Since its discovery in 2002, EAB has killed tens of millions of ash trees throughout the upper Midwest.
DANIEL HERMS, THE OHIO STATE UNIVERSITY, WWW.BUGWOOD.ORG

Nearly a decade after emerald ash borer (EAB) was first discovered in the U.S., there’s a call for new management of the pest. Countless hours of research have yielded refined treatment protocols that purport to control EAB and protect healthy ash trees – without the universal removal previously thought necessary – thus conserving the urban forest.

In January, the Coalition for Urban Ash Tree Conservation, comprising arborists, university researchers, agricultural scientists and entomologists, among others, issued an “Emerald Ash Borer Management Statement.” Its introduction reads:

“We the undersigned strongly endorse ash tree conservation as a fundamental component of integrated programs to manage emerald ash borer (EAB) in residential and municipal landscapes. Cost-effective, environmentally sound EAB treatment protocols are now available that can preserve ash trees through peak EAB outbreaks with healthy canopy intact. Used in association with tree inventories and strategic removal/replacement of unhealthy ash, tree conservation will help retain maximum integrity and value of urban forests. This integrated approach to urban EAB management is supported by university scientists with expertise in EAB management, commercial arborists, municipal foresters, public works officials, and non-governmental organizations (NGOs).”

Since its discovery in 2002, EAB has killed tens of millions of ash trees throughout the upper Midwest; as of February 2011, infestations had been confirmed in 15 states and two Canadian provinces. It’s estimated that ash trees represent between 10 and 40 percent of the canopy of urban and suburban communities, and it’s predicted that within the next decade, EAB will cause $10 to $20 billion in losses. That’s billion with a b.

Until now, the discovery of an infestation has meant immediate removal of the affected trees, plus removal of healthy ash trees within a prescribed radius of the confirmed sighting (usually 10 to 15 miles). It was thought that this surgical approach served to slow the ravaging spread of EAB, but it also laid waste to trees otherwise unaffected, resulting in devastating economic and environmental impacts felt throughout communities and the green industry alike. According to the Coalition, however, “Current science supports conservation via treatment as a sensible and effective tool for managing healthy ash trees in urban settings.”

Backed by the findings of university researchers, the U.S. EPA has registered three systemic insecticides for control of EAB. These are:

  • dinotefuran, registered for basal trunk bark or soil application;
  • emamectin benzoate, registered for trunk injection only; and
  • imidacloprid, registered for soil application and trunk injection.

According to the statement issued by the Coalition, “When applied using formulations, products and protocols documented as effective by university research, these treatments can provide environmentally sound control of EAB, sufficient to maintain a functional and aesthetically pleasing ash canopy.”

Insecticide formulations and application methods have been evaluated in the field by the authors of “Insecticide Options for Protecting Ash Trees from Emerald Ash Borer” (download at www.emeraldashborer.info/files/multistate_EAB_Insecticide_Fact_sheet.pdf), and the table opposite provides a quick and easy reference.


Click image to enlarge.

For more information on EAB, visit www.emeraldashborer.info.