94 - BRITISH APHIDES. 



Aphis instabilis, Bucldon. Plate LXVIII, figs. 1 — 5. 

 Apterous viviparous female. 



Incli. Millimetres. 



Size of body 0-050x0-025 l-27x0-62. 



Length of antennae 0030 0*76. 



cornicles O'OIO 0-25. 



Exceedingly variable as to colour, often pale 

 oclireous, yellow, green, or ferruginous red. Oblong. 

 Head very broad. Eyes brown. Dorsum much 

 furrowed. Cornicles very pale. Cauda small, pilose. 

 Legs short, stout, ashy grey. Two small tubercles 

 occur on the antipenultimate ring. 



Pupa,. 



Yar. 1. — Wholly pale yellow. Thorax deeply fur- 

 rowed. Nectaries pale, with black tips. Cauda 

 black, obtuse. Wing-cases black. Legs sooty-grey. 

 Abdomen slightly hoary, from a grey covering of white 

 powder. 



Var. 2. — Head and thorax ferruginous. Abdomen 

 bright green. Legs very pale yellow. Wing-cases 

 luteous. 



Winged viviparous female. 



On first emerging from the pupa, pale green. Head, 

 thorax, and band on the prothorax black. Eyes red. 

 Abdomen domed, with four pale spots on each carina. 

 Cornicles and tail pale yellow or green. More mature 

 specimens are ferruginous red. Head, thorax, and 

 the greater part of the abdomen black. Cornicles and 

 tail black. Legs reddish, with black femoral and 



