Pollen storage and foraging by honey bees (Hymenoptera : Apidae) in highbush blueberries (Ericaceae), cultivar bluecrop

We investigated pollen and nectar foraging of honey bees, Apis mellifera L. , from pollen-poor and pollen-rich, small and large colonies in blooming hi ghbush blueberry, Vaccinium corymbosum L. cv. Bluecrop fields. The proporti on of pollen foragers differed significantly between pollen-rich and pollen -poor colonies after storage levels were manipulated, but foraging and poll en stores returned to similar levels within a week. No differences were fou nd in small colonies, although the proportion of pollen foragers was high ( 46% and 45% from pollen-rich and pollen-poor colonies, respectively). Only 7.6% of pollen foragers carried Vaccinium sp. pollen in their loads indepen dent of treatment, day, and colony size, whereas 60.8% of nectar foragers c arried up to 100 tetrads of Vaccinium sp. pollen on their bodies. The avera ge proportion of Vaccinium sp. pollen carried by nectar and pollen foragers per day and treatment was less than 10%. Our research indicates that when colonies are placed in fields of blooming blueberry flowers, pollen foragin g is stimulated in large colonies with stores that are pollen poor, but pre dominantly for pollen types other than blueberry. This research indicates t hat nectar foragers are the major visitor of highbush blueberry cv. Bluecro p and suggests that increasing the number of nectar foragers rather than po llen foragers would result in more honey bees foraging on highbush blueberr y, in particular cv. Bluecrop.