Trophallactic interactions in the adult honeybee (Apis mellifera L.)

Trophallaxis, the transfer of food by mouth from one individual to another, occurs among adults of honeybee colonies. The drones and the queen consume but do not donate, while the workers are recipients and donors. They share the content of their crops and sometimes the products of their head glands. Such trophallactic interactions can frequently be seen non-randomly between all members of the colony. Their occurrence and success depend on factors such as sex and age of the consumers and donors, food availability and quality, time of day, weather and season. For the youngest workers, old workers, drones and the queen this flow - especially the flow of protein - has definite nutritional importance, since these bees need protein but have only a limited capacity to digest pollen and consume none or only small amounts of it. The system of trophallactic food flow and the existence of a specialised group, the nurses, who are responsible for consuming pollen and processing it as easily digestiblejelly enables the colony to have many members with a reduced digesting capacity. The food storer bees specialise in transporting harvested nectar within the hive, receiving it from foragers near the entrance and depositing it in other parts of the hive where it is processed into honey. This saves time and helps the foragers to harvest available food sources more efficiently. In addition to its nutritional value and the importance of transfer to specialists, receiving and donating food in the trophallactic flow of food provides information to colony members about the quality and quantity of food existing in the hive and can therefore be compared in its importance with the dance language and communication by pheromones.