An illustrative colony cycle of bumblebee species living in temperate regions (a). This is representative of the colony cycles of Bombus terrestris
(b) and B. impatiens
(c). Queen bumblebees emerge from hibernation, establish a nest as a single foundress and provision it with pollen and nectar. Egg batches are laid that develop into female worker offspring. Once these offspring have developed and emerged as adults they take over foraging duties from the queen, and tend to developing brood. After sustained colony growth, males and new queens are produced. These sexuals leave the colony and mate. The new queens hibernate while males and the remainder of the colony perish.