This series provides authoritative identification manuals of insects (and other terrestrial arthropods) of North Western Europe for a wide circle of users: ecologists, conservationists, biologists involved in fauna inventorying and monitoring, as well as insect collectors. The scope of individual volumes varies, reflecting different needs in the treatment of different groups. The geographical coverage focuses on Fennoscandia and Denmark, with some volumes treating more extensive parts of Europe.
All contributions are written in English. In addition to identification keys and descriptions, the volumes provide information on biology and distribution of the taxa treated. Strong emphasis is laid on illustrations, with most volumes providing numerous 'whole animal habitus' illustrations (frequently in colour) in addition to figures of diagnostic structural details.