ARLINGTON, Wis. – Mary Magnuson has spent a good amount of her summer scouting for insects.

The entomology student is serving a summer internship at the University of Wisconsin-Arlington Agricultural Research Station.

The Minnesota native wasn’t raised on a farm, but her work may help farmers in the future. Since September 2018 she has been screening different varieties of potatoes for insect resistance. The focus is mainly on the Colorado potato beetle, said Sean Schoville, her research adviser and an assistant professor of entomology at UW-Madison.

The beetle has repeatedly evolved resistance to pesticides. It can defoliate plants, resulting in serious yield losses or plant death.

“Mary measured how much of a plant beetles would consume, and whether the plant looked physiologically healthy,” Schoville said. “Potato plants produce secondary chemicals to protect them from insects.”

Magnuson’s findings will help researchers as they develop insect-resistant potato varieties in the future, he said.

“Mary has been wonderful to work with,” he said. “She’s mature, intellectually driven and is invested in agriculture. She also has great relationships with other researchers and farmers.”

Magnuson presented her findings in April at the UW-Undergraduate Symposium. Scientists will need to develop sustainable-control strategies, she said.

“Candidate varieties have been developed from crosses between cultivated- and wild-potato species,” she said. “We evaluated the resistance level of five resistant-bred potato varieties to Colorado potato beetle larvae by performing feeding assays. Our results suggest that some of those varieties might be repelling the larvae and could represent good candidates to replace regular potatoes in crops.”

At the research station Magnuson does crop scouting. She’s involved in weed-management projects as well as several insect-monitoring programs. She helps prepare for various field days as well as provides landscaping maintenance at the station.

“We have a black-light trap that collects weekly data on moths,” she said. “We also have an aphid trap, and I recently installed a western bean cutworm trap. I also just help out with whatever needs to be done around the station.”

She attended a crop-scouting school during spring break at UW-River Falls.

The school provided a multi-disciplinary approach to integrated pest management, said Jeff Breuer. He’s an assistant superintendent at the research station. It helped Magnuson in the crop-scouting work she does at the station.

Magnuson began her freshman year in September 2018 at UW-Madison. She originally intended to study evolutionary biology. But after working on the pesticide-resistance evolution project she changed her major to entomology.

“Insects are an interesting model through which to study evolution,” she said. “Entomology as a major also is flexible, which is nice because I’m planning on doing a double major in life-science communication.”

Magnuson’s internship is funded 50 percent by the UW-Madison College of Agricultural and Life Sciences entomology department and 50 percent by the research station.

Lynn Grooms writes about the diversity of agriculture, including the industry’s newest ideas, research and technologies as a staff reporter for Agri-View based in Wisconsin. Email to contact her.