Emerald ash borer (EAB) is an invasive and destructive pest of ash trees. The borer was introduced into the United States in the early 2000s, and has since spread from the Upper Mid-West through the Mid-Atlantic, North East, and South East. The borer is now confirmed in Granville County, NC. Granville County is approximatly 180 miles from Charlotte.
While EAB is still a good distance from the Metro Charlotte area, now may be the time to think about preventativly treating your ash trees. This insect only attacks trees in the genus Fraxinus, so only ash trees need to be treated for this pest.
Here is a link to a local news article about the discovery: http://www.wcnc.com/news/local/NC-finds-first-evidence-of-ash-tree-killing-bug-211900981.html
Here is a link about emerald ash borer for homeowners: http://www.emeraldashborer.info/homeownerinfo.cfm#sthash.04PANVdQ.dpbs