Emerald ash borer reaches Webster County
Kevin Lunn has known for years that a dangerous pest was making its way toward Webster County.
Ever since the emerald ash borer, an invasive insect that feeds under the bark of ash trees, disrupting the transport of nutrients and water throughout the tree, slowly killing it, started spreading across Iowa in the early 2010s, Lunn, the parks and forestry superintendent for the city of Fort Dodge, has been preparing the city for the eventual arrival of the insect.
Starting in 2014, the city began to remove the nearly 2,400 ash trees standing in city parks and on city rights-of-way, the space between the sidewalk and the curb. Currently, the city has removed 1,892 of those trees.
It was never a matter of if the emerald ash borer would arrive in Webster County, but when.
“(The Iowa Department of Agriculture) said there’s no way of stopping it,” Lunn said. “They said it was coming to Fort Dodge, so we wanted to be proactive and remove them because if it gets there and they start dying, they become brittle and then they can break off and cause different types of damage.”
The Iowa Department of Agriculture and Land Stewardship announced on July 1 that the EAB had been recently confirmed in Webster and Cerro Gordo counties.
The emerald ash borer sighting in Fort Dodge was actually kind of lucky.
Mike Kintner, IDALS EAB and gypsy moth coordinator, had been driving through Fort Dodge when he noticed some “thinning” in the canopy of some trees near Elmhurst Avenue and Dodge Circle.
“I was passing through the area and as I usually do when I’m in an area where (EAB) hasn’t been found, I take a pass through and look at trees,” he said.
When he spotted the thinning, he contacted Lunn, who came out with a city truck to inspect. They found some branches with “flecking,” which is when woodpeckers pull off flecks of the tree’s bark to feed on the emerald ash borer larvae underneath. Then they found the larvae, which do the majority of the damage to the trees.
Lunn estimates there are between 2,000 and 2,500 ash trees on private land in Fort Dodge city limits. Those property owners will be responsible for either removing their ash trees or treating them.
Ash trees can be treated through a variety of ways, including soil drenching and chemicals professionally injected into the tree’s trunk.
“If you plan on treating your ash trees, now is the time to start,” Lunn said.
The treatment is not a cure, Lunn warned, but is a way to prolong the life of the tree and prevent the infestation of the pest. Treatments will have to continue every year or two for the life of the tree, he said.
For those trees that have already been infested, as long as there is less than 30% die-back in the crown, or the tree top, the tree can survive. If the die-back is more than 30%, it’s too far gone, Lunn said.
Lunn also noted that it isn’t a quick process when a tree is infested with emerald ash borer.
“If they start seeing die-back on their ash tree, the tree isn’t going to die within a month or two,” he said. “It takes two to four years before it totally dies. It’s a slow death.”
So residents should have plenty of time to take care of their tree if it does start to die.
Residents can call the local Iowa State Extension and Outreach Entomology office at 515-294-1101 if they suspect an ash tree on their private land has been infested with EAB. The office will have resources and advice on how to manage the pest.
The adult emerald ash borer can only fly short distances, so much of the pests’ movement across the state has been aided by the transportation of infected wood products like firewood, Lunn said. This is why the public is asked to use only locally-sourced firewood.
The emerald ash borer has been identified in 73 Iowa counties, and it will likely continue to spread. The entire state is under quarantine for emerald ash borer, enforced by the U.S. Department of Agriculture, prohibiting the movement of living and dead material from ash trees, as well as hardwood firewood of all species, out of Iowa and into non-quarantined areas of other states.
“Many areas of the state have unfortunately already suffered the consequences of this destructive pest, but we continue to focus on tracking emerald ash borer in counties where it has not yet been confirmed,” Kintner said. “Knowing the whereabouts of this pest helps with treatment recommendations in immediate and surrounding areas.”