Emerald Ash Borer

Emerald Ash Borer

                Emerald Ash Borer is an invasive beetle species native to North Eastern Asia.  It is a member of the Buprestid Family of beetles, otherwise known as Jewell Beetles which often have a very bright metallic coloring.  The Emerald green color is very attractive but this invasive species is damaging and killing North American native Ash at an alarming rate from Michigan where it was first identified to Denver where it has moved to at this point. 

Emerald Ash Borer

Family    Buprestidae

Genus   Agrilus

Species plannipennis

Size        1/3”

Color     Metallic Emerald Green

                Emerald Ash Borers attack the secondary branches and trunks of healthy Ash tree by laying eggs in the crevices of the bark. The larvae hatch, enter the tree through the bark and begin to feed.  Agrilis species, or Flat-Headed Wood borers, have a distinctive flat broadened head and create a zig-zag or meandering damage in the cambium of the tree.  They have a one to two year life cycle so the infestation is not always immediately evident.  The feeding destroys conductive tissues just under the bark and cut off the flow of water and nutrients throughout the tree.  Dieback in the upper crown is the first indication of an attack and a Certified Arborist should be called to inspect the tree to determine if it is in fact EAB.  They leave a small “D” shaped exit hole in the bark as the adult beetle emerges to find another host tree.

                If the beetle is caught early there is a chance to treat the tree and stop any further damage but in some cases the damage can be too great, especially due to the often two year life cycle.  In many cases it gets caught in year three or four and this is often too late to save the tree. 

                Preventative treatment of any large healthy Ash trees is a good way to protect a specimen or otherwise highly values tree and helps reduce the overall spread through localized areas.