Beewolves are a major group of solitary, ground-nesting wasps belonging to the genus Philanthus of the family Sphecidae. (The common name beewolf derives from the females' practice of preying upon bees to obtain food for their young.) This book brings together information on the biology of more than two-thirds of the 34 North American species, including much previously unpublished data, it is the first book on these wasps to provide extensive material on the behavior of both males and females.