Destructive Beetles Found in Northeast Iowa
By Rick Smith, Reporter
ALLAMAKEE COUNTY, Iowa - The emerald ash borer, the killer of millions of ash trees in 18 states, is on the move in Iowa, the Iowa Department of Natural Resources reports.
The state agency on Tuesday said that larvae from the destructive borer has been found in two additional spots in Allamakee County in far northeast Iowa.
On May 14, 2010, state officials first identified the emerald ash borer in Allamakee County on an island in the Mississippi River.
Now, a statewide ash monitoring initiative has turned up the emerald ash borer in a tree at Pool Slough and a tree in the Black Hawk Point Wildlife Area south of New Albin.
Tivon Feeley, forest health program leader with the DNR, on Tuesday called the finding at Black Hawk Point particularly "significant" because the spot is the furthest to the west in Iowa that the borer infestation has been identified.
Feeley noted that the experience of states such as Michigan, Ohio and Indiana, has shown that ash-killer insect establishes itself before it is discovered.
"They're definitely on the move," he said on the ash borer in Iowa. " ... And in the next three years, I think we're going to see a big change for the state. I don't think it's just going to be a dot here and there in one or two counties. If we look at what happened in Indiana, they found just one or two in their northeast county in that first year, and just three years later, the entire state was lit up."
He noted that the emerald ash borer showed up south of St. Louis in Missouri, and now is across the state in Kansas City and has spread west into Kansas.
Feeley said budget constraints have prompted states to take a wait-and-see approach to the ash borer rather than, as in the past, spending large sums of public dollars to take down ash trees near where the bug has been spotted. It's possible, he said, that some ash trees in a forest might have some tolerance to the bug. Some states, too, are exploring the use of a particular kind of wasp that is a natural parasite to the borer, he said.
In Cedar Rapids, Todd Fagan, the city's arborist, on Tuesday called the new discoveries of the ash borer in Allamakee County "expected." He added that he suspects that the pest has spread deeper into the state, but for now, nothing has changed for Cedar Rapids, he said. In the last four years, the city has removed about 800 street ash trees, most in declining condition, and replaced them with different species of trees, a practice that will continue, Fagan said. The city likely has about 20,000 ash trees among its 80,000 to 100,000 street trees, he added.
Daniel Gibbins, Cedar Rapids' parks superintendent, on Tuesday called the news out of Allamakee County "frustrating if not surprising."
"It is a reminder that an early response by both landowners and cities to diversify plantings ... is critical to reducing the impacts of such devastating pests," Gibbins said.
Feeley and Gibbins both caution homeowners to consult with a qualified arborist if they choose to try to save a ash tree in the yard.
Feeley said an effective insecticide is available, though the DNR discourages its use if a homeowner is beyond 15 miles of a borer sighting. The chemical treatment, he said, is ongoing and can cost about $12 per diameter inch of a tree every three years. Often the insecticide can buy a homeowner some time to allow a new shade tree time to establish itself, he said.
Feeley said the DNR's statewide borer monitoring program involves the examination of 416 ash trees across the state. In each instance, a portion of bark from the tree has been removed to attract any nearby emerald ash borer into the tree.
Three of the insect's white grub-like larvae were found in a trunk of the tree at Black Hawk Point and two in a tree at Pool Slough in Allamakee, he reported.
Another 80 of the test or "sentinel" trees, most in southeast Iowa along the Mississippi River, have yet to be tested in the current examination of the state's 416 sentinel trees, Feeley said.