Montana State scientists explore mechanics of Yellowstone beetles

BOZEMAN – Scientists at Montana State University have examined the unique and extreme environments of nearby Yellowstone National Park for decades, but one team has recently published some of the first research exploring how insects manage to thrive in hot and often acidic places around the park’s thermal features.

Much of MSU’s past work has focused on microbes and other single-celled organisms that live in hot springs and other features in Yellowstone. Bob Peterson, an MSU entomologist and head of the College of Agriculture’s Department of Land Resources and Environmental Sciences, collaborated with colleagues at MSU and scientists at the University of Nebraska, Iowa State University and Augustana College on the new article focused on tiger beetles, titled “Hot Springs, Cool Beetles: Extraordinary Adaptations of a Predaceous Insect in Yellowstone National Park.” The work was published in the Annals of the Entomological Society of America on Feb. 28 and was featured by Entomology Today on April 11.

Peterson called the birth of the study’s main question a classic moment of scientific curiosity.

His own adviser from his alma mater, Leon Higley of the University of Nebraska, was visiting Yellowstone in 2006 when he noticed that tiger beetles were living on top of and near the thermal terraces at Mammoth Hot Springs near the northern border of Yellowstone. Higley, a tiger beetle expert, wondered how the insects could manage to keep themselves cool in such a warm environment, compared to where they are usually found.

“I knew it was too hot for the beetles to be there,” Higley said, “and yet there they were.”

Ten years after Higley’s initial observation, Kelly Willemssens—then a graduate student at the University of Nebraska and now a lecturer at Clemson University—centered her doctoral research on the intriguing beetles. The team compared Yellowstone’s beetles to populations of the same species in Idaho that were not in hot spring environments. Those beetles were known to dip their bodies in cool water, using evaporation to regulate temperature. The insects in Yellowstone can’t mirror that behavior, since the water that flows from the hot springs is over 100 degrees Fahrenheit and acidic or alkaline.

“Insects don't control their body temperature. They're not warm-blooded like us,” said Peterson. “They basically become the temperature of their surroundings. So, when you get up to those levels, proteins start breaking down and you die. In a non-hot-spring environment, there's much more behavioral cooling versus anything we've seen in the park. So, what's the difference?”

To explore that question, assistant professor Chelsea Heveran of MSU’s Norm Asbjornson College of Engineering collaborated on the work, aiming to identify exactly what adaptations the beetles had evolved to survive in environments that should be deadly.

Heveran is part of the Department of Mechanical and Industrial Engineering and specializes in researching biomaterials. She focuses primarily on properties of bone and other living materials, learning how to mimic them to build better structures, such as brick or concrete, based on the properties of nature.

Coupling their observation of the beetles’ behavior with structural analysis, it became clear that the Yellowstone insects had evolved different abdominal plates than their counterparts in cooler areas: Their abdomens reflected more heat than those of the Idaho beetles.

In researching the tiger beetles, Heveran led the use of some of MSU’s most advanced technology, examining specimens under specialized electron microscopes in the Imaging and Chemical Analysis Laboratory.

“These tools will let you take a very small specimen and zoom in to thousands or even hundreds of thousands of times in magnification and see what it looks like,” Heveran said. It’s the same technology that would let you see the texture on a human hair, or let you see little, tiny holes in bone. The microscopes there are just fabulous and really help our university stand out in the region and beyond.”

Beyond the thrill that comes with a scientific discovery, Peterson said the more detailed knowledge of how Yellowstone’s tiger beetles have evolved presents opportunities for applications in everything from materials to medicine.

“There’s the innovative potential to come up with products that might resist or reflect more heat,” he said. “These organisms also no doubt have heat shock proteins that help them physiologically deal with heat. Understanding how those proteins or genes are turned on and off could have medical applications, and these discoveries will directly inform that.”

The research included undergraduate and graduate student scientists from both MSU and Nebraska, and it opens new questions in environmental science, entomology and mechanics that current and future students can continue to explore. Bringing together numerous departments and institutions, plus collaborating with the National Park Service, made the work broader and more effective than any one entity could have accomplished alone, Heveran said.

“It's just so much fun and there's so many good training opportunities for students when they work in those spaces, because you have to really cleverly design your experiments to understand what nature has done,” she said. “In my personal experience, MSU is just about the most collaborative place. People are willing to work together, and that's really what makes MSU so special.”