What’s the buzz? Pollinators are hard at work

With the coming of spring, pollinators of all sizes are on the hunt for food. Bees, the most common group of pollinators in Alberta, are, without a doubt, the workhorses of the pollinator world and are essential for commercial crop production and preserving conservation areas and wild spaces. 

The province has more than 300 species of native bees and several introduced bee species like the honey bee and alfalfa leafcutter bee. Considered livestock, honey bees and leafcutter bees are essential to pollinate canola- and alfalfa-seed crops and require the support of a beekeeper to survive. 

“Lethbridge is bee central for honey bees in Canada,” says Dr. Shelley Hoover, a biology professor and bee researcher at the University of Lethbridge. “About 40 per cent of the honey bees in Canada are in Alberta. The biggest pollination market in Canada is hybrid canola seed production. When they’re trucking bees to canola pollination, there can be 10,000 hives on the road a night.” 

Honey bees also pollinate crops such as haskap berries, pumpkins and blueberries. Some Alberta beekeepers will move their bees to other provinces to pollinate berries and tree fruits. Bees are extremely hairy and have a slight static charge, which enables them to carry pollen all over their bodies.

“The way bees carry pollen varies,” says Hoover. “With honey bees, they have those packs of pollen on their legs. The leafcutter bees have a scopa on their abdomen and carry their pollen there. From a plant’s perspective, it’s good to attract a diversity of pollinators because they will visit the flower at different times of day and physically in different ways. That delivers pollen to different parts of the female reproductive system. There have been studies that show increased seed set with increased diversity of pollinators.”

But bees can’t do the job alone. Birds, bats, moths, beetles, butterflies, flies, such as syrphids (flower flies and hover flies), and wasps also play a role in pollination.

“The more diversity you have participating in an ecological process like pollination, the more resilient it is,” says Dr. Dan Johnson, a University of Lethbridge environmental science professor with expertise in entomology. “Some people say all we need are honey bees or leafcutter bees. There are many reasons why that’s not true, partly because of specializations for some insects but also because there are substitutions in ecology and certain close linkages. In other words, diversity is good for conservation,” he says.

When Johnson studied pollination of the Western Spiderwort, a species at risk in Canada, in field studies in southeastern Alberta, he found flies are important pollinators of the rare plant, adding to the previously known role of sweat bees. As a member of the Yucca and Yucca Moth recovery team, Johnson noted the sudden expansion of the moth north to Lethbridge and beyond, a good sign for the threatened plant that is both host to the larvae and benefactor of the pollination.

Homeowners and landowners can help pollinators thrive by planting diverse flowering plant species so flowers are available throughout the growing season. Native bees don’t travel as far as honey bees so providing them with nesting habitat, like some undisturbed soil, an old hole or even the stem of a flower from the previous year, is beneficial.

For native or wild bee species, plant native flowers. Many bee species like the raspberry family and sandfoin, a plant that’s also good for the soil because it fixes nitrogen. 

“I always tell people to plant trees and shrubs because, per square metre, you get a lot more flowers out of a flowering tree or shrub than in plants on flat ground,” says Hoover. 

She also suggests visiting the Pollinator Partnership Canada website to find planting guides for all areas of the country. For the Lethbridge area, check out the Moist Mixed Grassland Ecoregion planting guide. Other resources include the Lethbridge and District Horticultural Society and the Alberta Native Bee Council.