6 TWO DESTRUCTIVE ANTS. 



that is cleared the plants grow with great luxuriance. Frequently 

 these plants become quite conspicuous in the field. This redoubled 

 growth is due apparently to the fact that the underground tunnels of 

 the ants loosen up the soil and have somewhat the effect of deep plow- 

 ing. It is not likely that the increased growth under these condi- 

 tions offsets entirely the loss in the area where no plants are allowed 

 to grow, but it is sufficient to reduce the importance of the insect to 

 some extent. Mr. J. D. Mitchell, who has made many careful obser- 

 vations on this species, believes that the actual damage inflicted is 

 generally overestimated. 



The sting of the agricultural ant is at least as severe as that of a 

 bumblebee. It is speedily inflicted on any animal that approaches 

 the nest. Consequently, colonies located in the vicinity of houses 

 or on roads or paths frequently become decided nuisances. The best 

 local applications for stings are aqua ammonia or bicarbonate of 

 soda (baking soda). When fainting or dizziness occurs, as is fre- 

 quently the case, a few drops of ammonia taken internally will be 

 helpful. 



NATLRAL ENEMIES. 



Natural enemies exert some repressive influence upon agricultural 

 ants. The most important enemy among the birds is the great- 

 tailed grackle {Mef/aqxiscalvs major macroiirus) , commonly known as 

 the jackdaw. The following additional Texas birds are known to 

 prey upon species of Pogonomyrmex, according to records in the 

 Biological Sui-vey: Upland plover {Barfiainia Jonr/i(aii(/a),\n\vvo\y- 

 ing owl {Speotyto cunicularia hypof/a'a)^ Texas nighthawk {Clior- 

 deites aciitipennis texensis), scissor-tailed flycatcher {Mascivora for- 

 fcata), kingbird (Tyrannus fyranniis), rcdlnrd {Card'tnalh car-di- 

 nalis), and mockingbird {Mimvs polyglotto.a). The horned lizard 

 {Phrynosoma cormdnm) includes agricultural ants as a part of its 

 regular diet. 



REPRESSION. 



As in the case of the cutting ant, the destruction of this species 

 can best be brought about by the use of the solution of potassium 

 cyanid in water. Mr. J. D. Mitchell conducted experiments at Vic- 

 toria. Tex.. Avhich showed that this was a perfectly satisfactory 

 method. It is much cheaper and easier of application than in the 

 case of the cutting ant on account of the fact that the underground 

 portion of the nest is much less extensive. A pint of liquid is suf- 

 ficient for even a large colony, though sometimes a second applica- 

 tion may be necessary. 



Carbon bisulphid is also a good remedy and can be applied in 

 a very simple manner. All that is necessary is to pour about 2 



