We’re baaaack!: bumblebees return to the garden

In mid-July, all of a sudden, bumblebees reappeared in my garden again. Hurray!

Males and workers

Numbers continue to increase as we now have males and workers in the mix. In late July, nesting queens switch from laying eggs that will become workers, to laying eggs that will become males and queens. Depending on the bumblebee species, workers live from 2 to 6 weeks (according to Buzzaboutbees.net), so there’s an overlap of ageing, foraging workers and new males. So far, I have only seen one young, mammoth queen.

How can you tell whether a bee is a male or a worker? When I find bumblebees sleeping in, or under, flowers and leaves, I know they’re males. Males don’t live in bumblebee nests; they spend their days drinking nectar and looking to mate, and their nights camping out in the garden. They go to sleep very early, as early as 6:00 pm. They also seem prone to napping, and will stick up a middle leg (not finger) to tell others to buzz off.

Of course, to the trained eye, there are more scientific ways to tell if a bumblebee is a male or a worker: females have pollen baskets (shiny segments with long hairs) on their back legs; males have longer antennae (13 segments, while females have only 12); males have 7 bands across their abdomen instead of just 6; and males have no stingers. Visit the Xerces Society Bumblebee identification for more information.

Size isn’t an indicator of whether a bumblebee is male or a worker because bumblebee workers vary dramatically in size. The smallest bumblebee workers live and work in their dark nest for their whole lives tending to their mother and siblings. Some small workers join their larger sisters in foraging duties outside the nest. Perhaps their differing tongue lengths and body sizes allow them to visit a greater diversity of flowers. A Sting in the Tale, by Dave Goulson of the British Bumblebee Conservation Trust, has been my favourite book for learning about the bumblebees and their life cycle (at Ottawa Public Library).

Common Eastern bumblebees

I used to think that all the bumblebees in our yard were Common Eastern bumblebees. Now that I am learning to identify them, I am noticing look-a-likes, and some distinctly different bumblebees as well. Wildlife Preservation Canada and the Xerces Society provide a handy, single-page PDF ID guide for Bumble Bees of South Central Ontario. The sleeping male above is a Common Eastern bumblebee.

Brown-belted bumblebees

After reading the Wild Pollinator Partnership blog posts about their pollinator surveys in downtown Ottawa, I decided to take a closer look at the bumblebees in my garden. If a variety of bumblebee species live downtown, they might be in the ‘burbs as well. I discovered that some of my Common Eastern bumblebee visitors are actually Brown-belted bumblebees.

Two-spotted bumblebees

Other so-called Common Eastern bumblebees turned out to be Two-spotted bumblebees.

Red-belted bumblebees

I see many Red-belted bumblebees in the front pollinator garden. They love the mountain mint patch, perhaps because their can easily reach its nectar with their short tongues. These workers and males vary in appearance and can easily be mistaken for other kinds of bumblebees.

Identification resources

I find it very difficult to identify bumblebees, or any insect for that matter, without a picture for reference. I then use the following resources:

• Bumblebees of South-Central Ontario PDF from Xerces Society and Wildlife Preservation Canada
• Bumble Bees of Southern Ontario PDF includes drawings of bumblebees on flowers
• Bumblebees of North-Eastern United States, by the United States Department of Agriculture and the Pollinator Partnership
• Bumble Bee Identification – Eastern Canada, from Friends of the Earth
• BumblebeeWatch.org Photography Guide
• iNaturalist

A lone, rare bumblebee

We’ve also been seeing an extra-special bumblebee visitor — a member of a rare and declining bumblebee species. More on this lone bumblebee in my next blog post…