APPLE LEAVES, APHIS ATTENDANTS ANTS. 61 



rine matters are kept, and it is for the purpose of feeding upon 

 the honey-dew that the aphides secrete so copiously that they are 

 such constant attendants upon these insects. The mode in which 

 they obtain this from the plant-lice is quite interesting; with 

 their long flail- shaped antennae they gently touch the backs of the 

 plant-lice, whereupon these eject this sweet fluid, which stands in 

 the form of a small clear drop at the tip of one or both of the 

 nectaries or little horns towards the end of their bodies. This 

 the ant immediately sips, and by passing from one aphis to an- 

 other he obtains his fill of this delicious sweet. A family of ants 

 is thus supplied with an important part of its nourishment by dis- 

 covering a tree on which the aphides have located themselves, 

 and thereafter one after another of the ants may always be seen 

 passing up and down the trunk of the tree. Plant-lice have hence 

 been styled the kine or cattle of the ants, as they come to them 

 regularly to milk them as it were, and in return for this savory 

 food which they furnish the ants, some of the latter remain con- 

 stantly by them night and day to protect these small weak crea- 

 tures from being molested by their insect or other enemies. Thus 

 before we are able to inspect a colony of plant-lice we are first 

 obliged to brush off or destroy the ants which are guarding them, 

 and T have frequently noticed that when a colony of aphides 

 is newly established, and before it has been found by these in- 

 sects, it remains small and does not thrive and increase so rapidly 

 as when nursed and guarded by these industrious heroic creatures. 

 Thus a colony of the Cone-flower plant-louse (Aphis Rudbeckice) 

 a species which I described in the Fourth Report of the State 

 Cabinet, page 66, which has been established more than a fort- 

 night upon a stalk of golden rod (Solidago) near my door, al- 

 though it has not been molested by any destroyer, numbers only 

 twenty-five individuals, and these are scattered about upon the 

 stalk and leaves, seemingly pining in want of their accustomed 

 attendants to herd and nurse them. 



The species of ant which I have most frequently met with, asso- 

 ciated with plant-lice upon the apple tree, is a large black ant, 

 with a dark red thorax, and is very similar in its size and colors 

 to the wood-eating ant, (Formica hcrculeana, Linn. F. lignivcra. 



