Pieris brassicae (Linnaeus, 1758)

Description: Wingspan 58-63mm. This is the largest white butterfly in N. Ireland. The forewings of adults have broad black or dark grey tips on the upperside and there are two black spots on the underside. The underside of the hindwing is plain yellow. Females differ from males in being slightly larger and having black spots on the upper surface of the forewings. Markings on the adults of the summer generation are blacker than those on spring adults.

Similar Species: Other whites, but this species is larger with more extensive dark markings.

Key Identification Features:

• Large size
• Extensive black tips to forewings
• Uniform yellow underside to hindwing

Sets:

Flight Period: April to September in two broods which overlap in late June/early July. The second brood is larger than the first especially in years when a large immigration has occurred.

Status: This is a resident species but also a migrant. It is recorded from all lowland parts of N. Ireland, but is most common in the south and east reflecting the influence of migration on the local population. In the north and west and in upland areas the species is much more local or absent.

Ecology: The Large White is a non-colonial and strongly migratory species. Adults are highly mobile, searching the countryside for foodplants and nectar sources. In spring movements are generally northward. Adults fly strongly 1-2m above ground. It can be found in most open habitats but especially gardens and agricultural land. The foodplants are cultivated and wild members of the cabbage family especially cultivated cabbages and Nasturtium Tropaeolum majus. Caterpillars are communal and conspicuous grey and black with two yellow stripes. It overwinters as a pupa.

World Distribution: NW Africa, Europe, Asia Minor and Asia to the Himalayas

Bradley & Fletcher number: 1549 Agassiz number: 58.006

Additional information:

UK Butterflies account

Caterpillar: