Since 2002, the Emerald Ash Borer has killed millions of American Ash trees in the Upper Midwest and Northeast. It now is present in Eastern Pennsylvania. Adult beetles leave distinctive D-shaped exit holes in the outer bark of branches and the trunk. Adults are roughly 3/8 to 5/8 inch long with metallic green wing covers and a coppery red or purple abdomen. They may be present from late May through early September but are most common in June and July. Once trees are infested with the beetles, symptoms of the disease will appear in 2-3 years and the trees will die within 4-6 years. Please see https://treedoctor.msu.edu/ash/ashtree_id, for a description and photographs of the American Ash tree.
Various chemical treatments have been developed to combat the Emerald Ash Borer. Lower Merion residents who have Ash trees on their property should contact an International Society of Aboriculture (ISA) Certified Arborist to determine if their trees should be treated and the method of treatment that will be the most effective.
Additional information about Emerald Ash Borer and treatment options can be found at the websites listed below:
EAB General Info
USDA Forest Service
EAB Insecticide Multi-state Bulletin
EAB Homeowner Treatment Info