Buff-tailed Bumblebee

• Its workers vary extraordinarily in body size within a single colony.
• It feeds on nectar and pollen from a wide range of flowers.
• Colonies can reach 350 to 1,000 workers at their peak.
• fisiologíaIt can fly and pollinate at lower temperatures than most bees, thanks to a larger body and flight muscles that generate more heat.
• It pollinates by vibration. It grips the flower and vibrates its flight muscles at high frequency until the pollen shoots out of the anthers, something the honeybee cannot do. That is why it is indispensable in tomato greenhouses.
• Its commercial rearing revolutionised horticulture: boxed colonies have been sold since the late 1980s to pollinate protected crops, and today it is a global agricultural product.
• And that success is also its problem: commercial colonies have escaped or been released outside its range and have become invasive in South America, Japan and Tasmania, displacing native bumblebees and passing pathogens on to them.
• In Chile and Argentina its arrival has been linked to the collapse of the native bumblebee Bombus dahlbomii, the world's largest, now listed as Endangered.
• It detects electric fields: flowers carry a negative charge and the bumblebee a positive one, which lets it tell whether a flower has been visited recently.
• It can fly in the cold far better than bees can, warming its thorax with muscular vibration before take-off.

Skeleton type

Invertebrate - chitin exoskeleton (insect)

Habitat and environment

Meadows, gardens, farmland and temperate country across Europe; introduced to Tasmania and elsewhere for commercial pollination

Birth weight

Egg laid in a wax cell

Size at birth

A larva fed by the queen or the workers

Sexual maturity

The new queens emerge in late spring or summer and mate before hibernating

Gestation / incubation

Complete egg-larva-pupa-adult development over several weeks

Litter / clutch size

Colonies of up to 350-1,000 workers at their peak

Sources consulted: AnAge (genomics.senescence.info); Bumblebee.org; HoneyBee & Co.; Buzz About Bees; Animalia.bio; Insect Week; PMC (Asian bumblebee characteristics study, queen dispersal study); Fenologia comparada de Bombus terrestris en Europa del norte y region mediterranea; Andaltura, ficha Bombus terrestris

Best time: In northern Europe it flies from March to August, but in the Mediterranean region the cycle is reversed: the colony is founded in autumn or winter and the queens enter diapause through the dry summer, emerging in late September with the first rains. In Spain the queens are seen from February or March