Landscape Architect Articles

Emerald Ash Borer Strikes New Target in Chicagoland: Morton Arboretum Says Finding an01-17-08 | News

Emerald Ash Borer Strikes New Target in Chicagoland: Morton Arboretum Says Finding an "Urgent Reminder" for Municipalities to Act

Morton Arboretum staffer Eric Katora sets up a trap tree. He girdles it, sending the tree into decline, a state that attracts the borers. Later, such trees are checked for larvae.

Evidence of emerald ash borer infestation is the capital-D shaped exit holes of the borers. A thinning canopy or dieback are other indications of infestation.

In early January 2008, a Morton Arboretum staffer found larvae of the emerald ash borer (EAB) in six grave;trap trees acute; in Hazel Crest, 20 miles south of Chicago. It appears that dozens of additional trees are also infested. The six trees were part of 650 trees set up in 2005 and 2006 to detect the presence of borers throughout Northern Illinois.

The Morton Arboretum conducts the trap tree program with the Illinois Department of Agriculture and with funding from the federal Animal and Plant Health Inspection Service.

Trap Trees in 2006 detected the EAB near Elgin, Batavia and in Campton Township. The size of the EAB's grave;footprint acute; in Hazel Crest is not yet known. Edith Makra, an arborist with the arboretum who serves on the governor's Management and Science Advisory Panel for EAB, considers the finding significant, as the area is isolated and other municipalities may be already infested. She says communities around Chicago should inventory and assess their ash trees and plan to replace them eventually.

Since June 2006, the EAB has been found in four Illinois counties: Cook, DuPage, Kane, and LaSalle. The EAB has left an estimated 25-million ash trees dead or dying in the U.S. and Canada. It is estimated the cost to municipalities, private property owners and the nursery industry will be in the billions of dollars. One in five trees in the Chicago area is ash and there are some 130-million ash trees in the state.

About the Morton: The Morton Arboretum in Lisle, Ill. comprises 1,700-acre outdoor acres, has a collection of 4,057 kinds of trees, shrubs and plants from around the world and is open 365 days a year. Visit mortonarb.org for more information.