Pests and Diseases 69 



formed. One part of this kerosene emulsion should be 

 used to 15 or 20 of water. 



Whale-oil soap or fish-oil soap is a commercial article 

 prepared especially for treating insects. The amount to 

 be used will vary with the concentration of the soap and 

 the kind of insect to be treated. For soft-bodied insects, 

 such as aphides, 1 pound to 6 or 8 gallons of water will be 

 found useful. For more resistant insects, such as the 

 plant bugs, a concentration of 1 pound to 4 gallons may 

 be needed. 



Soda-sulfur spray will be found especially useful for 

 very soft-bodied insects such as aphides, rust mites, and 

 also for red-spider. For the last named, it is probably 

 the most efficient insecticide known. 



Caustic soda (98 per cent), 1 pound. 

 Flowers of sulfur, 2 pounds. 

 Water, 2 gallons. 



The sulfur should be mixed in cold water to a thick paste, 

 the soda added, and as it boils water added gradually to 

 make 20 gallons. This water should be added fast enough 

 to prevent burning, but not fast enough to stop boiling. 

 The result will be a dark coffee-colored liquid. It should 

 be strained through a fine-meshed cloth or spray-strainer 

 and kept in tightly corked jugs. One-half gallon of this 

 stock solution should be mixed in 40 gallons of water when 

 ready to use. 



Tobacco-sulfur spray is especially efficient for treating 

 thrips, particularly when infesting the bloom of vegetables 

 and causing them to drop. 



