Red mason bee

How to recognise it

A stocky bee of roughly honey bee size covered in dense gingery-red hair, with a black head. Females carry pollen dry on the underside of the abdomen, giving a foraging bee a bright yellow belly. Females have two small horns on the face, which is where bicornis comes from; males are smaller with a tuft of white facial hair and long antennae.

• Dense foxy-red hair over a stocky body, with a black head.
• Pollen carried on the underside of the abdomen, never on the legs.
• Seen carrying mud into small holes in walls, bee hotels and hollow stems in April and May.
• Gone entirely by early July, which rules out most confusions on timing alone.

Body length 8–13 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

Existing cavities and tubes; Hollow stems and plant cavities

Uses existing tubular cavities of 6-10 mm — beetle holes, hollow stems, gaps in mortar, and very readily the cardboard tubes of a bee hotel. Cells are provisioned in a line and separated by mud partitions, with a thicker plug at the entrance. She lays female eggs at the back and male eggs at the front, so the males emerge first and are not trapped behind their sisters.

Carries pollen

Scopa on the underside of the abdomen

On the wing

March to June

Lifecycle

1. 1EmergenceMales emerge first in early spring and wait near the nesting site. Females follow days later, mate, and begin nesting almost immediately.Late March into April in southern Britain, tracking spring temperature.
2. 2NestingA female works alone for the four to six weeks of her adult life, completing perhaps one or two cells a day. She dies before her offspring hatch.Four to six weeks.
3. 3Development and overwinteringThe larva eats its pollen loaf, spins a cocoon, and reaches full adulthood by late summer — then remains inside the cocoon all winter and emerges the following spring. It spends the great majority of its life as a dormant adult in a tube.Roughly ten months inside the cocoon.

Where it lives and what it does

Habitat

Gardens, orchards, hedgerows, woodland edge, old walls and brownfield land. It needs three things close together: spring blossom, nest tubes, and damp bare mud.

Distribution

Widespread across Europe and into western Asia and North Africa.

Behaviour

Fast, low and slightly chaotic in flight. Inside a blossom she tumbles about rather than working it methodically, and that clumsiness is exactly why she pollinates so well. She also moves between trees and species more readily than a honey bee does, which spreads pollen between varieties rather than around a single one — the difference between pollination and mere visiting in an orchard.

Pollination role

Outstanding, and for a specific mechanical reason. Pollen carried dry and loose on the abdomen sheds readily onto the next flower, where a honey bee's wetted corbicular pellet does not. She also flies in cooler, duller weather than honey bees, which matters enormously for fruit blossoming in April.

Among the most effective fruit pollinators known, per individual.

What it forages on

A generalist with a strong preference for spring blossom, particularly the rose family — apple, pear, plum, cherry, hawthorn and blackthorn.

Honey

Produces no honey

None. Each cell holds exactly enough pollen and nectar for one larva to reach adulthood, and there is no colony to feed through a winter.

Relationship with people

How people interact with it

Increasingly managed, in a way quite unlike beekeeping. Cocoons are sold, overwintered in a fridge and released to coincide with blossom, and commercial fruit growers in Europe, North America and Japan use mason bees at scale. For gardeners this is the easiest bee to help and the one most likely to occupy a bee hotel.

Management

Bee hotels work, with caveats. Tubes must be 6-10 mm across, closed at one end, sited in full morning sun facing south-east, and — the part usually missed — cleaned or replaced every year or two. An unmanaged hotel accumulates parasitic mites and fungal disease and eventually does more harm than good.

Conservation

Not threatened and probably increasing in gardens, where bee hotels and abundant blossom suit it. Its scarcer relatives are the ones under pressure.