Entomologists release wasps in Shongaloo and Minden to prey on invasive beetle killing ash trees
The LSU Ag Center and the U.S. Forest Service plan to release hundreds of tiny, nonnative wasps Tuesday in north Louisiana. It’s the second such release of the parasitoid wasp in an ongoing effort to contain damage from an invasive beetle killing native ash trees across the U.S.
The emerald ash borer was found in Michigan more than a decade ago. The beetles reached south Arkansas and north Louisiana this year. LSU AgCenter entomologist Rodrigo Diaz is in charge of biocontrol programs statewide. He says the wasps are released at two sites near Shongaloo and Minden in Webster Parish.
“We basically went to the field and located infested trees. Then, we opened the containers and let these parasitoids free next to the trees that were infested. They immediately start looking for trees because that is where their prey is,” Diaz said, who gets the wasps from a rearing colony in Michigan.
These ash trees play an important role in bottomland ecosystems and also have an economic value to the timber industry. Some insecticides can kill the emerald ash borer and save a homeowner’s ash tree. But that type of control, Diaz says, is not practical on the scale of a forest.
“The issue is, how we manage this pest in forests where of course there isn’t as much as an economic incentive to control these pests. Therefore, we need to find more sustainable alternatives, which is biological control especially in managing emerald ash borer in forested areas,” Diaz said.
Diaz is collecting data on how well the wasps overpower the beetles at these two sites, and will be able to have conclusive results in about one year. Diaz obtained a permit from the U.S. Department of Agriculture to use several species of wasps to manage the emerald ash borer.
The LSU AgCenter is working with the U.S. Forest Service, the Louisiana Department of Agriculture and Forestry and the U.S. Department of Agriculture’s Plant Health Inspection Service to get a biocontrol effort underway in north Louisiana.