Buff-tailed bumblebee (Bombus terrestris) Bombus terrestris, the buff-tailed bumblebee or large earth bumblebee, is one of the most numerous bumblebee species in Europe. Moreover, it is a eusocial insect with an overlap of generations, a division of labor, and cooperative brood care. The queen is monandrous which means she mates with only one male. Nests are usually found underground, such as in abandoned rodent dens. Colonies form comb-like nest structures with egg cells each containing several eggs. The queen will lay egg cells on top of one another. Colonies produce between 300 and 400 bees on average, with a large variation in the number of workerB. terrestris workers learn flower colors and forage efficiently. Sibillini, Umbria, Italy July 2020