Who are our garden visitors? Volunteers tracked four different species of bumble bee in the Habitat For All Garden last summer, but where are they now?
By Julie Reiff
Tiny flying teddy bears—that's what bumble bees make me think of. Round, fuzzy creatures almost bouncing from flower to flower, often covered in food, they remind me of Winnie the Pooh and his honey pots. But that image doesn't capture the enormous amount of work they do as pollinators in the garden.
Bumbles are generalist foragers. While feeding for nectar and pollen, bees may carry pollen from one flower onto another flower’s reproductive organ-successfully pollinating it.
Even as children we love to imitate the buzz of a bee, but did you know it's not just their flight that makes that sound? They also use that buzz to help gather pollen, clamping the flower in their jaws and vibrating their wings to dislodge pollen that would have otherwise remained trapped. Some plants— tomatoes, peppers, and cranberries among them—benefit significantly from "buzz pollination."
I often hear bumbles buzzing around before I see them, although they are a daily sight in the garden for most of the summer and rarely bother anyone. In fact, it's not uncommon to see several bees, wasps, and beetles on the same plant, happily loading up side-by-side on the nectar-pollen buffet.
Because bumbles are so furry, their whole bodies are often covered in pollen. One day, I thought I'd come across a fifth species in the garden, spotting one with a distinctive yellow stripe down its head. I learned from the Maine Insects group on Facebook that it was simply a Common Eastern Bumble that couldn't reach to clean all of the pollen off.
Some plants— tomatoes, peppers, and cranberries among them—benefit significantly from "buzz pollination."
Bumbles are social bees and belong to the same family (Apidae) as honey bees. Females in that family store collected pollen in specialized “pollen baskets,” on their hind legs.
But unlike honey bees, bumble bee colonies are annual, with only queens overwintering to the next year. And in Maine, bumble bee colonies rarely have more than 40 individuals. Honeybees facing colony collapse may have garnered more headlines, but The Xerces Society estimates that nearly a quarter of bumblee bee species are at risk of extinction.
Bumble bees are cavity nesters, choosing areas like grass tussocks, rock cavities, rodent borrows, and even abandoned bird nests. The queens are opportunists, looking for any suitably sized cavity each spring—sometimes above ground, such as in hollow trees, abandoned bird nests, rock walls, or under a tussock of grass, but they mostly nest underground. An abandoned rodent hole is a favorite, ready-made and already lined with fur. (You can learn more about bumble bee nesting here.)
And that is something to think about as you clean up your lawn or garden. Perhaps there is a sleeping queen, waiting patiently in that clump of tall grass or in that chipmunk hole for the kiss of spring to awaken her.
(Stay tuned for future posts on our other garden visitors...)
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