- Family: Whites and Yellows – Pieridae
- Subfamily: Mimic Sulphurs – Dismorphiinae
- Wing span: Medium-sized, 35–44 mm (1.38–1.73 in.).
- Wing upper side: White, forewing tip grey (female) or black (male).
- Wing underside: Light yellow, green and grey patches.
- Habitat: Forest edges and clearings.
- Flying time: Early May–late June. Second generation possible (July–August).
- Overwintering form: Cocoon.
- Larval foodplant: Meadow vetchling (Lathyrus pratensis), tufted vetch (Vicia cracca) and possibly also other Pea family (Fabaceae) plants.
There are three subfamilies of the Whites and yellows (Pieridae) in Finland. The Mimic sulphurs (Dismorphiinae) contains two species, the better known of which is wood white. The two other Pieridae subfamilies are the Whites (Pierinae) and the Sulphurs (Coliadinae).
The wood white is common in southern and central Finland and can be found here and there in Lapland. It usually rests with its wings against each other, so the upper surface is difficult to study without taking the butterfly in one’s hands. Its long, round-tipped wings and slow, fluttering flying style are characteristic properties of the species. The males fly around looking for females. Females lay their eggs one by one among the leaves that will be the caterpillar’s foodplant. The species is very difficult to differentiate from its close relative, the cryptic wood white.