Project Number: 5428-21000-013-03
Project Type: Specific Cooperative Agreement

Start Date: Jun 05, 2004
End Date: Jun 04, 2009

Objective:
Overall, our objectives are to identify specific environmental and management-related factors associated with the specific forms of mortality that vary seasonally and with cell position within nests. Expansion of the research to include pollen types used by females will not only improve our understanding of the causes of mortality (if pollen type and nutritional value is involved), but allow us to examine factors that influence the pollination efficiency of adult bees. With regards to the latter, relatively inexpensive forms of vegetation management (including weed control) may prove to have an important effect on pollination and bee mortality. However, it is not clear at this time whether elimination of alternative pollen sources will have a net positive or negative effect on the economics of seed production. For example, it is quite possible that the nutritional benefits of a diversified pollen diet outweigh the costs associated with bees directing part of their foraging activities to non-alfalfa plants.

Approach:
While continuing to examine the types of pollen carried , we will also examine: 1) Actual numbers of pollen grains carried by individual females. 2) Distribution of alfalfa pollen on bodies of bees. 3) Seasonal trends in pollen types used. 4) Distances from shelters at which bees forage for pollen. 5) Effect of flower densities and available pollen types on movement patterns of the bees. 6) Sexual differences in pollen types carried. To date, we have collected only females, but in 2004 we will collect both sexes; this will help determine the potential role of male bees in pollination.