Ivy bee

How to recognise it

About honey bee size, with a densely gingery-brown furry thorax and a black abdomen crossed by sharp, broad bands of pale orange-buff hair. In good condition it is one of the most strikingly marked bees in northern Europe — brighter and more contrasting than a honey bee.

• Flying in late September and October, when almost no other similar bee is on the wing. Timing alone gets most identifications right.
• Bold, evenly spaced buff bands on a black abdomen, and a foxy-orange furry thorax.
• Found on ivy flowers, and on very little else.
• Nests in large aggregations in bare or short-turfed ground, often in banks, lawns, footpaths and coastal cliffs.

Body length 10–15 mm (typically 13 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 light, well-drained, sun-exposed soil, and does it in aggregations that can run to tens of thousands of nests in a single bank. Each female works alone despite the crowding. Like all Colletes, she lines her cells with a waterproof cellophane-like secretion applied with a short brush-tipped tongue — which is where the family name plasterer bee comes from and why the cells survive in damp ground.

Carries pollen

Scopa — dense hairs on the hind leg

On the wing

September to November

The latest-emerging solitary bee in northwest Europe, and tightly synchronised with ivy flowering.

Lifecycle

1. 1EmergenceMales emerge first, in early to mid September, and patrol the nest site in numbers waiting for females. Females follow a week or so later.Early September.
2. 2MatingMales compete for emerging females in dense scrambling clusters — mating balls of a dozen or more males around one female, which is alarming to watch and entirely harmless.
3. 3NestingFemales provision cells with ivy pollen through late September and October, working alone, and die as the ivy finishes.Six to eight weeks.
4. 4OverwinteringThe larva eats its pollen store, develops, and spends nearly the whole year underground as a prepupa or adult before emerging the following September.Roughly eleven months.

Where it lives and what it does

Habitat

Coastal cliffs, south-facing banks, quarries, footpaths, churchyards, lawns and any light soil with sun on it, provided flowering ivy is within a few hundred metres.

Distribution

First described in 1993 from continental European material previously lumped with other Colletes. Recorded in Britain in 2001 in Dorset and now widespread across England and Wales and reaching into Scotland and Ireland — a documented northward expansion of hundreds of kilometres within a single human generation.

Behaviour

Fast, direct and single-minded. Females shuttle between an ivy patch and the nest bank repeatedly through the short season, and the nest aggregations are among the most conspicuous insect spectacles of the British autumn.

Pollination role

An almost complete specialist on ivy, which makes it a good pollinator of ivy and of very little else. It illustrates a general point better than most species: specialists are efficient and fragile, and the more tightly an insect is tied to one plant the more completely its fate is that plant's.

High on its host plant, negligible elsewhere.

What it forages on

Overwhelmingly ivy. Where ivy is scarce it will use other late flowers — asters, ragwort, heather — but the population depends on ivy being abundant.

Honey

Produces no honey

None. Each cell contains a single loaf of ivy pollen and nectar, sized for one larva.

Relationship with people

How people interact with it

Mostly encountered as an alarming-looking swarm over a lawn in September, and mostly reported as a problem it is not. Because it arrived recently and is easily recognised, it has also become one of the best-recorded insects in Britain — much of the range data comes from public sightings.

Management

Nothing needs to be done about a nest aggregation. The bees will be gone by November, the ground is not damaged, and the same site will very likely be used again next year.

Conservation

Not threatened, and expanding. Its spread is generally attributed to warming autumns extending the ivy flowering period at the northern edge of its range — the same shift that has made ivy honey a viable product in places it previously was not.