Wood white butterfly (Leptidea sinapis)
|Size||Wingspan: up to 50 mm|
UK BAP status: Species of Conservation Concern. European threat status: not threatened. Protected in Great Britain for sale only.
The wood white butterfly is a rather delicate-looking species, often overlooked along with other members of the white butterfly family. It is creamy-white with grey tips to the upper-forewings, and has grey veins on both upper and hindwings.
In the UK, this species is found largely in scattered populations in the south of England and in Ireland. It is more widespread in Europe, as far as latitude 66ºN in Scandinavia, and its range extends eastwards to the Caucasus Mountains and Siberia.
The wood white seems to show a preference for rough, un-managed pastures and shaded woodland edges, although it also occurs around coastal cliffs.
This butterfly lays its eggs on members of the pea family, particularly meadow vetchling, tufted vetch, greater bird's-foot-trefoil, common bird's-foot-trefoil and bitter-vetch. The eggs are laid in May, when the first brood of butterflies are on the wing, and they hatch in July. The wood white caterpillar is green with small black dots and has darker green stripes edged with yellow.
The male butterfly is more likely to be seen flying than the female. He searches for suitable mates along woodland rides and around the edges of scrub. Females spend most of their time feeding from flowers and, when the male finds a female, he performs a courtship display, nodding his head to and fro with his long tubular tongue extended.
Although never more than locally common, the wood white butterfly has declined severely over much of its UK range, especially in the north where it once occurred in much larger numbers. The main reasons are thought to be loss of the un-managed woodland habitat, greater levels of shade in woods and inappropriate management of woodland rides. The butterfly does not establish new colonies easily, and will not fly between isolated patches of suitable habitat.
Although there is no UKBAP action plan for the wood white, it has been identified as a Species of Conservation Concern. A number of conservation organisations, including Butterfly Conservation and English Nature, have prepared an action plan detailing the problems associated with this species. The principle concerns are to limit the decline of the butterflies’ populations and to research suitable woodland management for this species. Isolated colonies that are at risk of local extinction require special attention to ensure their survival.
Information supplied by English Nature.