Butterflies of Britain
Real's Wood White
Cryptic Wood White
Family - PIERIDAE
Leptidea sinapis, 1st brood male,
When seen in flight, it's possible to confuse this butterfly with a
Green-veined White, female Orange tip, or a Small White, but when
settled the differences in the markings are obvious. There are also
differences in the flight patterns. The
other "whites" have a direct and much more
purposeful flight, and they regularly settle to rest on leaves. The
Wood White however floats delicately and aimlessly at an almost
constant height just above the herbage, and in sunny conditions is
very reluctant to settle, even for a moment.
Male Wood Whites can be recognised by the heavier black markings on
the apex of the upperside forewings, and by the prominent white
patch on the underside of the antennae clubs.
Leptidea sinapis, female at common
spotted orchid, Dorset ©
There are several Wood White species found in
Wood White Leptidea
sinapis is found throughout Europe including Britain and
northern Ireland. It also occurs across much of temperate western
Wood White L. morsei is found in
s.w. Europe and across temperate Asia to Japan.
Eastern Wood White
L. duponcheli occurs from s.w. France to Iran.
Real's Wood White L.
reali is restricted to south-west Europe.
Cryptic Wood White
L. juvernica was formerly considered to be a race of
reali but DNA analysis has now shown it
to be a valid species. It is confined to the Republic of Ireland.
sinapis and reali cannot be
distinguished visually - identification can only be satisfactorily
determined by DNA analysis.
Leptidea sinapis, at roost on orchid,
Europe the Wood White is adapted to breed in a diverse range of
habitats including alpine meadows, woodlands, roadsides, gorges and
heaths, but in Britain, at the edge of it's range, the butterfly is
much fussier. The larval foodplants are common and widespread, but
the butterfly is very localised, confined to a small number of sites
in southern and central England.
In Surrey, Sussex and the Midlands the butterfly is highly
localised, occurring in a few of the larger coniferous woodland
complexes where it breeds in recently opened clearings,
and along ride edges. In Dorset, Northants and Oxfordshire it
occurs along disused railway cuttings. In the west Midlands it
breeds in old meadows adjoining woodland. In Devon it is found along
scrubby undercliffs near Lyme Regis. In north-east Hampshire there
are occasional sightings from a heathland / woodland mosaic, but
whether these are natural or the result of attempted introductions
The features that these sites have in common are that they are warm,
sheltered, damp, and have the larval foodplants and nectar sources
growing in profusion.
In the early 20th century the butterfly was far more widespread, but
has become far scarcer since the virtual cessation of coppicing and
the abandonment of hay meadows. At woodland sites where ride
widening, scalloping of ride edges and creation of semi-permanent
glades has been undertaken numbers have increased dramatically. It
is unlikely however that the butterfly will recolonise sites from
which it has already been lost, as it is a far from mobile species,
and will not venture away from it's isolated breeding sites in
search of new habitats.
In Surrey and West Sussex the butterfly
double brooded, the first brood emerging as early as late April, or
more typically in May; and the second
( partial )
brood emerging in late July or early August.
In south Devon the butterfly is always
double-brooded. Elsewhere in
is always single-brooded, emerging in May, and remaining on the wing
until late June or early July.
egg, like that of other Pierids, is
skittle-shaped, ribbed, and shiny. It is whitish in colour, and laid
singly on the underside of leaves of various vetches and trefoils. The
plants chosen are usually at the forest edge, and are typically shaded
for between 25-50% of the day. Most eggs are laid along east-west
rides, often in situations where flowery embankments rise behind
Leptidea sinapis, 1st brood female ovipositing on
Lotus corniculatus, Surrey ©
foodplants used vary from site to site and from brood to brood. At
Tugley Wood in Surrey for example the first brood oviposits almost
exclusively on bird's foot trefoil
while the second brood
lays on greater bird's foot trefoil
Lotus uliginosus. At nearby Kings
Park the eggs are laid much more commonly on bitter vetch
Lathyrus montanus; and at sites in
Dorset and Northants, meadow vetchling
L. pratensis or tufted vetch
Viccia cracca seem to be favoured.
caterpillars hatch after about 2 weeks but are heavily parasitised by
tine Trichogramma wasps which devour the
developing larva before it is able to hatch.
fully grown caterpillar is thin, pale green, with
a yellow line along each side, and a dark green
line along the back. It rests by day along the midrib of the
leaves, or on the stems of it's foodplants, and feeds mainly
nocturnally, leaving characteristic nibble marks on the edges of the
The chrysalis, like
that of the Orange tip, is pointed at both ends,
boomerang-shaped, and slightly flattened. It is pale
yellowish-green, with a thin pink line running down each side, and
is attached by the cremaster and a silken girdle to a grass stem,
close to the foodplant.
chrysalis in the wild is very difficult, as the camouflage is
superb. The easiest way to find it is to mark oviposition sites, and
to revisit and carefully search them in the winter, when the foliage
has died back.
Hibernation occurs during the pupal stage.
Whites visit a wide range of nectar sources including greater
stitchwort, bird's foot trefoil, wood forget-me-not,
spotted orchid, bugle and
vetch. Males can also sometimes be seen "mud-puddling" - imbibing
mineralised moisture from damp ground; and are occasionally observed
visiting herbivore dung.
sunny mornings males
patrol back and forth along woodland rides and around the edges of
clearings in search of newly emerged females.
Often copulation takes place before the female has had time to fully
expand her wings. The courtship process is very brief. The male
settles facing the female, and uses his proboscis to alternately whip
each hindwing of the female.
While this is taking place the female bends her antennae backwards as
if cowering in front of the male. A virgin female will usually respond
a moment later by lowering her abdomen and curving it forward.
Copulation then takes place and lasts for about 2 hours.
If however a male encounters a female that has previously mated,
something very odd happens. The females of almost all other butterfly
species have evolved rejection signals to make it clear to male
pursuers that they are unreceptive to their advances. In the case of
other "whites" such as Pieris brassicae
or Anthocharis cardamines an unreceptive
female will partially open her wings and raise her abdomen at an angle
of about 45%. Males of these species will usually persist for a few
seconds, but soon realise that they are onto a loser and fly off in
search of other females. In the case of the Wood White the females
have apparently not evolved a "no-go" signal. Consequently males do
not "understand" that they have been rejected. No amount of proboscis
whipping, wing-flicking or other attempts a stimulating the female
will produce any response. The female just sits there and waits half
an hour until the male eventually gives up.
Leptidea sinapis, 1st brood ( males on
right ) ©
Overnight, and in dull weather, the butterflies roost in sheltered
spots, often in little groups of 2 or 3, typically on the white
flowers of stitchwort,
the flowers of pendulous sedge or cock's
Leptidea sinapis at roost on greater stitchwort, Surrey /
Sussex border ©