Keri Wiginton/ Chicago Tribune
September 29, 2011
Mark Speckan, forestry crew chief for the Lake County Forest Preserve, releases one of two species of wasps onto ash trees in the Sedge Meadow Forest Preserve near Wadsworth on Thursday, Sept. 29, 2011. The goal of releasing the wasps is to protect the trees against the Emerald Ash Borer. The beetle's larvae feed on the inner bark of the tree, which affects the tree's ability to transport water and nutrients.