October, "09] JOURNAL OF ECO>>'OMIC ENTOMOLOGY 325 



has not proceeded far enough so that we can chiim to have "found a 

 remedy," as our correspondents would say. but in the course of two 

 years of observation certain simple measures for protecting residences 

 and food stuffs from the annoying inroads of the pest have presented 

 themselves. 



As one of the writer's assistants. ]Mr. T. C. Barber, has recently 

 found infestation by this ant exceedingly heavy at Delta, La., a point 

 on the Mississippi River opposite Vicksburg, Miss., with an elevation 

 of 87 feet and 325 miles above the mouth of the Mississippi, there 

 seems no longer any reason for not considering all of the Gulf States 

 subject to future infestation by this pest. The problem is therefore 

 one in which all southern entomologists are interested, and its novelty 

 is likely to appeal to those entomologists whose sphere of activity is 

 at present outside the territory likely to be invaded. 



It is for relief from the Argentine ant as a household nuisance 

 that most requests are made by correspondents. There is therefore 

 ample excuse for presenting to the economic entomologists at this 

 time a brief account of those measures which have been found to pos- 

 sess more or less utility in dealing with this pest. 



Sufficient has already been published regarding the habits of this 

 ant^ to make any detailed reference to them unnecessary in the pres- 

 ent paper. 



Direct Methods of Destruction 



Permanent relief from the inroads of this species can come only 

 through actual destruction of the ants themselves. The use of nothing 

 but repellents serves only to postpone the adoption of laborious meth- 

 ods of warfare and to permit the continued increase of the species. 

 Not only is it necessary to kill the ants outright, but it is also necessary 

 to adopt means which will destroy the queens. It is hardly necessary 

 to call attention to the marked difference between killing ants and 

 killing the usual insects with which we have to contend. If one kills 

 a female gypsy moth or boll weevil, for example, possible future 

 progeny of the individual insect is made impossible. Not so when the 

 worker ants are destroyed, for the rate of increase and the develop- 

 ment of future generations are in no way interfered with. This is 

 true for the simple reason that workers do not reproduce, the eggs 

 being deposited exclusively by the queens. Our observations indicate 

 that one per cent, or less, of the workers in a colony can keep the 

 remaining individuals fully supplied with food. "Were one to destroy, 

 by means of sprays or poisons, all foraging workers leaving a colony 



'Journal of Economic Entomology : Vol. I, p. 21-34 ; Vol. II, p. 174-192. 



