EAB, Where Are We Now?
Written by: Kyle Babicky, Certified Arborist WI-0889A
Posted: 2020 | Emerald Ash Borer | Insect Control | Spring
It’s no secret that Emerald Ash Borer (EAB) has had devastating effects throughout Wisconsin the past several years. This left many homeowners and municipalities with a difficult decision and only three options:
- Invest in treatments to keep their ash
- Remove the tree before it becomes a risk
- Let EAB run its course, which leaves a dead and unstable tree
Wisconsin had more time than our neighbors in Michigan and Illinois to prepare for the onslaught, but we’ve still learned a lot through experience the past several years while battling EAB. Below have been a few of our observations:
- They are sneaky – Even with the eye of a trained expert, ash trees hide EAB symptoms for several years. It’s also very common to never see the actual insect. The larvae stage is feeding inside the tree, and the metallic-green adults only fly around for a few weeks each summer.
- Not all treatments are equal – Treatments are highly effective, but they need to be proactive and they need to be trunk injected using a specific active ingredient. There are many treatments labeled to use for EAB, but many are not potent enough to work long-term. Our recommended trunk injections using emamectin benzoate have been very successful when started on healthy trees.
- Treatments take time – While the product itself is fast-acting, you may see the tree go through a stabilization period. Many trees will show “new” damage even after treatments have begun. This is usually from EAB feeding that occurred before treatments were started and the trees are showing delayed symptoms.
- If you’re starting now, it might be too late – EAB populations have been growing since their arrival, causing more damage every year. Any untreated ash tree in southeast Wisconsin almost certainly has extensive feeding damage, even if it’s hidden under the bark. We are absolutely willing to help you save your tree, but know that it could be a long shot. We also must consider the risk of a compromised tree.
- EAB is here to stay – We often get questions on how long ash trees need to be treated. Unfortunately, all evidence points to EAB being here to stay. If you’re treating your tree, plan on re-treatment every two years. There might come a day when EAB populations decrease and treatments can be altered, but we don’t recommend going there yet.
- Trees are fighters – There have been extreme cases where a tree loses the majority of its canopy, but starts anew from sprouts emerging from the trunk and larger branches. Trees like this might still have a fighting chance using drastic pruning methods and continued treatments. Many of our clients want to try anything to avoid removing a tree, and this may be an option in those cases, but needs frequent care and monitoring.
- EAB is not the only enemy – While EAB treatments should be the priority of any ash tree, we can’t ignore other stresses. Ash can also suffer from leaf diseases, root issues, and deficient soils to name a few. There may be additional treatments or procedures that benefit your tree.
- New opportunities – Being forced into ongoing treatments or losing a tree is frustrating. If you ultimately decide to move on from a tree, it can be an opportunity to add a new and unique tree to your landscape! We are very happy to help you with selection and planting.
Kudos to many of you have been treating your ash trees for years and are winning the battle against EAB. Stay calm and keep up the great work! If you’re seeing any concerns on your ash, or just want one of our certified arborists to visit and review it again, please don’t hesitate to contact us!