THE WALL BUTTERFLY 
49 
surface is granular, with a network pattern, becoming more 
regular round the middle and forming parallel longitudinal 
rows, giving it a slightly fluted appearance with transverse 
ribs, but to the naked eye the surface appears quite smooth. 
When first laid, the colour is a yellowish-green-white, and 
remains unchanged until shortly before hatching, when it 
becomes semi-opaque, encircled with black and grey streaks, 
produced by the long black hairs of the larva showing through 
the shell, and the crown is blotched with dark leaden-grey 
and ochreous. 
Larva. As soon as the young larva emerges from the egg, 
it eats the empty shell, and directly it has finished, it starts 
feeding on the grass blade upon which the egg was laid. 
The larva attains full growth after the third moult; it 
measures when fully grown 24 mm. long. The ground colour 
of the head and body is a rich green with a slight bluish tinge ; 
there is a medio-dorsal darker green stripe, bordered on each 
side by a very fine whitish line, and three pale indistinct lines 
at equal distances apart along the side, on the lower one are 
placed the pale orange spiracles ; below is a whitish stripe 
bordered by fine dark lines. The legs are whitish-green, the 
claspers green, and the anal points light green. Both head 
and body are covered with minute white warts, each emitting 
a fine hair, giving the body a somewhat rough, downy 
appearance. 
When ready for pupation, it spins a small pad of silk on a 
grass stem, and attaching itself by the anal claspers, hangs 
in the form of a hook and remains in this attitude for about 
forty hours, and then pupates. The larval state lasts about 
35 days. 
Pupa. The average length of the pupa is 15’9 mm. The 
head is rather broad and angular in front; the thorax is 
swollen and keeled dorsally, sunken at the waist; the dorsal 
outline of the abdomen is a gentle curve, and the ventral 
outline nearly straight. Along the dorsal surface are two 
rows of white stud-like tubercles; the spiracles are whitish ; 
along the abdomen is a medio-dorsal and a sub-dorsal stripe 
darker than the ground colour, also a paler lateral line. The 
surface is sprinkled with creamy-white granulations, especially 
along the wing nervures. The pupa is extremely variable in 
B.B. 
D 
