Since the discovery of Emerald Ash Borer, numerous chemical treatments have been developed and approved for use. Although widespread treatment of all ash trees may not be feasible, entomologists from several universities have been actively researching various treatment options. Their understanding of how EAB can be managed successfully with insecticides has increased substantially in recent years. It is important to note that research on management of EAB remains a work in progress. Scientists from universities, government agencies, and companies continue to conduct intensive studies to understand how and when insecticide treatments will be most effective.
Insecticides can extend the life and benefits of healthy ash trees during an EAB infestation. These applications are most critical for protecting trees in the years when surrounding ash trees are dying and the population of EAB is near its peak. They also buy time to allow the development of newer and better controls (insecticides and biological controls) for fighting EAB. If you elect to treat your ash trees, there are several insecticide options available and research has shown that treatments can be effective. Keep in mind, however, that controlling insects that feed under the bark with insecticides has always been difficult. This is especially true with EAB because our native North American ash trees have little natural resistance to this pest.
Based on research conducted by university scientists, and careful review of potential impacts on human health and the environment, the Environmental Protection Agency (EPA) has registered three systemic insecticides for control of EAB - dinotefuron is registered for basal trunk bark or soil application, emamectin benzoate for trunk injection only, and imidacloprid for soil application or trunk injection. View up-to-date information about these EAB insecticides, their application protocols, and their effectiveness.
The economics of treating trees on private property can be complicated. Factors include the cost of insecticide, the expense of application, tree size and the potential cost of removal and replacement. The benefits of trees, including an increase in property value, should be considered. Most products need to be applied annually but emamectin benzoate may be effective for two or more years. Certified Arborists provide expertise in properly treating EAB as well as expertly maintaining the health of ash and other trees and are listed at the ISA Arbor website.
Property owners are allowed to have their public parkway trees chemically treated. If a resident chooses to treat their public parkway tree(s), they must inform the Public Works Department so that their tree can be monitored. The Village will continue to monitor treatment advances and will be assessing the effectiveness of these treatments and their cost when developing a plan and budget for dealing with this insect in public parkway trees.