According to UI officials, there are 600 to 700 ash trees on the UI campus, amounting to almost 10 percent of the campus trees. And they may be at risk of falling victim to the emerald ash borer, an exotic Asian beetle that has destroyed ash trees in bordering states.
Andy Dahl, the aborist for the UI campus, said UI faculty and local officials have been monitoring the situation, but right now, it is a matter of “wait and see.”
“There may be some here; we just don’t know it,” he said. One of the problems with monitoring emerald ash borer is damage to an infected tree may not show for three to five years.
Harry Graves, the executive director of the Johnson County Conservation Board, said local officials have implemented techniques to reduce risks and identify any potential threats. These techniques include sentinel trees, which are ash trees with a ring of bark cut out around the base to weaken the tree and attract emerald ash borers, and traps that entice and capture the pest.
Dahl said Iowa Department of Natural Resources officials set as many as 10 of these traps on the UI campus last year, and they were unable to demonstrate any presence of the beetle. Dahl expressed concern over the effectiveness of the traps, given the short time span that emerald ash borer has been in North America.
Officials are considering chemical solutions, Graves said, but they are wary of the environmental risks.
He said one of the few things that can be done to prevent the bug in Iowa is not moving firewood from one area to another.
“Transportation of the insect most certainly occurred by the transportation of firewood,” said Graves.
Although a mature emerald ash borer has not been found in Iowa, larva from the bug, which has destroyed ash trees in Wisconsin, Illinois, Minnesota, and Missouri, was found in Clayton County, in northeastern Iowa, in early June, prompting conservation officials to increase their efforts to combat the invasive species.
The emerald ash borer “goes right underneath the bark and kills the cambium, the active growing part of the tree,” said Tim Englehardt, the director of the Clayton County Conservation Board.
“Our efforts are along the lines of education,” said Englehardt, who stressed the best way to combat the emerald ash borer is by educating people on the symptoms of infected trees and the importance of not moving firewood.
Engelhardt said the U.S. Department of Agriculture has rechecked the park in which the larva was originally found, and officials have not found any other evidence of a presence.
At a meeting last month hosted by the Clayton County Conservation Board, officials from Natural Resources and USDA and members of the local timber industry met to discuss the issue. They then outlined potential steps and procedures for quarantine regulations, which would restrict the movement of wood products from the area.
Robin Prusiner, an entomology official with the Iowa Department of Agriculture, said detection efforts are on the forefront of the agenda in keeping the emerald ash borer out of Iowa.
Despite their best efforts, she said, the practices currently used are “not incredibly efficient, [because] we haven’t had much time to work on them.”
She said that because the appearance of the emerald ash borer in North America is relatively new, first appearing in the Detroit area in 2002, officials have not had enough time to build an efficient system for attracting, identifying, and capturing specimens.
