MISSOULA — Montana has been battling invasive weeds for years with help from a small team connected to a worldwide scientific network and a lot of little bugs. The Montana Biocontrol Project uses biocontrol agents, or living things like insects and fungi, to combat weed infestations.
“Weed biocontrol is very based in science,” Project Coordinator Melissa Maggio said. “So, it's based on a theory that states one of the reasons that invasive plants are able to grow to these abnormally large infestations in the invaded range is because they've escaped their natural enemies.”
The project, based out of the Missoula County Department of Ecology & Extension, started in 2013 to increase coordination in weed control programs. They help educate about and implement biocontrol methods and agents across the state and region.
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Maggio said the newly-introduced predators can help whack major weed problems, like spotted knapwood and leafy spurge.
“Success with biocontrol is really bringing a balance back to the system,” she said. “So, rather than that target weed dominating a site and completely out-competing the native or beneficial vegetation, it's playing nice with those other plants.”
Biocontrol is an alternative to herbicide and hand-pulling weeds, which you need to repeatedly apply to keep the weeds down.
“The way we develop biocontrol agents is we typically work as groups. So, you know, Montana says, ‘Ugh! We have this new target weed, we have our more traditional weed management tools, but we need something else,’” Maggio said. “So, we reach out to our neighbors and they're probably also facing a lot of the same issues.”
They work with scientists and managers across the U.S. and internationally to fund researchers where the target invasive weeds are actually from — often in Switzerland.
“They figure out what natural enemies are utilizing them in the native range, and they take them back to their laboratories and they begin to study them,” she said.
Decades go into to researching potential biocontrol agents and their impacts, both abroad and at home. They are studied and approved by U.S. regulators to ensure they will only impact the intended target weed.
“Most of these biocontrol agents that we work with co-evolved with those target weeds so they can only feed on that target weed and they can only use that target weed to complete their life cycle,” Maggio said. “So, there's really no possibility of them switching over and having significant negative impacts on anything else.”
As the target weed population decreases, the agent’s population also decreases.
Once approved and in Montana, the biocontrol agents are studied at Montana State University. After that, the project team works with local officials, like extension agents, to get the bugs into landowners’ hands and onto weeds.
“We typically distribute over a million biocontrol agents in a year,” Maggio said. “These are teeny, tiny, little biocontrol agents.”
They host dozens of collections days throughout the spring and summer, where land managers gather up agents to spread them further.
“For spotted knapweed, this is a larger weevil that we're collecting and it doesn't fly,” she said. “It is out in August during the hottest part of the day ,so when we're miserable it's happiest, and we mostly just walk around fields of spotted knapweed and hand collect the weevils off of the top of the plants.”
Just like the plants, the research travels too. So does the education, the Montana Biocontrol Project website has guides and ways to get involved in the battle against invasive weeds.
“I know for sure that there's been researchers that have come to Montana to look at goldenrod to see if they can identify any potential biocontrol agents,” Maggio said. “So it goes both ways.”
