268 FUMIGATION METHODS 
effective against the grape root-worm, Fidia viticida. 
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 inse¢ts. 
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- 
