168 Principles 'of Plant Culture. 



liflower and turnip, to prevent their destruction by the 

 flea beetle.* 



294. Kerosene is a very useful insecticide for a class 

 of insects not readily destroyed by other means (316). 

 It has generally been used as an emulsion made with 

 soap and water, for which the following formulae are 

 good: 



a— Dissolve one quart of soft soap, or one-fourth piound 

 of good hard soap, in two quarts of boiling water; re- 

 move from the fire, and pour into a can containing one 

 pint of kerosene. Agitate violently in the can for three 

 minutes. For use, dilute with an equal quantity of 

 water; or 



b— Dissolve one-half pound of hard soap in one gal- 

 lon of boiling soft water; add at once two gallons of 

 kerosene, and chum or otherwise violently agitate for 

 five or ten minutes. For use, dilute with 15 parts of 

 soft water.f 



295. Lime Sulphur Wash is largely used for the con- 

 trol of scale insects. The wash is prepared by boiling 

 together definite amounts of stone lime and powdered 

 sulphur. As this material can be secured upon the 

 market in commercial form, home preparation is not 

 recommended. It is applied during the dormant period 

 of the tree usually at the rate of one part of lime sul- 

 phur to nine or ten of water. Solutions of one-fourth 

 pound to the gallon of water may be applied during 

 winter. 



♦ PhyUotreta viltata. 



t Caustic potash in solution Is also used at times In the control of • 

 certain scale insects. Solutions of one-fourth pound to the gallon of 

 water may be applied during winter. 



