The larva feeds on grasses such as Festuca ovina and Bromus erectus.
Arethusana arethusa olonizes mosaics of dry, gappy and meagre grasslands and higher, denser growing steppe-like grass felt (Bromus erectus and other grasses) and finally grove rich, woody areas such as downy oaks (Quercus pubescens).
Interestingly, all populations that are known to me in the Italian Valle di Susa and in Provence are located around Bromus erectus-rich grasslands, though observations of larvae in Provence in April and May succeeded on Festuca ovina agg. in a sparse undergrowth of downy oak some 10 meters away from the grasslands.
Hibernation takes place as L1. The caterpillars are easy to find in the spring during the day in damp, sunless weather close to the ground in the grass tufts. They are mature most often from mid-June to early July. The moths fly between late July/early August and September.
In Germany Arethusana arethusa was formerly encountered on the southern Upper Rhine. It became extinct presumably by habitat loss, climate extremes and eventually collecting, the details are unclear (Ebert & Rennwald 1991).
In the south, Arethusana arethusa is also highly local and scattered, but it still is endangered only moderately due to habitat loss (in the first place agricultural intensification, housing and industry development, abandonment).
The overall distribution ranges from Morocco across Southern Europe well into Asia (Tien Shan).