134 SPRAY MACHINERY AND SPRAY MATERIALS 

 SOAP SOLUTIONS. 



Satisfactory insecticides for soft-bodied insects can be 

 made from soap. Fish-oil soap is probably the best, although 

 common laundry soap is very good. The solution is made by 

 cutting up one pound of soap into small pieces and dissolving 

 it by boiling in 4 or 5 gallons of water. This is a good spray 

 for plant lice. 



NICOTINE PRODUCTS. 



The nicotine products are perhaps the most satisfactory 

 contact insecticides we have for the plant lice. The active 

 principle in these solutions is nicotine sulphate. Some com- 

 mercial products, namely, the Black Leaf 40 and the Xico- 

 fume, are ^ery good. These materials are made from tobacco 

 and are in a very concentrated form. They are usually pre- 

 pared by diluting the stock solution with 800 to 1000 parts 

 of water. 



Tobacco decoction is also used to some extent as an 

 insecticide. This spray is made by boiling 1 pound of tobacco 

 stems in about a gallon of water for one hour. Strain out the 

 refuse material and add enough water to make two gallons. 

 The tobacco products are excellent for controlling the plant 

 lice, and they do no injury to the most tender plants. 



KEROSENE EMULSION. 



Laundry soap . . | pound 



Kerosene 2 gallons 



Water . 1 gallon 



Kerosene emulsion is made by dissolving the soap by 

 boiling it in the full amount of water. Remove the mixture 

 from the fire and add the kerosene. Stir the mixture violently 

 for about fifteen minutes until it becomes a creamy mass that 

 will not separate. This is the stock solution. For use dilute 

 1 part of the emulsion with S to 10 parts of water for hard- 

 bodied insects, and 1 part with 12 to 20 parts of water for 

 soft-bodied insects. 



