474 Report of the Entomologists of the 



Dissolve the soap in the water by heating to the boiling point. 

 When all the soap is dissolved remove from the fire and, while 

 the solution is boiling hot, add the oil and agitate violently. 

 This may be conveniently done by pumping the mixture through 

 a small force pump. When sufficiently emulsified the mixture 

 will have the appearance of milk. If allowed to cool it becomes 

 thick like loppered milk. This is standard emulsion and may be 

 diluted with water as desired. For ordinary use against such 

 soft bodied insects as plant lice, 1 part of emulsion to from 10 

 to 15 parts of water is strong enough. 



The kerosene-water mixture. — This is the simple mixture of 

 kerosene and water without the use of soap or oil. The mix- 

 ing is done in the pump and nozzles of the spraying outfits 

 prepared especially for this purpose. The kerosene is held in 

 one tank and the water in another. The pump draws from both 

 tanks. The proportions of water and oil can be regulated at 

 will. 



The kerosene-water mixture has been used with good results 

 against both plant-lice and scale insects. When applying the 

 mixture to the foliage, care should be taken that injury to the 

 tender leaves does not result from the separation of the oil and 

 water. 



Whale-oil or fish-oil soaps. — These soaps, when properly made, 

 are among the most valuable of this class of insecticides. They 

 may be made from any of the numerous fish oils on the market, 

 but are usually sold under the name of whale-oil soap. The 

 value of the soap as an insecticide lies, largely, in the caustic 

 it contains. 



Whale-oil soap was first used as an insecticide in this country 

 nearly sixty years ago. It was recommended as a remedy for 

 the rose bug and was used for this purpose at a strength of 1 lb. 

 to 7^ gals, of water. The success which has attended its use 

 against the San Jos6 scale in the east, has brought it into quite 

 general use during the past few years. It now bids fair to take 

 the place of kerosene emulsion. 



