“Interwoven tapestry” of lakes and land: Iceland

Swarms of midges rise out of a lake in northern Iceland in such enormous numbers every spring and summer that they can impair breathing and darken the sky, giving the lake its name—Myvatn, or “midge lake.”

CALS entomology professor Claudio Gratton and other ecologists are trying to understand why the midge population can fluctuate by 100,000-fold across a decade, and what impact these massive swarms have on the surrounding landscape. It’s becoming clear that the billions of midges falling on land fertilize and alter the vegetation on the lakeside, but the causes behind such large fluctuations in the insects’ population remain a mystery.

Gratton’s research aims to better understand lake-dominated environments, including those of Wisconsin.

Lake Myvatn sits at the edge of the Arctic Circle, where the sun barely sets from May to August. The ecosystem is extreme yet simple; a relatively small number of species, like the midges, dominate. This bare-bones environment is perfect for exploring complex interactions within ecosystems.

In 2006, when Gratton first saw the huge numbers of midges rising out of the lake and dying on land, he thought of them as a living transfer of nutrients from water to shore. Gratton calculated that the midges were the nutritional equivalent of scattering a half-million Big Macs around the edge of the lake, which is about the size of Lake Mendota in Madison. He wondered how the lakeside responded to this nutritional glut.

To test how the midges alter the landscape, Gratton’s laboratory set up experimental plots in the vegetation around the lake. In some, they added dead midges; in others, they used netting to exclude them.

Over the years, Gratton’s team saw that where they added midges, grasses flourished. Normally starved of nutrients in the poor soil and outcompeted by heartier plants, the grasses took off in response to the influx of rotting- midge fertilizer. The research explained why grass grew in some areas and withered in others.

“Only by understanding the linkage between midges and grass can you explain this pattern in nature,” says Gratton. “The lake is causing that to happen.” Gratton was originally introduced to Lake Myvatn by colleague Tony Ives, a professor of zoology who has a lifelong connection to the island and researches fluctuations in the midge population.

Local shepherds have long called the grass in midge-infested areas “midge grass”—they
harvest the grass and feed it to their flocks. Gratton’s work suggests that the shepherds’
folklore contained a kernel of truth, and that midges might indirectly nourish the sheep by encouraging more grass growth.

Gratton and colleagues are extending these studies to the lake-filled Wisconsin landscape. Gratton and postdoctoral researcher Mireia Bartrons, now at the University of Vic in Spain, developed a model of how insect emergencies from Wisconsin lakes affect lakeside ecosystems. With more than 15,000 lakes and 34 percent of the state lying within 200 meters of a lake or stream, the scientists expect aquatic insects to affect a large share of the state.

Gratton sees ecosystems, whether in Iceland or the American Midwest, as an interwoven tapestry of interactions rather than isolated patches of land or water.

“The character of the land would change without these lakes,” says Gratton. “Our landscapes are completely interconnected.”

Ezra Schwartzberg

Ezra Schwatzberg

PhD’11 • Ezra Schwartzberg is the founder and director of Adirondack Research, an ecological and environmental consulting firm based in Saranac Lake, New York. Established in 2012, the firm focuses on social science, climate change and invasive species. The company’s tag lines—“We use science to inform decisions” and “We communicate science to influence policy”—describe its mission to use science for decisionmaking and for policy. Schwartzberg originally began his career in academia, with degrees from multiple universities around the country. It wasn’t until his postdoctoral research work at CALS that he gained the confidence to break off and start his own business, he says.

Patrick “PJ” Liesch

PJ Liesch

MS’10 • Patrick “PJ” Liesch—better known as Wisconsin’s “bug guy”—received his master’s degree in entomology from CALS in 2010 and worked as a research associate on campus. After Phil Pellitteri, the legendary king of insect diagnostics, retired in 2014, Liesch took on the position. As director of the UW–Madison Insect Diagnostic Lab, Liesch completes a variety of duties including communicating insect information to the public and acting as a bug identification guru to curious residents and businesses from all over Wisconsin. Liesch estimates that he tackles more than 2,000 cases per year. Liesch also serves as an instructor with the Wisconsin Master Gardener Program and the Wisconsin Pesticide Applicator Training program as well as with Farm and Industry Short Course. As part of his public outreach work, Liesch is a regular guest on Wisconsin Public Radio’s Larry Meiller Show.

