84 BRITISH APHIDES. 



a plentiful sprinkling of this black Aphis. It also 

 infests the shoots of the ivy, and once in early March 

 I found a small company sheltered within a curled 

 leaf of the holly, where probably the queen Aphis 

 or "stem-mother" had passed the winter. To 

 these food-plants may be added Polygonum ]jersi- 

 caria, Pucidanum palustre, Borago officinalis , Digi- 

 talis purpurea, garden marigold, and other culti- 

 vated plants. T have without success attempted to 

 transfer the Aphides feeding on the foxglove to the 

 common broom. I enclosed a flower-head of the 

 former, crowded with A. rumicis, within a fine netted 

 bag, and tied the same over a growing shoot of the 

 latter. The Aphides were in the apterous and winged 

 states. They refused to accommodate themselves to 

 the new food, and soon died, although the broom is 

 often much infested with a small variety of Aphis 

 rumicis. 



The almost omnivorous character of this insect 

 has misled some authors into making new species. 

 Walker gives twenty-three synonyms, and probably 

 there are more. 



Mr. Wallace seems to assign the first steps in the 

 acquisition of colour to the male, and ascribes this 

 change to some unknown law, dependant upon the 

 greater presumed activity of that sex. Climate and 

 character of food possibly have their influence in some 

 way affecting both size and form. Such influences 

 make a decided opinion very difiicult as to whether 

 certain Aphis forms uniformly found on different 

 plants are specifically one or not. Thus, variations of 

 A. rumicis occur on the furze, the broom,the euony- 

 mus, and the evergreen oak. They have all distinct 

 names, according to some authors. Aphis ulicis is 

 shining black and deeply pitted. Aphis genistce is dull 

 black with legs wholly black. Aphis euonynii, accord- 

 ing to some, is dull black with legs wholly luteous. 



The winged forms of these insects, however, cannot 

 be distinguished from the winged forms of A. rumicis. 



