Comprises about 1,324 species. This is 300 more than any figure given for Psychidae so far.

In Psychidae Arnscheid and Weidlich provide for the first time a complete tool for identifying the European bag worm moths. The book will provide a sufficient overview of the systematics and distribution of the European Psychidae. A total of 246 species is recognized. Description and diagnoses are accompanied by colour figures of the adults, usually depicting variation of male and female if the latter are winged. Black and white photographs of the male genitalia of most species (excluding parts of Naryciinae and Taleporiinae due to their similarity) are given for the first time. Notes on distribution and bionomics are added for every species. One new subfamily, one new genus and three new species are described.

This text brings together fundamental information on insect taxa, morphology, ecology, behavior, physiology, and genetics. Close relatives of insects, such as spiders and mites, are included.