THE INSECT WORLD. 



395 



and gardens, or in grass-plots, and they are sometimes decidedly 

 troublesome in such localities. Where this occurs, there is noth- 

 ing better for getting rid of them than bisulphide of carbon. Pour 

 a quantity into each of the openings of the disk or hill, closing 

 them up by stepping on each as it is treated. The fumes will 

 penetrate the chambers in every direction, and if a sufficient 

 amount has been used, will kill not only all the adults, but all 

 larvae as well. A single application is usually all that is necessary ; 

 but in a very large colony it may sometimes happen that the 

 farther chambers are not reached by the fumes, and that the nest 

 reappears near by ; rarely in the old spot. When that occurs, a 

 second treatment is tolerably certain to be effective. It has been 

 recommended that, to get the best results, holes be poked with a 

 stick into different parts of the hill, but I have not found this of 

 any great advantage. It has also been recommended that, after 

 pouring a considerable quantity — say three or four ounces — into 

 the main opening of the nest, the vapor be exploded by means 

 of a match held at the end of a stick. When this is done the 

 nest is completely wrecked, and the poisonous vapor is forced to 

 every portion of the galleries, so that escape is almost impossible ; 

 while larvae and pupae are buried so thoroughly that they can 

 never make their way to the surface, even if not killed by the 

 fumes. This is a very good method where a large nest is to 

 be dealt with ; but whoever attempts it must remember that the 

 vapor of the bisulphide is exceedingly inflammable, and must 

 make certain that he is far enough from the opening of the nest 

 to prevent being caught by the flash. Ants are never desirable 

 in a cultivated field ; they have no business there, and are cer- 

 tainly of no benefit to the farmer, even if they do not directly 

 feed upon plant tissue. 



Wherever the corn-root louse is injurious, late fall ploughing 

 should be practised to destroy the nests of the ants. If the 

 ploughing be done before the ants have gone into winter-quarters, 

 * they will either build a new nest sufficient for their purpose, or 

 will move with their belongings to a spot in which they are able 

 to winter ; so no good will be accomplished. If the ploughing 

 be deferred until frosty nights and cool days discourage activity, 

 the ants will be unable to repair damages, or will not have suffi- 

 cient time to re-establish themselves before they become torpid. 



