Mon, 18 May 2015 15:56:27 GMT — Arborists are working to help some ash trees in central Illinois fight off potential infestations by emerald ash borers.
The destructive pest has killed millions of trees in the U.S. in the past decade.
The State Journal-Register reports they were found in November in Sangamon, Mason, Logan, Christian and Menard counties in Illinois.
Steven Green, an arborist in Springfield, recently worked with a team of interns to treat four trees along Illinois Route 97 to stave off effects of any infestation.
They injected a chemical that costs about $500 a liter into the trees' trunks that will last about two years.
The trees date back to 1934 and were planted by the New Deal-era Civilian Conservation Corps as part of the state's first highway beautification project.