This book contains full descriptions of cystoid nematodes (32 species which in them female body does not turn into a hard-walled cyst), belonging to 10 genera in the subfamilies Ataloderinae and Meloidoderinae (Tylenchida/Tylenchomorpha) reported from everywhere in the world. They are plant parasites living in the soil or in plant roots. They induce feeding sites in their host tissues and cause significant economic loss. This book is amply illustrated with line drawings and light photographs based on microscopic and sub-microscopic observations.