APHIS EUMICIS. 83 



Wholly black, very shining. Some specimens are 

 slightly ferruginous brown. Antennee short, stout, 

 black at the tips ; the middle joints and also the tibia, 

 amber-yellow. Wings short and coarse; insertions 

 yellow ; costa and stigma greenish ; other veins 

 brown. 



When the imago issues from the pupa the colour is 

 brown, and the cornicles and antennae are green. The 

 hue soon, however, changes to dusky, and then shining 

 black. Koch does not notice the white flecks on the 

 lDupa3, but Kaltenbach points out that in this respect 

 the pupjB of A. rumicis are like the pupa3 of Aphis 

 ]}a])averis and others. 



This Aphis greatly varies in its choice of food. Its 

 common food-plant is the curled dock Bumex crisinis, 

 and the thistle Gardtms lanceolatus, the flower stalks of 

 which are often hidden by the congregated thousands. 

 The stalks of the broad bean also are very liable to be 

 similarly encrusted by them, and then both the garden 

 and field crops are totally destroyed. In 1854 its 

 ravages in the turnip fields of Yorkshire were very 

 marked, many hundred acres being utterly ruined. 



Rustics give the name of the " collier " or the " black 

 dolphin " to this Aphis, as they do the " green dolphin " 

 to the pea Aphis ; and Kirby and Spence suggested the 

 name Phthiriasis for the diseased condition it brings 

 on vegetation. 



The oviparous female is very like the other apterous 

 form. According to Walker it very generally chooses 

 the common furze for hibernation. In the year 1846 

 these bushes were profusely dotted with her eggs. 

 The male is black and winged. 



The humble-bee, Bomhis, is said to visit this species 

 of Aphis for the sake of its secretions.* 



The elegant pale green brushes composing the flower 

 heads of the garden rhubarb, a plant of the same 

 natural family as our dock, is often made unsightly by 



* Vide " Migrations of Aphides," Walk., 'Ann. Nat. Hist.,' 1847, xli, 

 p. 373. 



