News On the Hunt for the Emerald Ash Borer By Potomac Local News Published July 19, 2011 at 12:47PM Purple boxes have been hung along the sides of many roads in Northern Virginia to detect the presence of the Emerald Ash Borer, an invasive Asian beetle that threatens the ash tree population. (Mary Davidson/PotomacLocal.com) This article is FREE to read. Please Sign In or Create a FREE Account. Thank you. Author Potomac Local News View all posts