Stress from the current drought, an early spring warm-up and an apparent boom in the number of emerald ash borers are knocking out Chicago-area ash trees at a rapid pace this year.
While the destructive Asian beetle first arrived in the Chicago area in 2006, its population started growing exponentially just this year, said Scott Schirmer, emerald ash borer program manager for the Illinois Department of Agriculture.
“Now that it’s really established in areas,” he said, “it has hunkered down and started reproducing like crazy” and has had “plenty of ash trees to attack and complete its life cycle in.”
The accelerated infestation couldn’t have happened at a worse time because most trees are already suffering under the excessive heat and dry conditions, local experts said.
“You add on the aggressive nature of emerald ash borers on these trees, and they’re really under attack right now from both bug and environment,” Schirmer said.
Above-average temperatures in March were an additional stress, causing ash trees to leaf early, only to shut down again when temperatures cooled. “They kind of had to start up twice,” he said.
Yet, the warm spring may have benefited the emerald ash borer, giving it more time to reproduce. “It just gives them a head start on their ability to spread out and cause more damage,” Schirmer said.
Southwest suburban Tinley Park likely will need to remove about 1,000 damaged ash trees from its parkways this year, about five times as many as were removed last year, said Public Works Director Dale Schepers.
“Everybody can see around town that this year, the ash borer took a pretty tremendous toll on our urban forest,” he said.
Crews began removing hazardous limbs and dead trees about a month ago, but to deal with the extra workload, the village plans to hire a contractor, Schepers said.
The village has budgeted about $160,000 for a contractor and an additional $100,000 for replacement trees, which will be planted in the fall. Still, that amount will likely replace only about half the trees that need to be removed, he said.
Plans for dealing with the emerald ash borer vary among municipalities. Some try to fight off the insects, others remove and replace the trees, and still others do a combination of both, Schirmer said.
“It comes down to philosophies and what the village is able to commit to,” he said. “There’s really no right or wrong answer. It’s really an individual, case-by-case basis.”
This summer, Schaumburg officials said they want to shift their resources to treating more trees with chemicals to slow the effects of the beetles rather than removing the trees. That comes with a bigger price tag — up to $1.5 million this year from $480,000 last year, according to village officials.
In Naperville, officials approved $467,000 for treatments, but they also expect to spend nearly $1 million to remove and replace others. About half the city’s 16,300 parkway ash trees are estimated to be infested.
In Oak Forest, city arborist Joe Petrizzo said the suburb is only a few years away from losing the rest of its 1,800 ash trees. Every tree is showing signs of damage from the pest, and the city is making plans to remove more than 700 this year.
“We actually had to hire a contractor to help us out because we’re overwhelmed,” he said.
Homer Tree Care in Lockport was awarded a contract not to exceed $200,000 for the work, he said. The city also has $20,000 in grant funds to pay for replacement trees, but that will cover only a fraction of the cost.
“This year it really took off, and it’s really bad,” he said. “We just can’t keep up with it.”
