TWO DESTRUCTIVE ANTS. 7 



ounces into the opening of the nest. The opening need not be closed. 

 As the gas is much heavier than air, it sinks into the innermost 

 recesses and kills all of the ants in the colon}'. Setting fire to the 

 liquid is of no benefit. In fact, it is likely to lessen its efficiency. The 

 l^oison may be applied at any time of the day, regardless of the 

 number of the ants that are outside the nest. The destruction 

 of the colony depends upon the killiug of the queen, and she reuiains 

 in the nest at all times, except when the swarming flight is under 

 Avay, for a very short time in the spring. 



Sometimes Paris green or other arsenicals are used in the attempt 

 to control this species. They are generally applied by simply pour- 

 ing a handful into the openings. Many of the ants are killed, but 

 a large part of the brood is not affected, and the colony soon becomes 

 as numerous as ever. In some cases where this method has been 

 followed persistently the ants have moved their nest a few feet away 

 and have become reestablished perfectly in a short time. For these 

 reasons the use of arsenicals can not be considered satisfactory. 



Another method sometimes followed, which is of little practical 

 use, is trapping the ants in bottles. If a large bottle is buried in the 

 ground in the vicinity of the nest with the neck flush with the sur- 

 face the ants soon begin an exploration and fall inside. The noise 

 they make in the bottle attracts many others. In this way in the 

 vicinity of a populous colony a large bottle may be filled in a short 

 time. The objection to this procedure is that it only reduces the 

 strength of the colon3^ The immature stages and the queen are not 

 affected, and the colon}^ soon regains its former numbers. 



Approved : 



James Wilson, 



Secretary of Affiicidture. 



Washington, D. C., January 18, 1912. 



ADDITIONAL COPIES of this publication 

 -Ti- may ho procured from the Sijperintend- 

 ENT OF Documents, Government Printing 

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