A bumblebee (genus Bombus) with a tiny brown mite on its wing gathers nectar from a flowering Goldenrod (Solidago) plant. Bumblebees, like their relatives the honeybees, feed on nectar using a long hairy proboscis which is folded under the head during flight. A few yellow grains of pollen can be seen adherent to this bee’s back and head, demonstrating why bumblebees are important agricultural pollinators. However, the small brown creature near the middle of the bumblebee’s wing is a mite. Many bumblebees have tiny mites clinging to their bodies. In most cases the mites are difficult to see, but sometimes they can cover large parts of the bumblebee’s body.
Most of the mite species that live with bumblebees are harmless to them and simply cling to the bumblebee so that they can be transported to new nests. When in the bee nest, the mites usually feed upon the wax, pollen, nest debris, and other small insects, but do not feed on the bees. Then, when they reach a certain stage in their life cycle, the mites cling to worker bees, and are transported onto flowers. From these flowers, the mites then attach to other visiting bees, and are transported to new nests.
Bumblebees do not carry the destructive Varroa mites (Varroa destructor and V. jacobsoni) common to honey bees that harbor deformed wing virus and a fungal parasite called Nosema ceranae which can eventually destroy a honey bee nest. However, the pathogens themselves are capable of infecting adult bumblebees and can then destroy their colonies. Around the world, many species of bumblebees have suffered steep declines and some, such Cullem's bumblebee (Bombus cullumanus), have gone extinct.