Date of Award:


Document Type:


Degree Name:

Doctor of Philosophy (PhD)



Committee Chair(s)

Carol von Dohlen


Carol von Dohlen


Terry Griswold


Nancy Huntley


Karen Kapheim


Luis Gordillo


Bees are the most important pollinators of flowering plants and are necessary for pollinating both wild plants and many of the crops that produce the food we eat. There are many different species of bees, with about 20,000 species worldwide and 4,000 species in the United States. Even though bees are important pollinators, there is still much we do not know about how many species there are and their biology. In order to better understand the species and their biology, I performed three projects that help fill these gaps by reviewing the species of a poorly known bee group, examining the different ways bees carry pollen, and then reviewing how bees gather pollen from flowers. To better understand bee diversity, I examined a group of species in the subgenus Heteroperdita in the genus Perdita (Andrenidae). I described nine species that were new to science, found the opposite sex of three species, and found that one species was a duplicate of a previously described species. This work increased the number of species in Heteroperdita to 22 and increased the number of species in the genus Perdita to 636. I then explored how pollen is carried back to the nest in two distantly-related bee groups, the genera Perdita and Hesperapis (Melittidae). I found that different species can carry pollen in one of three different ways: moist, dry, or glazed. Interestingly, how the bees carry pollen appears to depend on the shape and stickiness of the pollen grains that the bees prefer. I then reviewed how bees gather pollen from flowers. I combined previous research and my own observations of bees to classify the different pollen gathering behaviors into seven different types. I then examined why bees use different pollen gathering behaviors and provided a set terminology to refer to each behavior. Overall, this dissertation advances our knowledge of the diversity of bees and their relationships with flowers, which will support efforts to understand and conserve these important pollinators.