Emerald Ash Borer Update: Still None Known in Iowa

Attention to and concern about the emerald ash borer remains high with numerous calls, email messages and samples received this month. Here are the answers to the most common recent concerns or questions.

  • There are no known infestations of emerald ash borer (EAB) in Iowa. A large number of specialists and regulatory persons have descended on the site of a reported larva (see news release from June 4, 2009), and have found NO evidence that EAB is present.
  • We hope that education and common sense will circumvent intense insecticide sales pressure, misinformation and fraud to prevent unnecessary treatment and expense.
  • It is not prudent to treat ash trees with insecticide to prevent EAB until there is a confirmed infestation within 15 miles of your tree.
  • It is a waste of time, money and insecticide to treat ash trees at this time of year (June). No treatment is guaranteed to always be effective, but treatments are doomed to fail if applied at the wrong time of year (outside the treatment window of mid-April to mid-May).
  • Treatments will not be effective on trees that are not healthy and vigorously growing (full, thick canopy, good shoot elongation and no loose or injured bark).
  • Now is the time to be evaluating tree tree health and diversity in your landscape in order to be making tree replacement decisions. A new guide on suggested tree replacements for ash is available from Dr. Jeff Iles, ISU Extension Horticulturist.
  • A new ISU Extension publication is available on how to use insecticides to protect high-value, ash trees from (EAB) damage. Pamplet PM 2084, Emerald Ash Borer Management Options, offers recommendations for homeowners and for commercial pesticide applicators on products that can be used to protect healthy ash trees from attack by EAB.
  • A publication on Options for Protecting Ash Trees from Emerald Ash Borer is available from the North Central IPM Center.

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