This book is part of a series designed to facilitate identification of South American insects likely to be encountered in, on, or near water, on wetlands, and in unusual aquatic habitats. It permits identification of all known adults and larvae. Each volume of the Encyclopedia of South American Aquatic Insects begins with a short general introduction. The scope of this volume is the Plecoptera. It includes all species known from South America as of the year 2002 and permits a state-of-the-art identification of the species. In the case of specimens belonging to undescribed species or those not previously reported from South America, it permits identification to genus or family and gives the reader reasonable certainty that his specimen does not belong to the known fauna of the continent. The keys are richly illustrated to permit non-specialists in the group to reliably identify specimens. Taxonomic revisions are intentionally avoided, but doubtful taxa are so designated in the keys. The volume is meant for anyone interested in identifying aquatic stoneflies, including entomologists, stream biologists, ecologists, zoogeographers, fishery biologists, and naturalists. Already published within this encyclopedia: -Encyclopedia of South American Aquatic Insects: Collembola ISBN: 0-7923-6704-9-Encyclopedia of South American Aquatic Insects: Ephemeroptera ISBN: 1-4020-0775-2-Encyclopedia of South American Aquatic Insects: Plecoptera ISBN: 1-4020-1520-8 Forthcoming book titles: -Encyclopedia of South American Aquatic Insects: Odonata-Encyclopedia of South American Aquatic Insects: Orthoptera-Encyclopedia of South American Aquatic Insects: Heteroptera-Encyclopedia of South American Aquatic Insects: Neuroptera, including Megaloptera-Encyclopedia of South American Aquatic Insects: Trichoptera-Encyclopedia of South American Aquatic Insects: Lepidoptera-Encyclopedia of South American Aquatic Insects: Coleoptera-Encyclopedia of South American Aquatic Insects: Diptera-Encyclopedia of South American Aquatic Insects: Hymenoptera