Approximately one third of all human food is prepared from plants dependent on animal pollinators. Bees provide much of this valuable pollination service.
The best-known bee is the honeybee (Apis mellifera), which was introduced from Europe almost 400 years ago. Native to Africa, western Asia, and Europe, honeybees are now one of the most widespread and abundant insects. Indigenous North American bee species, on the other hand, face a number of threats, mostly as a result of human activities, including intensive agriculture, urbanization, overgrazing, pesticide and herbicide use, destruction of riparian corridors, and habitat destruction and fragmentation.
Although the honeybee is probably the most familiar bee, our native bees are incredibly important. Many native bees, such as the bumblebee or the mason bee, are actually more effective and efficient pollinators than the honeybee. Some native bee species emerge earlier in the year than honeybees, making them important pollinators of early spring blossoms.
Unlike honeybees, the majority of our native bees are solitary. This means that each female prepares her own nest, provisions it with food (nectar and pollen) for her offspring, lays her eggs, and provides little further care. Although solitary bees nest separately, some may build their nests in groups, possibly to take advantage of a good nesting site. The females of other species may share a common tunnel but build their own egg chambers branching off from the tunnel. Because they do not have a large nest or colony to defend, solitary bees tend to be much less aggressive, stinging only if trapped, slapped, or handled.
Bumblebees are the most social of our native bees. They form a temporary colony that breaks up with the onset of winter. Some bumblebee species can be a bit aggressive in defending their nest if disturbed. Away from the nest, however, like any bee, they are unlikely to sting unless threatened.
A shortage of pollinators is becoming noticeable in our agricultural areas. The pollinators of blueberry crops in New Brunswick suffered significant population reductions when pesticide was sprayed in neighbouring forests to control spruce budworm. This resulted in serious economic losses for the blueberry industry. Many farmers across Canada now rent pollinators to ensure proper crop development. Reductions in bee populations could have severe consequences for food crops, garden plants, and wilderness areas.
Bees come in a variety of shapes and sizes. There are over 20,000 species of bees in the world, more than 4,000 in North America, and almost 1,000 species in Canada. Although it takes an expert to identify these bees to species, there are some clues that can help identify a bee as belonging to a particular group of bees. Size and appearance can help, but bees are often grouped together based on their nesting behaviour — the type of nest they build and how it is lined.
The following information is meant as a general guide to some of the types of bees in Canada. Read on to learn more about some of the species.
Family Colletidae, subfamily Hylaeinae
Masked bees are small (4 – 9 mm), wasp-like, and relatively hairless. They are mostly black or occasionally a muted blue or green. Masked bees are so called because most species have distinct yellow or white markings on the face. They lack specialized hair for transporting pollen. Instead, they swallow the pollen, carry it back to the nest in their crop, and regurgitate it into the nest cell.
Nest: Masked bees nest in pre-existing holes in plant stems and galls, insect tunnels in dead wood, and abandoned bee and wasp nests. Nests are lined with secretions that resemble cellophane. Most species are completely solitary.
Family Colletidae, subfamily Colletinae
Plasterer bees are small to rather large (7-14 mm), hairy bees with a convex abdomen covered in bands of small hairs. Females have large pollen brushes on their hind legs.
Nest: Plasterer bees dig their nests in the ground, although some nest in pithy stems. Nests are lined with secretions that resemble cellophane. These bees are solitary, but in good nesting sites there can be large numbers of nests close together.
Small Mining Bee
Family Andrenidae, subfamily Andreninae
Small mining bees are actually variable in size (8-14 mm). These somewhat hairy bees are usually black or brown, although some have a metallic green cast. Female mining bees have depressions covered in silvery hairs on each side of their faces. Males occasionally have yellow markings on their faces. Pollen hairs are found on the hind legs of females.
Nest: Small mining bees dig long branching tunnels in the ground. The female loosens the soil with her jaws and front legs, and later uses her hind legs and abdomen to push soil to the surface. Nests are lined with secretions that give it a waxy finish. Most small mining bees are solitary, but in some species two or more females will use different parts of the same nest.
Family Andrenidae, subfamily Panurginae
Dagger bees are smaller (4-9 mm) and less hairy than small mining bees. Most are relatively hairless. They sometimes have yellow or cream markings. Pollen hairs are found on the lower portion of the female’s hind legs.
Nest: Dagger bees make nests in the ground, preferably in sandy soil. These nests are generally unlined or partly lined with a waxy membrane. Many species are solitary, although some are communal.
