LITERATURE FOR 1916 ON ANTS AND MYRMECOPHILS 423 



water by crawling to the top. Such balls may attain a diameter 

 of 6-8 inches and may float about for hours in still water. Upon 

 coming in contact with a solid substance the ball breaks up and 

 the ants crawl out. If coal-oil is poured on the water the ball 

 breaks up and the ants soon die. 



Wheeler (25) cites an interesting case of dispersal of a tropical 

 ant (Pheidole feregrina, New Sp.), a small colony of which was 

 conveyed in a floating log from the main coast of Brazil to San 

 Sebastian Island, which is about forty miles off shore. Wheeler 

 points out, in this connection, that it is not necessary that an 

 entire colony should be transported to ensure the widening of 

 the distribution of the species; one fertilized queen would be 

 sufficient. Dr. Herman von Ihering, who has been experiment- 

 ing on this phase of ant dispersal, is quoted by Wheeler as 

 saying, that his experiments with bamboo and other kinds of 

 wood, containing ant colonies, have demonstrated that the ants 

 which he used are decidedly resistant to submersion, provided 

 the nest entrances are closed. 



Wheeler (20), while going over the Pergande collection of 

 ants, found a series of workers of the Indian ant Triglyphothrix 

 striatidens. These workers were collected in Louisiana, where 

 the ant must have been introduced quite recently. The original 

 home of this ant is Southern Asia and Wheeler's is the first 

 record of its occurrence in the United States. The species, 

 according to Wheeler, is now pretty well spread over the tropics. 

 Its introduction into other parts of this country is but a matter 

 of time, if indeed not already accomplished. 



Barber (1) states that the greatest means of dispersal of the 

 Argentine ant in the United States is by steamboats and rail- 

 roads. They will, he says, ride in lumber, fruit, vegetables, etc. 

 For this reason infestation usually starts around the wholesale 

 grocery and commission merchant houses. 



CONTROL OF ANT PESTS 



The study of the control of any pest is primarily a study in 

 animal behavior. The study of the control of ant pests consists 

 largely, in the discovery of substances that will either repel 

 or poison them. The literature on this subject should, there- 

 fore, furnish one with data concerning ant sense organs, their 

 location, sensitivity, etc. However, this rather purely biological 



