This species closely resembles Pieris rapae, the wing shape is a little more rounded, the black markings on the upperside are more accentuated and the shape of the discoidal front wing spot is often more rectangular.

The egg is pale yellowish and is a bit shorter and broader than the egg of Pieris rapae. Eggs are laid singly on the underside of the leaves of the larval foodplant.

In the first two instars, the larva can be identified by the black head capsule (same colour as the body in Pieris rapae). In the third instar, this head capsule turns greyish. Older caterpillars resemble Pieris rapae caterpillars but often have a more bluish hue to the green body colour and the yellow dorsal line and lateral spots are even more present.

Several Cruciferae are used, in Northwestern Europe mainly Iberis and Diplotaxis.
Research has shown that butterflies that recently colonized an area have a different preference for host plants than native butterflies, including Alliaria petiolata, Diplotaxis tenuifolia, Brassica oleracea and Sinapis arvensis.

In Southern Europe this is a species from rocky, often calcareous environments. In the expansion zone in Central and Northwestern Europe it uses suburban gardens and road sides where larval foodplants can be found in a similar xerothermic context.