The Fauna Indicativa characterizes ecological preferences and biological traits of all species of dragonflies, grasshoppers, ground beetles and butterflies of Switzerland in tables. In most cases, entries for preferences and traits are given as numbers and either specified as scaled values or Yes- No decisions. Other characteristics are specified as letters. The entries are specific to populations in Switzerland and are based mostly upon literature data and the assessment by experts. The Fauna Indicativa is a tool for the ecological evaluation of faunistic data and may form the base for developing indicators for monitoring. With the help of this tool, arthropod communities can be used in an easy way for the description of state and change of habitats in Switzerland. Examples for the applications of the Fauna Indicativa are given.