98 Forests and Trees 



in a small amount of water before being diluted. For general 

 spraying against leaf-feeding insects, two pounds are mixed 

 with 40 gallons of water; but for bad infestations of canker- 

 worms, especially when the caterpillars are more than one- 

 half grown, three or four pounds to the barrel of water should 

 be employed. 



"Lead arsenate is also used in the form of a powder. One 

 pound of the powder will do the work of about two pounds of 

 the paste. 



"For use in small quantities: 



Lead arsenate i tablespoonful 



Water i gallon 



"Paris Green is used at the rate of four ounces mixed in 40 

 gallons of water for general spraying against leaf -feeding insects. 

 When a stronger mixture is required the poison may be increased 

 to five ounces in 40 gallons. There must always be added at 

 least as much freshly slacked lime as Paris Green to prevent 

 burning the foliage, and the spray mixture must be kept well 

 stirred while spraying is in operation. 



Paris Green 4-5 ounces 



Fresh lime - 1 pound 



Water 40 gallons 



" For use in small quantities : 



Paris Green i heaping teaspoonful 



Mixed in water 3 gallons 



Freshly slacked lime .... 3 ounces 



"Kerosene or Coal Oil Emulsion; a very effective spray 

 mixture for the control of plant lice, and other sucking insects. 

 It must wet the insects in order to affect them, therefore the 

 application should be thorough. 



