300 
PIERIDAE 
black ; the point of the beak and dorsal keel are variegated 
with yellow; the spiracles are also yellow. When the pupa 
is attached to the food plant, it is more or less of a green 
colour to harmonise with its surroundings. The green form 
is usually only sparsely speckled with black. It is attached 
by a silken cincture round the middle and by the cremastral 
hooks to a pad of silk. The pupal state varies according to 
the broods. Those producing the summer emergence of 
butterflies remain in pupae only about fourteen days, while 
the pupae that go through hibernation live for eight months. 
Imago. The wing expanse of the male averages 63 mm. ; 
the female is larger, sometimes expanding 76 mm. The sexual 
difference is very dis¬ 
tinct. The ground col¬ 
our is lemon-yellowish- 
white ; the apex of the 
fore wing is broadly 
margined with grey or 
black in the spring 
brood, and usually with 
black in the summer 
brood ; there is a black 
spot on the costal mar¬ 
gin of the hind wing ; 
the bases of the wings 
are more or less dusted 
The Large White (Female 
ab. fasciata, 25.7.1906. R . Adkin coll.) 
with black scales, which also run along the costa of the 
fore wing. The head and front of the thorax is clothed 
with olive-yellow, blending into greyish over the rest of the 
thorax and abdomen; the antennae are black The female 
differs in having the hind wings more tinged with yellow and 
two additional round black spots near the middle of the fore 
wing, also a club-shaped black mark along the inner margin. 
In the spring brood, known as ab. chariclea, the apical 
markings on the fore wings are usually much greyer than 
those of the summer -brood, which are generally black and 
often more heavily marked. 
The under side of both sexes is similar. The fore wing is 
white with a pale ochreous-yellow apex, and there are two 
black spots near the middle of the wing. The hind wing is 
