Amygdalin in almond nectar and pollen - Facts and possible roles

Nectar and pollen within flowers are usually the primary attractants to floral visitors. Chemical analysis of almond nectar and pollen in this study revealed that they contain the secondary compound amygdalin. Floral display often reflects pollinator characters, and almond flowers are accordingly designated as "bee flowers". A previous study in Israel showed that when almonds bloom early in the season they attract honeybees, but later in the season the bees shift toward other species that start blooming. In this study, we offered honeybees sugar solutions containing various concentrations of amygdalin. These preference experiments revealed that in mid-summer bees were not selective, whereas early in the summer they were more discriminating, and consumed faster the sugar solutions with the lower amygdalin concentrations. Possible roles of amygdalin in almond nectar and pollen are discussed.