Field Notes—

The Bumblebee: A Humming Garden Companion

By Curtiss Clark

This question always comes up when schoolchildren tour our newspaper office: Why do they call it The Newtown Bee?

We point out the similarities between reporters and worker bees who tirelessly search for news or nectar that is useful to the community as a whole, always noting that the bee was a symbol of industry back in the 19th Century when the paper was founded. Of course, we are flattering ourselves. Compared to bees, we are slackers.

I have been watching bees for decades. I started “keeping” honeybees in the 1970s and gave it up 20 years later when parasitic varoa mites were decimating bee populations.

The mite crisis altered my longstanding master/slave relationship with my bees — they did all the work, and I appropriated all their surplus honey in exchange for providing them with wooden hives and frames for their brood and honeycomb. They kept the hives clean and productive year after year and pollinated the flower gardens and fruit trees in the neighborhood, and I basically ignored them until it was time to raid the hives again.

The mites ruined this cushy arrangement, forcing beekeepers like me to closely manage and medicate their hives, often without success. Eventually, my hives died out, and all my bee equipment is now stored in the barn. We now get our honey at the store.

Varoa mites have effectively wiped out the feral honeybee populations in Connecticut. Apart from working orchards, where commercial honeybee hives are trucked in each spring for the growing season, I have only seen one honeybee in the wild in the past two summers. Bumblebees have taken up the slack.

As much as I wish feral honeybees would make a comeback, I have to admit the humming bumblebees make the garden a more companionable place. Compared to honeybees, they are gentle, slow to anger, and notwithstanding their Type B personality and methodical plodding pace, they are extraordinarily efficient pollinators.

Pollen is a source of protein essential to bees as they raise their brood. They collect it in pollen baskets on the outer surface of their hind legs, and on productive days they look like they are wearing jodhpurs. Because they are big and fuzzy, extra pollen sticks to bumblebees as they make their rounds. When they fly, an electrostatic charge builds up on their hairs, so when they waddle into a pollen-laden blossom, pollen grains cling to them the same way Styrofoam packing peanuts cling to your sweater on Christmas morning. As they make their rounds, they distribute the pollen, which is great for the garden.

Bumblebee colonies are mere mom and pop operations compared to the autocratic honeybee mega-enterprises, where 10,000 to 30,000 female worker bees and hundreds or thousands more male drones are rigidly organized around a single queen bee. Bumblebee colonies can have as few as 30 individuals and sometimes as many as a few hundred and are pretty laid back in their approach to the future. They produce enough honey to sustain themselves for their seasonal foraging, but there is not the huge surplus that honeybees produce to ensure a large colony’s survival through the winter. You won’t ever see a jar of bumblebee honey.

This is a critical time of year for bumblebees. Since midsummer, the numbers of small drones (drones don’t sting, by the way) and larger young queens have been increasing. As the temperature drops, the queens that are successfully fertilized by the drones will go off by themselves to find a cozy nook for the winter — in the leaf litter under a hedge, or in a crevice under a tool shed, or, if she’s got a good realtor, an abandoned mouse nest.

These are the chosen ones who will emerge after the last frost in the spring and start new colonies. All the others go about their business well into fall bumping along from zinnia, to goldenrod, to chrysanthemum, quaffing nectar until a cold snap kills them.

Cooler temperatures will slow bumblebees down, but they can still fly in temperatures as low as 50 degrees F. Since they are warm-blooded creatures, they have to maintain a temperature of at least 86 degrees in their thorax in order for their wing muscles to work. And they use these muscles to maintain that temperature.

Bumblebees have the amazing ability to disengage their wings from the muscles that control them. Vibrating those wing muscles at normal liftoff and flight speed —130 beats per second or more — without actually taking flight generates a lot of heat quickly in the small space of the thorax. It’s enough to keep bumblebees out and about long after other winged insects have succumbed to the cold.

One final thing. There is a persistent myth about the bumblebee that scientists have “proven” that it cannot fly, but not knowing that, the bumblebee goes about its rounds anyway. This canard arose from a supposed conversation between a biologist and an aerodynamic engineer. The engineer supposedly did some quick calculations on the back of a napkin and concluded that the bumblebee’s wings weren’t big enough to generate the lift to get its mass airborne.

This story has been used over the years as an anti-intellectual skewer to puncture all kinds of scientific notions. The aerodynamics of bumblebee flight, however, have been completely explained. The engineer in the bogus tale incorrectly assumed that bumblebees have fixed wings like airplanes, when, as we all know, their wings move. The wings bend and torque in flight to produce vortices in the air that produce lift on both the upward and downward stokes.

The bumblebee is not a scientific conundrum. It’s a scientific marvel. But not knowing that, the bumblebee goes about its rounds anyway. That’s why I prefer the common British name for this wonderful garden companion — the humble bee.