While social wasps, like hornets and yellow jackets, garner most of the publicity (most of it negative), the vast majority of wasp species, including digger wasps, spider wasps, and mud-daubers, are solitary. Elegant in appearance and distinctive in their actions, solitary wasps have long fascinated observers and have been the subject of narratives by such naturalists and scientists as Jean Henri Fabre, Niko Tinbergen, and Howard Ensign Evans. Each adult female solitary wasp forages alone and, if she builds a nest, it is occupied solely by herself and her own offspring. Females use their stings mainly for hunting, rather than for defense, and exhibit a wide range of foraging and parental behaviors. Solitary wasps are of special interest to ethologists and evolutionary biologists. Kevin M. O'Neill provides readable yet thorough accounts of the natural history of the major families of solitary wasps and also surveys the current state of scientific research on these insects. Numerous comprehensive tables of quantitative data serve as an excellent reference for biologists. Topics covered in Solitary Wasps: Behavior and Natural History include: *classification of the solitary wasps and their relation to other Hymenoptera*foraging and nesting behaviors* mating and parental strategies*thermoregulation*natural enemies*defensive strategies*directions for future researchSolitary Wasps: Behavior and Natural History is the first general survey in more than 25 years to be dedicated to its subject and is the best place to turn for information about the biology and compelling behavior of these common insects.