8 FARMERS' BULLETIN 862. 



This spray has been used with success for more than a year and is 

 recommended as the preferred insecticide for mealybugs. It has been 

 applied to a very large variety of plants during the winter season 

 without injury. Oranges and lemons are treated safely, though 

 grapefruit has been known to be stained slightly. The grade of dis- 

 tillate is very important, and only that of a gravity approximating 

 28 Baume should be purchased. This is an untreated black oil, very 

 distinct from the stove distillate (32-3-l: Baume), which is com- 

 monly used for spraying. The cost of cresolated distillate emulsion 

 is about 1^ cents a gallon. 



SOAP-POWDER EMULSION. 



Distillate emulsion * gallons 5 



Soap powder pouncls__ 10 



Water to make gallons 100 



Preparation. When the bottom of the spray tank is covered with water, start 

 agitator and sift in the finely ground soap powder. The distillate emulsion is 

 added when the tank is almost filled. 



Soap-powder emulsion is effective against the mealybug as well as 

 against citrus scales. It is more injurious to the foliage than creso- 

 lated emulsion, however, and may cause moderate or even severe 

 dropping of the leaves unless applied under favorable climatic con- 

 ditions. (See " Season for spraying," p. 9.) The cost is about 

 J cent a gallon. 



HOW TO SPRAY A TREE. 



Trees first should be pruned of all dead wood and opened up so 

 as to allow the ready use of the nozzle on the inside. In spraying 

 for mealybug control the results accomplished are quite as dependent 

 upon the method of application as upon the insecticidal properties of 

 the material used. The upper, or dorsal, surface of the mealybug is 

 tough and resistant to most commercially usable dips and sprays, 

 the place of greatest vulnerability appearing to be a series of tubes 

 which lie beneath the fringe of wax. This protective fringe, which 

 is very resistant to most insecticides, must be removed by the spray 

 to insure quick destruction of the insect; and to effect this removal 

 careful treatment with a driving spray is required. 



A power machine capable of maintaining 200 to 250 pounds 

 pressure should be used. A very satisfactory type of nozzle is shown 



1 Formula for distillate emulsion : 



Distillate (28 Baume") gallons.. 20 



Liquid fish-oil soap do 4 



Hot water do 16 



Pour hot water into spray tank. Start agitator, then add soap. Next slowly pour in 

 distillate. Pump back into itself through nozzle for 20 minutes, after which pump through 

 fine nozzle into storage tank. This emulsion keeps indefinitely. 



