Black-veined White

• Wing span

  Large, 51–70 mm (2.01–2.76 in.). Females larger than males.

• Wing upper side

  Translucent white, wing veins black (male) or dark brown (female).

• Wing underside

  Like upper surface.

• Habitat

  Open forest and grazing land.

• Flying time

  Mid-June–mid-July.

• Overwintering form

  Caterpillar.

• Larval foodplant

  Rowan (Prunus padus), bird cherry (Prunus padus), hawthorns (Crataegus), apple tree (Malus domestica) and other Rose family (Rosaceae) trees and bushes.

Black-veined whites are quite rare in Finland and variations in the size of population are quite large. The black-veined white is the only blotchless white butterfly species in Finland. The only markings on its wings are its black veins. It is also the largest member of the Pierinae subfamily in Finland.

Black-veined whites are social and appear in large groups, often sucking moisture from damp roads. The females lay their eggs in groups of 30–100 among the leaves of the host plant. The caterpillars live in large groups and overwinter as a colony in a cocoon among entwined leaves. The abundance of the species varies greatly from year to year.