A fully developed Emerald ash borer. | Sun-Times Media file
Updated: December 29, 2012 6:22AM
There are 3,146 public ash trees in Gurnee and every one of them is “standing dead” because of the Emerald ash borer, a small bug that causes a lot of damage, Jake Balmes, Public Works street division supervisor, maintains.
“We expect to eventually lose one-third of our community’s public parkway (ash) tree canopy. The streets lined with ash trees will soon be bare,” Balmes told the Village Board on Monday night.
However, Gurnee “is ahead of the curve”, he indicated because of prompt action taken and the use of new technologies, such as chemical treatments, to control the borers.
In a committee-of- the-whole discussion, Balmes said since they were first discovered in Illinois in 2006, the dreaded Emerald ash borers have been responsible for killing millions of ash trees. Gurnee’s tree infestation was first confirmed in 2011.
“Man appears to be a primary spreader by selling and distributing diseased firewood throughout the state,” Balmes said. Ordinarily, the spread of natural infestation averages about five to 10 miles per season.
The borers are originally from Asia, are active only during summer months and die off during the cold winter. They lay their larvae in bark crevasses where they feed on the tree trunk’s nutrients, destroying its vascular system.
Balmes said the cost to treat, remove and replace Gurnee’s public parkway trees is expensive, estimating his village team has already spent $132,000 in staff time and expenses on the project.
To save costs, the village now relies primarily on saving a diseased tree by using special chemical treatments, rather than a more labor-intensive approach of tree removal and replacement.
“A small hole is drilled into an ash tree and chemicals are injected. They spread throughout the trunk and into its leaves. It really works well in preserving the tree and killing the larvae,” Balmes said. More than 2,600 trees have already been chemically treated, he said.
Balmes suggests continuing the treatments on a three-year rotation basis, and removing and replacing roughly 150 dead ash trees annually, particularly where ash tree ratios are most dense.
“Research suggests that if we can weather the initial infestation, we may be able to safeguard our ash trees long term,” he said.