Miami releases killer wasps targeting destructive emerald ash borer

A winged, hero wasp from Asia is coming to save a Butler County forest from the destructive emerald ash borer.

The unusual strategy comes from scientists and students at Miami University who are working with an Oxford Twp. tree farm to help save it from the borer insect that has killed ash trees locally and across America.

The biological control program involves releasing thousands of tiny Asian wasps — parasitoids — on ash trees this month.

Asian “murder hornets” are getting a lot of media attention lately, and Steve Sullivan, who is director of the Hefner Museum of Natural History at Miami University and in charge of the recent parasitoids wasp release, wants to make sure no one confuses the two.

The wasps used by Miami — Tetrastichus planipennisiare — are about the size of a mosquito and of no danger to humans or pets, said Sullivan.

“Most wasps, especially parasitoid wasps, are tiny, microscopic invertebrates that have stingers but almost invariably cannot sting humans,” he told Miami officials. “This is because the stinger is modified into an ovipositor, a tube for laying eggs within other invertebrate— in this case in the larvae of the emerald ash borer.”

John Kinne and his wife own the tree farm and sought their former school’s help with eradicating the emerald ash borer.

“I wanted to participate because ash trees are an important part of Ohio’s ecology,” Kinne said. “They’re important for crop value; the wood is great for furniture, flooring, cabinets and baseball bats; and they are beautiful trees.”

According to Miami officials, the parasitoid wasps being released are produced and supplied by the U.S. Department of Agriculture (USDA) Emerald Ash Borer Parasitoid Rearing Facility in Brighton, Michigan.

In order for the Animal and Plant Health Inspection Service (APHIS) — an agency of the USDA — to approve the Kinne property for the program, there had to be an active emerald ash borer invasion in progress and a substantial number of healthy ash trees.

Biological control – introducing natural predatory insects into an environment - is a way to reduce pest populations without resulting to the application of toxic chemicals.

Two USDA agencies, the APHIS and the Forest Service, started a biological control effort shortly after the emerald ash borer was detected in America in 2002.

“To date we have lost millions of ash trees throughout the United States and this is devastating to our forests” said Sullivan on a video about the project produced by Miami.

The goal of introducing the Asian wasps locally, he said “is to establish a predator on the emerald ash borer and save our native forests.”

Sullivan said biological studies take a long time. In this case, the wasps will need time to establish themselves and then have an impact on the beetles. It then takes more time for the ash trees to respond.

Miami students are monitoring the experiment and tracking the impact of the wasps.

“The data we collect will help us to understand if the releases did any good,” he said. “We want to know if the wasps are actually killing off beetles in a way that’s going to save our forests.”

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