78 



POPULAR SCIENCE MONTHLY. 



have become gorged with food; this can be observed in the 



drawings. 



The cow of the yellow ant should not be confounded with her 



harmful cousin, Phylloxera vastatrix, the deadliest enemy of the 



grape. Fortunately for us, this 

 last-mentioned aphis does not 

 abound in the United States; in 

 France and other European coun- 

 tries, however, phylloxera has 

 occasioned the loss of millions of 

 dollars. 



Notwithstanding the fact that 

 the ants are exceedingly zealous 

 in guarding their property, many 

 of the aphides fall victims to the 

 assaults of their enemies. The 

 most cunning, insidious, and 

 crafty of their foes are the ich- 

 Lakva, Eggs, and Adult of Apih.- neumon flies, three varieties of 

 Lion ( Chrynopha). Slightly modified which are continually, during the 



from Com stock. , -.. 



summer months and m autumn, 



endeavoring to cradle their young in the bodies of the aphides. 



One of these flies, which can be seen in the drawing, is quite 

 large; I am inclined to believe, therefore, that their larvae do not 

 pupate in the bodies of their hosts, but undergo further metamor- 

 phoses elsewhere. Another of these flies is very small, hardly larger, 

 in fact, than the insect which it selects as a living cradle for its 

 young. The ichneumon shows rare intelligence, inasmuch as she 

 invariably deposits her eggs on the young members — the calves, as it 

 were — of the herd; she seems to know that the older aphides would 

 die before the ichneumon grubs arrived at a suitable age for pupa- 

 tion; hence she selects the young ones. She runs here and there 

 about the colony until she finds a young aphis; then, curving her 

 abdomen between her legs, she will quickly lay an egg on the body 

 of the unconscious insect. When the egg hatches the larva feeds on 

 the body of its host (carefully avoiding the vital organs, however) 

 until the time arrives for it to undergo further metamorphoses. The 

 animated cradle and cupboard eventually dies, but not until its 

 queer baby has arrived at an age at which it has no further use 

 for it. 



The ants are fully aware of the fact that the ichneumon is a 

 deadly enemy of their cows; hence, when one of these flies is seen 

 hovering over the herd, they at once become alert and endeavor to 

 chase her away whenever she alights. She manages, however, to 



