The Aphelenchida, Longidoridae and Trichodoridae are groups of nematodes that include almost 1000 species from some 40 genera. A number are of known agricultural importance, both in their own right as parasites of fungi or higher plants and/or as vectors of certain plant viruses. This book aims to provide a practical, working guide to the taxa of the Aphelenchida, Longidoridae and Trichodoridae, in such a form as to facilitate usage by both specialist taxonomists and general nematologists.