HYMENOPTERA 



361 



One of the characteristic harvesting ants of this country is Pogond- 

 myrmex barbatus and its subspecies. It occurs in Texas and is known as 

 the " agricultural ant." It forms rather large colonies and its nest pre- 

 sents a bare, circular area from five to ten feet in diameter produced by 

 destroying all of the plants around the central opening. The sting of 

 this ant is as severe as that of the bumblebee and its bare areas in fields 

 of alfalfa, corn, and cotton bring about considerable loss to the farmer. 



The shed-builder ant, Crematogaster lineolata. — In the tropics, ants 

 belonging to several genera build carton nests attached to branches of 

 trees. We have this one common species in the Northern States and 

 Canada. This is a small ant, the workers measuring from § to £ of an 

 inch in length. It is usually yellowish-brown, with a black abdomen; 

 but it varies greatly in color. Its favorite nesting-place is under stones 

 or underneath and within the decayed matter of old logs and stumps. 

 Out of this material the ants sometimes make a paper-like pulp with 

 which they build a nest attached to the side of a log, or even to the 

 branches of a shrub at some distance from the ground. While such nests 

 are uncommon these ants often build small sheds at some distance from 

 the nest, over the herds of aphids or coccids from which they obtain 



Fig. 604. — A "cow-shed" built by ants. (From A. B. Comstock, Handbook 

 of Nature Study.) 



honey-dew (Fig. 604). In these cases the aphids or coccids are huddled 

 together on a branch, from which they are deriving their nourishment, 

 and are completely covered by the " cow-shed " built by the ants. 



THE FUNGUS-GROWING ANTS 





Among the many remarkable examples of insect behavior none is 

 more remarkable than the habits of the fungus-growing ants. These ants 

 cut pieces of leaves from various plants and carry them to their nests 



