Eastern carpenter bee

How to recognise it

Large and stout at up to 25 mm, with a shining, almost hairless black abdomen and a yellow-haired thorax with a bare black spot in the middle. The bare shiny abdomen is what separates it from a bumblebee at a glance.

• Shining bare black abdomen — bumblebees are furry all over.
• Yellow furry thorax with a bare black central spot.
• Perfectly round entrance holes about 12 mm across in unpainted softwood.
• Males hover aggressively in front of people and cannot sting; they have a pale patch on the face.

Body length 19–25 mm (typically 22 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

Tunnels excavated in wood

Excavates a clean round entrance hole in dead, dry, unpainted softwood — decking, fascia boards, fence rails, dead branches — and then turns to run a gallery with the grain. Tunnels are reused and extended over years, and a long-occupied timber may hold a substantial branching system.

Carries pollen

Scopa — dense hairs on the hind leg

On the wing

April to October

Lifecycle

1. 1Overwintering as adultsAdults overwinter in tunnels and emerge in spring already mature, which is why very large bees appear on the first warm days.Autumn to spring.
2. 2Nesting and nest sharingFemales provision cells in galleries. Related females frequently share a tunnel with one reproducing and others acting as guards — a step towards sociality without a caste system.
3. 3New generationNew adults emerge in late summer, feed, and overwinter in tunnels.

Where it lives and what it does

Habitat

Gardens, parks, woodland edge, farmland and suburban structures throughout eastern North America.

Distribution

Eastern and central North America, from southern Canada to Florida and Texas.

Behaviour

Powerful and loud. It is also a notorious nectar robber: rather than entering deep flowers it bites a slit at the base and takes the nectar without touching the anthers, and honey bees and other insects then use the holes. Its size lets it force open large flowers other bees cannot manage.

Pollination role

An effective pollinator of large open flowers and a buzz pollinator of some crops, and simultaneously a significant robber of deep tubular flowers, where it contributes nothing.

Moderate overall — genuinely useful on some plants and a net-zero visitor on the deep flowers it robs.

What it forages on

Broad, with a preference for large open flowers, and habitual robbing of deep tubular ones.

Honey

Produces no honey

None. Solitary, with provisions sized per cell.

Relationship with people

How people interact with it

Widely treated as a structural pest, and the damage is generally modest — it uses wood that is already dead and dry, and serious structural harm is rare though repeated reuse of the same timber over years can accumulate. The hovering males cause far more alarm than the tunnelling does.

Management

Paint or varnish deters it, since it needs bare untreated wood. Providing a block of unpainted softwood elsewhere in a sunny spot gives it somewhere better to go. Killing them is unnecessary and removes a pollinator.

Conservation

Widespread and not threatened. Its constraint is standing dead wood, which tidy management removes.