In an effort to minimize further environmental harm, we have begun a program of Emerald Ash Borer treatment and control. See Fred’s articles in the Daily Camera and in Boulder Country Home & Garden Magazine.
What is the Emerald Ash Borer?
The Colorado Department of Agriculture reports:
Emerald Ash Borer (EAB) was found in Boulder, CO, in September 2013. As a non-native insect, EAB lacks predators to keep it in check. … [It] is responsible for the death of millions of ash trees …
The City of Boulder reports:
EAB is a federally quarantined, invasive tree pest … [Since its discovery in Michigan in 2002], the small green metallic colored pest, originally from Asia, has spread … to 21 states, unfortunately now including Colorado.
How to recognize it
EAB is very difficult to detect in the early stages of attack; sometimes visual signs do not appear to the untrained eye for 3 or 4 years after the first borers arrive. Later, the signs, as shown in the images to the right, include:
- The metallic-green adult beetle is tiny and bores out of the tree via tiny D-shaped holes. (right)
- Years after the initial invasion, trees show loss of foliage at the crown with new growth at the base. (top right)
- The larvae live under the bark, burrowing serpentine galleries into the sapwood which disrupt the flow of water and nutrients. (bottom right) Eventually, the bark may crack.
What should you do about it?
Ash trees may be removed or treated. When treated, there are four basic control options:
- Soil applications of systemic insecticides.
- Spraying non-invasive systemic chemicals onto the trunk.
- Spraying persistent contact insecticides onto the bark of the entire tree.
- Injections of systemic insecticides into the lower trunk which then move systemically up the tree. These include TreeAzin®, the preference of Berkelhammer Tree Experts.
TreeAzin®, a formulation of Neem Tree seed extract, or Azadirachtin, is injected into Ash trunks in late Spring through mid-Summer. Unlike the other treatments, this product is completely bee-safe and, unlike some of the alternatives, it breaks down before the leaves fall in Autumn.
View this explanatory video about TreeAzin® from Oakville, Ontario.
Under investigation by Boulder Forestry Division staff and others is an experimental treatment using parasites that attack the Emerald Ash Borer larvae itself.
View Michigan State University’s Knight Center for Environmental Journalism’s video for details.