Bumble Bee

Bumble Bee Fact Page
Bumblebees (Bombidae) leave their nest in the autumn, and the fertilized queens hibernate in some protected place during the winter. In the spring each queen builds a nest of moss or grass, preferably in a deserted rodent nest. From scales secreted by abdominal glands, she makes a honeypot of wax and then makes a cell and half fills it with pollen before depositing her eggs in it. The queen covers the eggs with a layer of wax and sits on them like a brooding hen, sipping honey from her pot. After the larvae hatch, they eat the pollen and grow, then spin cocoons in which to pupate. When the workers emerge, they cut away the upper half of the cells, and the remainder is used as a receptacle for nectar.
Bumblebee populations vary from year to year, depending on environmental factors; but one typical nest collected in Wisconsin contained one queen, 515 adult workers, 117 worker and 119 queen pupae, 101 larvae, 308 eggs contained in 18 cells on cylinders of pollen, and 709 empty worker cells filled with honey.
The larger workers maintain the covering over the nest and collect food, and the smaller ones care for the young larvae and do the inside work. Only males are produced late in the summer, and female larvae literally may be thrown out to control the population. When workers lay eggs, the queen may chase the workers away and eat the eggs; but if the queen dies or is removed, one of the larger workers will take her place within four hours or less. The difference in size of workers depends upon the amount of food they have available to eat when they are larvae.
Bumblebees are superior to other bees in pollinating red clover, since they have a tongue that is 2.5 mm (0.1 in) longer than that of honeybees. Artificial methods of rearing bumblebees have been successful, but a better technique may be to encourage natural populations by providing forage plants that bloom eight to nine weeks prior to red clover, so that the colonies have abundant food on which to raise their young.