Family Halictidae, subfamily Halictinae
Halictid bees are small to medium-sized (3-12 mm) and generally black or metallic coloured. Many species are green or have green stripes. Halictid bees have bands of pale hairs on the abdomen. Pollen hairs are found on the hind legs of females. Sometimes called sweat bees, certain species are attracted to the sweat of humans in hot weather.
Nest: Most halictid bees nest in soil, but some will nest in dead wood. Nests are lined with a wax-like secretion. Sociality varies among the different species from solitary to semi-social.
Family Melittidae, Genus Macropis
Oil-collecting bees are small to medium sized (7-12 mm) with a robust body. Males have yellow face marks. The hind legs of females are covered in short, dense velvety hairs and also fine, feathery hairs for the collection and transportation of floral oil.
Nest: Oil-collecting bees generally nest in burrows made in the soil. Cells are lined with oil from flowers. All species are dependent on oil collected from flowers of Lysimachia for larval food. All oil-collecting bees are solitary except for one species in which females may share a nest.
Family Megachilidae, subfamily Megachilinae, genus Megachile
Variable in size (7-20 mm), leaf-cutter bees have large heads and wide jaws. They are usually black with long pale hair concentrated below the thorax and abdomen (where they collect the pollen). The top of the abdomen is mostly bare but each segment is fringed with find bands of white hair.
Nest: Leaf-cutter bees use pre-existing cavities, such as hollow plant stems, beetle tunnels, and crevices in dead trees. Nests are lined with oval or circular pieces of leaves or petals that they cut out and carry to the nest. Most leaf-cutter bees are solitary but they may form large clusters of nests in one area. In a few leaf-cutter species, several females will share a single nest entrance but each one will form her own cells.
Family Megachilidae, subfamily Megachilinae, genus Osmia
Mason bees are medium sized (10-14 mm), hairy bees, which are generally metallic blue-green or sometimes black in colour. Stiff hairs on the abdomen allow mason bees to carry pollen.
Nest: Most mason bees nest existing cavities, such as under bark, in beetle tunnels and hollow stems, or in the abandoned nests of other bees or wasps. These bees line their nests with mud or plant material, or a mixture of the two, that they have collected and brought to the nest. Plant fibres are chewed into a paste before use. Mason bees are solitary, but they will nest close together.
Dwarf Carpenter Bee
Family Apidae, subfamily Xylocopinae, genus Ceratina
Dwarf carpenter bees are slender, relatively hairless, and generally dark in colour (often black or metallic green or blue). They range in size from 3-12 mm. Many dwarf carpenter bees have yellow or white markings, at least on the face. Females are often dark all over with a yellow bar in the centre of their face. They have pollen hairs on their hind legs.
Nest: Nests are excavated in the broken or burned stems of raspberries, sunflowers, elderberry, sumac, and other pithy plants. Their cells are unlined. Dwarf carpenter bees are mostly solitary, although sometimes mothers and daughters will nest together.
Family Apidae, subfamily Nomadinae
Cuckoo bees are relatively hairless, medium-sized (10-15 mm), wasp-like bees that are red-brown with yellow, white, or black spots. They have no pollen hairs.
Nest: Female cuckoo bees do not create a nest but instead lays their eggs in the nests of other bees.
Family Apidae, subfamily Apinae, genus Bombus
Bumblebees are large (13-25 mm), hairy bees that are usually black and yellow. The hind legs of females have a wide, concave area for collecting pollen.
Nest: Bumblebees usually nest underground in abandoned rodent burrows. They secrete wax to make the cells. Bumblebees live in seasonal colonies that die out for the most part come winter — only the queens survive through to spring. They will defend the colony. Bumblebees create limited amounts of honey to allow the colony to survive through times of food shortage.
Family Apidae, subfamily Apinae, species Apis mellifera
Honeybees are medium sized (12-19 mm), golden brown bees with striped abdomens. The pronotum is very hairy, but the abdomen has little hair. The hind legs of females have stiff hair for transporting pollen.
Nest: Honeybees nest in hollow trees and artificial hives. Combs of cells are made with wax. Highly social, honeybees are able to communicate the location of food sources and other information. They create large amounts of honey to allow the colony to survive the winter.
Anthophoridae, subfamily Anthophorinae, tribe Eucerini
Long-horned bees are stout, medium to large (15-20 mm), fast-flying bees with velvety fur. Male long-horned bees can usually be distinguished by their very long antennae. Pollen hairs are found on the hind legs of females.
Nest: Long-horned bee nests are built in the ground and lined with a wax-like secretion. These bees are solitary, although some species will nest in large groups.
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