Larvae are 26-32 mm long when mature, white to cream colored, somewhat flattened, have 10 abdominal segments, and a pair of pincer-like appendages on the last segment. They produce winding S-shaped feeding galleries in the inner bark and outer sapwood. Galleries become progressively larger and are packed with fine, sawdust-like frass. Identification of Ash Trees
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The adult emerald ash borer is only 7.5 to 13.5 mm long. Color is bronze to golden green overall, with darker, metallic, emerald-green wing covers. Adults are active during summer months (in Michigan) and feed on ash foliage.
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Chrysobothris chrysoela is a native beetle in the same family as the emerald ash borer (Buprestidae). It attacks weakened individuals of many hardwood trees including ash. The adult is metallic green, but unlike the emerald ash borer it has spots on its wing covers and has a wider body. The exit holes of C. chrysoela are similar in size to those of the emerald ash borer (3-4 mm wide), but are somewhat more oval-shaped rather than distinctly D-shaped.
Principle Reference: McCullough, D.G. and S.A. Katovich. 2004. Pest Alert: Emerald Ash Borer. NA-PR-02-04. USDA For. Serv., St. and Priv. For., NE Area, Newtown Square, PA.