250 THE ENTOMOLOGIST. 
broad-leaved sallows (Salix caprea, cinerea, &c.), on the upper 
side of which they lay their young, but I could get neither the 
adults nor the larve to feed on the willows with long and 
smooth leaves (S. alba, &c.).* The young all appear to mature 
at the same time, and are laid, if the female is not disturbed, in 
one batch. The number in one family varies from twenty-eight 
to forty. With one doubtful exception, none of the thirty 
females from which I obtained young laid a second batch, as 
occurs, for example, in the Coccinellide. 
The young larve when first laid are orange yellow, but they 
rapidly darken and become quite black. The larva, at least 
when older, has a pair of dorsal, protrusible vesicles close 
together between the seventh and eight abdominal segments. 
They are pink in colour and can be extended about one-twelfth 
of an inch when the larva is disturbed. The larva is full-fed 
in about fifteen days, when it descends to the ground and 
becomes quiescent; it is not till four to six days later that the 
bright orange pupal stage is assumed. The sexes of the pup 
can be easily distinguished both by the size and by the form of 
the ventral surface of the last two abdominal segments. Shortly 
before emergence the legs and head, the centre of the prothorax and 
the scutellum become quite dark, and the wings darken slightly. 
The adults emerge after about twelve days, the total time 
from the laying of the young larva being about thirty-three 
days. Actual dates are as follows:—Larve laid, May 15th; 
full-fed, June 2nd; pupated, June 8ih: emerged, June 20th. 
The adults then remain for the whole of the rest of the year on 
the sallows without producing a second brood; hibernate, 
probably among the dead leaves, &c., on the surface of the 
ground, and emerge again in the following spring, when they 
pair and lay the young of the next generation. 
The original parents, having laid their young in May, 
continue feeding and survive for the rest of the year, so that 
from the end of June onwards there are adults of two 
generations together on the plants. Several females which laid 
young in May, 19138, and which therefore emerged from the 
pupa in June, 1912, were still alive in November, 1913, giving 
an adult life of at least eighteen months. All, however, 
perished during the winter. 
I hope next year to study the life-history in more detail, and 
also recommend to anyone the observation of the method of 
reproduction of allied species. I should be much indebted to 
any reader who could let me have living adults of P. rufipes in 
the spring. 
** Cornelius (J. c.) makes the interesting remark that larvee which he 
found on Salix aurita refused to eat S. caprea, although other larvee laid on 
the latter took it quite readily. 
The John Innes Horticultural Institution, Merton, Surrey. 
