Barbut's Cuckoo Bee - Bombus barbutellus

Alternative names
Psithyrus barbutellus

It bears a close resemblance to its host, Bombus hortorum, but has an almost circular face, most unlike the very elongated face of Bombus hortorum.

Identification difficulty

Occurs in a wide variety of habitats and visits are made to a wide variety of flowers.

When to see it

Over-wintered females can be found from late April onwards, males and new females in July to September.

Life History

During spring the over-wintered, fertilised female Bombus barbutellus searches for a small nest of the host bumblebee, Bombus hortorum. It enters the nest and eventually dominates, or kills the host queen. The parasite female then lays eggs which will develop into either males or females of Bombus barbutellus. All foraging and nest duties are carried out by the host workers. It is likely that this species will also attack Bombus ruderatus.

UK Status

This species is distributed widely throughout most of Britain but is infrequently encountered.

VC55 Status

Uncommon in Leicestershire and Rutland where there were only three confirmed records prior to 2016.

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Leicestershire & Rutland Map


Yellow squares = NBN records (all known data)
Coloured circles = NatureSpot records: 2020+ | 2015-2019 | pre-2015

UK Map