SMfTHSONIAN INSTITUTION LIBRARIES 



3 9088 01272 7558 



Kerosene emulsion lias proved to be the most effective remedy for 

 the control of this pest. This emulsion, when properly made accord- 

 ing to the formula below, can be sprayed with safety on any tree dur- 

 ing the dormant period —in winter or earl) 7 spring before the buds 

 open at a strength of 20 to 25 per cent. A nozzle throwing a tine 

 spray should be used. Can' should always he exercised to prevent the 

 liquid from running down the trunk of the tree and collecting about 

 the roots, as the oil, which will be retained by the soil around the roots 

 for an indefinite period, might seriously injure or kill the tree. 



K ISKOSKK I KM! LSI* >\. 

 Stock solution i tili per rent oil i. 



Kerosene (coal-oil, lamp-oil | gallons. . 2 



Whale-oil or laundry soap (or l quart soft sua]) i pound. . \ 



Water gallon. . I 



Dissolve the soap in boiling water, then remove from the f re, add the 

 kerosene immediately and thoroughly agitate the mixture until a creamy 

 solution is obtained. This ran be done by pouring the mixture into 

 the tank of a spray-pump and pumping the liquid through the nozzle 

 back into the tank. This is a stock solution which must be diluted 

 before using. In order to make a 20 per cent emulsion, add to each 

 gallon of the stock solution about 2^ gallons of water and agitate thor- 

 oughly before using. For ti 25 per cent solution add to each gallon of 

 the stock solution 1| gallons of water and agitate thoroughly. This 

 strength will kill a large percentage of the hibernating females, with- 

 out injury to the trees. 



If a good naphtha soap can be obtained the preparation of the emul- 

 sion will be simplified. It will be unnecessary to heat the solution, 

 since the kerosene will combine readily with the naphtha and soap and 

 form a perfect, cold, milky-white emulsion when the mixture is thor- 

 oughly agitated. If naphtha soap is used, double the amount called 

 for by the formula, and emulsify in soft (rain) water. 



Approved: 



James Wilson. 



Secretary of Agriculture. 

 Washington, D. ('.. April ■!. 1907. 



Cir.i>8] 



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