Host plants:
The larvae feed on Prunus spinosa and related Prunus and Crataegus species.
Habitat:
Theria primaria inhabits hedges and bushy areas with the host plants, most often in warm lowlands.
Life cycle:
The moths occur especially in January and February. The larvae are found between April and June.
Remarks:
Theria primaria is quite widespread in Europe, but is regionally quite local.