Rachel Mallinger

Rachel Mallinger

MS’09 PhD’15 • Rachel Mallinger discovered her interest in insects as a biology major. An undergraduate research project involved pest control, which introduced her to entomology, a field that combined many of her passions. In 2009 Mallinger came to Madison, where she completed an MS in agroecology and entomology and a PhD in entomology. Mallinger is now doing postdoctoral work with the USDA as a research scientist in the sunflower entomology lab in Fargo, North Dakota. There she works with sunflower breeders in order to make the flowers more attractive to pollinators. When she’s not observing bees, Mallinger takes care of her six-month-old son, works in her vegetable garden and tries to squeeze in some of her earlier pastimes, including dancing, hiking and cross-country skiing.

Anthony Orth

Anthony Orth

BS’93 PhD’00 • As an undergraduate, Orth was inspired by entomology professor Walter Goodman and proceeded to write an honor’s thesis about the work being done in his lab. “I learned resourcefulness, resiliency and independence of mind because it was largely just Walt and me and a few other students,” says Orth. He remained on campus and completed a doctorate in entomology before discovering his interest in genomics. He also met his future wife, Elisabeth Gardiner PhD’00, and ventured with her to San Diego, Calif., where they both landed jobs focused on human biology. Orth works for Novartis, a multinational pharmaceutical company, where he sifts through the human genome seeking new therapeutic targets for human disease. Though his work today does not directly pertain to entomology, Orth says that the whole-organism CALS training he received was invaluable and that the methods he utilizes today directly relate to what he learned.

Christine Buhl

Christine Buhl

PhD’13 • Christine Buhl discovered her passion for entomology as an undergraduate at Oregon State University. “There was a moment when I looked at a small, seemingly innocuous wasp under a microscope for the first time and saw a complex world of body armor, colors and textures, and just felt the need to explore more,” says Buhl. She came to Madison to earn her PhD in entomology and begin her diverse career path. Over the years she has worked for universities in Oregon, Texas and Wisconsin, with the U.S. Department of Agriculture, the U.S. Geological Survey, county public health departments, and various environmental consulting groups. Currently Buhl is back in Oregon working as the state forest entomologist at the Oregon Department of Forestry. Her main focus is providing technical assistance regarding insects and diseases found in urban and forest trees and conducting aerial and ground surveys of damage.

Elisabeth Gardiner

Elisabeth Gardiner

PhD’00 • Elisabeth Gardiner began her training in entomology as a PhD student in CALS. “It was my hope that I could learn some really cool techniques in a lab focused on human biology and bring those techniques back to entomology,” she says. While at CALS she met her future husband, Anthony Orth PhD’00, and gave birth to their first child before completing her doctorate. During her postdoctoral fellowship with the Scripps Research Institute in San Diego, Calif., and her first industry job, Gardiner learned that her training in entomology could be directly applied to human biology, which unlocked a world of opportunity. Today Gardiner works as the chief science officer at Meditope Biosciences in San Diego, where she focuses on developing antibody therapeutics to target and eliminate cancer.

Ashley Bennett

Ashley Bennett

PhD’09 • With a PhD in entomology followed by numerous postdoctoral research positions, Bennett’s passion for entomology remains strong. Her early research at CALS focused on conserving beneficial insects in urban landscapes, an area of study and practice she continues today as an urban IPM and small farms extension specialist at New Mexico State University. Her favorite part of her job is educating homeowners on how they can create a comfortable coexistence between people and bugs in order to benefit local landscapes, prevent harmful pests and protect valuable insect populations. Her job includes a lot of outdoor activities, but Bennett’s love for nature continues even outside of her career. In her free time she enjoys hiking, biking, insect photography and tending to her family’s 30-acre tall grass prairie.

Brian Aukema

Brian Aukema

MS’99 MS’99 PhD’03 • Growing up on a corn, soybean and swine farm, Brian Aukema was drawn to bugs, trees and the outdoors at an early age. At CALS, he took advantage of the wide variety of majors, emerging with two master’s degrees (in entomology and biometry) and a PhD in entomology. After completing his doctorate, Aukema joined the University of Minnesota, where he runs a lab in forest entomology and enjoys teaching as an associate professor. Though he’s currently running with the Gophers, Aukema is still loyal to his Badger heritage. “Defending our choice of a ‘W’ in front of our house on football Saturdays” accounts for a large portion of his fall weekends, he says.

David Coyle

David Coyle

PhD’11 • David Coyle directs the forest health and invasive species program for Southern Regional Extension Forestry, an agency that works to identify, prescribe and implement a mix of education and technical services to increase the efficiency of forestry programs throughout the southeastern United States. He also is a member of the forestry outreach staff in the D.B. Warnell School of Forestry and Natural Resources at the University of Georgia. From his home base in Athens, Coyle oversees the training of federal, state and local forest health professionals. Through this work, he ensures that forestry experts are informed and knowledgeable about the region’s plants, insects and diseases.