Be on the lookout for Emerald Ash Borer This Summer
As the 2021 summer season wound down, more trees with emerald ash borer (EAB) were identified in the Twin Cities metro and surrounding areas. Residents in the area should be prepared this summer to look at their ash trees and check for any of the symptoms of emerald ash borer. As most people know by now; emerald ash borer is an exotic pest that has been attacking and killing ash trees across the United States. The adult emerald ash borers are, as their name suggests, an emerald-green color with a maroon colored underside. The adults are winged beetles about half an inch long. It’s the white larvae (called flat-headed borers) that actually cause the damage to our ash trees by mining their way through the phloem layer of the tree causing serpentine, s-shaped galleries, or tunnels.
Very seldom are the adults seen and the larvae are hidden beneath the bark of the trees. One must be very “tuned-in” to their trees to notice the subtle changes as EAB larvae damage the conductive tissue of the trees. Take some time to get acquainted with your trees. Learn to identify the ash trees on your property and what healthy trees look like. An infested tree will slowly begin to decline. The top growth will slowly thin out, usually in the 3rd or 4th year of being infested. Woodpeckers will commonly find the larvae in the 3rd or 4 th year and start pecking away at the tree. The pecking action will cause the darker outer bark of the trees to fall away, exposing the lighter, nearly white inner bark. This symptom is called blonding and is often the first sign tree owners will notice.
The blonding on the tree trunk will usually begin near the top of the tree on the south side as this is where the pest begins feeding in 1-2” diameter branches in the upper canopy of ash trees. Also look up in the tree for bark splits where sometimes the s-shaped galleries can be spotted in the exposed wood in the splits. As the infestation of a tree progresses year to year, sometimes the d-shaped exit holes can be seen in the 5th and 6 years of infestation. By the 6th year ash trees are usually dead. When ash trees die from emerald ash borer they become very brittle and dangerous. These dead stems become very unpredictable when they are felled, and special care is needed to remove standing dead ash trees. It’s recommended that a professional tree removal contractor be hired for the removals.
If your ash tree begins to look anemic and you notice any of the above-mentioned symptoms it’s likely infested and should be inspected by a certified arborist and the proper arrangements be made. If your tree still appears healthy and you choose to protect it, treatment options are available from Shadywood Tree Experts. Treatments are most effective when they begin before the tree is infested, so it’s important to contact us soon if you have ash trees.
Steve Schumacher, Shadywood Tree Experts consulting arborist