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What You Need To Know About Emerald Ash Borer, Japanese Beetle

Dr. James E. Zablotny

The Emerald Ash Borer is about the size of a grain of rice. But since first seen in the state back in 2010, the infestation has resulted in the loss of thousands of Ash trees.

Soil pH could be perfect. Water may be plenty. But infestations are unpredictable
and can bring even the greenest growth to heel.

On this episode of Talk of Iowa, it's Hort Day! Host Charity Nebbe speaks with two plant specialists about invasive insect scourages here in Iowa.

"We only have a decade of experience with the Ash Borer, but in that time, it has moved over about three-fourths of the state," said Donald Lewis, an entomologist at Iowa State University. "And Ash trees that are attacked by the emerald ash borer are killed within three to five years."

But he says, so long as it's caught early enough, there are some chemical treatments. Professional arborists inject insecticides into the trunk of the tree that will get rid of lightly infested ash trees. But the dying trees, he said, aren't coming back.

"The chemicals work very well. Insecticide treatment of ash trees will protect trees," he said. "It's something you'll have to do every other year for years to come, however. It's not a one-and-done. You're going to have to keep that protection up."

Later in the hour, we're joined by horticulturist Cindy Haynes to answer listener questions about their gardens.


  • Donald Lewis, professor of entomology at Iowa State University
  • Cindy Haynes, associate professor of horticulture at Iowa State University
Hort DayHorticultureInsectsTrees
Charity Nebbe is the host of IPR's Talk of Iowa
Zachary Oren Smith is a reporter covering Eastern Iowa