14 SPRAYING CROPS 



less harmful to the foliage even than Paris green, is 

 quicker in effect, and should supplant the latter as an 

 insecticide. It is used in the same way and at about 

 the same strength as Paris green." 



Hellebore is a vegefeble poison, and kills both by 

 contact and by being eaten. It may be applied in 

 water, i ounce to 3 gallons, or i pound to a barrel. 

 It is especially excellent in destroying the imported 

 currant worm. 



Pyrethrum, or Insect Powder, is made from the 

 powdered flowers of plants of the genus Pyrethrum. 

 The greatest obstacle to the use of Pyrethrum has 

 been the difficulty in obtaining the pure, fresh article. 

 After long exposure to the air it loses much of its 

 insecticidal value. It is used mainly as a dry powder 

 or in water (i ounce to 3 gallons) ; but may also be 

 used in the form of a tea, or a decoction, a fume, or 

 an alcoholic extract diluted. 



Arsenite of Lime Persons having a large amount 

 of spraying to do often use this in place of Paris 

 green, as it is much cheaper. It is made by boiling 

 for 15 minutes or more 



White arsenic 2 pounds 



Salsoda 8 pounds 



Water 2 gallons 



After the arsenic is dissolved this makes a stock 

 solution which may be used at the rate of I pint to a 

 barrel of water, adding also 2 pounds of freshly slaked 

 lime. The chief objection to this is in the danger of 

 having white arsenic around the premises. It looks 

 so much like flour, baking powder and other domestic 

 powders that it is dangerous to the family. 



Kerosene Pure kerosene has lately come into 

 use as an insecticide for scale insects, especially the 

 San Jose scale. It is to be applied only to dormant 



