West Windsor is about to be invaded — again! This time, however, it is an insect. We know its name — the Emerald Ash Borer (EAB).
Is it dangerous? Yes — if you are an ash tree (Fraxinus sp.) It can kill you if it gains entry through your bark. Its larvae consume tissues around the cambium just below the bark, effectively destroying the “artery” that transports the tree’s nutrients and water from the soil to its leaves.
Where is it coming from? Originally the Far East but it was first sighted in the U.S. midwest and is now reported to have invaded northern and southern New Jersey. Its adults could inevitably wing their way into West Windsor — perhaps in the next year or so.
How will we know it has reached West Windsor? Sightings in May or June of winged adult beetles — dark metallic green in color, 1/2 inch long, 1/4 inch wide. While healthy ash trees are susceptible, the beetle may prefer to lay its eggs in already stressed trees. The canopy of infected trees begin to die back, usually starting at the top of the tree. Up to half of the branches may die in one year and the tree could be clinically dead in two years. As beetles emerge from an ash tree’s branches or stem, they leave a characteristic 1/8th inch “D” shaped exit hole.
Is there any defense? Systemic insecticide treatment (through the roots or via injection) can be effective in protecting healthy trees but will require careful application, probably best done by a professional Certified Arborist. The time and application rates must be carefully calculated. Arial spraying in the spring when the borers are looking for trees in which to lay their eggs is possible but not a practical option due to the costs and potential exposure to overspraying.
How big a problem is an EAB invasion to West Windsor? There are about 2,000 ash trees along local streets and another 500 or more in township parks. Many more have been planted in private homes and residential developments. Their loss would not only affect the visual delight they provide in summer and fall but reduce their contribution to oxygen replenishment, pollution abatement, and climate enhancement. Costly remedial and salvage measures could potentially exceed hundreds of thousands of dollars.
What could West Windsor residents do? Determine if you have ash trees on your property. Hire an arborist to help you decide if and how to treat your trees before they are infested. Carefully inspect ash trees in your neighborhood during the summer for symptoms of EAB attack. Report sightings of winged EAB or evidence of attack to the Township: 609-799-2400.
Salvage of dead ash trees requires that no diseased wood be moved from the original tree’s location unless the wood is chipped and treated, or burned. Otherwise the infestation will be widespread with distribution of wood (e.g. as firewood) containing eggs, larvae, or pupae.
For additional information, consult a special EAB posting on the township’s website: www.westwindsornj.org
Ronald Slinn
Vice Chair,
Shade Tree Commission
