Pollen sources for Apis mellifera L (Hym, Apidae) in Surinam, based on pollen grain volume estimates

Every 3 or 4 days over a 1-year period, pollen samples were taken from Apis mellifera hives in Surinam in order to identify pollen sources, and to determine how these sources varied during the year. The second aim of this study was to compare the results of pollen counts with relative volume estimates. Each sample contained up to 15 pollen types. On the basis of relative volume estimates in combination with frequency, we found that the most important year-round pollen sources were Cecropia sp, Palmae type 1, Cocos nucifera, and Compositae type 1. Pollen types that were periodically important included Ceiba pentandra, Myrtaceae type 1, Abutilon type, Spondias mombin, and Terminalia sp. Up till now the importance of pollen sources has been measured directly by counting pollen grains. In this paper we show that such data do not reveal the actual importance of these sources for the bees. Data from the volume estimates show a much more diverse bee diet during the year as well as on a single day than that shown by the pollen counts