After months stuck indoors because of cold weather and then the pandemic, spring’s arrival has been especially welcome this year. I’ve particularly enjoyed early spring bees in the garden. Like a doting godparent, I fretted, fussed, and followed them around with my camera. After all, they’re daughters of last year’s bees — my old garden companions.
Solitary bee life cycle
We’re most familiar with bees that nest in colonies, like honeybees and bumblebees. Each colony has one queen that lays eggs, and lots of workers that tend the nest and gather food for the queen and her offspring.
The majority of native bees, however, are solitary. Most females are queens, creating and provisioning their own nests. Seventy percent of solitary bees create nests in the ground, while the rest use cavities, like old stems or tunnels in wood. Solitary bee offspring develop during the warm weather of summer and fall, overwinter in the nest, and then emerge the following year. I’ve over-simplified their life cycle a bit, but that’s basically how it goes. The Bee Friendly website includes a timeline for The Life Cycle of Bees throughout the year.
To keep overwintering bee offspring safe and sound in their nests, I leave my garden alone in the fall and winter, and then clean up in mid-spring — after insects have left their winter shelter. Heather Holm, author of my favourite pollinator gardening and identification books, shows How to Create Habitat for Stem-nesting Bees in a PDF info-graphic. For more detail on how and when I clean up my garden, see Pollinator garden spring clean-up.
I also avoid disturbing the soil as much as I can so I don’t destroy ground nests. Ground-nesting bees dig nest tunnels in areas of bare ground where there’s no mulch, landscape fabric, or dense plant roots. Like cavity-nesting bees, ground-nesting bee offspring also overwinter in their nests and emerge the following year. I still do add, divide, and move plants, but I try to plan more instead of digging repeatedly. I’m also trying to add smaller plants that require smaller holes, and letting self-seeding do some of the planting work for me. If I see a bee entering a ground-nest where I want to work, I just leave the changes until next year.
The first early spring native bees I noticed in my garden this year were mining bees (genus Andrena). There are many different types of mining bees, but I can’t distinguish between them. They’re a bit smaller than honeybees, with furry heads and thoraxes, and shiny black abdomens.
By the time mining bees appeared in late April, the Pussy Willow catkins were almost gone. I guess the cold spring delayed them. Before, only honeybees were out gathering pollen from the earlier male Pussy Willows. Throughout May, I watched mining bees visiting many shrubs and trees that bloomed in quick succession. I didn’t see any visiting my woodland perennials, perhaps because I only have small patches so far.
I watched mining bees coming and going from their nest holes all over the yard — sometimes in open areas of the vegetable garden, sometimes in bare spots in the lawn, and sometimes right next to a plant, leaf, rock, or stick. They flew back and forth around their nest entrance before descending into a hole. I also spotted other insects lurking that parasitize ground-nesting bee nests and tried to shoo them away.
According to Heather Holm’s Houzz article Invite Mining Bees to Your Garden by Planting Their Favourite Plants, some kinds of mining bees will also emerge in the fall. Many are specialists, gathering pollen from only one species of native plant, such as asters and goldenrod, to provision their nests.
Cellophane bees were also common in the garden this spring. These bees are smaller than the mining bees, have blond hair, and stripey abdomens. They’re also ground-nesters, but they line their nest tunnels with a waterproof film that looks like plastic wrap. Holm’s article, Invite Cellophane Bees to Your Garden by Providing Patches of Bare Soil, explains that these bees like to nest near one another in groups. I didn’t notice any of their nest neighbourhoods in my garden.
I was also delighted to see numerous queen bumblebees this spring. Their favourite plant in my garden is always the ‘PJM’ Rhododendron I bought almost 20 years ago. One day, we spotted 3 queens visiting the flowers on this shrub at the same time.
These bumblebee queens are offspring of last year’s bumblebee queens. In late summer, bumblebee queens produce males and queens, instead of the usual workers. In the fall, all of the bumblebees in a colony die, except for the new queens. They burrow in the ground to overwinter, and emerge in early spring to fatten up, find a nest site, and start new colonies.
This year, I’m particularly grateful to have a garden, and for the company of this year’s first native bees. I can’t wait to see who else joins me in the garden.