152 REPORT OF THE COMMISSIONER OF AGRICULTURE. 



REPORT OF PROGRESS IN EXPERIMENTS ON SCALE- 

 INSECTS, WITH OTHER PRACTICAL SUGGESTIONS. 



BY H. G. HUBBARD, Special Agent of the Division. 

 SOAP EMULSIONS. 



Further experiments with kerosene emulsions prove that various soaps 

 can be readily made to combine with the oil, and that the soap and 

 kerosene emulsions are as effective as those formed with milk. The use 

 of soap materially reduces the cost, except where milk is abundant and 

 cheap, as is very seldom the case in Florida. 



Common bar soap, soft soap, and whale-oil soap have been tried and 

 found to be almost equally good. Whale-oil soap, when of good quality, 

 may be preferred, as it is stronger, and adds to the insecticidal proper- 

 ties of the emulsion. 



The following formula is one which has proved in practice useful 

 where a moderate quantity of emulsion is required. It gives a wash of 

 sufficient strength to kill the eggs of the scale-insects commonly found 

 in Florida: 



KEROSENE AND SOAP EMULSIONS. 



Formula. 



Kerosene. 2 gallons = 67 per cent. 



Common soap or whale-oil soap pound ) Q o 



Water 1 gallon j =33 P ercent - 



Seat the solution of soap and add it boiling hot to the kerosene. 

 Churn the mixture by means of a force-pump and spray-nozzle for five 

 or ten minutes. The emulsion, if perfect, forms a cream, which thickens 

 on cooling, and should adhere without oiliness to the surface of glass. 

 Dilute, before using, one part of the emulsion with nine parts of cold 

 water. The above formula gives 3 gallons of emulsion and makes, when 

 diluted, thirty (30) gallons of wash. 



The percentage of oil can be increased considerably without danger 

 to the plant, and a stronger emulsion may, in fact, be required in coping 

 with some of the Aspidiotus scales, upon which we have had no opportu- 

 nity to experiment. But the amount of kerosene in the emulsion cannot 

 be greatly reduced without weakening too much its power as an insecti- 

 cide. 



The amount of soap may also be varied, but less than one quarter ot 

 a pound to the gallon of water forms an unstable emulsion. 

 . After another year of experiment and practical experience in the use 

 of kerosene emulsions as a remedy for scale-insects we see no reason to 

 change the opinions expressed in former reports. 



The distrust of kerosene naturally felt at the outset has in time given 

 place to confidence, and the emulsions are now widely used by orange- 

 growers in Eastern Florida. Many groves treated with kerosene emul- 

 . sions have been under our own observation, and the results have been 

 uniformly beneficial. Want of thoroughness in applying the wash, 

 however, frequently renders repeated applications necessary. 



The invention and introduction of the cyclone nozzle by the Depart- 

 ment of Agriculture greatly diminishes the labor of applying the liquid 

 to orange trees and insures success with ordinary care and attention, at 



