The Threat

Emerald Ash Borer (EAB) is a non-native, invasive insect that is causing an extinction level event to North American ash species. The beetle was introduced to North America in 2002, when it was first found in Michigan. Since that time EAB has killed millions of ash trees as it has spread across the country. At this time it has been found in Colorado, South Dakota and Nebraska. Currently it has not been found in Wyoming or the Sheridan area. However, it is not a matter of "if" but "when" the beetle arrives in Sheridan.

The City of Sheridan has 366 ash trees growing on public property, but if you factor in private ash trees Sheridan has thousands of trees that will come under threat when EAB arrives. If these ash trees are not chemically protected they will die. Ash trees that are killed by the beetle can not be left standing as the compromised wood causes these trees to fail in 1-3 years after death. Due to this, Emerald Ash Borer, poses the largest threat to our community forest going forward.

At this point, Emerald Ash Borer, has not been found in Sheridan. The Sheridan Community Forestry Program is actively trapping and monitoring for the beetle each year, but it is most likely that a homeowner will find it first.

What Can You Do?

The first thing we can do as citizens is learn to identify what an ash tree looks like. Do you have an ash tree on your property? Does your neighbor? With more eyes on our ash trees, we will have a better chance of early detection. A good resource for identifying ash trees can be found here.

The second action we can take as a community is to identify what ash trees we want to protect when the beetle arrives. If you have an ash tree that you want to save, the time to prune that tree is now. An arborist who can properly prune your ash tree will encourage the health of the tree long term. By removing dead wood now it will also be easier to identify changes in your tree that can be indications of the arrival of EAB. Finally, once EAB does arrive, pruning cuts create open wounds in the tree which release pheromones that can attract beetles. By pruning your tree now, it will give your ash tree time to compartmentalize those wounds.

Once Emerald Ash Borer arrives, chemical protection of your tree will need to take place if you want to save it. Until we have found the beetle there is no need to begin chemical applications. The cost of these applications are directly related to the size of your tree and will need to be reapplied every 1-3 years depending on product used. These chemical applications can be expensive depending on the size of tree, the product used and how many ash you own. These chemical applications will also need to be done by a International Society of Arboriculture (ISA) certified arborist. If you are serious about protecting your ash tree(s), beginning to set aside money to afford these applications may be a wise decision to make.

To learn more, read the resources listed below:

Emerald Ash Borer Quick Guide
Assessing your ash tree for EAB (video)
Wyoming and the Emerald Ash Borer
Homeowner Decision Guide

Overview of Insecticides for Emerald Ash Borer

City of Sheridan

Common Pests