Emerald Ash Borer Update

Infestations discovered in 2012

In March, EAB was verified on trees in a residential area of Warrington in Bucks County. In early June, two sites in Perry County were identified: a campground in Liverpool, PA and a truck pull-off on Route 322 east as you enter Perry County. June also brought confirmation of emerald ash borer in Venango County, at a campground in Emlenton, PA, and on a trap at the USDA-APHIS Otis Lab’s trap efficacy test site in Selinsgrove, PA in Snyder County. In late July, the pest was confirmed in Jefferson County.

What does this mean to you and your customers?

Ash trees in landscapes can be successfully protected from this unintentionally introduced pest, primarily with systemic insecticides that move in the tree’s vascular system. It is important to begin treatment before the tree’s vascular system is too badly damaged by the emerald ash borer larval feeding. Treatment is less likely to be effective if more than 50 percent of the crown shows dieback after attack by this pest.

To treat or not to treat, that is the question

Not all ash trees are candidates for treatment, but those that are critical to your customers’ landscapes, or those planted as memorial trees or to commemorate life events should be given consideration. The Cooperative Emerald Ash Borer Program publication, “Insecticide Options for Protecting Ash Trees from Emerald Ash Borer” recommends beginning to treat trees when the emerald ash borer is confirmed in your county, or if valuable trees are within 10 – 15 miles of a confirmed infestation in a neighboring county. It does not recommend prophylactic treatments for trees that are more than 15 miles away from a confirmed infestation because that would be a waste of money. Monitoring for the emerald ash borer is suggested in those locations.

It is important that your customers understand that treatment is an ongoing process rather than a one-time event. If experience in western Pennsylvania can serve as a guide, many ash trees show no symptoms even though they are lightly infested; they do not become symptomatic until the infestation is severe. By then, it may be too late to save them.

Information on the emerald ash borer’s movement across Pennsylvania was taken from Greg Hoover’s website, “Timeline of EAB Detection in Pennsylvania.”

For more information

• Emerald ash borer and updates on its movement
  
• "Insecticide Options for Protecting Ash Trees From Emerald Ash Borer"