Bumblebees: The sumo wrestlers of pollination (What’s in Your Backyard)
By DAVID WASMUTH
For Montclair Local
The 1930s could have been an anxious time for bumblebees. It was then, the story goes, that an entomologist discovered that bumblebee flight defied the laws of aerodynamics — they could not, so to speak, legally fly.
Fortunately, bumblebees either don’t keep up with science or decided on a campaign of mass civil disobedience. They continued to fly.
Their flight has since been proven physically possible, to the relief of any science-minded bumblebees. It should also be a relief to Montclair residents who grow (or eat) vegetables, since bumblebees are the best pollinators for much of our most popular produce.
Bumblebees are also among the earliest pollinators, emerging on cool early spring mornings when most insects prefer to sleep in. With their plump, furry bodies, bumblebees are the teddy bears of the insect world. Their insect version of a fur coat keeps them well-insulated on those chilly mornings.
They are also highly motivated. Unlike honeybees, bumblebees don’t overwinter in colonies. After mating in the fall, each queen finds a tiny protected hole in the ground where she hibernates, alone. She awakens hungry in the spring, with lots of work ahead of her; it’s up to her to establish a new colony, and she’s on her own.
The newly emerged queen seeks the pollen of early spring flowers for the strength to lay her first eggs and build herself an underground wax chamber, often in an abandoned mouse or chipmunk burrow. Her first batch of around eight eggs will hatch, pupate and produce infertile adult females in from 20 to 30 days. These new bees get to work immediately, foraging for nectar and pollen, expanding the nest, rearing the next generations and caring for the queen as she devotes her time and energy to laying more eggs.
By late summer, the colony reaches its peak population, ranging from 50 to 500. While Podunk-sized compared to a honeybee hive, it is enough to qualify bumblebees as the only social bee species native to America.
As summer ends, the queen starts wrapping things up; unlike honeybee hives, bumblebee colonies operate on a strictly annual basis. She now lays two special sets of eggs. One set, unfertilized, will hatch the colony’s first and only males (drones). The second set gets spa-like treatment: larger chambers, more food, pampering by the workers. These will be next year’s queens.
Each drone will claim his own territory and wait to mate with any new queen who passes by. After mating, the drone’s job is over, and he dies. Once the new generation of queens has left the nest, the old queen also dies, along with her worker bees. The newly minted queens, now fertilized, gorge on pollen from late season flowers before retreating to small, shallow holes — not the colony’s burrow — to hibernate and repeat the cycle.
Lifestyle differences between the bumblebee and the non-native honeybee go beyond colony size, location and longevity. Bumblebees make honey, but they don’t store massive reserves for future use the way honeybees do; a typical softball-sized bumblebee nest contains about a teaspoon of honey. Perhaps their one-year cycle gives them a more live-for-today attitude.
Honeybees may be the first bees that come to mind when we think of pollination, but if there were pollination awards bumblebees would beat honeybees in every category. They forage for longer hours and in worse weather, they have more interest in gathering pollen as opposed to nectar, and they visit more flowers per minute. Their hairy bodies pick up more pollen than do smooth-bodied honeybees. And with their sumo wrestler builds, bumblebees are the only pollinators strong enough to pry open certain tightly closed native flowers, such as turtleheads and bottle gentian.
One special skill sets bumblebees apart: “buzz pollination.” Certain plants, including tomatoes, potatoes, eggplants and peppers, have downward-facing flowers with tightly packed pollen. To access the pollen, a bee must hold on upside-down from below and vibrate her body until she receives a pollen shower. No honeybee would attempt such acrobatics, so, if you like ratatouille or french fries with ketchup, thank a bumblebee.
In keeping with their cuddly looks, bumblebees are docile. Females can sting if seriously provoked, but bumblebee stings are very rare. In fact, bees in general have no interest in stinging while foraging and can be safely observed from very close up. Some people even pet foraging bees, a bridge I’ve yet to cross.
Diverse bumblebee species inhabit most of the temperate world, with 49 different species in the United States alone. Many are not doing well, and several are considered threatened. They face the same challenges as honeybees, but, unlike honeybees, native wild bees don’t have human caretakers to restore their numbers each year. Problems include habitat loss, pesticides and pathogens carried by managed honeybees.
Montclair homeowners can take steps to help out. Most obviously, don’t allow pesticides in your yard. You can also extend the foraging season by planting early-blooming spring ephemerals, such as spring beauties and Virginia bluebells, and fall-blooming flowers such as asters. Replacing parts of your lawn with flower beds makes more food available, as does allowing clover (a bumblebee favorite) in the remaining lawn. Leaving fall leaves on the ground gives next spring’s queens safe places to overwinter.
Is that too much to help this good-natured, fuzzy little creature keep us supplied with pasta sauces and blooming flowers?
In “What’s in Your Backyard,” Sanford Sorkin and David Wasmuth alternate writing about the birds and beasts you may see around your house. Wasmuth is a local environmentalist and amateur naturalist. He is a Rutgers Environmental Steward and the founder of the Montclair Backyard Habitat Project. Seen a bird or animal you want to know more about? Write to us at email@example.com.