All About Solitary Bees

Did you know we have over 300 different species of bees in Alberta? That’s a lot of different kinds of bees! Most of those species of bees fall under a category called “solitary bees”, which are bees that do not live in a hive. 

Solitary bees live alone, and lay their eggs in tree cavities (tunnel-nesting species) or holes in the ground (ground-nesting species). Because they don’t live in hives, solitary bees don’t have a queen to protect, and as such are less aggressive than the bees we normally think of. Many solitary bees don’t even have stingers! 

Unlike honey bees and bumblebees, solitary bees do not produce honey or wax. Most solitary bees don’t even look like regular bees - many species aren’t even black and yellow! Solitary bees are also more efficient pollinators, because they don’t have an efficient way of transporting pollen and nectar like hive-nesting bees do.

You may have heard of a Bee Hotel before. Bee Hotels are wooden nesting structures for solitary bees to lay their eggs inside of. The mother bee will lay her eggs in the tunnels in mid to late summer, the eggs will develop inside the tunnels over the winter, and then they will hatch in the spring. You can make your own, or buy one from our online shop!

Let’s learn a little bit more about some different species of tunnel-nesting and ground-nesting bees that you may see in your backyard, or using your bee hotel.


Tunnel-Nesting Species

This category of bees naturally nests in tree cavities. Not all species are able to create their own tunnels by chewing away wood, so instead they will use holes that already exist, such as the ones found in bee hotels or in decaying trees! Here are just a few of the common types of tunnel-nesting bees you might find in the Edmonton region.

Leafcutter Bee

Photo by Bernhard Plank (CC BY-SA 3.0)

Photo by Bernhard Plank (CC BY-SA 3.0)

Material Used to Cap Tunnels: Leaves

Taxonomic Family: Megachilidae

Size: 5 mm to 20 mm

Fun Facts: Leafcutter Bees have large mandibles to help them chew leaves apart to use for their nest. However, they cannot chew into wood, so they nest in pre-existing holes. Leafcutter Bees do have stingers, but they are very gentle creatures and will not sting unless you try to hold them. 


Mason Bee

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Material Used to Cap Tunnels: Mud

Taxonomic Family: Megachilidae

Size: 8 mm to 12 mm

Fun Facts: Mason Bees are in the same family as Leafcutter Bees, but use dirt and mud to build their nests and cap off the tunnels, rather than leaves. Mason Bees are also often metallic blue or green. Unlike some species of bees, members of the Megachilidae family carry pollen on their bellies, rather than on their legs.


Carpenter Bee

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Material Used to Cap Tunnels: Chewed Wood or Pulp

Taxonomic Family: Apidae

Size: 12 mm to 24 mm

Fun Facts: Carpenter Bees are one species of bee that are able to chew through wood to make their own tunnel to lay eggs in. They look similar to bumblebees, but are black in colour. You can tell if a Carpenter Bee made a tunnel because they leave a small pile of sawdust at the entrance hole. Male Carpenter Bees can’t sting, and females have a stinger, but very rarely use it.


Masked Bee

Photo by Katja Schulz (CC BY 2.0)

Photo by Katja Schulz (CC BY 2.0)

Material Used to Cap Tunnels: Translucent Waxy Secretion

Taxonomic Family: Colletidae

Size: 4 mm to 10 mm

Fun Facts: As their name suggests, Masked Bees have yellow markings on their face that make them look like they’re wearing a mask. Unlike the three types of bees above, Masked Bees are not covered in long hairs that collect pollen. Instead, they swallow the pollen to store it safely in a sac inside of their body called a crop.


Ground-Nesting Species

This category of bees nests in the ground. Some species have the capacity to dig their own tunnels, while others need to use natural cavities in the ground. Either way, leaving patches of bare soil in your yard or garden helps these little guys to thrive. Below are two of many types of ground-nesting bees you could see in Alberta.

Plasterer Bee

Photo by Gail Hampshire (CC BY 2.0)

Photo by Gail Hampshire (CC BY 2.0)

Taxonomic Family: Colletidae

Size: 8 mm to 12 mm

Fun Facts: Plasterer Bees can secrete a wax-like substance that they use to line the walls of their nest. This waxy substance helps to keep water out of the tunnels, which is especially important when it rains or when they nest in moist soil. All bees in the Colletidae family have a very unique tongue that is short and forked. It is used to secrete the translucent cellophane-like substance.


Mining Bee

Photo by  Ocrdu  (CC BY-SA 4.0)

Photo by Ocrdu (CC BY-SA 4.0)

Taxonomic Family: Andrenidae

Size: 6 mm to 12 mm

Fun Facts: Mining Bees make their nests in underground tunnels. Usually, they will dig a single tunnel with chambers branching off from the main tunnel for the eggs. Each mother bee creates its own tunnel for its eggs, making them part of the solitary bee category, however, many Mining Bee tunnels may be in close proximity of one another, which makes it seem like they are living together in a colony. Mining Bees do have a stinger, but it isn’t strong enough to make it through human skin.


Remember, these are just a few of the over 300 species of bees found in Alberta! Most of our bee species in Alberta are less than 3 mm in diameter, and don’t have the black and yellow colouration that we normally associated with bees. Next time you’re out in the garden or on a nature walk, try to count the number of different species you see!