Fighting mile-a-minute vine, organically

The Recorder, October 4, 2018, by Sarah Robertson

To fight the invasive mile-a-minute vine on a Montague farm, state officials released weevils, tiny insects that have an appetite for the non-native species, as a form of biological control.

“We didn’t even know what the plant was at first,” said Sarah Voiland, co-owner of Red Fire Farm. “We were like, what is this weird weed we’ve never seen before?”

Polygonum perfoliatum, also known as the devil’s tail or tear thumb, can grow up to six inches a day and is covered in sticky, thorn-like hairs that make removing the vine by hand a painful task. With triangular leaves and clusters of blue berries, the vine grows over native vegetation, blocking sunlight and smothering other life.

“Because the seeds are spread by birds, it can start in new areas and start new populations and spread quickly and grow quickly,” said Cynthia Boettner, a biologist and coordinator for the Fish and Wildlife service’s invasive species plant control initiative.

Originally a problem in the mid-Atlantic states, the vine has moved north and is already a major problem in eastern Massachusetts. Mile-a-minute has been found on properties in Greenfield, Deerfield, Montague, Erving and Amherst, according to Boettner, with none yet found west of Interstate 91.

“We have certain parts of the farm where the mile-a-minute has been very aggressive,” Voiland said. “They’re pretty impressive in terms of what a plant can do.”

Sarah and Ryan Voiland started their Montague farm in 2009 on what had been a tree nursery. Scientists believe that the mile-a-minute vine, native to Asia, spread to the United States on foliage shipped overseas and interstate.

“Red Fire Farm inherited this problem,” said David Sagan, a private lands biologist with the Fish and Wildlife service who oversaw the weevil release with Boettner.

As a certified organic farm, Red Fire can’t use herbicides used elsewhere to fight in invasive plant. After years of frustration, hand-pulling, mowing and weed-whacking, the weevils are the latest attempt to keep the vine at bay.

“Being an organic farm … makes this project more challenging, but it also forces us to be using methods that aren’t as harsh on the land,” Boettner said. “It’s been a good education process for all of us.”

So far, the weevils have made progress, but they are no silver bullet.

“What we’re hearing is the weevils haven’t been as effective as they’ve hoped, or as effective as in the mid-Atlantic,” Boettner said. “We’re hoping western Massachusetts will provide a different climate and conditions that will make it more viable, but we’re not counting on it.”

The Fish and Wildlife Service is taking an “early detection, rapid response” approach to managing the mile-a-minute vine. By the time the insects arrived on the farm, other weevils had already found their way to the mile-a-minute vine, Voiland said, but the Fish and Wildlife Service wanted to bolster their population to study the effects.

“I think that for these new invaders especially, we have a good chance of keeping them at bay, and we have a good chance at restoring certain high priority properties,” Boettner said.

By helping sites like Red Fire Farm with weed-pulling and the weevil release, they are working outside the bounds of the Silvio O. Conte National Fish and Wildlife Refuge — on private property — to stop the mile-a-minute vine, before it becomes unmanageable. They teamed up with representatives from Massachusetts Department of Agricultural Resources (DAR) and the New England Wild Flower Society to locate mile-a-minute infestations.

The DAR received a grant this year from U.S. Forest Service that included funds to use weevils as a biocontrol agent across the state. The first weevils were released in eastern Massachusetts around 2010 after the mile-a-minute was first detected in Massachusetts in 2006.

Weevils have been used elsewhere in the U.S. to control invasive species like Giant salvinia in Louisiana but are a nuisance in southern California where they are attacking palm trees.

“There is always a little bit of worry that maybe you introduce something that then becomes a problem,” Voiland said.

According to Sagan, the species of weevil used on Red Fire Farm, Rhinoncomimus latipes, only feed and reproduce in the presence of the mile-a-minute vine.

“This is another insect that is not native to here, but mostly only attacks the mile a minute vine,” he said.

Keeping up

Fish and Wildlife officials are asking for the public’s help in identifying other potential mile-a-minute infestations in the state. The first sighting of the vine in the Connecticut River watershed was by a Greenfield resident in 2009 who had read about the invasive species in a MassWildlife magazine.

Keeping tabs on other invasive species like bittersweet and Japanese knotweed is a challenge that requires time and attention. About 12 people work on invasive species control in western Massachusetts between the U.S. Fish and Wildlife Service, MassWildlife and state Department of Agricultural Resources, so they must use resources wisely.

“Those of us that are concerned about invasive species are really struggling to prioritize, so we spend our some most wisely and try to enable the biodiversity of our area,” Boettner said. “With climate change and new species coming in all the time it is an uphill battle.”

For information on how you can help, contact the Silvo O. Conte National Fish and Wildlife Refuge at 413-548-8002.