Gypsy Cuckoo Bumble Bee | NWT Species at Risk

Gypsy Cuckoo Bumble Bee

Bombus bohemicus

NWT List of Species at Risk:

No status

NWT SARC Assessment:

Data Deficient

Federal Species at Risk Act list:

Endangered

COSEWIC Assessment:

Endangered

NWT General Status Rank:

At Risk

Description:

Gypsy Cuckoo Bumble Bee is a medium-sized bumble bee. The upper segment of the hind leg has a convex, densely hairy outer surface and lacks a pollen basket. Females usually have a white-tipped abdomen or at least a white patch on the back of the abdomen. Sides of the thorax are mostly black in both sexes. The Gypsy Cuckoo Bumble Bee can be distinguished from other cuckoo bumble bees found in the Northwest Territories (NWT) by black hairs on the top of the head; other similar species have pale hairs.

Length: Females, 1.7 to 1.8 cm (0.67 to 0.71 in); Males, 1.2 to 1.6 cm (0.47 to 0.63 in)

Report Gypsy Cuckoo Bumble Bee sightings to WILDLIFEOBS@gov.nt.ca

Check out the Field Guide to Bumble Bees of the Northwest Territories.

Distribution

Gypsy Cuckoo Bumble Bee is found in northern regions around the world.

Range map information

Habitat and biology

Gypsy Cuckoo Bumble Bee is a ‘social parasite’. Like other cuckoo bumble bees, they do not collect pollen or establish their own colonies. Instead, they take advantage of the nests and workers of other ‘host’ bumble bees. Potential host species found in the NWT include McKay's Western Bumble Bee, Yellow-banded Bumble Bee and Cryptic Bumble Bee (sometimes called White-tailed Bumble Bee).

Gypsy Cuckoo Bumble Bees require host bumble bee nests, which are typically underground in abandoned rodent burrows. In spring, the Gypsy Cuckoo Bumble Bee female emerges from her overwintering site and searches for a host nest. She displaces the host queen and lays her own eggs. The host workers then raise her offspring. Her eggs develop into males and females, which emerge and mate in late summer and fall. The mated female Gypsy Cuckoo Bumble Bees overwinter; others are killed by frost. Females probably overwinter in soil, mulch or rotting logs.

Population size and trends

Cuckoo bumble bees are naturally less abundant than other bumble bees because they do not produce workers. In the past 20 to 30 years there have been large population declines of Gypsy Cuckoo Bumble Bee in eastern Canada and the species has disappeared from many of its former sites. However, Gypsy Cuckoo Bumble Bee can still be found in western Canada.

Population size and trend in the NWT is unknown. Gypsy Cuckoo Bumble Bee was recorded at Norman Wells and Fort Simpson in 2017-18.

Threats

Potential threats in the Northwest Territories include: declines in the populations of host species, like McKay's Western Bumble Bee and Yellow-banded Bumble Bee; introduction of exotic bumble bee species for pollination, which can spread diseases to native bees; and the use of pesticides and herbicides. At high densities, imported honey bees can outcompete native bumble bees for pollen.

Protection and recovery

In 2019, the NWT Species at Risk Committee assessed the status of Gypsy Cuckoo Bumble Bee as Data Deficient. This means there was not enough information to determine the status in the NWT.

COSEWIC assessed Gypsy Cuckoo Bumble Bee as Endangered in Canada in 2014. The species was listed as Endangered under the federal Species at Risk Act (SARA) in 2018.

Area:

Dehcho, Gwich'in, Inuvialuit, Sahtú, South Slave, North Slave / Tłı̨chǫ

Status Report and Assessment of Western Bumble Bee, Yellow-banded Bumble Bee, and Gypsy Cuckoo Bumble Bee in the NWT (2019)

Links:

Field Guide to Bumble Bees of the Northwest Territories