Researchers Set Sights on Uprooting Land-Based Invasive Species

As invasive carp and zebra mussels continue to infest the state’s waterways, more Minnesotans are becoming aware of the destruction invasive species can cause to native ecosystems—and how important it is to stop them from spreading.

But stemming the spread of invasive species in the water is only half the battle. Experts are also working to curb invasive species that thrive on land. These plants, insects, and fungi wreak havoc on the state’s ecosystems and carry a hefty price tag—at least $3 billion a year in Minnesota alone.

This year, the University of Minnesota’s Minnesota Invasive Terrestrial Plants and Pests Center (MITPPC), part of the College of Food, Agricultural, and Natural Resource Sciences, launched 11 new projects to research land-based (terrestrial) invasive species. The projects are supported by $4.6 million in state funding from the Minnesota Environment and Natural Resources Trust Fund.

Robert Venette, Ph.D., MITPPC’s director, said the research focuses on applying knowledge to reduce or eliminate some of the greatest threats to the state.

“We are talking about new pathogens, weeds, insects, and other animals that are not native to Minnesota and could cause (or have caused) real ecological, economic, or social harm in the state,” he said. “Anyone who is concerned about the future of agriculture, forests, prairies, or wetlands should be concerned about terrestrial invasive species. New insects, pathogens, and weeds can transform landscapes and upset biologically-based economies.”

One recent example, Venette said, is the spotted wing drosophila, which is driving several state berry producers out of business. This fruit fly plants its larvae in berries, grapes, and other fruits as they ripen. The larvae then damage the fruit from the inside and make it more susceptible to further harm from fungi, bacteria, and other insects.

Each of the 11 new invasive species projects is a team effort, with collaborators in public, private, and nonprofit groups both within and beyond Minnesota lending a hand. Researchers at the U are working with organizations such as the Minnesota Department of Natural Resources, the US Forest Service, and Johns Hopkins University.

“We are pushing to expand knowledge of the biology and management of invasive species and apply that knowledge to eliminate or reduce the threats they pose,” Venette said. “As part of that model, we work closely with external partners to help ensure that our research makes a real difference.”

Saving the Soybeans

Several of the projects funded this year take different approaches to a common goal: protecting Minnesota’s soybean crop. Minnesota farmers grow about 3 billion bushels of soybeans a year, and the crop is the state’s top agricultural export commodity, with nearly $2 billion in exports in 2014.

Among the main threats to soybeans are soybean aphids—tiny yellow insects that infest the crops and can destroy up to 40 percent of them. Current prevention methods rely on broad-spectrum insecticides, which can have negative environmental effects, especially in large quantities. Two researchers are leading projects to solve the problem.

One is Robert Koch, Ph.D., assistant professor of entomology with the College of Food, Agricultural, and Natural Resource Sciences (CFANS), who aims to decrease the need for insecticide by developing soybean varieties that resist aphids. His team will also explore how remote scouting techniques, using aerial drones that hover over farm fields, can help spot aphid-infested crops.

The other, George Heimpel, Ph.D., Distinguished McKnight University Professor of entomology in CFANS, is pursuing a different approach. Heimpel aims to find out if he could counterbalance the problem created by one insect by introducing another: a small, parasitic wasp known as Aphelinus certus. The wasp preys upon soybean aphids, limiting the size of their populations and potentially  cutting down on the need for insecticides.

While those two projects look for aphid solutions, a third team looks to quash a different soybean threat. A fungus call Fusarium virguliforme, relatively new to Minnesota, can cause sudden death syndrome in soybeans and rot the roots of other legume crops. But researchers don’t know enough yet about how the fungus spreads and how it causes these diseases.

Dean Malvick, Ph.D., professor of plant pathology in CFANS, is leading a project that aims to fill in these gaps in knowledge to better understand the fungus and develop tools that will help researchers breed soybean varieties that can resist it.

See the full list of invasive species projects funded by the state Environment and Natural Resources Trust Fund this year.