268 FUMIGATION METHODS 



effective against the -grape root- worm, Fidia vitidda. 

 To facilitate the application of -carbon bisulphid the 

 McGowen injector was invented. It is a very con- 

 venient instrument, and can be adapted to nearly all 

 uses of carbon bisulphid for underground insects. 



Destroying ants in lawns and other places. Usually 

 by careful observation the common ants, excepting, 

 perhaps, the little red ants frequenting houses, can be 

 traced to their outside homes. The treatment consists 

 in making one or more holes in the nest with a stick 

 or iron bar, one to two feet deep, and pouring into each 

 hole a couple of ounces of carbon bisulphid. The hole 

 should be closed immediately. The vapor may be 

 exploded at the mouth of the hole with a match, in 

 order to drive the fumes deeper into the chambers. If 

 the latter method is adopted, the hole should be 

 covered with fresh earth immediately after the explo- 

 sion, so as to put out the fire and retain the fumes. 

 Otherwise a large portion of the gas will be burned 

 and the efficiency of the treatment considerably 

 lessened. After the explosion the vapor burns with a 

 colorless, invisible flame. Carefully observe this point 

 before an attempt to recharge a nest is made. Other- 

 wise an explosion might follow, with serious results to 

 the operator. If a large area is infested the holes 

 should be about one and one-half feet apart each way. 

 After the carbon bisulphid has been applied the ground 

 should be thoroughly watered to prevent too rapid 

 diffusion of the fumes. 



White grubs and mole crickets, sometimes found in 

 lawns and gardens, can be treated in the manner de- 



