FOX31 Denver

State experts to release wasps to kill emerald ash borer beetles

The Emerald Ash Borer is an invasive insect that is responsible for the death or decline of tens of millions of ash trees in 21 states. (Photo: Colorado.gov)

DENVER — It’s a unique plan to save tens of thousands of trees in Colorado and it involves a parasitic wasp — 1,000 of them to be exact.

The Colorado Department of Agriculture hopes the wasp will kill the emerald ash borer, a shiny green beetle that has invaded the state.

“It’s pretty bad,” said John Kaltenbach, a biological control specialist for the Colorado Department of Agriculture. “It’s probably the worst pest Colorado has ever seen.”

The theory is the beetle hitched a ride in some wood being shipped to Michigan from east Asia and it went undetected.

Years later, the infestation has killed millions of ash trees in the Midwest and now it is in Colorado, specifically in Boulder. It is not known how the beetle got to Colorado, but the state is trying to control the ash borer population by introducing a stinger-less wasp that will kill the beetles’ eggs.

“This is the best shot in a long, widespread control,” Kaltenbach said Tuesday, next to a Mason jar full of emerald ash borer.

He explained the adult borer munches on leaves, while the larva eats the inside trunk of the tree. The larva creates these curved pathways up and down the inner bark, which will eventually kill the ash tree.

“If it is a healthy tree, it could take three to five years for the tree to die,” Kaltenbach said.

The Colorado Department of Agriculture will be placing pill bottle-looking contraptions all around Boulder. Each bottle contains about 50 wasps the size of a pepper flake. The tiny insect will leave and find EBA eggs and begin to do its work on killing the growing population.

And they won’t bother humans or any other insects.

“They were screened and tested in labs and went through a rigorous process to make sure they won’t go for anything other than Emerald Ash Borer,”  Kaltenbach said.

Find more information on the emerald ash borer.