FUMIGATION WITH CARBON BISULPHID 269 
scribed for ants. One ounce per square yard divided 
between three or four injections will be satisfactory. 
The most favorable time for treating the grubs is after 
they descend in the ground in the fall and before they 
come up again in the spring. In midsummer many of 
the small insects near the surface will escape injury 
from treatment. Carbon bisulphid may also prove 
useful for the destructive nematode worms. 
for borers in trunks of trees clean out the mouth of 
the burrow and insert a small quantity of carbon bisul- . 
phid and close the hole with thick clay or other 
material. The borers are easily killed without injury 
to the tree. The saving of time fully pays for the 
small amount of carbon bisulphid required. A spring- 
bottom oil-can may be used for applying the liquid. 
Melon plant-lice can be treated successfully with 
carbon bisulphid. The method consists in covering 
the young vines with tight boxes, 12 to 18 inches in 
diameter, made of wood or paper, and introducing 
under each box a saucer containing one or two tea- 
spoonfuls of carbon bisulphid. The vines of older 
plants may be gathered about the hill and folded under 
large boxes or tubs. In such cases a greater but pro- 
portional amount of material must be used. The 
covering is usually left over the plants from three- 
quarters to an hour. With 50 to 100 boxes a field 
may be treated quite rapidly. This method of intro- 
ducing the bisulphid can be improved by boring a hole 
about one inch in diameter in the middle of the top of 
each box, and fastening a small bunch of cotton-waste, 
rags, or any absorbent material. By fitting a stopper 
