All About The Emerald Ash Borer

The Emerald Ash Borer a.k.a. Agrilus Planipennis is an insect wreaking havoc on ash trees across North America. This unwanted little bug has caused what we consider to be catastrophic tree death in areas across the U.S. and Canada leaving a trail of dead or dying ash trees in its wake. Many say it is the worst case of tree death/illness in U.S. history. So, what should you know about the Emerald Ash Borer and how its arrival might affect you? Here we take a close look at this bright green beetle and why it poses such a threat to North America’s ash trees and eco-system.

Where Do Emerald Ash Borers Come From?


The Emerald Ash Borer is an Asian beetle found throughout China, Japan and Korea. While the actual arrival date of the beetle is a little fuzzy, it was in the early 2000s that they were first spotted in Michigan. The bugs would have come to the area via an infected shipment from Asia, probably two years before they were first detected. This two-year period would have given the beetles time to spread their eggs to ash trees in and around Detroit. It is most likely the bugs were attached to wood packing materials and flew off the packing in search of food.

What Exactly is the Emerald Ash Borer?


This wood-boring insect is a small, brilliant green beetle that is a member of an insect family known as Buprestidae. You can spot an Emerald Ash Borer as they are quite distinct thanks to their striking narrow, metallic blue-green bodies. They are no larger than about half an inch.

In general, most wood-boring beetles serve an important purpose in our forests and landscapes because they support the natural process of the eco-system. They help manage tree growth and natural forest succession, while also providing food for other wildlife in the area. However, when it comes to this little fellow, the infamous Emerald Ash Borer is considered an invasive species. It is not native to North America and therefore interferes with the natural balance of the eco-systems it enters.


The issue with invasive species is that because they are not native to an area, they often lack predators that help keep their numbers in check. Here in North America, the Emerald Ash Borer has no natural predators, leaving it free to travel about unharmed, while its population explodes. Once beetles reach adulthood, they can fly, mate and reproduce. And this is where the trouble begins, as the larvae of the beetles feed on ash trees. They are recognizable by their creamy white color and light brown heads.

Why Do Emerald Ash Borers Pose a Threat?


While the ash trees of Asia are more resistant to the beetle, our ash trees are far more vulnerable to their feeding. As well, in Asia, there are native predators co-existing with the ash borers helping to control their population.


When Emerald Ash Borers lay their eggs on ash trees, the larvae are unleashed and free to feed on the wood beneath the tree bark. This area is called the “phloem tissue” which plays a very important role in sustaining tree health. Phloem tissue aids in transporting nutrients throughout the tree, acting like a highway that carries the vital carbohydrates, the tree produces through the photosynthesis process. This, in turn, allows the tree to grow, store sustenance and respire for health. The intricate feeding trails left behind by the larvae stop the tree from taking in sustenance and as a result, the tree eventually dies.

How Do Dying Ash Trees Impact the Environment?


The eco-system is very delicate and complicated. Every living thing contributes to the balance right down to the specific species of tree. Although the Emerald Ash Borer only feeds on ash trees, their infestation still impacts both forested and urban areas in a number of ways including:


  • Interfering with the composition of tree species
  • Creating natural forest succession challenges
  • Damaging nutrient cycling for the forest
  • Increasing risk for non-native plant species invasion
  • Challenges for forest recovery and new growth
  • Economic impact on local governments who foot the bill for tree removal, treatment and/or replacement


As well, the death of tens of thousands of trees in city parks and on city streets contributes to urban heat islands, as cooling urban canopies are lost. 

How Many Areas have Emerald Ash Borers?


Since their initial arrival, the beetles have travelled to 33 U.S. States as well as five provinces in Canada. It is estimated adult ash borers won’t fly more than a mile or so over a two-year period. This has allowed them to slowly progress along the east coast, into the mid-north and south. They have yet to reach the states on the west coast.

What Can Be Done to Stop the Devastation?


Efforts are underway to curb the spread of the beetles to the western states. However, everyone can do their part to help including:


Be Firewood Smart


Although these beetles fly, people often unknowingly give them a helping hand in their travels. The number one step you can take to stop the spread further west is to never transport firewood even a short distance. If you transport firewood infested with beetles, you can quickly take them to areas it would have taken them years to reach. This is how the beetles reached as far as Colorado. The further you take the wood, the more harm you can cause. If you are camping, always wait to purchase firewood at a supply store in the immediate area and leave your wood at home.


Check for Ash Trees on Your Property


Ash trees are recognizable by their “compound” leaf that has a series of leaflets that grow off the main stem. The leaflets are very simple and are not toothed around the edges. In other words, they don’t have that serrated edge you might see on an elm tree leaf. They also have white flowers in the spring giving way to orange or reddish berries in the fall. They are somewhat similar to hickory trees and the easiest way to tell the difference is that hickory trees have three larger leaflets at the top of the stem and bear nuts, not berries. If you think you have an ash tree on your property but aren’t sure, you can reach out to our team and we can visit to make a positive identification. 


Look for Dead or Dying Trees on Your Property


It’s always a good idea to have dead or dying trees on your property checked by a tree specialist. First, they can be infested by pests, including the Emerald Ash Borer and second dead trees and branches can cause serious damage to your home, vehicle, property or your neighbor’s property. If it is an ash tree, and it is dying because of Emerald Ash Borers, the beetles can continue to feed on a dead tree for quite a while. This puts other ash trees on your property and the surrounding area at risk. Telltale signs you have Emerald Ash Borers in your ash trees include:


  • Thinning and yellowing leaves
  • D-shaped holes in the bark
  • Leaf and bark loss


Our tree experts can assess the tree’s condition to check for ash disease or beetle infestation. Once we identify the issue, we can recommend treatment or removal. To reduce the risk of spreading the beetles, we can also ensure the deadwood is disposed of safely. 


Get Proactive with Hi-Value Insecticide to Kill the Beetles


If you know you have ash trees on your property, and there are dying ash trees in your area, there is a treatment available to prevent an infestation in your trees. The treatment has to be applied either early on in the infestation or before infestation occurs. Unfortunately, once the infestation takes hold, it becomes harder to attack the beetles and save your tree. Your best bet is to give us a call to assess your tree. We can recommend the best treatment and be certain it is handled properly.


Diversify Your Landscape with Insect Resistant Trees


Trees are always vulnerable to new threats such as disease or insects. Therefore, a good strategy to keep trees hale and hearty is to diversify the trees you choose to plant on your property. By doing this, you can keep a good balance of healthy trees alive and reduce the risk of losing an entire canopy of trees. This is the same strategy cities use to protect their parks, natural landscapes and forests from damage. Diversity slows the spread of diseases while allowing trees to build resilience if one species is killed off by a new pathogen or pest.


Report Beetle Survivors


Unfortunately, the beetles will probably be very successful in eating their way through the U.S. ash tree population. However, there will be some trees that manage to survive. Scientists can use the survivors to look for differences in their makeup and discover a way to create a heartier ash tree. If you have an ash tree on your property, you can let authorities know so they can take note of its location and keep tabs on its progress. Through this monitoring, it is possible a new ash tree species can develop to revive the population across the country.


If you believe you have ash trees on your property, the Ash Tree Medic can identify the tree and assess it for damage. We will provide treatment if your tree still has a chance to survive or remove the tree from your property safely.