The Fuzzy Friend

Kelly’s Field Notes

Common Name: Bumble bee

Order: Hymenoptera

Family: Apidae

Genus: Bombus

Species of Note (There are over 250 species of bumble bee! Less than 50 live in North America):

• Patagonian bumble bee or “flying mouse” (Bombus dahlbomii) - the largest bumble bee species in the world, 40 mm in length (1.6 in), an endangered species. Native to southern Argentina and southern Chili.

• Common eastern bumble bee (Bombus impatiens) - the most common eastern bumble bee

in North America, found in the eastern temperate regions of the U.S. (from the coast to the Great Plains) and Ontario, Canada.

• Western bumble bee (Bombus occidentalis) - found from California north to Alaska, while once the most common western bumble bee its numbers have dropped over 40% in the past decade, it is now considered a vulnerable species. Possible reasons for their drop in population is the fungus Nosema and/or the invasion of European honey bees.

• Buff-tailed bumble bee (Bombus terrestris) - found throughout Europe, but introduced to Northern Africa, the Mediterranean islands, Japan, Tasmania, and other countries.

• Cuckoo bumble bee (Bombus vestalis) - they have lost the ability to collect pollen (no pollen baskets), so they will fly into another bumble bee hive, kill the queen and emit pheromones to trick the colony into taking care of her and her offspring. Some species are more successful when not killing the original queen (Bombus bohemicus).

Description:

Bombus comes from the Greek word bombos “a buzzing sound.” The bumble part of their name comes from the word bombelen in Middle English, meaning “to hum.” Over 34% of bumble bee species are in decline due to habitat loss, pesticides, invasive species, and pathogens.

Bumble bees are plump, stocky, fuzzy, social bees usually found in higher latitudes, though there are species in South America. Their colonies are not as large as honey bees, having an average size of 50 to 400 individuals, though rarely some hit 1,000. Like our friends the honey bees, bumbles vary in size depending on species and within species. The queen is the largest in the hive at around 22 mm (.9 in), then males are a little smaller than she is 15 mm (0.6 in), and workers are the smallest. On average, worker bumbles are about 10 mm - 18 mm (0.4 to 0.7 in) in length. They are generally not aggressive and rarely sting unless harmed or in defense of their hive. Bumble bees are one of the only native bees to North America that are truly social (remember honey bees are introduced!).

Bumble bees do not create honey, they store nectar and pollen for consumption. Each hive starts over again after the winter so there is no need for storage, though it has been hypothesized some hives do remain active over the winter in Britain (workers and queens have been seen foraging). Some bumbles have very long tongues! This allows them to feed on plants with deep flower tubes. They are also excellent pollinators, providing a larger fruit yield and bigger fruit than plants pollinated by honey bees. Bumble bees also visit twice as many flowers per minute than honey bees.

Buzz Pollination:

Buzz pollination is necessary when pollen is firmly held in the anthers of the flower. This technique, used by bumble bees and solitary bees, shakes the pollen free from the anthers which the wind is otherwise not strong enough to do. The anthers of these plants completely enclose the pollen, forcing the pollen to pop out of a hole at the top. The stigma of these plants are positioned below the anthers, so when vibrated it would be less likely to self-pollinate. This type of pollination is important for many crops such as tomatoes, eggplants, potatoes, blueberries, and cranberries, among others. You may have noted that the crops listed are New World plants. This is important because honey bees cannot buzz pollinate, making North America’s native bumble bees and solitary bees very important to our agriculture! Because of this it also puts buzz pollinators at risk of pesticide exposure. For example, studies have shown that in upstate New York potato flowers are only pollinated by the yellow-banded bumble bee (Bombus terricola).

Life Cycle:

Bees hives start with the queen. The queen emerges from hibernation and collects pollen and nectar. The queen then creates a new nest and begins laying eggs on top of the collected pollen. She even sits on them like a bird! It takes about a month for the eggs to hatch into workers. The workers then take over the foraging and care of larvae. Like honey bees, at the end of the season the queen produces drones (males) and new queens. They leave the nest, find mates, and the cycle continues (with the males dying after mating). The former queen and all of the workers will die at the end of the year. The average lifespan of a worker in two to six weeks.

The “Play” Study:

A study came out in 2017 where researchers taught bumble bees to roll balls to receive sugary treats. The researchers noticed the bees moved the balls even when no treats were offered. Some researchers believe this is play, others believe it is an example of housekeeping.

