HYMENOPTERA 943 



Subfamily A/[YRMICIN^ 



The Myrmicine Ants 



In this subfamily the pedicel of the abdomen consists of two 

 segments (Fig. 1178) and the frontal carinas cover the antennal in- 

 sertions. This is a large 

 subfamily ; more than 

 half of the species of ants 

 found in America north 

 of Mexico belong to it. 

 The following species will 

 serve to illustrate the re- 

 markable differences in 

 habits of its different Fig. 1178.— A myrmicid. 



members. 



The little yellow house-ant, Mononiorium pharaonis. — This is the 

 species commonly known as the "little red. ant" although it is light 

 yellow in color. It is the most troublesome of all ants that invade 

 our dwellings. When these ants build their nests within the walls 

 or beneath the foundations of a house it is almost impossible to dis- 

 lodge them. By trapping and destroying the workers their nimibers 

 can be lessened somewhat ; but so long as the queens are undisturbed 

 in their nests the supply of workers will continue. Sometimes the 

 nests can be reached by pouring carbon bisulphid into the crevices 

 from which the workers come. 



The thief ant, Solenopsis molestus. — This is a species with minute 

 yellow workers and much larger brown females and blackish males, 

 which is common in open grassy places, where it may have independent 

 nests under stones. But they often make burrows in the walls of 

 nests of other and much larger ants, from which they emerge to prey 

 upon the larv^ and pupae of the larger ants, which are unable to 

 follow them into their tenuous burrows. 



The harvesting ants. — Several genera of myrmicine ants feed on 

 seeds, and as they collect these seeds and store them in their nests 

 they are known as harvesting ants. It was to these ants that Solomon 

 referred. They have also been known as agricultural ants ; for it was 

 formerly believed that they sow around their nests seeds of the plants 

 from which they collect the grain that they use. But this has been 

 disproved. Most of our harvesting ants are confined to the warm 

 and arid regions of the Southwest, where insect prey is scarce and 

 the ants are compelled to feed on seeds. A single species, Pheidole 

 piltjera, which is a southern species, occurs along the coastal plain as 

 far north as Massachusetts. 



The shed-builder ant, Cremastogdster lineoldta. — In the tropics ants 

 belonging to several genera build carton nests attached to branches 

 of trees. One of these genera is Cremastogdster of which we have a 

 common species, C. lineoldta, in the Northern States and Canada. 

 This is a small ant, the workers measuring from 3 to 4. 5 mm. in length. 



