APHIDID.l-:. 



279 



Pemphigus buhsaiuus (Hart.) 



This species is found on the leaf-stalks of poplar (fig. 2G1), chiefly 

 on the black Italian species, the black burry poplar, and also on the 

 young woody twigs of the Lornbardy pop- 

 lar. The gall is smooth, globular, highly 

 coloured, and with an opening at the side. 

 In July or August the leaves, with galls on 

 the foot-stalks, having fallen prematurely, 

 may be jiicked up, and the insects found 

 in all their respective stages of metamor- 

 phoses. 



The stem-mother (fig. 262) is larger than 

 any of her progeny. The legs are short, 

 and the creature comparatively helpless. 

 The antennff are four-jointed, and the corn- 

 icles absent. 



The larva (fig. 263) is of a very light- 

 green colon i\ 



The pupa (fig. 264) is of a pale-green 

 colour, with a slight mealy dusting, and shows signs of wings at a 

 very young stage. The antennae are longer than in the green aphis, 

 but the joints are not easily distinguished. 



g. ii\\.-<U:n oil Uaf-Malk of 

 pnplar mused by Peiiipliigus 

 bursarius. 



Pig. 26: 



•■•-./Ppmiiliigusbur 

 a-liicida skcloli.) 



■M:i. — Ldri'al staiji' 0/ Pempliigns bur- 

 ns. (l''rniii camera-luciila sketch.) 



The winged viviparous female (fig. 265) is black, and the body and 

 wings are dusted over with a white powdery matter. The antennae are 

 six-jointed, the third joint being the longest ; and the third, fourth, 

 fifth, and sixth are ringed. Buckton says the sixth joint is smooth, 



