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Emerald Ash Borer (EAB)

The Denver Forestry Department recommends the protection of high-value ash trees immediately!

The emerald ash borer, also referred to as EAB, is a green jewel beetle native to eastern Asia that feeds on ash species. It is highly destructive, and is a federally quarantined, invasive tree pest responsible for the death or decline of more than 50 million ash trees. Experts from infested states, the Colorado State Forest Service and the City of Denver Forestry Department recommend the protection of high value ash trees immediately! Ash trees have no natural resistance to EAB and are helpless without our assistance. The symptoms and detection of EAB can take 3-5 years to confirm after the tree becomes infested. Got Ash Trees? Call DLC Arbor.

EAB has not been detected outside Boulder yet, but the likelihood of an invasion is considered inevitable. Studies of traffic and wind show the majority head from Boulder straight toward Denver. The City of Denver is now selecting trees in poor health for removal and identifying high quality trees for treatment in 2016. Denver forestry officials state that ash represents approximately 20% of the total number of trees on both private and public land. Take the advice from officials in areas already devastated by EAB: “Don’t wait to start.”

Starting now means several things. Remove poor quality, neglected trees that are already riddled with ash/lilac borers and aren’t otherwise worth saving. Choose species other than ash for new planting. Treat your valuable ash trees with systemic insecticides, and prune, fertilize and water to improve vigor. At this early stage, the required insecticides are less toxic and less expensive than during later stages of infestation. These insecticides also protect your tree from existing problems like ash/lilac borer, ash twig beetle and aphids.

More information about this tree insect can be seen by clicking:

How Much Do EAB Treatments Cost?

The largest costs associated with EAB Treatment are tree service labor and trip charges. Multi-year trunk injection treatments may be the most cost-effective since they reduce labor and trip charge costs. However, the tree owner needs to remember to reapply the treatment every two years. For example, a yard has four mature ash trees. They are 19", 16", 22" and 29" inches across at chest high. The cost to treat these trees with insecticide is about $10-$14 per inch. Treatment cost for all four trees would be $860 to $1204. Call 303-378-8000 now for an appointment with our arborist to discuss EAB treatment options.

How Long Do You Treat Ash Trees For EAB?

It depends. The fact that most trees are planted in the Denver Metro Area may play to our advantage. The emerald ash borer will infect ash trees in a particular location. The tree insects will thrive and their population will bloom since the ash trees have no immunity. Once all the ash trees die or become EAB resistant because of insecticides, the insect population decreases and the infestation dissipates. There are no native ash forests in Colorado so the EAB cannot hide and re-infect more ash trees.