Emerald Ash Borer (EAB), Agrilus planipennis Fairmaire
This Asian beetle, discovered in 2002 in southeastern Michigan and Windsor,
Ont., infests and kills North American ash species (Fraxinus sp.) including
green, white, black and blue ash. Damage is caused by the larvae, which feed in
tunnels (called galleries) in the phloem just below the bark. The serpentine
galleries disrupt water and nutrient transport, causing branches, and eventually
the entire tree, to die. 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.
(Information cited from EmeraldAshBorer.info)
Watch the video - Emerald Ash Borer - "The Green Menace"
Helpful links about the Emerald Ash Borer