Super Powers:

• Repeated Stinging - unlike honey bees bumble bees do not have barbed stingers, so they can sting repeatedly.

• Cold Resistant Bodies - fuzzy, densely furred (setae) little bodies keep these bees active! Their setae are longer and denser than honeybees. Often, they are the first bees you’ll see in Spring and the last bees out in the Winter. They also sun themselves and need very little sunlight to increase their body temperature.

• Self-Heating - bumble bees can shiver their flight muscles without flapping their wings. This heats up the muscles, which take up a considerable amount of space on their bodies. Because of this they can remain active in temperatures that are too cold or wet for other bees. This ability makes them important pollinators!

• Learning - bumble bees have been trained to not only pull strings to receive a treat, but also learn from watching each other!

Bumblebees in Culture:

• In A Midsummer Night’s Dream William Shakespeare refers to bumble bees as “humble bees.”

• Charles Darwin in On the Origin of Species also refers to them as “humble bees.”

• Dumbledore is a regional term in Britain for bumble bee.

• Bees, in general, have been represented in art

Book Recommendations:

Carril, Olivia Messinger, and Joseph S. Wilson. Common Bees of Eastern North America. Vol. 123. Princeton University Press, 2021.

Chittka, Lars. The Mind of a Bee. Princeton University Press, 2022.

Wilson, Joseph S., and Olivia Messinger Carril. "The bees in your backyard." The Bees in Your Backyard. Princeton University Press, 2015.

References:

Alem, Sylvain, et al. "Associative mechanisms allow for social learning and cultural transmission of string pulling in an insect." PLoS biology 14.10 (2016): e1002564.

Arbetman, Marina P., et al. "Global decline of bumblebees is phylogenetically structured and inversely related to species range size and pathogen incidence." Proceedings of the Royal Society B: Biological Sciences 284.1859 (2017): 20170204.

Batra, Suzanne WT. "Male-fertile potato flowers are selectively buzz-pollinated only by Bombus terricola Kirby in upstate New York." Journal of the Kansas Entomological Society (1993): 252-254.

“Bumblebee Fact Sheet | Blog | Nature | PBS.” Nature, www.pbs.org/wnet/nature/blog/bumblebee-fact-sheet/.

‌Carril, Olivia Messinger, and Joseph S. Wilson. Common Bees of Eastern North America. Vol. 123. Princeton University Press, 2021.

Colla, Sheila R., and Claudia M. Ratti. "Evidence for the decline of the western bumble bee (Bombus occidentalis Greene) in British Columbia." The Pan-Pacific Entomologist 86.2 (2010): 32-34.

Gösterit, Ayhan, and Fehmi Gürel. "Comparison of development patterns of imported and native Bombus terrestris L.(Hymenoptera: Apidae) colonies in the Mediterranean coastal region." Turkish Journal of Veterinary & Animal Sciences 29.2 (2005): 393-398.

Inari, Naoki, et al. "Spatial and temporal pattern of introduced Bombus terrestris abundance in Hokkaido, Japan, and its potential impact on native bumblebees." Population Ecology 47.1 (2005): 77-82.

Kobilinsky, D. (February 17, 2016). "Rare bumblebee makes comeback". The Wildlife Society. https://wildlife.org/rare-bumblebee-makes-comeback/

Loukola, Olli J., et al. "Bumblebees show cognitive flexibility by improving on an observed complex behavior." Science 355.6327 (2017): 833-836.

Pampell, Rehanon, et al. "Bumble bees (Hymenoptera: Apidae: Bombus spp.) of interior Alaska: species composition, distribution, seasonal biology, and parasites." Biodiversity Data Journal 3 (2015).

Semmens, T. D., E. Turner, and R. Buttermore. "Bombus terrestris (L.)(Hymenoptera: Apidae) now established in Tasmania." Journal of the Australian Entomological Society 32.4 (1993).

Widmer, Alex, et al. "Population genetic structure and colonization history of Bombus terrestris sl (Hymenoptera: Apidae) from the Canary Islands and Madeira." Heredity 81.5 (1998): 563-572.

Wilson, Joseph S., and Olivia Messinger Carril. "The bees in your backyard." The Bees in Your Backyard. Princeton University Press, 2015.