INSECTS INJURIOUS TO TREES 



135 



insects, smothering or stifling them. The standard solu- 

 tions for this purpose are kerosene emulsion, soap and water, 

 tobacco extract, or lime-sulfur wash. 



. 



FIG. 97. A Gas-power Spraying Apparatus. 



The boring insects are eliminated by cutting out the 

 insect with a knife, by injecting carbon bisulphide into 

 the burrow and clogging the orifice immediately after 

 injection with putty or soap, or in some cases where the 



