The emerald ash borer, an invasive beetle, has slowly spread across the state of Iowa in recent months and years. First evidence of the insect’s presence in the state of Iowa came around 2010, according to press releases from the Iowa Department of Natural Resources and the Iowa Department of Agriculture and Stewardship.
But it wasn’t until February of this year that Iowa City was confirmed to have an infestation of emerald ash borers. Johnson County was the 30th county in the state with such a designation — the total number of infested counties in Iowa has now reached 35.
Emerald ash borers prey on and destroy ash trees. Adults measure close to a half inch in length and can be identified by their metallic-green shell. The grub-like borer larvae live under the bark of the ashes and burrow into the wood, destroying pathways for water and nutrients, eventually causing the trees to die.
Visible symptoms of an infected tree include canopy death (starting from the top downwards), D-shaped exit holes, peeling bark, bored traces and an increased activity from woodpeckers.
According to the Iowa City government’s website, there are approximately 2,000 ash trees on city property, and according to the University of Iowa’s facility management — cited in a press release — there are roughly 560 ash trees on campus: about 7% of total tree species.
Efforts to prevent the spread of the insects include stopping transportation of firewood between counties and states, and by notifying an arborist or contacting the Iowa Department of Natural Resources website.