Hertfordshire & Middlesex Branch

Green-veined White

Pieris napi

Widespread and common resident

Distribution and Status

This butterfly is very widespread and common in our branch area. Little change in range and abundance since the 1980s although it now appears to be absent in some parts of north-east Hertfordshire. On the other hand, there are more reports in central Middlesex than previously. It is not a garden pest and is more associated with wooded and damp areas than the other 'whites'

Habitat Requirements

In many habitats but prefers woodland edges, hedgerows and damp meadows. It is much scarcer on dry chalky soils

Larval Foodplants

Garlic Mustard Alliaria petiolata, Hedge Mustard Sisymbrium officinale, Cuckooflower Cardamine pratensis in first brood, Watercress Nasturtium officinale. [Horse-radish Armoracia rusticana, Rape Brassica napus and other Brassicaceae plants]

Adult Food Sources

Buddleia Buddleja davidii, Garden Lavender Lavandula x intermedia, Bramble Rubus fruticosus agg.

Behaviour/Observation notes

The Green-veined White is often seen in the same places in the wider countryside as the Small White although it is more common in the damp and sheltered areas. Its weak and fluttery flight helps to identify this butterfly on the wing to experienced observers but the best way to distinguish the two species is by markings on the wings especially on the undersides where the green veins are characteristic of this species. Pairings of this butterfly are probably more often observed than of the Small White in the wild

Life History

The Green-veined White overwinters as a pupa and emergence of the adults usually starts in April. The second generation is nearly always greater than the first with the highest numbers often occurring in late July and early August. It has been known that some pupae from the first generation stay in diapause until the following year. Small, fresh plants are selected for egg-laying on the underside of a leaf. Larvae feed on the leaves of the foodplant. When fully-grown pupae are formed generally away from the foodplant close to the ground

Further information

Photo gallery
Branch Annual Report (2023)
UK distribution map
Full list of larval hostplants (Pieridae)
Stevenage butterflies - additional notes
Account for 2022