Serbian weevils unleashed to control weeds in Banff

BANFF, Alta. — Hundreds of tiny beetles have been released in Banff National Park to try to fight a weed.

Known as weevils, they are being used as a biological control agent to kill yellow toadflax, an invasive species that’s taken root throughout the national park.

“A weevil is a very small insect that lays its eggs within the plant and reduces the plant’s distribution by stressing it out,” said Jane Park, a fire and vegetation specialist with Parks Canada.

A total of 350 weevils — each one the size of a grain of rice — were released last week into a small test site at an undisclosed location.

Park said it’s the first time they’ve used a biological control agent in Banff National Park to prevent the weeds from overtaking native plants.

Officials went through an environmental assessment and got help from Rosemarie De Clerck-Floate, a scientist with Agriculture and Agri-Food Canada in Lethbridge, Alta., before the weevils were released into the park.

“They are little weevils that come from Serbia,” De ClerckFloate said. “They’ve co-evolved with their host plant, which happens to be this invasive weed that came from that area of the world.

“It’s a long process getting them over here.”

De Clerck-Floate said the weevils are regulated by both the Canadian Food Inspection Agency and the United States Food and Drug Administration.

She said she first received approval to use the weevils as a bio-control agent in 2014.

“I immediately started releasing them in different climatic areas in Alberta and British Columbia, both northern and southern,” she said. “They establish pretty well everywhere, which is really good, and they overwinter.”

De Clerck-Floate said their release in Banff National Park is her highest elevation at 1,400 metres above sea level.

“I have a feeling they’ll do OK,” she said.