The Rosalia longicorn (Rosalia alpina) is one of the most beautiful beetle in France and is a protected specied. It belongs to the Cerambycidae family, also called longicorns or longhorns because of the length of their antennae. This insect is 15 to 40 mm long and its elytra are blue-gray with black spots. This coloration serves as good camouflage with their preferred habitat, the European Beech. The Rosalian longicorn lay eggs in dead or dying trunks of this tree. The development time for the larvae is particularly long: several years.
This insect can be seen in the Cévennes National Park, in the summertime.