Emerald Ash Borer Treatment

What are Emerald Ash Borers?

Emerald ash borers are invasive, bright metallic green insects that originate from Eastern Asia. The Emerald ash borer infestation began in Michigan in June 2002, when they were accidentally brought in packaging materials. They are about 1/2″ long with a flattened back and purple abdominal segments under their wing covers. An adult Emerald ash borer can be hard to spot and may be mistaken for a Japanese Beetle.

The larvae, however, are what really do all the damage to the trees. These white, legless larvae tunnel deep beneath the bark during the late summer, fall, and winter months, disrupting the flow of water and nutrients throughout the tree. Green, black, white, and blue ash trees are among the species most susceptible to emerald ash borer damage. Infested young ash trees may die before reaching maturity and producing seed.

The loss of ash trees can affect entire ecosystems, contributing to increases in invasive plants, changes in soil conditions, and disruptions for wildlife that depend on ash trees. While they are mainly hidden under the bark, there are warning signs to tell if a tree is infested.

Warning Signs of Emerald Ash Borer Infestation

One of the first warning signs is foliage dieback in the canopy. Dieback typically begins at the top of the tree and gradually spreads until large sections become bare. Increased woodpecker activity can also indicate a problem, as the birds often peck beneath the bark searching for emerald ash borer larvae.

If you notice bark splitting or the insect’s distinctive winding galleries beneath the bark, your tree may already be infested and should be evaluated for treatment as soon as possible.

Emerald Ash Borer Prevention

First, learn the warning signs of infestation and report suspected emerald ash borer activity to your State Plant Health Director.

Next, do not move firewood from one place to another. Although you can’t always spot it, the beetle may live in cut wood such as firewood. Moving firewood can spread the beetle, its larvae and its eggs to healthy trees. Burn your firewood where you buy it.

Preventive treatments can help protect healthy ash trees before infestations become severe. Even trees that appear healthy may benefit from routine protection in areas where emerald ash borers are present.

Emerald Ash Borer Treatment

Insecticides

If the warning signs of emerald ash borer are identified early, you may be able to save your ash trees. Insecticides labeled specifically for emerald ash borer control may help protect trees and limit further damage.

Woodpeckers & Nuthatches

Researchers believe that native birds such as woodpeckers and nuthatches may help reduce emerald ash borer populations by feeding on the insects and larvae beneath the bark of infested trees. These birds can adapt their feeding behavior to take advantage of this food source and may provide a natural layer of defense for ash trees.

If you’d like to encourage these beneficial birds to visit your property, consider creating a bird-friendly habitat. Native trees and shrubs, bird feeders, reliable water sources, and safe nesting areas can all help attract a variety of birds, including woodpeckers and nuthatches. Dead trees and snags, when safe to leave standing, may also provide valuable feeding and nesting opportunities.

While birds alone cannot eliminate an emerald ash borer infestation, encouraging natural predators can be one part of a broader tree care strategy. Combined with regular monitoring, early detection, and appropriate treatment options, a healthy bird population may help reduce the number of insects affecting your trees.

FAQs about Treating and Preventing Emerald Ash Borer Infestations

Can an ash tree survive an emerald ash borer infestation?

Sometimes. If an infestation is discovered early enough, treatment may help protect a tree and slow further damage. However, trees that have already experienced significant canopy loss or extensive internal damage may be more difficult to save. The sooner action is taken, the better the chances of success.

How quickly can emerald ash borers kill a tree?

The answer depends on the size, age, and health of the tree, as well as the severity of the infestation. Because the infestation interferes with the tree’s ability to stay healthy and transport essential resources, damage can worsen over time and eventually lead to tree death if left untreated.

Do I need to treat a healthy ash tree?

Think of preventive treatment as an investment in a tree that’s still strong and healthy. Emerald ash borer damage often begins before visible symptoms appear, which means waiting for a tree to look unhealthy may reduce your treatment options. Protecting a healthy ash tree is often easier than trying to save one that’s already experiencing significant damage from an established infestation.

If you have mature ash trees that provide shade, beauty, wildlife habitat, or value to your property, taking action before problems appear can help improve the chances of keeping those trees healthy for years to come. Regular monitoring and early intervention are often your best defenses against emerald ash borers.