Yellow-faced bees
A genus rather than a single species — Around 700 to 900 species worldwide, on every continent except Antarctica, with a remarkable radiation in Hawai'i where a single colonising ancestor produced more than sixty endemic species. General statements below are statements about the group.
The bees that look least like bees. Yellow-faced bees are small, black, effectively hairless and marked with pale yellow or white on the face, and almost everyone who sees one assumes it is a small wasp. They carry pollen internally, swallowed into the crop and regurgitated at the nest, which means they have no pollen brushes at all — the feature people use to recognise a bee is simply absent. Seven Hawaiian species were the first bees anywhere to be protected under the United States Endangered Species Act.
Can it sting?
Females have a sting and it is too small and weak to be of any consequence to a person; most people could not tell if one had tried. There is no colony, no store and nothing worth defending. Males cannot sting.
How to recognise it
Small, slender, shiny black and almost hairless, with distinctive pale yellow or ivory markings on the face — a full mask in males, usually two side stripes in females. Often with small pale marks on the legs and thorax edges. Nothing about the body says bee at a glance.
- Effectively hairless and shiny black, which rules out almost every other bee.
- Pale yellow or white facial markings, more extensive in males than females.
- No pollen visible anywhere on the body, ever — it is carried inside.
- Small, usually 4 to 8 mm, and often seen entering the cut end of a hollow stem.
Body length 4–9 mm (typically 6 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
- Hollow stems and plant cavities; Existing cavities and tubes
Nests in narrow pre-existing cavities — hollow or pithy stems, beetle borings, old gall chambers, and the smallest tubes in a bee hotel. Like other Colletidae they line each cell with a self-produced cellophane-like membrane, applied with a short forked tongue, which waterproofs the cell and holds the semi-liquid provision the larva feeds on.
- Carries pollen
- Carried internally
- On the wing
- May to September
Lifecycle
- EmergenceAdults emerge in late spring and early summer, later than most spring solitary bees.May to June in temperate regions.
- NestingThe female swallows pollen and nectar at the flower, flies back to the stem, and regurgitates a semi-liquid provision into the membrane-lined cell before laying on top of it. Carrying the load internally means her flight is unencumbered and there is nothing to brush off.Several weeks.
- Development and overwinteringThe larva consumes the liquid provision, and overwinters in the cell as a prepupa inside the stem, emerging the following year.Roughly ten months.
Where it lives and what it does
- Habitat
- Gardens, hedgerows, brownfield land, heathland, coastal scrub and woodland edge — anywhere with dead stems left standing and small open flowers nearby.
- Distribution
- Worldwide. Hylaeus is one of the very few bee genera to have reached remote oceanic islands unaided, and the Hawaiian radiation of over sixty endemic species from a single ancestral colonisation is among the most striking examples of island evolution in insects.
- Behaviour
- Quick and inconspicuous. They work small, shallow, open flowers — umbellifers, mignonette, brambles, spurges — that larger bees find uneconomic, and they are far more abundant in most habitats than the number of records suggests, simply because they are not recognised.
- Pollination role
- Modest per individual and genuinely useful in aggregate, particularly for small-flowered plants that attract little else. Internal pollen transport reduces incidental transfer compared with a dry-scopa bee, so they are less efficient pollinators than mason bees for the same number of visits — a direct consequence of how they carry the load.
Lower per visit than external-carrying bees, because internally carried pollen cannot fall off in flight.
- What it forages on
- Mainly small open flowers with accessible nectar. Several species are specialists, and the Hawaiian endemics in particular are tied to native coastal and montane plants that have themselves declined.
Honey
Produces no honey
None. The provision in each cell is a semi-liquid pollen-and-nectar mixture for a single larva, and it is consumed within weeks.
Relationship with people
- How people interact with it
- Almost entirely unrecognised, which has real consequences: a bee that looks like a wasp gets swatted, and a bee nobody records looks absent from survey data. The Hawaiian species are the exception, and their listing in 2016 as the first bees protected under the US Endangered Species Act put an obscure genus briefly in the news.
- Conservation
- The Hawaiian yellow-faced bees are among the most threatened bees in the world, squeezed by habitat loss, invasive ants and the decline of the native plants they depend on. Elsewhere the genus is widespread, and its main pressure is the removal of dead stems — the tidying of gardens and verges takes away the only nest sites it has.
Sources
- The Bees of the World — Johns Hopkins University Press (2007) · Textbook
- Field Guide to the Bees of Great Britain and Ireland — Bloomsbury (2015) · Field guide
- HoneyHQ editorial synthesis — HEKNO Ltd · HoneyHQ synthesis
How sources are selected and weighted is set out in the sources and evidence policy.
Guides covering this bee
- Nectar plants explainedNectar is a payment. Understanding what the plant is buying, and how it controls the price, explains most of what flowers do and why some are useless to some bees.
- Pollen plants explainedPollen is protein and it is what bee larvae are made of. A garden with abundant nectar and no pollen supports adult bees and produces no new ones.
- Most bees are not honey beesAround 20,000 bee species exist. Roughly 90% are solitary, almost none make honey, and most of the ones in genuine trouble are not the one on the jar.
- How far do bees travel to forage?A honey bee will fly ten kilometres if she has to and would much rather fly one. A solitary bee may not manage three hundred metres. That gap decides what 'planting for bees' actually means.
- The best plants for beesA shortlist chosen on three criteria: how much nectar and pollen the plant produces, how accessible it is to different bees, and when it flowers. Season coverage matters more than any individual plant.
- Specialist bees and the plants they cannot do withoutA large minority of bee species collect pollen from one plant genus and will starve rather than switch. For them a flowery garden is not forage — it is scenery around the one thing they need.
- Nesting habitat: the half of bee gardening that is not flowersAround seventy per cent of bee species nest in bare ground and most of the rest in stems, wood or cavities. A garden can be full of flowers and offer nowhere at all to live.
- Plants for solitary beesNine bee species in ten are solitary. They are small, short-tongued, short-lived and often tied to particular plants — which makes open shallow flowers, a long season and untidy ground more useful to them than a border of showy perennials.
- How to identify a beeColour is the first thing people reach for and the least reliable thing available. Body shape, size, how the pollen is carried and where the animal is nesting will get you to a group in seconds — and a group is usually as far as anyone honestly gets.
Tools for supporting this bee
- Plant recommendation tool
Which plant fills this specific gap?
- Bee-friendly garden planner
What should I plant in the space I actually have?
- Flowering calendar
What should I plant so that something is always in flower for bees?