Host plants:
The larvae feed on some Erodium species (Geraniaceae), e.g. Erodium carvifolium, E. foetidum, E. glandulosum, E. cazorlanum, E. daucoides etc. Usually only one species is used in a given location. I recorded eggs and ovipositions on E. foetidum in the Catalonian Pre-Pyrenees.
Habitat:
Polyommatus morronensis usually inhabits shallow, stony pastures and dry, rocky mountain slopes from approximately 1000 to more than 2000 m, on both calcareous and acidic ground.
Life cycle:
The adults fly in one or two generations, according to altitude and site. In case of a single generation, they peak in July and August. In case of two generations they are on the wing between late May and early October. The adults often visit the flowers of the larval host plants.
Oviposition takes place quite variably on the leaves (boths sides) and onto the lower parts of the plant. Another type of oviposition is onto the old and dry fruit stands. There the eggs are searched most easily. The young larvae bury themselves partly into the leave or stem and cause mines. The larva hibernates.
Endangerment factors:
Polyommatus morronensis is locally endangered by afforestation and bush encroachment, but also by too intense grazing and global warming.
Remarks:
Polyommatus morronensis occurs locally, but in many mountain ranges of the Iberian Peninsula, from Sierra Nevada in the south to the Pyrenees in the north. In the Pyrenees, there are also a few known sites in France (Hautes-Pyrénées).