Emerald Ash Borer
Answers to Frequently Asked Questions
Q. What is emerald ash borer?
A. Emerald ash borer is an exotic beetle native to Asia and was discovered in southern Michigan in the summer of 2002.
Q. How did it get to North America?
A. The beetle most likely arrived in packing or shipping material by cargo ships or airplanes originating from its native Asia.1
Q. How serious a threat is the emerald ash borer?
A. So far, the emerald ash borer has killed more than 20 million trees in Michigan, Ohio and Indiana.1
Q. How does emerald ash borer kill trees?
A. Adult beetles lay eggs on the bark of ash trees. The eggs hatch and the larvae tunnel and feed beneath the bark, disrupting the water and nutrient conducting tissues between the leaves and roots.1
Q. How is emerald ash borer spread?
A. Emerald ash borer adults can fly at least 1/2 mile from the tree where they emerge. Movement of infested ash nursery stock, firewood or logs can spread emerald ash borer into uninfested areas.1
Q. What is being done to control the emerald ash borer?
A. Several universities, state and federal agencies are studying and working on controlling the spread of emerald ash borer. Ohio, Indiana and Michigan have established quarantine zones that prohibit the movement of ash material out of the quarantined area in an attempt to slow the spread of the borer. Research is continuing on detecting and controlling emerald ash borer adults and larvae.
Q. Are there insecticide treatments available to control emerald ash borer and protect ash trees?
A. Early trials using a variety of insecticides and treatment methods have shown inconsistent results. Each treatment method has resulted in good control in some locations and poor control in other locations. Research on chemical control of the emerald ash borer is still in the early stages. Continued research and trials may yield improved methods and results in the future.2
Q. Should I treat my ash trees?
A. Protecting ash trees from emerald ash borer requires a long term commitment of both money and time as the trees will require yearly treatments for the life of the tree. The annual cost of treatment ultimately exceeds the cost of removing and replacing the ash tree. Consideration may be given to treating specimen or valuable trees before there are signs of infestation in an attempt to protect the trees. While there has been some success in protecting uninfested trees, success is not assured. Ultimately, the homeowner will need to make the decision to remove the tree and replace it or invest in a long-term commitment to try and protect the tree.2
Q. What types of treatments are available?
A. There are a variety of treatments currently being used including soil-applied systemic insecticides, trunk-applied systemic insecticides and protective cover sprays. The type of method used will be determined by factors such as the size, location, age and condition of the tree. Each method has advantages and drawbacks. An assessment of the tree should be done before determining the type of treatment used.2
1: Information drawn from www.emeraldashborer.info
2: Information drawn from “Insecticide Options for Protecting Ash Tree from Emerald Ash Borer and Their Effectiveness”. Ohio State University Ash Alert Team. Daniel A. Herms and David J. Shetlar.