|photo by Jose M. Rus|
Like all other bumblers out and about this time of year, she's a mated queen who spent the winter buried beneath duff or fallen leaves, and her plan is to build a big royal family.
Since we usually only see a single bumblebee at a time, it's easy to assume that they are solitary creatures. But like the honeybee, the bumbler builds a colony.
She'll seek out the abandoned burrow of a mouse or other rodent and line it with dried grasses, leaves, or moss. When she's satisfied with her cozy, insulated nest, the queen secretes wax from glands on her abdomen, and fashions it into small cups called "honey pots." After visiting early-blooming flowers or trees, she regurgitates the collected nectar into the pots. In one pot she places the pollen she's combed off her fur using her feet. To this pot she adds her first eggs, usually eight or so. She seals the pot with wax and then presses her abdomen against it to brood her eggs like an old hen, and sip from the other honey pots when she needs more energy.
Larvae will hatch from the eggs, grow, and spin silk cocoons. When they emerge, these sterile females have work to do. The queen mum is already incubating more eggs, and these new workers need to find pollen and nectar for their sisters. At its largest, the colony may consist of two or three hundred sisters.
Bumblebees manufacture only enough honey to feed the family through the warmer months. They don't need to stockpile extra because, unlike honey bees, the entire colony will not live through the winter.
When summer wanes, the queen will start producing fertile offspring. Up until now, to each eggs she's laid, she added a sperm from a special sac. Now she withholds sperm from some of the eggs, and these hatch into male bees (drones), which have no stingers and do no work for the colony. They've got just one job to preform before they die: to leave the colony, find a virgin (or maybe not-so-virgin) queen and mate.
Meanwhile, the colony is feeding some larvae extra food for a longer period of time, and these develop into queens. At maturity the queens will go looking for drones, following the advertising pheromones the males leave on twigs and leaves.
A queen may mate with several males before heartily gorging herself on the last of the season's nectar. When it gets chilly, she'll tuck herself away for a long winter's nap. Come spring, she'll extricate herself from the duff and trundle off to being raising a whole big batch of daughters and a few sons.
Have you seen a bumblebee queen this spring?