The Role of Pollen in Honeybee Colonies

Abstract

The nutrients that workers derive from pollen provide all the proteins, lipids, vitamins, and minerals required for brood-rearing; the primary consumers of pollen are nurse bees which feed the brood. The greatest net increase in nitrogen content of bees is obtained when bees are fed their normal diet based on pollen. The most rapid rates of growth in young workers occur during the first week after eclosion and pollen must be available for the normal development of the wax glands, and subsequently comb construction. Under temperate zone conditions the relative abundance of pollen-rich flowers in spring drives brood-rearing. Likewise, increased access to pollen or protein resources is positively correlated with worker longevity. The amount of pollen required increases proportionately with the quantity of brood. Pollen-fed bees produce more comb than pollen-deprived bees. Pollen foraging seems to be regulated by at least three mechanisms: young larvae, stored pollen, and empty space. The amount of brood is a positive stimulus; while the quantity of stored pollen acts as an inhibitory stimulus for pollen foraging activity. Brood pheromone affects pollen foragers but not nectar-foraging behaviour. Camazine (1991) argued that the pattern of comb contents could be generated by a self-organizing algorithm of three simple rules: (1) the queen lays eggs in the centre of the comb; (2) workers deposit pollen and nectar at random; and (3) bees preferentially remove pollen and nectar from the brood nest relative to the honey storage area. Subsequent theoretical work supports this view.