Each volume in this series illustrates the adults of all species of Geometrid Moths in photographical color plates of the best quality. Sexual dimorphism as well as polymorphism is also illustrated, and all subspecies are illustrated when possible. Most species are shown in natural size, but larger groups of small species such as the genera Idaea and Eupithecia are shown enlarged. The following information is provided for each species: full name; original reference to all available nominal names (valid names and synonyms); diagnosis based on external features, including detail figures where necessary; male and female genitalia of all species with line drawings or photographs; a summary of the European distribution and also of distribution outside the area treated; a map of the European distribution; phenology with detailed information about flight period or periods, with reference to various parts of the distribution area; information about how the species hibernates; biology including