Emerald Ash Borer
What is an Emerald Ash Borer?
Emerald Ash Borer is a green jewel beetle native to eastern Asia that feeds on certain ash species. Adults are dark metallic green in color with a red or purple abdomen under the wings. The insect is about a 1/2 inch long and 1/8 inch wide. The larvae of this particular insect is white in color. The Emerald Ash Borer is very destructive and can infest and kill numerous true ash species. The larval stage of this insect feeds under the bark of the tree cutting off the flow of required water and nutrients. Infested trees will slowly die over a period of time usually taking 2-4 years before mortality.
What are the signs of Emerald Ash Borer?
The visibility of an attack of the Emerald Ash Borer may go undetected for more than a year after its initial infestation. Other ash problems can be easily mistaken for Emerald Ash Borer presence to include environmental factors, disease, or other insects. Common signs of infestation are loss of leaves, thinning of upper branches, tunnels under the bark in an “S” shape, as well as “D” shaped exit holes. Emerald Ash Borer was first found in North America in 2002. It has been confirmed to be detected in 25 states including Colorado. Fortunately the insect has only been detected in the City of Boulder. Beings that Emerald Ash Borer typically fly less than 1/2 from their emergence tree it is likely that long distance movement has been directly promoted by human movement of the wood.
There are a few different preventative options to protect the ash trees on your property as well as control an attack. The decision to treat individual ash trees on a preventative plan is addressed on a case by case basis. Treatment options are designed around the size of trees and location. Preventative care can be achieved by systemic insecticides that are applied as soil injections or drenches, systemic insecticides applied as micro- injections, systemic insecticides applied as lower trunk sprays, and protective cover sprays that are applied to the trunk and main branches. Timing of these applications are very crucial and it is suggested that a certified arborist is consulted.