Fun facts about bees

When people think of bees, they typically think of a big, fuzzy black and yellow striped insect that lives in a large colony with a queen. This narrow image overlooks the beautiful diversity of bees—most of which are solitary.

Bees have extremely diverse social tendencies.

On one end of the social spectrum, some species live in tightly knit colonies with thousands of workers caring for the young of a single reproductive queen, like honeybees and bumblebees. But, only 10% of species are this social¹. Thirteen percent of species are parasitic¹: they infiltrate and lay eggs in the nests of other bees so they don’t have to raise their own young. Parasitic species don’t collect pollen so they generally aren’t considered very good pollinators, but they are important for maintaining biodiversity and ecological balance. The remaining 77% of species are considered solitary, because each female is capable of building her own nest and caring for her young¹. Many solitary bees exhibit moderate forms of sociality. For example, females of the same species may nest in proximity to others, like a neighborhood, or within the same nest and care for their young separately, like an apartment building, and may even share nest care responsibilities, like co-parenting. Even though they may form social relationships, we generally refer to this 77% as solitary bees. 

Several solitary bees native to Ontario, Canada. 

Leafcutter Bee

Leafcutter bees cut leaves to line their nests. Their scientific name is Megachile, meaning “big lips” in Greek. The left image is a plant that some leafcutter bees have visited, the right image is a leafcutter bee carrying a leaf back to her nest. The feature image on this article is a lead cutter bee covered in pollen inside her nest, showing off her big lips.

Solitary bees have an unconventional appearance.

Unlike honeybees and bumblebees, solitary bees come in all shapes, sizes and colours. In Ontario, bees can be black, silver, gold, red, brown, blue, and bright shiny green (Figure 1). Some are fuzzy while others are look hairless. They can range in size from 5 mm to 25 mm long. Solitary bees are often named after their habits or looks. Carpenter bees excavate cavities in wood, digger bees burrow underground, masked bees have markings on their face, sweat bees like licking the salt from people’s skin as they sweat, and leafcutter bees line their nests with big chunks of leaves (Figure 2). Solitary bees rarely sting, and when they do, it’s not very painful. Imagine lightly pricking yourself on a cactus thorn. Sometimes you might have to second guess yourself and think “did they actually sting me?”. So next time you see something that might be a bee, don’t be afraid to take a closer look.

Female solitary bees build their nests underground or in above-ground cavities. 

    Most species burrow into dirt or sand, while 25% nest in either pre-existing cavities or chew their own cavities, typically in dead wood or plant stems². Within the nests, a mother will build cells that each contain a mix of pollen and nectar for the larva to eat when it hatches (Figure 3). Between the cells, the mother will add nesting material such as chewed up leaves, chunks of leaves, mud, pebbles, plant resin, or secretions of a cellophane-like substance, depending on the species. Only females partake in nest building, so males are not welcome in the nests. Instead, males sleep in empty cavities or flowers.  

Honeybees are not native to North America.

They’re native to Europe and imported globally for honey, wax, and to help pollinate crops. Honeybees can be excellent tools for pollinating crops  because they can be transported easily and ordered from commercial businesses. However, despite their benefits, honeybees can negatively impact native bees by consuming too many resources or spreading pathogens. If you want to save the bees, don’t keep honeybees. When we say, “save the bees!”, we should really say, “save the native bees!”. On top of this, honeybees aren’t always the most efficient pollinators. For example, mason bees (Osmia spp.) are more effective at pollinating apples³, pears⁴, and almonds³ compared to honeybees. Several solitary bee species are available commercially, but domesticating and transporting livestock can spread pathogens and throw off the balance of natural ecosystems. The most sustainable way to encourage pollination is by fostering healthy and attractive environment for solitary bees to thrive in.

To support native bees, you can provide food.

Bees need abundant access to nectar and pollen to feed themselves and their young. Having a constant rotation of native wildflowers that attract pollinators from early-spring until late summer is a great way to ensure bees never go hungry. To find out exactly what species are best for pollinators in your area, check out the Ecoregional Planting Guides at Pollinator.org (for the Ottawa area, see the Algonquin guide). If you’re low on garden space, medium to large flowerpots and planters can double as a food source and ground nesting habitat. Growing a variety of flowers with various shapes, sizes, and colours from different plant family can foster bee diversity. Spring weeds (like dandelions) are some of the first flowers to bloom, which bees love, so keep them in your garden until other flowers bloom. You may think weeds are ugly, but bees find them delicious. 

You can also support native bees by providing nesting habitat.

To help ground-nesting bees, keep patches of undisturbed bare soil. Their offspring take up to a year to develop, so turning up your soil will disturb the nests from the previous year. It’s best to leave your garden as wild and undisturbed as possible. To support cavity-nesters, leave dead plant stems and dead wood (logs, tree stumps) in your garden, and you can buy or make your own “bee hotel”. You can drill tiny holes into dead wood, between 6 – 10 mm in diameter and up to 7 inches long, making sure the back end is covered (if you’re drilling through wood, caulk the back end). Make sure to have less than 20 cavities in one spot, as a high density of nests can attract predators and parasites⁵. Despite what sources says, it is not imperative to clean out used cavities because some species are attracted to pre-used cavities^6,7. 

Limit pesticide use.

Avoid using any kind of pesticide as much as possible. Even very light usage can have detrimental and long-standing effects on bees and other helpful insects. Using pesticides in agricultural crops is sometimes unavoidable in order to produce sufficient crop yield, but pesticides are not necessary for personal gardens used to cultivate enjoyment, aesthetics, functional outdoor spaces, and habitat for wildlife. Instead, try using natural pest control methods, such as spraying a cayenne pepper mixture to control mites or collecting ladybugs to eat aphids.

Solitary bees are incredibly diverse and fascinating creatures that are crucial for pollination and biodiversity.

The best way to support them is to educate yourself, provide suitable nesting habitat, grow their favorite native flowers, and avoid pesticides. You can help save the native bees by letting your garden grow wild.

References

1. Danforth, B. N., Minckley, R. L., Neff, J. L. & Fawcett, F. The Solitary Bees: Biology, Evolution, Conservation. (Princeton University Press, 2019).

2. Michener, C. D. The Bees of the World. vol. 1 (JHU press, 2000).

3. Bosch, J. & Blas, M. Foraging behaviour and pollinating efficiency of Osmia cornuta and Apis mellifera on almond (Hymenoptera, Megachilidae and Apidae). Applied Entomology and Zoology 29, 1–9 (1994).

4. Monzón, V. H., Bosch, J. & Retana, J. Foraging behavior and pollinating effectiveness of Osmia cornuta (Hymenoptera: Megachilidae) and Apis mellifera (Hymenoptera: Apidae) on “Comice” pear. Apidologie 35, 575–585 (2004).

5. Groulx, A. F. & Forrest, J. R. K. Nesting aggregation as a predictor of brood parasitism in mason bees (Osmia spp.). Ecol Entomol 43, 182–191 (2018).

6. Torchio, P. F. Field experiments with the pollinator species, Osmia lignaria propinqua Cresson (Hymenoptera: Megachilidae) in apple orchards: IV, 1978 Studies (Hymenoptera: Megachilidae). J Kans Entomol Soc 57, 689–694 (1984).

7. Pitts-Singer, T. L. Olfactory Response of Megachilid Bees, Osmia lignaria, Megachile rotundata, and M. pugnata, to individual cues from old nest cavities. Environ Entomol 36, 402–408 (2007).

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