9701190 WOLF Bees vary in their choice of pollen plants. Generalists are bees that collect pollen from many plant species, while specialists collect pollen from only a few related plants. Biologists do not fully understand why some bees are generalists, whereas others specialize. Bee pollen choice is important for several reasons. First, many native plants depend on pollination by particular bees for seed set. Additionally, some native bees are used as crop pollinators, and many others hold such potential. In this research, Paul Wolf and doctoral candidate Sedonia Sipes will study pollen choice in Diadasia, a genus of specialist bees whose members specialize on different plant families. Many species visit only plants in the mallow family; others specialize on cacti or sunflowers. It is unknown when, or how often, these changes in host specialization have occurred during the history of this bee genus. The researchers will use DNA analysis to determine how Diadasia species are related, to infer the frequency and order of host-switching. They will also quantify the degree to which Diadasia are restricted to their preferred hosts. Finally, the researchers will examine morphological characteristics that may be adaptive to specialized pollen collection. The work should add to the understanding of specialization in bees, and provide some of the basic information needed to evaluate the potential of these bees for crop pollination.
