A rare species in Belgium, almost exclusively known from the southern provinces. Where both Theria species occur together, this T. rupricapraria is the most abundant.

The larva lives on Crataegus or Prunus spinosa.

The adults fly from January onwards till March and because of the early flight period they might be overlooked in some areas. The flight period is slightly later than that of T. primaria. They come to light.

ID: Male; the central band contrasts much more with the ground colour than in T. primaria and it is more narrow towards the dorsum; both pre- and postdiscal lines well indicated. Female; the forewings about 1/2 the length of the abdomen; the central band smaller and darker than in T. primaria (when fresh the colour is black) and sharply defined, and it narrows towards the dorsum side.