The Emerald Ash Borer is a highly invasive species, capable of populating a large area in a very short period of time. It is also highly recognizable thanks to its metallic green coloring. The insect makes no distinction between natural, wild growth and landscaped growth, attacking the leaves and bark of the Ash tree species wherever it happens to grow.
Emerald Ash Borers (EABs) are related to native species of North American tree borers. In that respect, they share some similarities in how they feed, mate and otherwise operate in adulthood. Adults appear in the late Spring months and into early August, as one generation lives per year. The adults that emerge leave a small yet tell-tale "D" shaped hole in the bark of the Ash tree they inhabit and proceed to feed off of the tree's foliage before mating several weeks later.
Upon mating, the female beetle can lay upwards of 50 to 100 eggs on the surface of the tree, allowing the larvae to easily begin boring into the tree once they are born. Larvae dig into the area just under the bark and continue boring tunnels while feeding on the sapwood inside the tree. This draining of tree fluids continues from the summer season into the fall. The death of the tree begins due to starvation. The small tunnels block or destroy the xylem in the tree trunk which allows water to move up the tree. Ash trees that are infected and already dying will have seasons where only a few branch cluster grow leaves, while other parts of the tree have none (like in winter). Suffering Ash trees will try to grow new shoots from the base of their trunks in an effort to stay alive.
Ash trees represent a tremendous amount to the natural beauty, ecosystem and economy to areas. The larvae are instrumental in the internal destruction of the tree itself and the only known resolution to the insect's expansion is the complete removal of all infected trees. This usually results in an entire neighborhood's treescape changing because Ash trees were popular decades ago in urban and suburban planning. Only this species was planted for blocks and now, if infected, blocks lose their shade and character.
Research and a quarantine of infected areas and trees is currently ongoing throughout many states and provinces. It is said that the presence of Woodpeckers might be an indication of infestation because Woodpeckers seem enjoy hunting the larvae under the bark. At this time, the EAB feeds only on Ash trees (known as Fraxinus spp.). If you suspect your Ash tree of infestation, contact your local government to have the village/city look at your tree.