Battle against ash borer continues
Three layers of government sought answers to a common enemy that's laid waste to millions of ash trees.
On Friday, state, federal and DuPage County municipal leaders looked at options to combat the emerald ash borer that included surveillance and natural predators.
The pests have killed more than 15 million trees in Michigan. So far, they've been spotted in areas of Kane County including Fermilab in Batavia, Evanston, Wilmette, Winnetka and most recently in Glendale Heights.
"We're all in this together. It's not an isolated challenge," U.S. Sen. Dick Durbin said at the briefing held at Lisle's Morton Arboretum.
Durbin told leaders funds for low-interest loans should be available for municipalities to fight the insect. Tactics for identifying borers include inspections and creating "trap trees" with stripped bark that make them more vulnerable to the bugs.
Towns were also encouraged to compile a list of ash trees and develop policies to deal with an infestation.
Meanwhile, the Illinois Department of Agriculture is conducting a more comprehensive survey in 35 counties targeting 5,200 ash trees to check for infestation.
The state quarantined 18 northern Illinois counties including Cook, DuPage, Lake, and McHenry in July, forbidding the removal of ash wood.
Adults borers are smaller than a dime in size. Females lay eggs in the bark of ash trees. The larvae burrow into a tree's vascular system, which distributes water from the roots, destroying it.
Insecticides applied to ash trees but are not 100 percent effective, experts say.
There is some hope that natural predators could control the spread of the pest.
U.S. Forest Service entomologist Therese Poland described research involving insects from China that are natural enemies of ash borers. Two parasitic insects, including a minuscule species of wasp, destroy ash borer eggs and larvae.
The forest service in July received permits to conduct controlled studies of the parasites in Michigan.
Twenty percent of the urban forest in Chicago and the collar counties are composed of ash trees, said Arboretum official Clement Hamilton.
Ironically, many ashes were planted in the wake of the Dutch elm disease infestation. The lesson now is to plant a variety of species.
"The goal is to diversify the urban forest so no one species is that dominant," Hamilton said.
The trees at the Glendale Heights shopping mall where the ash borer was found have been destroyed. The village is working on a policy to address the problem and assist residents, Mayor Linda Jackson said.
Naperville forestry supervisor Jack Mitz said the city is using the trap tree method to get early warning of the borer.
While he believes a sighting is "inevitable," Mitz was encouraged by Poland's studies. "It's encouraging because the biological controls seem feasible," he said. "They have potential."