It does not appear as though the emerald ash borer infestation will go away any time soon.
The question then becomes, how long is the city of DeKalb willing to continue paying to protect hundreds of ash trees?
Since 2012, the city has spent tens of thousands of dollars to protect hundreds of ash trees from the tiny green beetles, insects native to China that are killing many area ash trees. The beetle’s larvae kill the trees by burrowing into them, disrupting the trees’ systems for moving food and water and eventually starving them.
The trees are treated by drenching the soil around them with a chemical that repels the borer.
This year, the DeKalb City Council accepted a bid of as much as $25,000 from Trugreen to treat 859 ash trees on city property.
The effectiveness of the treatments is not universally accepted – Sycamore city officials have declined to treat any of their trees and instead are removing them. In DeKalb, the treatments appear to have preserved more than 90 percent of the roughly 930 trees that Dave Clanton of Clanton Tree Co. says he initially treated in 2012.
The council had committed to treating its ash trees for as many as five years, and 2014 is year three of the program. But scrutiny is growing on demands on the city’s general fund revenue.
With no means of eradicating the ash borer in sight, this might be a program that is more delaying the inevitable need to remove the trees rather than ensuring they can survive for decades to come.
Ash trees became popular in part because they grow quickly and can thrive on parkways, unlike some species of trees. However, they appear to have been over-used in some neighborhoods, and removing them creates a noticeable void.
Tall, mature trees add character to neighborhood parkways. They provide shade for people and habitat for birds. Scientific studies show they make people happier.
But ash trees are not the only species capable of providing those benefits. If the only way to save the ash trees is with costly annual treatments, the best strategy might be to develop a tree replacement program.