Vestal Cuckoo Bumblebee – Bombus vestalis

Bombus vestalis (Geoffroy, 1785)

Length male 15-19 mm, female 20- 24 mm.

This species of cuckoo bee grows up in the nests of the Buff-tailed Bumblebee (Bombus terrestris). This parasitic bee differs from having a conspicuous yellow patch on either side of the abdomen. Other differences include a lack of pollen baskets on the legs, thinner coats, and making a soft murmuring rather than a definitive buzz. This is a short-tongued bee. Also called the ‘Southern Cuckoo Bumblebee’. Similar to the Gypsy Cuckoo-bee (Bombus bohemicus), where the patches aren’t so dominant and are smaller.

Like all cuckoo bees, they have no worker caste as their own, so they invade the hosts’ nests and take the work force for its own. Important plant pollinators.

The female will seek out its host’s nest and will fight off any hostilities towards her, eventually killing the queen of the nest and her offspring, and effectively she will run the show from then onwards, utilising the remaining workers for her and her young’s own benefits. Its hosts’ nests are generally old mouse holes. Feeds on nectar and pollen.

Seen March to August, and found in differing habitats, including gardens and grassland. Males regular in suburban gardens. Common in the south of England and Wales.