The Scarabaeoidea is one of the largest superfamilies in the Coleoptera and includes approximately 2,200 genera and about 32,000 species worldwide. Scarabs have diversified into most habitats, and they are fungivores, herbivores, necrophages, coprophages, saprophages, and carnivores. Some scarabs exhibit various levels of parental care and sociality. Some are myrmecophilous or termitophilous. Many possess extravagant horns, others are able to roll into a compact ball, and still others are highly armored for inquiline life. Some are important agricultural pests that may destroy crops, while others are used in the biological control of dung and dung flies. Scarabaeoids are popular beetles due to their large size, bright colors, and interesting natural histories. Because of the popularity of the group, there exists an erroneous impression that the superfamily is taxonomically well known. However, even with a lengthy history of study, the group is in real need of continuing research. The papers in this volume cover a wide array of research topics on Scarabaeoidea, including evolutionary relationships, character trait evolution, species concepts, descriptions of new taxa, keys for identification, nomenclature, historical biogeography, methods, and basic life history information. These papers are a valuable contribution to our knowledge of scarabaeoids, and they will provide a foundation for future research.