Honey bee (Apis mellifera L.) activity on sunflowers (Helianthus annuus L.)

Abstract

The numbers of honey bees appearing on sunflowers were studied at half hourly intervals during the flowering of a crop together with the availability of nectar and pollen during the same period.
Nectar was the major attractant being available to honey bees throughout the day. Pollen was present in abundance for a period during the morning and to a lesser extent in the afternoon. Pollen was collected passively by worker bees foraging for nectar.
Passive distribution of pollen both within and between sunflower heads by nectar-seeking honey bees would increase fertilization of sunflower varieties displaying self.incompatibility.