Posted on: 11 March 2021Share
The emerald ash borer has been ravaging ash trees across the United States for some time. This insect invaded so quickly and furiously that arborists and scientists were not initially able to do much for the trees that became infested. Owners just came to accept that if an ash tree became infested with emerald ash borers, that tree would soon die.
Now, however, that is all changing — and EAB infestations are not, necessarily, a death sentence. Arborists have begun treating EAB infestations by injecting the trunks if infested trees with insecticides. Here's a closer look at this treatment and how it works.
How do you know your tree needs the injections?
If you have any ash trees in your land, you must keep a keen eye on them and call your tree care company at the first sign of an EAB infestation. Common signs of an infestation include:
- D-shaped holes in the tree trunk
- Bright green beetles anywhere on the tree, although they're often seen on the leaves
- Sudden dieback of one or more of the tree's branches
The earlier the injections are given, the greater the tree's chance of surviving.
What is in the injections?
The injections contain many of the same pesticides that are often sprayed onto trees to fight other types of insect infestations. There are a few different brands formulated with different active chemicals. Common ones include imidacloprid and emamectin benzoate.
At this point, you may wonder why these can't just be sprayed on the tree. It's because the emerald ash borers feed on the vascular tissue of the tree, not on its leaves. So to kill the ash borers, one needs to get insecticides into the vascular tissue, which can only be done by injecting the tree.
What happens when you have the tree injected?
When your tree care professional arrives to treat your ash tree, they will typically start by drilling a hole into the base of the trunk. This hole will go all of the way into the tree's deep vascular tissues, which carry water from the roots to the leaves. Then, the insecticide preparation is injected into the drilled hole. The hole may be plugged before your tree care professional leaves.
With any luck, your tree should begin recovering in the coming months, as EABs eat the injected vascular tissue and die. Some trees do still succumb to the infestation, but at least the injections give your tree a fighting chance. For more information about emerald ash borer treatment, contact a local arborist.