A program that had released over 35,000 wasps at Cedar Bog Nature Preserve in the last three years to combat the emerald ash borer has been discontinued.
The U.S. Department of Agriculture program proved ineffective in combating the loss of ash trees, according to Tracy Bleim, Cedar Bog’s Nature Preserve site manager.
USDA.gov reports the ash borer was first discovered in southeast Michigan and adjacent parts of Canada in 2002. It is suspected to have been in the U.S. since the late 1990s. The species is originally from Asia and is thought to have entered the country through packing materials coming from the Asian region.
“Once a week we would receive a shipment of wasps from the USDA lab in Michigan,” said Bleim. Once received, the wasps were released into the bog in hopes to naturally combat the ash borer.
Outside of using a natural predator like the wasp, not much can be done to control the ash borer in the preserve.
“Insecticides can’t be used, the water would move the poisons around, affecting other parts of the preserve,” Bleim said.
The ash trees are still monitored in hopes the seed line is still there for future growth.
“For now, I’m cutting back seedlings in hopes that the emerald ash borer will move on once they run out of ash trees,” Bleim said. “From what I’ve heard, they will go after even the small ones.”
The wasp program has worked in other locations.
“It is a little cool here, but it’s hard to say why it didn’t work,” Bleim said. The wasps just didn’t seem to adapt to the environment, she added.
Since the bog is a preserve, trees can’t be replanted. So growth has to happen naturally.
“The ash trees will have to come back on their own,” said Bleim.
With the ash tree gone, Bleim has seen other species of trees starting to take its place.
“I’ve seen a lot of Tulip trees; they seem to be enjoying the sunlight,” she said.
It has been reported that the ash borer is now going after the the White Fringe Tree, according to Bleim.
All 16 species of ash trees are at risk in the U.S., according to USDA.gov.
The ash tree’s wood is used for flooring, tools and baseball bats, along with many other uses. The loss of the trees could impact the economy at the industrial level.