What’s Happening to Our Ash Trees?

Back in February, I read an article titled, “Every Ash Tree in CT to Die Within the Decade.” The headline couldn't be bleaker, but I didn’t really think about it again until this week as the trees began exploding in beautiful green. Ash trees are a staple in our area, with many standing proudly for hundreds of years. So what could be killing them, and what can we do to stop it?

The demise of our ash trees can squarely be blamed on an invasive, non-native species of beetle aptly named the emerald ash borer. It’s an insect that was first found in Michigan more than 20 years ago and since then, it has made its way to the east coast where it has made a feast of our beautiful, bountiful trees. In less than a decade from when the bug takes its first bite, it will eat the tree until it kills it. The mass exodus of ash trees now is because we’re hitting the eight-year mark from when the ash borers first made their homes in Connecticut. Now billions of Connecticut trees are dying all at once.

Emerald ash borers both eat ash trees and live in them. They lay their eggs underneath the bark and when the larvae hatch, it feeds on the tree’s most essential parts, the cambium or “growth” layer and the phloem or “circulatory” layer. The sheer volume of ash borer larvae is too much for a tree to handle and because they spread so fast, they can attack the tree much faster than the tree has the time or ability to fight for itself.

So is there a solution to the problem or are all of our ash trees doomed? Truth be told, the billions are trees that are already affected sadly don’t have a chance. What’s worse is that the emerald ash borer doesn’t have any native predators, so unless a tree has been treated with insecticide, it is almost certainly going to be infiltrated. However, there may be an unlikely ally that can help us protect future ash trees and maybe even save the species. It’s the parasitic wasp.

The name of this insect is very telling of how it operates. The parasitic wasp lays its eggs inside the body of an emerald ash borer and literally eats it from the inside out. They are currently being bred and shipped to Connecticut in an attempt to control the infestation of ash borers. But truth be told, the ratio of wasps to borers is barely enough to suppress the issue, nevermind control it. So the infestation will, unfortunately, have to run its course until the beetles eat themselves out of food and move on.

Until that day comes, the state’s Department of Agriculture hopes that new trees will develop a natural resistance to the beetle and that the hopeful decrease in their population will be controlled by the parasitic wasps. My advice? If you have an ash tree in your yard, it's worth a call to your local expert to find out more about the insecticides available to you. Trees that aren’t treated are in grave danger, so don’t wait to save yours.

Bob O’Donnell is the owner of O’Donnell Bros. Inc., a Bristol-based home improvement company established in 1975. Email your questions to info@odonnellbros.com with the subject line “Ask the Pro.” All questions may be considered for publication. To contact Bob for your remodeling needs, call O’Donnell Bros. Inc. at (860) 589-5155 or visit http://www.odonnellbros.com. Advice is for guidance only.