Chicago Department of Streets and Sanitation Crews Inoculate 17,500 Ash Trees in First Ten Weeks of Treatment Season

City completes 50 percent of its goal to treat 35,000 trees in 2013

The Chicago Department of Streets and Sanitation today announced crews have successfully treated the first 17,500 ash trees as part of the City’s aggressive forestry plan to combat the emerald ash borer insect.

“The emerald ash borer threatens nearly 20 percent of Chicago’s parkway trees which enhance the beauty of our city and offer countless environmental benefits to our communities,” said Mayor Rahm Emanuel. “Protecting these valuable assets not only supports a healthy environment, but can prevent the costly removal and replacement of thousands of trees.”

As outlined in Mayor Emanuel’s 2013 budget, the City is investing approximately $2 million in an emerald ash borer program, compared to $110,000 in 2012. The average cost to inoculate a tree is $46, compared with $1,000 to remove and replace a tree.

For the first time ever, the City has a dedicated workforce tasked with inoculating ash trees. The City has hired and trained 26 general laborers to implement the first year of the multi-year plan to combat the insect which threatens approximately 85,000 of the City’s parkway trees. In 2013, 35,000 ash trees will be treated, compared to the 18,000 total parkway trees that have been inoculated in Chicago since the treatment became available in 2009.

Emerald ash borer inoculation crews are targeting areas of known infestation to slow the progression of the insect and manage tree mortality. Forestry crews began treating in early May and will continue through September, when treatment is believed to be most effective.

The ash trees are being inoculated with Emamectin Benzoate which has been proven to kill 99 percent of emerald ash borer insects within a tree. Emamectin Benzoate protects the tree for up to three years.

The emerald ash borer is an exotic beetle native to Asia that was discovered in southeastern Michigan in 2002. The beetle has killed more than 30 million ash trees in southeastern Michigan alone, with millions more dying in Ohio, Indiana, Illinois, and other infested states.

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