by Wayne Cardinalli
Now that spring is imminent get ready to hear the unmistakable buzz of a queen bumblebee. You’re right if you think she looks like she has something important to do!
A hungry queen bumblebee foraging on Dutchman's breeches (Dicentra cucullaria), an early spring ephemeral (disappears in summer) native to southern Ontario woodlands.
In spring, hungry queen bumblebees emerge from their underground hiding-spots to look for food and search for a nest site. If you see a big bumblebee early in the spring, it is a queen. They need early, spring blooming flowers that provide both pollen and nectar. Native, woodland flowers are especially good choices, as are flowering shrubs and trees. If a bumblebee queen has a poor start in spring, it jeopardizes the success of her nest throughout the summer, and reduces the likelihood of a new generation of queens for next spring.
TIP - You can help: Try growing these early spring native woodland wildflowers in shaded spots your garden: Spring Flowering Plants of Ontario.
A bumble bee's life cycle
Once a queen chooses a nesting spot, she gathers pollen and lays eggs on it. She also builds and fills a little honey pot, so she can eat while she sits on her egg. She stays in the nest and vibrates her body to keep the eggs warm. This early bumblebee nest phase takes a few weeks. When the worker bumblebees emerge, they take over the foraging duties and the queen spends the rest of her life in the nest laying eggs, and helping care for her offspring.
Once the queen's eggs begin to hatch, she will not leave the nest again. Her workers (all of which are female) will leave the nest and collect the pollen she needs to continue laying eggs. She will also lay enough male eggs to be able to keep fertilizing her and any new queens that hatch. The males and new queens will leave the nest as soon as they are hatched. The males leave the nest but hang around just outside to be able to mate with the new queens as they fly away. They have no other purpose than to mate with the Queens, and therefore have no stingers.
At any given time, there are no more than 50 males and somewhere between 40 and 400 workers alive at the nest at a time.
It is relatively easy to provide flowers for bumblebees because they are generalist foragers, meaning that they will visit a wide range of flowers for pollen and nectar. Therefore, you will find bumblebees not only in wildflower sites, but also in some non-native ornamental and vegetable gardens if they contain plants rich in high-quality pollen.
In the fall most of the bumblebees die, except for new, mated queens. These queens leave the nest and burrow under leaves or underground to wait for spring. It is important to provide lots of fall flowers, especially asters and goldenrods, so queens can build up stores to last them all winter in their dormant state. To help queen bumblebees overwinter successfully, keep leaf litter on the ground during fall and through the spring.
Bumble bees have unique traits.
They are strong enough to force their bodies into deep flowers that other bees cannot access. Then they unhinge their wings and use their wing muscles to vibrate their bodies, causing the sticky pollen to cascade over their hairy thorax and abdomens.
Because vibrating their bodies helps to keep them warm, they can live in cooler seasons and forage in the cool hours of dawn and dusk.
Top pollinators, their longer tongues make them more efficient at pollinating some native plant species.
Bumblebee buzz pollinating a flower
But...bumble bees are in trouble and need our help
In Canada, 42 of our 400+ native bee species are bumblebees, 16 of which are native to southern Ontario. Most populations are in steep decline, with at least 3 species threatened or critically endangered.
Climate change is threatening bumblebees, see Bumble bees being crushed by climate change and Climate change is killing off bumblebees.
But the primary cause of bumble bees’ population decline is habitat loss and land fragmentation, along with pesticide use. See Canadian researchers warn of 'cascading impacts' as bumblebee species decline. When core species disappear it triggers a cascade of species decline all the way up the food chain — the loss of these important insects is having an impact throughout our entire ecosystem.
Human behaviour is driving the decline, and so it is within our power to make it stop. Take action: you can help bumblebees and other insect populations in your yard by avoiding pesticides and replacing lawn with native plant habitat.
Blooming Boulevards’ mandate is to increase and link pollinator habitat.
Making gardens with native plants is a vital aspect of this program.
In this Year of the Garden, why not take advantage of our Boulevard Garden Program, and create a beautiful wildflower garden right on your boulevard?
Get inspired…
The Corner Pollinator Garden and Wildlife Habitat - Berit Erickson’s wonderful blog
Wildlife Preservation Canada offers a handy, free poster that illustrates common Bumblebees of Southern Ontario as well as the Bumblebees of South-Central Ontario PDF.
For more detailed information for identifying bumblebees, consult the Bumblebees of the Eastern United States PDF from the USDA Forestry Service and the Pollinator Partnership.
Add your sightings on Bumble Bee Watch by taking photos and submitting them for ID confirmation.