This book provides a comprehensive, species-by-species account of all the world’s tree-dwelling aphids. It can be used both as an identification guide by entomologists and taxonomists, and as a database in studies of biosystematics and biodiversity. In all, 1758 aphid species are covered, feeding on trees in 355 genera. There are detailed host lists and illustrated keys to the aphids colonising each tree genus, followed by a systematic treatment of the aphid species in alphabetical order of genera, with information on appearance in life, host range, distribution, life cycle and natural enemies. There are 722 drawings, 108 photographs and more than 1800 literature references. The volume will be a standard reference for workers in entomology and forestry.