Common eastern bumblebee

How to recognise it

A medium-large bumblebee with a black body and a single yellow band on the thorax, the abdomen almost entirely black behind it. The plainness is diagnostic in a genus where most species carry several bands.

• One yellow thoracic band and an otherwise black abdomen — plain by bumblebee standards.
• Eastern North America, and abundant in gardens and farmland.
• Frequently seen in glasshouses and polytunnels, where colonies are placed commercially.
• Short-tongued, and a habitual nectar robber.

Body length 10–21 mm (typically 15 mm).

Biology

Social organisation

Eusocial, colony dies each autumn

A true colony with a queen and workers, but only for one season: everyone dies in autumn except mated new queens, who overwinter alone. Bumblebees.

Colony size at peak

100–500 individuals

Colony lifespan

One season in the wild; a defined working life of several weeks in commercial use.

Winter

Mated new queens overwinter alone. Commercially reared colonies are not overwintered.

Castes

Queen, Workers, Males, New queens

Nesting

Burrows in the ground; Existing cavities and tubes

Nests underground in abandoned rodent burrows, and readily in cavities under buildings and decking. Its adaptability to disturbed and urban habitat is a substantial part of why it is thriving.

Carries pollen

Corbicula (pollen basket) on the hind leg

On the wing

March to November

Lifecycle

1. 1Early emergenceQueens emerge early and found colonies readily, including in urban settings.March to April.
2. 2Long colony seasonOne of the longer North American bumblebee seasons, running well into autumn.
3. 3Commercial rearingIn commercial production, colonies are reared year-round in controlled conditions and shipped in boxes with a defined working life.

Where it lives and what it does

Habitat

Farmland, gardens, urban parks, woodland edge and glasshouses across eastern North America.

Distribution

Eastern and central North America, and expanding. Also shipped to and established in areas outside its native range, including Mexico and parts of western North America, which is itself a concern.

Behaviour

Adaptable, urban-tolerant and a capable buzz pollinator, which is the basis of its commercial value — tomatoes, peppers and blueberries all require buzz pollination that honey bees cannot perform. Like other short-tongued bumblebees it robs deep flowers rather than entering them.

Pollination role

Enormously important commercially and ecologically. It buzz-pollinates the glasshouse crops honey bees cannot service, and it is an abundant wild pollinator across its range.

Very high, particularly on buzz-pollinated crops.

What it forages on

A broad short-tongued generalist, favouring accessible flowers and robbing the deep ones.

Honey

Keeps only a few days of stores

A few days' worth in wax pots. It is a pollinator rather than a honey producer.

Relationship with people

How people interact with it

Reared commercially at enormous scale and shipped widely, which has made it both economically vital and a vector of concern. Colonies escaping glasshouses establish readily, and pathogen spillover from reared colonies into wild populations is implicated in the declines of the rusty patched and western bumblebees.

Management

Sold in boxes for glasshouse use with a defined working life. Best practice is to prevent escapes and to avoid outdoor deployment outside the native range — advice that is frequently not followed.

Conservation

Not remotely threatened; it is one of the few bumblebees increasing. The conservation concern runs the other way, through pathogen spillover and through establishment outside its native range.