Formerly a single species, this has now been split into two separate species: the Common Rustic (Mesapamea secalis) and the Lesser Common Rustic (Mesapamea secalella).
A kidney mark on the forewing is always visible and at least partly outlined in white.
Generally very variable, the two cannot be reliably separated without examination of their genitalia, but the Lesser Common Rustic seems more rare and the very dark forms with almost white stigmata tend to be mostly Mesapamea secalella.
As a consequence, I am not sure that the photo shows a Common Rustic. 

Collesalvetti, Livorno, Tuscany, Italy, 22 September 2019