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 



