Apidae

Of the 179 species of native Apidae bees found in Canada, 82 of them occur in Alberta. Honey bees also are in the Apidae family, but they are introduced. The Apidae family is one of the most diverse groups of bees in Alberta in terms of the number of species and number of genera.

Members of the Apidae family are highly variable, but they tend to be large, hairy, fast-flying and have long tongues. Many of the females have dense scopal hairs that make the bee look like it’s wearing chaps or a polished area on their hind legs called a corbiculae where they pack pollen mixed with nectar in a basket formed by a rim of hairs.

Anthophora (digger bees)

Of the 11 species of Anthophora bees found in Canada, 6 of them occur in Alberta.

Anthophora are medium to large (up to 3 cm long), robust and hairy bees that resemble bumble bees. They have scopal hairs on hind legs which they use to they carry dry pollen, unlike bumble bees which create moist masses of pollen which they pack into pollen baskets. Many have extremely long tongues.

Anthophora are solitary nesters, although they may be found in large aggregations. Most nest in the soil and larva develop in cells with waterproof linings produced by a Dufour’s gland. Some, including A. occidentalis and A. peritomae nest in cutbanks or chinking in old log cabins and under decks. A. peritomae nests in tightly packed sand and sandstone. They overwinter as mature larvae or adults.

Anthophora  are polyectic, with wide floral preferences, including:

●       Aster

●       Arctostaphylos

●       Astragalus

●       Cirsium

●       Delphinium

●       Lupinus

●       Oxytropis

●       Penstemon

●       Phacelia

●       Solidago

Cleptoparasites are Melecta, Xeromelecta and Zacomsia.

Bombus (Bumble bees)

Forty-six species of bumble bees occur in North America. Twenty-eight of Canada’s 41 bumble bee species occur in Alberta. Alberta has some of the richest (most diversity of species) bumble bee habitat in North America.

The most recognizable members of Alberta’s native bees are bumble bees. They are large, densely hairy bees in a variety of colour combinations of yellow, black and sometimes orange. They are the largest bees in Alberta, with the Nevada bumble bee (Bombus nevadensis) measuring up to 25 mm in length. Except for the cuckoo bumble bees (sometimes classified in a subgenera, Psithyrus) and males, bumble bees possess a corbiculae on the hind leg, which is a broadening of the tibia leaving a polished surface surrounded by bristles that create a basket for a gummy mix of pollen and nectar.

Like all bees, an adult bumble bee emerges from the pupa fully grown. Queens are larger than males and most of the queen’s daughters. The size of the bee is related to which species it is, as well as how well fed it was during its larval stage. Later in the summer when there are fewer flowering plants, offspring may be much smaller than the bees produced earlier in the season when more food is available.

Bumble bees are described as eusocial because the queen is assisted by her daughters in raising other young bees. The queen mates with a male in the fall, then overwinters as a fertilized queen until she emerges in the early spring. She will then search a location for her nest, which is usually underground but may be in an abandoned mouse nest, inside a building wall or in a bird house.

During the first phase of the colony, the queen gathers nectar and pollen to provision her nest. She moulds the pollen into a lump on which she lays her eggs. She continues to forage to feed this first generation of sterile female workers until they mature and can begin to supply the nest with pollen and nectar. After this generation matures, the queen remains in the nest to lay more eggs, some of which become new queens or males. Typically, a bumble bee nest will have fewer than 200 individuals (compared to about 60,000 in a honey bee hive). Near the end of the summer the queen lays some male eggs in addition to female ones. The females born at this time become queens, not sterile workers, and they mate soon after they emerge in the late summer fall as adults. The males die after mating and the fertilized queens overwinter to emerge in the spring to establish a new nest. All the workers and drones and the old queen die at the end of summer; the only survivors are the new queens, already mated. They find a secluded and safe place to overwinter, emerging in the spring to start a new colony.

Bumble bees are tough. They are more tolerant of the cold than most adult insects so they are some of the first bees seen in the spring and are the last bees flying in the fall. They are robust fliers and can forage in windy conditions that have other insects huddling in grass.

