Insect Enemies and Allies 



197 



U. S. D. A. 



FIG. 150, Using a compressed-air type of sprayer. Notice the upward turn 

 of the nozzle for underspraying. Air is compressed in the tank by means of a 

 pump, as it is in an automobile tire. 



The most effective spray for plant lice is tobacco Tobacco 

 extract. It may be purchased as a very concentrated 

 liquid, to be diluted according to directions on the bottle, 

 or it may be made by soaking tobacco stems in a bucket of 

 water. Tobacco spray spreads over the leaves better 

 if a little soap is dissolved in it. 



The biting insects are usually killed with a stomach 

 poison made of some compound of arsenic. Paris green 



