Table of contents
Introduction
Barbut’s Cuckoo Bumblebee (Bombus barbutellus) is a distinctive parasitic bumblebee found across parts of the UK during late spring and summer. Unlike most bumblebees, it does not build its own nest or collect pollen. Instead, it infiltrates the nests of other bumblebee species, relying on them to rear its young.
This species is most often encountered in gardens, meadows, hedgerows, and open countryside where its host species is present. Although it resembles a typical bumblebee at first glance, closer inspection reveals several unusual traits linked to its cuckoo lifestyle.
Like many specialist bees, Barbut’s Cuckoo Bumblebee is affected by habitat loss, changes in land management, and declines in its host species. In this guide, you’ll learn how to identify it, avoid confusion with similar cuckoo bumblebees, and understand its role in the wider ecosystem.
Identification & Key Facts
| Attribute | Details |
|---|---|
| Common Name | Barbut’s Cuckoo Bumblebee |
| Latin Name | Bombus barbutellus |
| Size | ~14–18 mm |
| Location | Widespread but local across the UK |
| Active Months | May to August |
| Habitat | Gardens, grassland, hedgerows, woodland edges |
| Nesting Behaviour | Parasitic – invades host bumblebee nests |
| Social Behaviour | Parasitic solitary (no workers) |
| Flora | Thistles, knapweed, clover, meadow flowers |
| UK Status | Locally common |
How to Identify Barbut’s Cuckoo Bumblebee
Barbut’s Cuckoo Bumblebee has a long-faced appearance with a slim body shape compared to many social bumblebees. It typically shows pale yellow bands on the thorax and abdomen, combined with a pale tail, giving it a relatively soft colour pattern.
In the UK, it is most often seen feeding on flowers in summer rather than entering nests, as it relies on the nests of its host species for reproduction. Its lack of pollen baskets on the hind legs is a key identification feature.
Physical Characteristics
- Female – Robust and bumblebee-like but lacks pollen baskets; long face and smooth hind legs.
- Worker – None present (cuckoo species do not produce workers).
- Male (Drone) – Slimmer than the female, often with longer antennae and similar colour pattern.
Similar Species
Barbut’s Cuckoo Bumblebee is commonly confused with other cuckoo bumblebees:
- Vestal Cuckoo Bee (Bombus vestalis) – Parasite of Buff-tailed Bumblebee, usually darker overall.
- Red-tailed Cuckoo Bee (Bombus rupestris) – Has a distinctive red tail.
- Southern Cuckoo Bee (Bombus vestalis) – Broader face and different host preference.
If you’re unsure which bee you’ve spotted, our Bee Identification guide can help you narrow down UK species by size, colour, and behaviour.
Why Barbut’s Cuckoo Bumblebee Matters
Although it does not collect pollen for its young, Barbut’s Cuckoo Bumblebee still contributes to pollination as an adult while feeding on nectar-rich flowers. Its presence also reflects healthy populations of its host species, making it an indirect indicator of ecosystem balance.
As a specialist parasite, it highlights the complexity of pollinator relationships and the importance of conserving entire communities rather than focusing on single species.
FAQs
No. Despite its parasitic behaviour, it is not aggressive towards people and rarely stings.
It is mainly active from late spring through summer, typically May to August.
It is locally common but dependent on the presence of its host species.
Females can sting, but stings are uncommon and usually only occur if the bee is handled.
How You Can Help
Supporting Barbut’s Cuckoo Bumblebee means supporting healthy bumblebee communities overall:
🌿 Plant Bee-Friendly Flowers
- Thistles, knapweed, clover, meadow wildflowers
🚫 Avoid Harmful Pesticides
- Avoid insecticides that reduce nectar sources or harm host bumblebees
🏡 Provide Nesting Spaces
- Allow rough grass, undisturbed areas, and natural nesting sites for bumblebees
By encouraging diverse, flower-rich habitats and avoiding over-management, you help support Barbut’s Cuckoo Bumblebee and the wider pollinator network.