Bumble bees forage on a wide variety of flowering plants.  Tongue lengths vary from one species to another, which results in preferences for particular types of flowers. Bees with long tongues tend to collect pollen and nectar from tubular flowers, such as Astragalus (milk-vetch), Penstemon (beardtongue), Delphinium (larkspur) and Oxytropis (locoweed). Bumble bees with short tongues generally prefer shallow flowers such as Epilobium (fireweed), Helianthus (sunflower), Potentilla (cinquefoil), Solidago (goldenrod), Ribes (currant) and Fragaria (strawberry).

Some bumblebee species have become social parasites of other bumblebee species. These cuckoo bee females will kill the queen of another species and take over her host’s nest. Cuckoo bees are distinctive because the females do not have corbiculae, and they are robust bees with a more curved abdomen than non-cuckoo bumble bees.

Diadasia (chimney bee)

Two of Canada’s three species of Diadasia bees occur in Alberta.

Diadasia are medium-sized, very hairy bees, with pale bands of hair stretching across abdomen, head narrower than the thorax, with stiff and widely-spaced scopal hairs on hind legs.

They nest in tunnels which they dig straight into the ground. These tunnels often have a turret, and may be located the middle of dirt roads or trails. They are bees of desert and grassland habitats.

Diadasia are oligectic (narrow flower preferences), with Alberta’s species favouring Opuntia and Sphaeralcea although they also forage on Penstemon, Astralagus, Monarda, Cirsium, Salvia, Melilotus and Asteraceae.

Epeolus (cuckoo bee)

Five of Canada’s 13 species of Epeolus bees occur in Alberta.

Epeolus are medium-sized (6 – 10 mm) bees with bright patterns. They have a chunky thorax with white and black stripes of close-cropped hair on their abdomens, and short, wooly hair across thorax which creates a “smiley face”. Because they are parasitic bees and don’t provision their own nests, they do not have pollen-carrying hairs.

Epeolus are cleptoparasites of Colletes bees. The female enters the Colletes´ nest where she punctures the cellophane-like covering of the nesting cell with spines on the end of her abdomen. She then lays an egg in the unsealed cell. The Epeolus larva consumes the egg of the host bee and feeds on the pollen intended for the Colletes bee larvae. 

Although they do not collect pollen, Epeolus bees have been observed nectaring at a variety of flowers, including Potentilla, Eriogonum and Melilotus. 

Keys and Guides

Cleptoparasitic Bees of the Genus Epeolus Latreille (Hymenoptera: Apidae) in Canada

Eucera (long-horned bee)

Two of Canada’s 10 species of Eucera bees occur in Alberta.

Eucera are large bees (13 – 18 mm). The females have pollen-collecting hairs on their legs and the males are distinctive because of their very long antennae. They are typically seen in the spring.

The Eucera are solitary bees. They nest in sand or clay soils in flat areas or shallow embankments where nest aggregations may occur.  Nest entrances have a mount of excavated soil heaped symmetrically around them, and a brood cell lining is produced by the female’s Dufour’s gland. Males may gather together for sleeping.

 Floral preferences include

●       Allium

●       Astragalus

●       Balsamorhiza

●       Lupinus

●       Mertensia

●       Penstemon

●       Phaecelia

●       Sphaeralcea

●       Taraxacum

Eucera are hosts of Epeolus cuckoo bees.

Holcopasites (cuckoo bee)

Of the five species of Holcopasites bees found in Canada, three of them occur in Alberta.

Holcopasites are small (3.5 – 7.5 mm) bees with a black roughened thorax and bright red abdomen. They are cleptoparasites of Calliopsis, a ground nesting bee.

 Floral preferences include:

●       Echinacea

●       Grindelia

●       Erigeron

●       Solidago

●       Melilotus

Melecta (cuckoo bee)

Of the three species of Melecta bees found in Canada, two of them occur in Alberta.

