Non-native bumblebees becoming common in Lower Mainland: study
UBC researchers says eastern bumblebees represent more than 40% of all bees they observed
A new survey by University of British Columbia researchers suggests that many of the bees buzzing around the Lower Mainland are not native species.
Risa Sargent, an associate professor with UBC's Faculty of Land and Food Systems who heads the Plant Pollinator and Global Change Lab, says Bombus impatiens, otherwise known as the common eastern bumblebee, is now the most common bumblebee found in the Lower Mainland.
The scientist says the species represents more than 40 per cent of all bees the researchers observed.
Bumblebees, she says, have been imported from Ontario and Europe for use in B.C. greenhouses, largely in the Lower Mainland, as a pollinator for crops such as tomatoes, peppers and cucumbers.
Sargent and colleague Sarah Knoerr surveyed pollinators in agriculture areas in Delta and Richmond, suggesting they have escaped greenhouses.
"It went from, OK, it's going to be in the greenhouses, it's going to do this great service and we're not going to let it out," she said. "And then, OK, it's getting out," she said of the eastern bumblebees.
When some species are introduced, she says, they fail to survive in their new environment.
"They just don't go anywhere," she said, but "Bombus impatiens is going places fast."
The researchers created a map detailing observations of eastern bumblebees from labs, field surveys, and data collected by members of the public, which were then verified by experts.
According to Sargent, the timing of the observations suggests that it wasn't just one event where bees escaped. It seems to have occurred a number of times, as evidenced by the range that the bees have reached.
The eastern bees are considered a non-native species, rather than an invasive species, which would be considered ecologically harmful.
Still, Sargent says there are concerns that growing numbers of eastern bumblebees could affect the native bee population by competing for resources and nesting sites.
In an interview with UBC News, Sargent recommended having legislation to require imported colonies to have a "queen excluder," a barrier that prevents queen bees from escaping at the end of their reproductive cycle.
Sargent says members of the public can use the online platform iNaturalist to log bee sightings that can later be verified by experts.
She also says residents looking to support the bee population can avoid pesticide or herbicide use and look to "naturalize" their lawn to include native plants that attract pollinators, birds and other visitors.
Ministry reviewing report
In a statement, a Ministry of Agriculture and Food spokesperson said they were reviewing the UBC report to see how it could be used to support a more sustainable farming environment in B.C.
"The ministry recognizes the importance of pollination in food production and is always open to ideas and suggestions that can improve food security and environmental stewardship," the spokesperson wrote.
A spokesperson for the Canadian Food Inspection Agency said that it was reviewing its bumblebee import program with the goal of protecting Canadian bee populations and plant health. Currently, bumblebee imports are only allowed from the U.S.
"Queen excluders are not a main focus of this review," the spokesperson wrote. "[They] may be considered following the risk assessment process if updates are needed to the import requirements and corresponding risk mitigation options."
The spokesperson added that it would talk to industry and government stakeholders as part of its review.
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With files from Darius Mahdavi