10 THE ARGENTINE ANT. 
and assistance in experiments carried out in the infested orange 
districts. 
GENERAL CONSIDERATIONS. 
Twenty years ago the Argentine ant was first noticed in New Or- 
leans, La., by Mr. Edward Foster, reference to whose interesting 
account of the ' i Introduction of Iridomyrmex Tiumilis Mayr into New 
Orleans" will be found on a subsequent page. The species had 
doubtless been introduced years before that time, but was gathering 
strength and establishing itself for a considerable period before its 
numbers became sufficient to attract attention. Mr. Foster men- 
tions it as occurring in 1891 in "fair numbers." Since then it has 
increased from a few scattered and apparently insignificant sped- 4 
mens to armies and hordes numbering myriads of individuals. It { 
has spread from a few blocks on the water front of the Mississippi 
River over practically the entire city, and has sent out vast numbers 
of colonists for hundreds of miles along the railways and waterways 
radiating from New Orleans. These pioneers have succeeded in 
founding scores of communities of more or less importance in the v 
smaller cities and towns. Each of these communities is in turn , 
furnishing its quota of migrants, and these are extending the affected 
territory in all directions from the original source of infestation. 
Thus, instead of the dispersion being from one source only, it is now 
taking place from hundreds of different points. From an unknown 
and little noticed insect this ant has developed into one of the fore- ] 
most household pests in the world, and its ravages affect, directly or 
indirectly, the majority of the crops grown in the South. Former 
indifference to its movements has given way to concern at its approach, 
which, in the orange belt at least, means heavy depreciation in the 
value of property. 
Continuous study for several years has served to enlighten us on 
most of the salient features in the life history and economy of the i 
species. A considerable number of poisons and repellents have been 
tested and have given good results. Methods of isolating, ditching, • » 
and winter-trapping have been devised, and have proved their prac- 
tical value in large experiments under field conditions. 
Just how much territory this ant will ultimately infest we can not 
foretell with accuracy from the data at present available. It is i 
quite safe, however, to venture the opinion that the species will 
eventually spread over a considerable portion of the Southern States — 
certainly over all of the orange and sugar-cane belts, and perhaps over 
all of the cotton belt. In California it is likely to cover the territory 
corresponding in temperature to the belts mentioned for the South, 
which will include the belts occupied by oranges and other tender 
fruits. 
