The larvae possibly feed on Thalictrum minus.

Lesser meadow-rue (Thalictrum minus) grows extensively on ledges in the dale.

The other diagnostic species are Avena strigosa, Anchusa arvensis, Erodium cicutarium, Galium verum, Thalictrum minus, Tripleurospermum maritimum and Honkenya peploides.

Thalictrum minus is a perennial herb in the family Ranunculaceae that is native to Europe, Northwest Africa, Yemen, Ethiopia, South Africa, Southwest Asia, and Siberia.