This book uses a modern phylogenetic framework to shed new light on the life histories and evolution of solitary bees. It explains the foraging behavior of solitary bees, their development, and competitive mating tactics. The book describes how they construct complex nests using an amazing variety of substrates and materials, and how solitary bees have co-opted beneficial mites, nematodes, and fungi to provide safe environments for their brood. It looks at how they have evolved intimate partnerships with flowering plants and examines their associations with predators, parasites, microbes, and other bees. This up-to-date synthesis of solitary bee biology is an essential resource for students and researchers, one that paves the way for future scholarship on the subject.