The City of Dubuque is treating about 300 healthy Ash trees on public property with insecticide to try to save them from the Emerald Ash Borer infestation. About 30 Ash trees in Dubuque’s Flora Park that are in poor condition will be cut down. Steve Fehsal is manager of the park division in Dubuque’s Leisure Services Department.
“Typically trees that are in poor or very poor condition are slated for removal. Treatment will not really serve any purpose,” he says. “We are only treating healthy ash trees at this time.”
Emerald Ash Borers were discovered in Dubuque in August. Ash trees account for a sizable share of the tree “canopy” in Dubuque. For example, of the 360 trees in Flora Park, 107 are ash trees.
“For the city trees that the city owns on parkways and right-of-ways and parks, it’s about 24 percent of our tree population,” Fehsal says.
In January of last year the City of Dubuque adopted a game plan that calls for “selective removal” of ash trees that are in poor condition. Fehsal says destruction of infested trees kills the larvae and prevents adult Emerald Ash Borers from migrating to other trees.
“You can remove a tree any time of the year. Obviously it’s easier to clean up in the winter months when there’s no leaves on it,” Fehsal says. “However, we make the determination in the spring and summer months by how the tree leafs out in the spring and how it reacts to the summer.”
“High-risk” trees are being removed first in Dubuque. Officials in Cedar Rapids estimate about 30 percent of the trees that line the streets in Cedar Rapids are ash trees. Officials in Des Moines say there are about 35,000 ash trees on city-owned property in the capital city.
The Emerald Ash Borer feeds on the inner bark of ash trees, ultimately causing the tree’s death. The insects were first found in Michigan 14 years ago. It was found in Iowa for the first time in 2010. According to the Iowa Department of Agriculture, tests have confirmed infestations in the following 29 counties: Allamakee, Des Moines, Jefferson, Cedar, Union, Black Hawk, Bremer, Wapello, Jasper, Henry, Muscatine, Boone, Story, Appanoose, Lucas, Mahaska, Marion, Monroe, Keokuk, Clinton, Dallas, Polk, Scott, Davis, Poweshiek, Lee, Montgomery, Dubuque and Linn Counties.