Great purple emperor
The males of the great purple emperor (Apatura iris) are among the most beautiful butterflies in Europe thanks to their rich colours. The blue colour is not caused by colour pigments, but by refraction of light. Depending on the angle of incidence of the light, the wings shine in deep blue or dark brown.
Photo © I. Rosenzweig, CC BY-SA 3.0, Wikimedia
Our most beautiful butterfly loves spicy cheese
The Great purple emperor (Apatura iris) is a majestic and extremely attractive butterfly that occurs only relatively rarely in Switzerland and is therefore classified as potentially endangered in the Red List of Butterflies. Its caterpillars prefer to feed on the leaves of the saline willow, which is why the species is most likely to be found in damp forests, such as floodplain forests. The hatched butterfly likes to circle around treetops and looks for sexual partners at these rendezvous sites. On the ground below, however, it is rarely seen.
Strangely enough, the adult purple emperor does not feed on nectar like most other butterflies, but prefers to suck on moist ground, leaking tree sap, excrement, sweat or small dead animals. If the butterflies are to be lured down from the treetops, it is best to lay out a little spicy cheese, which they particularly like.