Erica tetralix
"P. argus" lays its eggs differently based on its environment. In heathland, they lay their eggs at the base of "Erica tetralix", "Calluna vulgaris", "Erica cinerea", and "Ulex europaeus". In mosslands, the butterflies tend to lay their eggs on the underside of the fronds of the Bracken Fern. This fern appears to be preferential for oviposition because they attract ants. In limestone grasslands, "P. argus" lays eggs at the stem of "Lotus corniculatus" and at the base of "Helianthemum chamaecistus."