Among the various groups of aquatic insects, mayflies (Ephemeroptera) are of special interest for professional limnologists and entomological researchers as well as for naturalists in general and even the dedicated fly angler. Identification has traditionally been considered difficult and implementation in environmental monitoring and freshwater management has led to an ever increasing demand for exact information on taxonomy and ecology. The present handbook is designed to provide for the first time an up-to-date standard work for Ephemeroptera identification, including last instar larvae...