INTERRELATIONS OF INSECTS 



2 95 



The honey ant whose habits are best known, through the studies of 

 McCook and others, is Myrmecocystus melliger, of Mexico, New Mexico 

 and southern Colorado. In this species some of the workers hang slug- 

 gishly from the roof of their little dome-like chamber, several inches 

 underground, and act as permanent receptacles for the so-called honey, 

 which is a transparent sugary exudation from certain oak-galls; it is 

 gathered at night by the foraging workers and regurgitated to the 

 mouths of the "honey-bearers," whose crops at length become dis- 

 tended with honey to such an extent that the insects (Fig. 289) look 

 like so many little translucent grapes or good-sized currants. This 

 stored food is in all probability drawn upon by the other ants when 

 necessary. 



Leaf-cutting Ants. The most dangerous foes to vegetation in 

 tropical America are the several species of A tta (Fig. 290, ^4). Living 



FIG. 290. A, leaf-cutting ant, Atta cephalotes. B, wandering ant, Eciton drepanophorum; 

 C, Eciton omnivorum. Natural size. After SHIPLEY. 



in enormous colonies and capable of stripping a tree of its leaves 

 in a few hours, these formidable ants are the despair of the planter; 

 where they are abundant it becomes impossible to grow the orange, 

 coffee, mango and many other plants. These ants dig an extensive 

 underground nest, piling the excavated earth into a mound, sometimes 

 thirty or forty feet in diameter, and making paths in various directions 

 from the nest for access to the plants of the vicinity; Belt often found 

 these ants at work half a mile from their nest; they attack flowers, 

 fruits and seeds, but chiefly leaves. Each ant, by laboring four or five 

 minutes, bites out a more or less circular fragment of a leaf (Fig. 291) 

 and carries it home, or else drops it for another worker to carry; and 

 two strings of ants may be seen, one carrying their leafy burdens toward 

 the nest, the other returning for more plunder. 



The use made of these leaves has been the subject of much discus- 

 sion. Belt found the true explanation, but it remained for Moller to 

 investigate the subject so thoroughly as to leave no room for doubt. 

 The ants grow a fungus upon these leaves and use it as food. The bits 

 of leaves are kneaded into a pulpy, spongy mass, upon which the 



