For the love of solitary bees and their impact on Canadian ecosystems

solitary-bee-on-a-leaf Photo by Jaco Visser/Shutterstock

If you start your day with a cup of coffee, or enjoy a nice piece of chocolate or fruit, you can thank bees. One out of every three bites of food comes from insect pollination globally, with bees being the main pollinators of fruits, vegetables, and wildflowers. Canada has over 800 species of wild bees, most of which are solitary bees. Solitary bees can and do handle pollination of our fruits, vegetables, herbs, and flowers, but they are experiencing population declines due to habitat loss and increased pesticide use.

The lifestyle of a solitary bee is far different from that of the more familiar honey bee: solitary bees live alone instead of in a hive, almost none produce honey, and they are generally non-aggressive. To help us gain a better understanding of solitary bees and their impact on Canadian ecosystems, the David Suzuki Foundation has launched a citizen science program called the BIMBY (Bees In My Backyard) Project, which places the scientific monitoring of bees in the hands of Toronto residents.

Participants install on their property a custom-made bee hotel, made from a plastic tube about 15 cm deep, stuffed with three different sizes of paper tubes. They monitor the guests throughout the summer to learn what types of solitary bees live in their yard. Jode Roberts, project lead for the BIMBY Project, explains that a solitary bee will crawl into a tube, lay an egg, build a cell wall, and then repeat the process.

Different species of solitary bees have different methods of creating cell walls: mason bees use mud, leaf-cutter bees use mushed-up leaves, and cellophane bees use sap to create a cell cap that looks like crème brûlée.

Participants take pictures of the bee hotel every two weeks and send them to Dr. Scott MacIvor at the University of Toronto Scarborough. Dr. MacIvor and his team look at the cell structures to see what species of solitary bee have chosen the participant’s yard as a home. The households also send in photos of blooms in their yard, so that researchers can determine which flowers solitary bees prefer to frequent for collecting pollen and feeding their young.

For residents and cottagers outside Toronto, lots can be done to protect solitary bees. If you’d like to help record the types of bees in your area, Roberts highlights the iNaturalist app for smartphones, which allows users to share a snapshot of a plant or animal with the local naturalist community to identify and record various species. And if you have a green thumb, creating natural habitat is key to protecting wild bee species.

“As you drive up to cottage country, you’ll see on both sides of the road that there’s monocultures of plants that don’t provide a whole lot of services or food and shelter for bees and butterflies,” says Roberts. In the past, he says, many of those fields would have been split with pollinator patches, or the ditches would have been full of pollinator-friendly plants.

“Now, because we’re spraying intensive pesticides across much of the landscape, there’s just more of an imperative to be planting pollinator-friendly plants in our yards, gardens, and cottages.” Adds Roberts, “The best we can do is just to have more natural habitat, not human-made habitat. So having a log or some branches and raspberry cane sitting somewhere in your yard makes for better habitat than the elegant-looking bee hotels you can buy.”

For cottage-owners looking to turn their property into a bee sanctuary, the first step to creating better habitat is to plant native wildflowers. Cities, municipalities, local conservation groups, and native plant nurseries can provide lists of native flowers for a particular region.

Select a diversity of flowers that bloom at different times, from spring into the fall, so that bees have an all-season buffet of flowers to choose from. Black-eyed Susans and New England asters are wildflowers that bloom in the fall and provide the fuel bees need to make it through winter hibernation. Roberts also advises planting wildflowers in bunches so bees don’t have to travel long distances from flower to flower to find their next meal.

The last tip for creating a bee oasis is especially tempting if you want to devote more of your cottage time to relaxation: ease up on the yard work. “In our efforts to clean and tidy our gardens we often do things that are displacing or discouraging wild bees and butterflies,” says Roberts “A lot of people like to put mulch down to keep weeds from growing, but it also means that ground-nesting insects can’t get into the ground. If you mow all the grasses that are flowering, then the flowers are gone as a food source for a lot of critters. So mulch less, mow less, and avoid pesticides. Just keep it natural. And spend more time on your dock sipping drinks.”

Want to learn more about the BIMBY Project? Check out their website.

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