Bringing In Pollen
Verhalten der Bienen
Pollen is the colony's protein source. According to the Celle Bee Institute, a strong colony needs more than 25 kilograms a year.
Pollen is the colony's protein source. According to the Celle Bee Institute, a strong colony needs more than 25 kilograms a year. A pollen load weighs at most about 10 milligrams, so at least 50,000 foraging flights are needed for one kilogram. It is stored near the brood nest; when packing it in, the bees add honey stomach contents and glandular secretions, which preserve the pollen and partly digest it.
Because the bee usually forages with flower constancy, the color of the pollen loads reveals what is currently in flow. However, this does not allow reliable identification of the source plant. The nutritional value varies greatly: crocus, willow, fruit trees, rapeseed, and heather are rich, while spruce, pine, hazel, and alder are poor.
Pollen coming in at the entrance is an indication of brood, and thus of a laying queen, but not proof. With a pollen shortage, the hypopharyngeal glands of the nurse bees develop poorly, the queen is fed worse, and lays less. Winter bees in particular need pollen, since they build their fat body from it. There is no full substitute for pollen.