Caddis flies are important indicators of environmental quality in aquatic biotopes. This Atlas is the first book which enables the identification of the entire European caddis fly fauna since McLachlan's Revision and Synopsis of 1874-1880. Identification of European caddis flies has proved difficult as a result of the widely scattered literature, and has therefore been a matter for specialists for more than hundred years. This Second Edition of The Atlas of European Trichoptera contains over 1400 species which means an increase of 25% since the first edition of 1983. Identification of specimens is one of the most difficult tasks in Zoology. This volume presents information which will enable the reader to develop his own opinions and will also help him reach decisions concerning the accuracy of his own results. The identification of specimens is undertaken by comparing the detailed drawings of the most important characteristics of all species known in Europe, the Mediterranean countries north of the Sahara, the Canary islands, Madeira, the Azores islands and the adjacent eastern regions including the Arab Peninsula and Iran. The fauna of Turkistan and Siberia is partially included. Explanations of the drawings are provided mainly by symbols which enable the use of this book independent of language. This concept has been proved successful in University courses. The introductory chapters are in English, German and French. Should a reader not understand any of these languages, the translation of these few pages, including the pages of explanations, will provide sufficient understanding for the entire book.