from the Neighbors Against Bad Bugs organization states that a property owner should begin insecticide treatments when EAB is found within 15 miles of the owner’s trees.
Not all trees are worth saving, but trees that are healthy, located in the right spot and valuable to the landscape are worth the investment of pesticide.
“We are not going to save every tree,” forester Dell said. “We will look at health, structural soundness and the sustainability of the site.”
For instance, trees located in areas where they will affect power lines, cause sidewalks to buckle, or are lopsided or already affected by disease will not be saved, she said. Those trees will be replaced with a variety that is appropriate to the site, she said, and the city has been fortunate to receive a grant that will cover some of those costs.
However, trees on private property are the responsibility of a property owner. A homeowner who wants to report a problem tree or with a question about their trees can call the city’s 3-1-1C Citizen Contact Center to request assistance. (Dial 812-244-2311 or simply 311.)
A lot of information about the Emerald Ash Borer is available online and through state agencies.
For information on hiring a professional to treat larger trees, go to www.TreesAreGood.com.
For a list of replacement trees, management tips and information on how to identify ash trees, go to www.eabindiana.info.
For more information on EAB, go to www.entm.purdue.edu/EAB.
To report a suspected case of EAB, call 1-866-663-9684.
Reporter Lisa Trigg can be reached at 812-231-4254 or firstname.lastname@example.org. Follow her on Twitter @TribStarLisa.