INSECT PESTS 



253 



aceto-arsenite of copper, is a dry green powder extensively 

 used upon field crops. It is made up in various strengths 

 with water, 1 pound to 150 gallons being near the average. 

 When used on stone fruits it is made much weaker, while for 

 potatoes it is used stronger. In preparing it the poison is 

 formed into a paste with 3 or 4 pounds of lime and a little 

 water and is then diluted to the proper degree. The foliage 



Photograph by Batemau Manufacturing Co. 



FIG. 183. Spraying trees in winter to destroy scale insects 



of many plants is injured by Paris green, and it is gradually 

 being replaced by arsenate of lead, which does not have this 

 defect. Arsenate of lead is a white pasty mixture that may 

 be purchased of dealers in seeds or drugs. It is used as a 

 spray in the proportion of 2 or 3 pounds to 50 gallons of 

 water. The poison sticks well and does not injure the foliage, 

 two qualities which make it desirable. Poisons should not be 

 left where children and farm animals may find them. 



