Bryony bee

How to recognise it

A medium mining bee, black with pale hair bands and — distinctively — red or orange markings on the sides of the first two abdominal segments in the female. Males are slimmer and less strongly marked.

• Red-orange markings on the sides of the front abdominal segments.
• Found on white bryony flowers and effectively nowhere else.
• Flies May to August, wherever the host climbs through a hedge.
• Carrying the distinctive large spiny pollen of a cucurbit.

Body length 10–13 mm (typically 11 mm).

Biology

Social organisation

Solitary

Each female builds and provisions her own nest with no workers and no caste. Most of the world's bee species.

Nesting

Burrows in the ground

Digs burrows in bare or sparsely vegetated ground close to a stand of the host plant, often in hedge banks, verges and disturbed ground.

Carries pollen

Scopa — dense hairs on the hind leg

On the wing

May to August

Lifecycle

1. 1Emergence timed to the hostAdults emerge as white bryony comes into flower.May to June.
2. 2ProvisioningFemales collect bryony pollen exclusively. Bryony is dioecious, so a female must find male plants for pollen and the bee visits both sexes.Several weeks.
3. 3OverwinteringThe larva develops on the provision and overwinters underground.Roughly ten months.

Where it lives and what it does

Habitat

Hedgerows, scrub, verges and woodland edge wherever white bryony grows, on well-drained and often calcareous soils.

Distribution

Across central and southern Europe. In Britain, southern and eastern, and expanding northwards over recent decades in step with its host plant.

Behaviour

A strict oligolege on a single plant species, which makes it a good demonstration of how a specialist's distribution is really a map of its host. Because white bryony is dioecious and only male plants offer pollen, the bee's requirements are narrower still than the plant's distribution suggests.

Pollination role

The principal pollinator of white bryony, which is visited by comparatively few other insects.

High on its host and zero elsewhere.

What it forages on

White bryony pollen exclusively for provisioning. It takes nectar more widely.

Honey

Produces no honey

None. One pollen loaf per cell.

Relationship with people

How people interact with it

Unknown to almost everybody, and a good argument against clearing hedgerow climbers indiscriminately. White bryony is toxic and regarded as a nuisance, and it is also the entire basis of this bee's existence.

Conservation

Not currently threatened in Britain and expanding, which makes it one of the more cheerful specialist stories. Its fortunes are tied entirely to the host plant.