This very widespread species is similar to the small white but
unlike that species not a pest of commercial or domestic cabbages. It
is often the first non-hibernator to
emerge in the spring and remains common in a variety of habitats -
usually partly shady or on the edge of woods - throughout the year
until the
autumn.
The green colour of the veins on the underside hindwing is an
illusion created by black scales on a yellow ground. The amount and
intensity of this dark scaling is very variable, as the pictures above
show. It is usually very obvious in the first brood of the year but
generally much weaker in later broods. Sometimes the pattern is almost
imperceptible, being reduced to a vague shadow around some veins. The
upperside, in contrast, is more strongly marked in later broods. Unlike
that of the small white, the dark apical mark extends further down the
outer margin than along the costa, but unlike that of southern small
white, it does so in broken form, often looking like a succession of
diminishing triangles.
The female is generally easily distinguished from the female mountain
green-veined white. The latter is heavily suffused in grey on an often
yellowish ground. Males are not so easy. Because both species are
usually common where found and rarely, if ever, overlap, it generally
suffices to wait for a female to appear to confirm the species. If no
females turn up, other clues like habitat, altitude and season are
useful - mountain green-veined white, as the name suggests, is a
mountain butterfly of more open habitats. Sometimes it is possible to
recognise a male green-veined white as not
being mountain green-veined white, because the former is variable while
the latter is not. But some male green-veined look identical to the
normal mountain green-veined form.
Like its close cousins, the green-veined white spends the winter as a
chrysalis. The caterpillars feed on a wide variety of wild Brassicaceae.
