142 BRITISH APHIDES. 



eggs. Its colouring is not unlike that of tlie vivi- 

 parous female, but the hind tibiee are dilated. 



Walker describes the pupa of the male as crimson 

 in colour. The winged male occurs in October. 

 The body is yellow, the thorax and head brown. The 

 wings large, and strongly veined. The cubitus and 

 stigma brown. 



Taken at Chichester in June, by thousands, on the 

 leaves and young shoots of the garden-plum ; the 

 shoots being encrusted for six or eight inches by the 

 larvtS. A few scattered winged forms nestled under 

 the leaves even at this early date. The trees most 

 commonly affected, however, are the white and black 

 poplars, Populus alba and P. 7iigra. Kaltenbach says 

 also it feeds on P. tremula and P. dilatata. 



The form of this insect somewhat differs from the 

 rest of the genus, and Walker proposed a new genus, 

 Arctajihls for its reception. 



Genus XIII. PTEROCOMMA,* Bucldon. 



Vertex rather flat, frontal tubercles none. 



Antennge short and seven-jointed. The third joint 

 the longest, and the seventh about equal to the sixth. 



Body long and oval. 



Cornicles short and cylindrical, but longer than in 

 Hyalopterus and Chaitopl torus. 



Rostrum rather long. 



Legs moderate. 



Wings very long and somewhat narrow ; the costal 

 and submarginal veins much incurved. 



Cauda very small. 



As yet this genus is represented only by one species, 

 which has several characters pertaining to the genera 

 Aphis, Hyalopterus, and Gallipterus. 



* Froiu TTTfpbv, a wing ; Kofj/xct, an iucision or notch. 



