CONTKOL OF GARDEN DISEASES AND INSECTS. 11 



proportion specified in the formulii will give satisfaction. An exam- 

 ination of a freshly sprayed vine will show w^hether there is sufficient 

 soap in the mixture. If the spray draws together in drops and 

 leaves part of the foliage dry, more soap should be added. Where 

 possible, fish-oil soap should be used, but if it can not be procured, 

 cheap laundry soaps will do. The composition of the cheap soaps is 

 variable, and if too much soaj) is used, some injury may result to 

 tender foliage. 



In the use of nicotine sulphate the effective application of the spray 

 is of the utmost importance, since it is primarily upon this that the 

 success or failure of the treatment depends. If the liquid has stood 

 for any length of time it should be agitated thoroughly before use. 

 The insects themselves must receive a thorough coat of the spray or 

 they will not be killed, and immediate inspection after spraying 

 should show the foliage occupied by the insects to be completely wet. 



Spraying should be done as early as possible, always on the 

 frst appearance of the insect^ not only because it is good practice 

 to keep the plants free from pests, but because more thorough work 

 can be done on small plants. 



SOAP PREPARATIONS. 



Soaps of most kinds are of value in solution as w^ashes and as 

 sprays in the control of certain noxious insects. Both hard and soft 

 soaps are employed, and so-called wdiale-oil soaps, usually manufac- 

 tured from fish oil, are of great value and much used. Among these 

 are cresol soap and resin fish-oil soap. Such soap is usually pre- 

 pared by dissolving 1 pound in 4 to 10 gallons of w^ater. On some 

 hardy plants a solution of 1 pound of soap to 2 gallons of water can 

 be used, but this strength is harmful to delicate plants and must 

 be used with caution. The best strength for ordinary plants is 

 about 1 pound in 6 to 10 gallons of w^ater, applied as a spray. It 

 is of most value against plant-lice, minute leaf-bugs, leafhoppers, 

 and thrips, and against some forms of small soft-bodied and sensi- 

 tive insects and their young. Soaps possess no particular advantage, 

 however, over nicotine sulphate or kerosene-soap emulsion, but are 

 easier to prepare than the latter. 



Neutral soaps of the Castile type are much used on plants grown 

 under glass and as a means of checking the ravages of plant-lice, 

 thrips, red spiders, and some other forms of small insect pests. They 

 are particularly valuable against many insects which obtain their 

 food by suction. 



HOMEMADE SOAP. 



Homemade soap can be prepared by following the directions 

 ])rinted on cans of lye for household use. It will save considerable 



