Host plants:
The larvae feed polyphagously in the herb layer, along coasts (e.g. Engalnd, Germany: Sylt) often on Armeria. I recorded many larvae on Rumex acetosella in the Sierra de Gredos (Spain, Avila) in March 2023.
Habitat:
Polymixis lichenea inhabits various open to semi-open habitats in the low lands and up to medium-high altitudes in the mountains. In the Spanish Sierra de Gredos I recorded the larvae in embankments on acidic ground along roads through a mixture of maquis and open Quercus pyrenaica scrub and woodland in about 1000-1300m. Polymixis lichenea is especially known from coastal areas and rocky slopes.
Life cycle:
The pupa aestivates in a cocoon in the soil. The moths emerge in autumn, mainly between September and early November, according to the region and weather. The larvae develop in the more humid winter and spring.
Remarks:
Polymixis lichenea occurs from NW-Africa (including the Canaries) across SW-Europe (Iberian Peninsula, France, Italy) to parts of western Europe (southern half of Great Britain, NW-Germany, W-Denmark).