This is the fourth Royal Entomological Society handbook on aphids, and completes the coverage of the British species. It covers seven subfamilies, represented in Britain by 105 species in 35 genera. They encompass a great diversity of life-styles, ranging from the Eulachnini with Cinara and other major pests of conifers, to the Eriosomatini and Pemphigini, which induce galls on elms and poplars and then migrate to colonise the roots of various herbaceous plants. For each subfamily there are keys for the identification of tribes, genera and species, and also for morphs within species. The systematic account includes biological information and photomicrographs of each species. Wherever possible distinguishing characters are provided that are amenable to the non-specialist, including field keys to aphids on conifers and plant roots.