Imperiled Glacier Stone Fly Found In Wyoming

Dec 18, 2017

An adult glacier stonefly
Credit Joe Giersch, USGS

Scientists at the University of Wyoming have discovered an insect thought to be extinct in the region in four streams in the Tetons.

The glacier stonefly was believed to only survive in streams in Glacier National Park and the Beartooth Absorka Range in Montana. UW Invertebrate Zoologist Lusha Tronstad said the discovery has put the decision-making process on hold over whether to list the species.

“This was a large range extension,” Tronstad said. “And so they extended their time to make the decision so they could investigate what does this mean because the species is known 500 miles away from where we previously thought it was restricted to.”

Because of this new information, the U.S. Fish and Wildlife Service has extended the comment period for listing the glacier stonefly.

Oliver Wilmot is one of the invertebrate zoologists at the University of Wyoming who discovered the insect in Wyoming. He says even though the stonefly’s range is larger than previously thought, it’s still not out of danger.

“Their habitat is essentially vanishing with glacier recession. And so, you know, we’re not really sure what the future holds for them but the glaciers are going to disappear eventually, and they can’t go any higher because these are already alpine environments.”

Wilmot says the glacier stonefly is important to its ecosystem, breaking down plant debris for other species in tiny, cold streams melting out of glaciers. But he says these specializations make the insect vulnerable as climate change melts those glaciers.