Shrinking populations of bees' preferred plants could help to explain the worldwide decline in many wild bee species.

Credit: Bert Pijs/Minden Pictures/FLPA

Jeroen Scheper of Wageningen University in the Netherlands and his colleagues carefully scraped pollen grains off the legs of museum specimens of 57 Dutch bee species to identify which plants the bees had fed on. The bees were collected before 1950, and thus before many wildflower populations began to decline because of agricultural intensification. The study revealed that bees whose favourite plants have declined the most are now showing the steepest drop in population numbers. Populations of larger bees, which have greater food requirements, also showed big decreases.

The findings support calls to plant specific flowers for these threatened pollinators.

Proc. Natl Acad. Sci. USA http://doi.org/xdd (2014)