- Family: Whites and Yellows – Pieridae
- Subfamily: Whites – Pierinae
- Wing span: Medium-sized, 34–48 mm (1.36–1.92 in.).
- Wing upper side: Forewing white, tip with black patches, middle of leading edge with black blotch. Hind wing grey, with white blotches and white strip.
- Wing underside: Forewing white, tip with green patches, middle of leading edge with black blotch. Hind wing green, with white blotches and white strip.
- Habitat: Dry slopes and disturbed surroundings, with scant vegetation e.g. gravel pits.
- Flying time: June–July (wanderers), late July–late September (Finnish generation).
- Overwintering form: Cocoon.
- Larval foodplant: Different Mustard family (Brassicaceae) plants such as tower mustard (Arabis glabra) and sea rocket (Cakile maritima) along coasts.
The bath white’s markings are quite reminiscent of female orange tips, but it has a larger black blotch on the leading edge of its forewings which is often divided in two. Additionally, the black tips of its forewings are not continuous, as they are on orange tip, but are broken up with white patches.
The bath white wanders to Finland from southern countries and is only spotted in Finland occasionally. Sometimes the species has succeeded in breeding in Finland, however. Males fly around looking for females, who lay their eggs one by one among the leaves of the food plant.