The Macrosiphini are the predominant group of aphids on herbaceous plants in Britain, and the world. There are 305 British species and subspecies, comprising 49% of the Aphididae on the British list. They include many important pest species, some of which are highly polyphagous. This Handbook provides a checklist and a list of native host plants, along with keys to tribes, genera and species. Biological information is provided about each species, and morphological features of almost all the species can be examined on the accompanying CD.