88 BULLETIlSr 351^ U. S. DEPAETMENT OF AGEICULTUEE. 



In the second case it was evident that combining gasoUne emulsion 

 and miscible oil added to the efficiency of the oil. The greatest effi- 

 ciency was obtained when 5 parts of miscible oil were added to 3 

 parts of gasoline (emulsified) and 92 parts of water. In the third 

 case it was evident that adding nicotine did not increase the efficiency 

 of miscible oil. 



Cottonseed Oil. 



The third group consisted of 10 experiments made with cottonseed 

 oil. This was a promising oil and both its penetration and wax- 

 solvent powers were greatly increased by the addition of gasoline. 

 The highest efficiency was obtained by using an emulsion containing 



Cottonseed oil 5 gallons. 



Gasoline 3 gallons. 



Soap 2 pounds. 



Water 92 gallons. 



combined as indicated on page 67. This oil proved nearly as effective 

 as linseed oil. 



Linseed Oil. 



The fourth group consists of 5 experiments made with raw lin- 

 seed oil. It was soon evident that this oil was promising. It was 

 very efficient when used alone as a 10 per cent emulsion, but it gave 

 even better results when combined with gasoline. The gasoline 

 component increases the fluidity of the oil, dissolves the protecting 

 wax film, and tends to asphyxiate the scales. After the emulsion has 

 penetrated to the underside of the scale this component evaporates, 

 while the other component, after smothering the scale, becomes inert. 

 In this respect it is superior to the oils ordinarily used against this 

 scale. The best results are obtained by using an emulsion made up 

 as follows: 



Raw linseed oil 5 gallons. 



Gasoline 3 gallons. 



Laundry soap ^ 2 pounds. 



Water 92 gallons. 



When made as indicated on page 82, this emulsion applied in the 

 spring before the buds burst will control the terrapin scale at a single 

 application and at a cost for material of from 1 to 8 cents per tree. 

 This was found to be the most effective treatment of any of the reme- 

 dies tried against this insect. 



Mixed Oils. 



Group 5 contains only two experiments. They show conclusively 

 that there is no advantage in mixing linseed and cottonseed oils. 



^ This is the minimum amount; more may be required if the ^oap is mild. • 



