Development of a Regional Pollen Library to Investigate Foraging Patterns in Apis mellifera

Wolfin, James
Journal Title
Journal ISSN
Volume Title
University of Delaware
The European honey bee (Apis mellifera) is an agriculturally significant beneficial insect that contributes an estimated $15 billion per year through the ecosystem service of pollination. Since the onset of Colony Collapse Disorder (CCD) in 2006, beekeepers have seen annual losses in overwintering colonies rise from nearly 15% to over 30% in many cases. One of the critical components to reestablishing healthy, sustainable bee colonies in the United States is ensuring that bees have suitable sources of nutrition, specifically pollen. Pollen can vary in nutritional quality depending on the % crude protein, so it is critical that bees obtain forage from floral sources that have pollen grains with high amounts of protein. In order to determine the nutritional quality of a pollen grain, it is necessary to be able to identify a pollen grain. Additionally, the type of landscape coverage surrounding bees within their foraging range may impact the amount and diversity of pollen grains that are foraged by a colony. Pollen grains were collected from four sites in the Mid-Atlantic to create a fully functional pollen library, in partnership with Discover Life. Grains were analyzed according to a variety of morphological characteristics to ensure that users would be able to identify grains to the lowest taxonomic rank possible. We examined bee-collected pollen from The University of Delaware Botanical Garden (UDBG) in Newark, Delaware and The Mount Cuba Center in Hockessin (MCC), Delaware, to determine which pollen species were most prevalent. The pollen library, while still in progress, currently contains 256 species and a fully functional identification guide that will help users of all academic backgrounds identify pollen. While more pollen was collected at MCC, it was found that differences in foraging totals were not statistically significant. Analysis of bee-collected pollen suggested that bee foraging patterns do change temporally, as different species/genera became prevalent at different time periods. This research warrants further investigation to determine the nutritional quality of the most prevalent pollen grains, and shows the need for an extensive pollen library.
ecology , Wildlife Conservation , apis mellifera