Emerald Ash Borer is small metallic green beetle that has killed millions of Ash trees since its discovery in the United States in 2002. It was discovered in northern Illinois in 2006. In the summer of 2014 Emerald Ash Borer was found in Peoria and Tazewell County. After the Emerald Ash Borer lays eggs in an Ash tree during the summer months, the eggs hatch in the fall and turn into larvae which tunnel around the cambium layer during the winter months. As a result of the destruction of the cambium layer, the tree can no longer transport the necessary water and nutrients throughout the tree, thus causing tree decline and eventual death.