Orange-tip (Anthocharis cardamines)
Along with the first primrose A. cardamines is a true indicator of spring, being one of the first butterfly species to emerge that has not overwintered as an adult. The male and female are very different in appearance. The more-conspicuous male has orange tips to the forewings, which give this butterfly its name. These orange tips are absent in the female and she is often mistaken for one of the other whites, especially the Green-veined White (Pieris napi), Small White (Pieris rapae) or Wood White (Leptidea sinapis).
This beautiful insect is found throughout England, Wales and Ireland, but is somewhat more local further north and especially in Scotland. It inhabits a wide range of habitats, which include flower rich country lanes, hedgerows, riverbanks, woodland margins, rides and damp sheltered meadows where its main larval foodplants can be found; Cuckooflower (Cardamine pratensis) and Garlic Mustard (Alliaria petiolata). In most regions this butterfly does not form discrete colonies and the male, in particular, appears to wander in every direction as it flies along hedgerows and woodland margins looking for a mate or sources of nectar.
The above images from a favoured Sussex site …