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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 larvae to feed on the willows with long and 

 smooth leaves {S. alha, &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 Coccinellidse. 



The young larvre 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 pupae 

 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 shghtly. 



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: — Larvae 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, 1913, 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 {I. c.) makes the interesting remark that larvae which he 

 found on Salix aurlta refused to eat S. caprea, although other larvae laid on 

 the latter took it quite readily. 



The John Innes Horticultural Institution, Merton, Surrey. 