Melecta bees are some of the larger (12 – 13 mm) of the parasitic bees. They are recognizable because their fuzzy thoraxes have an abrupt hump, giving them a bulky appearance and, typical of parasitic bees, the females do not have pollen-carrying scopae. 

Melecta females break into closed brood cells of Anthophora species, lay an egg on the cell wall, then reclose the cell with mud and saliva.  The Melecta larva will kill the host’s young, feed on the pollen provisioned by the host, and overwinter as an adult.

Floral preferences include:

●       Erigeron

●       Grindelia

●       Astragalus

●       Ribes

●       Potentilla

●       Penstemon

Melissodes (long-horned bee)

Seventeen of the 24 Melissodes bee species found in Canada occur in Alberta.

Melissodes are medium-sized (10 – 15 mm) bees which are mostly black with abdominal white stripes. The females have scopa on their hind legs and males are notable because of their very long antennae. They are typically late summer/fall bees.

Melissodes are solitary ground nesters although some species may share the same nest entrance. Females sleep in their nests at night, but males huddle together on flower heads.

Flora preferences

Melissodes are oligolectic, depending almost entirely on flowers in the Asteraceae family, and many are specialists on sunflower (Helianthus).

Melissodes are hosts to the cleptoparasite Epeolus.

Neolarra (cuckoo nomad bee)

Both of the two species of Neolarra bees found in Canada, also occur in Alberta.

Neolarra are very tiny bees (3 – 3.5 mm) with slim bodies and red or black abdomens, and a coating of short, white hairs over most of their bodies.

They are cleptoparasites of Perdita bees and are found primarily in arid, sandy regions.

Floral preferences include:

●       Asteraceae

●       Capparaceae

●       Malvaceae

●       Polygonaceae

●       Rosaceae

Nomada (cuckoo nomad bee)

Of the 50 species of Nomada bees found in Canada, seven of them occur in Alberta.

Nomada bees are usually colourful, with striking yellow, black, white and even red markings. They are relatively small (3 – 13.3 mm), almost hairless and wasp-like. They have lost all the adaptations that serve to carry pollen as they are parasitic bees and don’t need to do so.

Nomada is chiefly parasitic on Andrena bees. They are often seen in early spring, flying low, searching for the ground nests of their hosts. When they locate a nest, they wait until the host female is absent, then they enter the nest and lay an egg. The egg of the cuckoo bee develops rapidly and grows into a larva that will kill and eat the resident larva as well as the food reserves in the nest. Some Nomada overwinter as mature larva, and others as adult.

Like non-parasitic bees, adults are known to visit flowers and feed on nectar. Reported floral preferences include:

●       Asteraceae

●       Ceanothus

●       Chrysanthemum

●       Coreopsis

●       Erigeron

●       Geranium

●       Grindelia

●       Lactua

●       Meliotus

●       Oxalis

●       Potentilla

●       Ranunculus

●       Rubus

●       Rudbeckia

●       Salix

●       Senecio

●       Solidago

●       Trifolium

Triepeolus (cuckoo bee)

Of the 15 species of Tripeolus bees found in Canada, six of them occur in Alberta.

Triepeolus are medium to large bees (8.5 – 16 mm), marked with bold patterns of black and white bands of dense, flattened hairs. Legs are often red or reddish, rarely with red on antennae, head, and thorax.

Triepeolus  are cleptoparasites of Colletes, Eucera and Melissodes and Anthophora bees.

They nectar at a variety of flowers, most notably on Asteraceae family.

Xeromelecta (cuckoo bee)

The only species of Xeromelecta bee found in Canada occurs in Alberta.

Xeromelecta are large (up to 18mm) robust bees with a distinctive hump on its thorax, giving it a bulky appearance.

It is a cleptoparasite of Anthophora bees.

Zacosmia (cuckoo bees)

The only species of Zacosmia bees found in Canada occurs in Alberta.

Zacosmia bees are small (5 – 7 mm), covered in very short, white hairs with touches of brown, with an extremely domed thorax. They are cleptoparasites of Anthophora. They have been observed on Aster, Chrysothamnus, Euphorbia, Sphaeralcea, Salvia.