Are Your Rare Precious Trees at Risk? Emerald Ash Borer
Recently, there has been a groundswell of concern with the Emerald Ash Borer; an invasive pest imported from Eastern Asia. It is thought to have been introduced in solid wood packing shipped from China, destined to Michigan. Since its introduction into the United States, it is believed that over 40 million Ash trees have succumbed to this ravenous pest. The Emerald Ash Borer (EAB) was first detected in Pennsylvania in June of 2007. On its march across the state, it has been detected in the majority of the northern counties, only recently being discovered in Lehigh, Northampton, Bucks and Philadelphia counties. As of September 2016, the infestation has covered 62 counties. Recent discoveries in Chester County and possibly as close as the Newlin Mill Park (unconfirmed through the Pa. Dept. of Agriculture at this time) bring the pest to our front door. Unfortunately, it is too late to save the majority of our beloved Ash trees.
Initially, it is difficult to determine which Ash trees are affected by the EAB. The tree normally starts with a reduced, or lean canopy with a noticeable “blonding” of the bark where the larvae is consuming the sapwood or cambium layer of the tree. This causes a girdling of the tree, eventually killing the tree completely. Death of the tree occurs in one to three years after infestation begins. Sometimes, the exit holes can be found on the exterior of the bark. They show as a hole in the bark in the shape of a “D”. Woodpeckers exacerbate the problem while exposing the inner bark searching for the borer larvae, which they consume. The Ash tree is known for its hardness, strength and straight grain and has been used by artisans for hundreds of years in the making of baskets, tool handles, guitar bodies and even baseball bats. Unfortunately, when the tree dies, the branches quickly become brittle and will shear off in windy weather, causing problems with nearby houses, electric lines, streets and public places.
It has been stated that the EAB infestation is the worst tree related problem since the demise of the American Chestnut. It far exceeds the beech blight and Gypsy Moth outbreak of the recent past, and shows no sign of diminishing until the Ash tree is a distant memory.
In most counties affected by the EAB, the Ash tree has been quarantined;, meaning it is illegal to transport the wood to other non-infested areas. Landowners have three basic choices when it comes to dealing with Ash trees on their properties. They can let the trees die naturally, cut them down, or treat them with a systemic chemical preventative. Chemical treatment is costly and timing is crucial. It can cost @ $10 – 15.00 per diameter inch of the tree to treat the tree, and the process must be repeated on a three year cycle. Since the pest is new to our area and without any real natural enemies, it remains to be seen whether the state’s Ash trees can survive for the long term.
As a homeowner, it is increasingly important that you remain vigilant in protecting your valuable trees and those of your neighbors. Our parks will no longer be the same without this majestic and useful tree, and we should do everything in our power to prevent the loss of this “gem of the forest”.