ANTS AS DOMINANT INSECTS. 9 



ground and capture myriads of living insects and their larvae. So 

 efficient are they in exterminating all kinds of vermin, including rats 

 and mice, that they are welcomed into the houses, even if their owners 

 are obliged to vacate for the time being. In some countries, the ants 

 are regarded as useful allies in destroying the insect pests of planta- 

 tions. According to Magowan, quoted by McCook (1882) : " In many 

 parts of the province of Canton, where, says a Chinese writer, cereals 

 cannot be profitably cultivated, the land is devoted to the cultivation of 

 orange-trees, which being subject to devastation from worms, require 

 to be protected in a peculiar manner, that is, by importing ants from 

 the neighboring hills for the destruction of the dreaded parasite. The 

 orangeries themselves supply ants which prey upon the enemy of the 

 orange, but not in sufficient numbers ; and resort is had to hill people, 

 who, throughout the summer and winter, find the nests suspended from 

 branches of bamboo and various trees. There are two varieties of 

 ants, red and yellow, whose nests resemble cotton bags. The orange- 

 ant feeders are provided with pig or goat bladders, which are baited 

 inside with lard. The orifices they apply to the entrance of the nests, 

 when the ants enter the bag and become a marketable commodity at 

 the orangeries. Orange-trees are colonized by depositing the ants on 

 their upper branches, and to enable them to pass from tree to tree, all 

 the trees of an orchard are connected by a bamboo rod." 



Many years ago McCook suggested that foreign ants might be 

 advantageously introduced into our country for similar purposes. 

 This suggestion was apparently followed by the Department of Agri- 

 culture when it recently introduced a Guatemalan ant, the " kelep " 

 (Ectatomma tubcrculatum } into Texas for the purpose of destroying 

 the very injurious cotton-boll weevil. This experiment resulted in 

 failure owing, as I have shown (19040, 19046), to the selection _of 

 an inappropriate species. Notwithstanding this failure, McCook's 

 suggestion still merits careful consideration on the part of economic 

 entomologists. 



The activities of ants in excavating their nests have a very useful 

 aspect. Most of the species, especially in temperate latitudes, nest in 

 the ground, and many of them in so doing are obliged to comminute 

 and bring to the surface, often from a depth of several feet, consider- 

 able quantities of subsoil. This is spread over the surface either by the 

 elements or by the ants themselves and exposed to the sun and atmos- 

 phere. The burrows, moreover, quickly conduct air and moisture into 

 the deeper recesses of the soil. Thus the ants act on the soil like the 

 earthworms, and this action is by no means inconsiderable, although as 

 yet no one has studied it in detail. The common garden ant (Lasius 



