THE PEARL-BORDERED FRITILLARY 
95 
the most suitable for the 
health of the larvae, as they 
produced the greatest number 
of survivors. A brood of 
larvae which attained their 
hibernating stage by the mid¬ 
dle of June all stopped feeding 
and entered into hibernation, 
although at times they were 
subjected to very high tem¬ 
peratures ; some were kept in 
a temperature rising as high as ioo° for several days, but they 
all persistently hibernated. 
The larvae start emerging from hibernation from about 
the middle of March when the weather is sufficiently warm, 
and they become active when the temperature reaches 52° 
with sunshine. 
The larva attains full growth after its fourth moult and 
when 330 days old ; it then measures from 22 mm. to 25 mm. 
long ; it tapers slightly towards the head. The ground colour 
of the dorsal surface is black, and the ventral surface smoky- 
brown ; the entire surface above the spiracles is freckled 
with indistinct greyish markings and speckled with extremely 
minute white dots ; along each side is a broad checkered 
black and white spiracular band. There are six longitudinal 
rows of rather short, conical, but sharply-pointed spines, each 
bearing a number of finely-pointed bristles. The larvae vary 
in respect to the colour of the dorsal spines ; in some they 
are entirely black, in others the basal half of each spine is 
bright lemon-yellow. They 
feed during the day, at night 
they rest away from the plant. 
A larva kept under careful 
observation from the time it 
hatched from the egg to pupa¬ 
tion occupied 330 days. It 
pupated on May 24th and the 
butterfly emerged on June 2nd, 
remaining only nine days in 
the pupa. 
The Pearl-bordered Fritillary (ab. 
captured in the New Forest, 1912). 
The Pearl-bordered Fritillary (ab. 
captured in the New Forest, 1914). 
