110 CALIFORNIA VEGETABLES. 



and allowed to dry it is very discouraging to slugs and is 

 otherwise promotive of plant growth. 



Remedies for Sucking Insects. These are pests both 

 large and small which bring distress to plants without 

 visibly consuming their substance, as has already been de- 

 scribed. They are not affected by poison on the surface. 

 They must be killed by applications which destroy by con- 

 tact with the exterior of the insects. The universally 

 approved remedy for this large class of pests is kerosene 

 emulsion. If properly made and diluted, it is harmless 

 to the plant and deadly to the insect. The formula which 

 is most easily prepared and most available for garden 

 work, is that devised by Prof. A. J. Cook of Claremont, 

 Los Angeles county, as follows : 



Common laundry soap ... % pound 



Kerosene 3 pints 



Water 4% gallons 



Cut up and dissolve the soap in six quarts of boiling 

 water in a five-gallon oil can. Eemove from the fire and 

 add the kerosene, stirring vigorously for ten minutes. 

 This should make an emulsion from which the oil will 

 not separate when cool. It can be diluted with water 

 enough to fill the five-gallon can, and is then ready for 

 application with a garden syringe or spray-pump, and 

 it will kill all insects which are covered with a film of 

 it. A fine rose sprinkler can be used, but it is wasteful 

 and the application does not penetrate as w r ell as from 

 a spray nozzle. 



The kerosene emulsion will of course kill the insects 

 for which poison has been prescribed and is available 

 whenever the use of poison is thought to be undesirable. 



Whenever insects do not yield to the treatments pro- 

 posed, or whenever the use of these remedies does not 

 seem to be practicable, it is well for the grower to apply 

 to the Agricultural Department, University of California, 

 Berkeley, sending a specimen of the insect and of its 

 work, if possible. An answer embodying the latest in- 



