APHIS MALI. 45 



Apterous viviparous female. 



Inch. Millimetres. 



Size of body O-llOxO'OSO 2-79x2-02. 



Length of antenna9 0'050 1'27. 



cornicles 0-010 0-25. 



This insect varies so much in form and colour that 

 it almost may be considered as dimorphous. The 

 first progeny from the Qgg, when full grown, called 

 Altmiitter by Koch, is considerably larger than the 

 insects subsequently born of her. The adult queen 

 Aphis or stem-mother is thus described : 



Body globose, domed, of a dark slaty grey, mottled 

 with green. Head, neck, and thorax distinctly 

 separated. Abdomen globular and soft ; each segment 

 is furnished with a minute spine at each edge. An- 

 tennae and legs short, dark grey. Cornicles black and 

 inconspicuous, as also is the tail. Eyes dark brown. 



The subsequent viviparous broods have a variety of 

 colours, as bright green, yellowish, ferruginous red, or 

 brown. Probably these tints in great measure are 

 dependent upon the more or less recent stages of 

 growth after a moult. Their form is considerably 

 more oval than that of the first spring form, from 

 which, indeed, they so much differ, that, if the indi- 

 viduals were not indifferently mixed and feeding 

 together on the same leaf, we might hesitate to think 

 them of the same species. 



The synonyms of this insect are very numerous 

 and much involved. The American forms seem to be 

 equally variable. 



The Pupa. 



This much resembles the larva in form, but usually 

 its colour is paler yellow, with three green abdominal 

 stripes. The head shows two rudimentary stemmata 

 between the antennas, which become developed only in 

 the imago. Wing-cases reddish. Cornicles yellow, 

 tipped with brown. 



