Emerald ash borer has been found in Bloomington, Illinois, which is significantly outside of the quarantined area of northeastern Illinois. Bloomington is about 55 miles directly south of the Peru area, the only other known emerald ash borer infestation outside of the Chicago metropolitan area. The beetles were captured by one of the large purple traps that have been placed throughout Illinois and many other states.
With a new infestation, it is important to emphasize some of the factors involved with emerald ash borer control. There are several systemic insecticide options that can save even infested trees for at least several years. They include imidacloprid (Merit and others), emamectin benzoate (Tree-age), and dinotefuran (Safari). Most are administered by trunk or root-flare injection, but imidacloprid can also be applied via soil injection and soil drench. Application to the soil is made within 2 feet of the trunk. Dinotefuran is applied as a surface trunk application with PentraBark.
Trunk injections result in movement of the insecticide through the tree in about 2 weeks; whereas, soil application takes about 2 months to move through the tree. In infested areas, trunk injection is the preferred method of application for the first year of treatment. Regardless of the treatment method and insecticide used, annual treatment is recommended.
We recommend treatment for emerald ash borer only within 15 miles of a known infestation. This provides plenty of time for the beetle to be present in closer, undetected areas, allows for flights of longer distances after the beetle is established in an area, and allows at least 2 years of treatment to fully protect the tree.
Additional infestations continue to be found in northeastern Illinois. For a full listing of infested locations, go to the Illinois Department of Agriculture emerald ash borer Web site at http://www.agr.state.il.us/eab/. This is also an excellent Web site for other emerald ash borer information and has an extensive list of relevant Web sites.
The University of Illinois has a fact sheet on insecticidal control of emerald ash borer, as well as a home-owner fact sheet, at http://www.ipm.uiuc.edu/. The homeowner fact sheet is new and provides background on the insect, as well as management options. Both fact sheets are posted as pdf files that can be downloaded and printed as needed for local distribution.