PLUM APHIS OR ''green FLY." 149 



of soft-soap and paraffin ; and at p. 87 of the same volume it 

 is stated that the conchision arrived at from experiments (for 

 •which authority is given) with kerosine emulsion for plant- 

 lice is that this mixture is a perfect remedy against these 

 insects if the application is thoroughly made. 



This application is of such great value as an insecticide in 

 the case of many kinds of leafage, also to destroy insects 

 harhouring in bark, and for other preventive and remedial 

 purposes, that I give the following recipes for preparing the 

 emulsion, which would probably answer as well with paraffin 

 oil substituted for the kerosine, which is not so much used 

 with us as in the United States of America.* 



Kerosine and Soap Mixture. — " To make this I use one- 

 fourth of a pound of hard soap, preferably whale-oil soap, and 

 one quart of water. This is heated till the soap is dissolved, 

 when one pint of kerosine oil is added, and the whole agitated 

 till a permanent mixture or emulsion is formed. The agita- 

 tion is easily secured by use of a force-pump pumping the 

 liquid with force back into the vessel holding it. I then 

 add water, so that there shall be kerosine in the proportion 

 of one to fifteen." — (Prof. A. J. Cook, in Bulletin 26 of the 

 Agricultural College, Michigan, U.S.A.) 



I give the above recipe first, because, being noted as a 

 satisfactory application for the Apple Aphis, it may be pre- 

 sumed the proportion of kerosine would not be enough to 

 injure ordinary bark ; but all experimenters should bear in 

 mind that the strength and amount of mineral oil used must 

 be well considered, and the same strength may not be safe on 

 all parts of young trees, or on all conditions of leafage. 



Another recipe is for " kerosine emulsion " of the ordinary 

 strength for general application, i-iz. kerosine or refined coal 

 oil, 1 pint ; common laundry soajD, ^ oz. ; rain-water, ^ pint. 

 The soap was boiled in the water till all was dissolved, then 

 the boiling soapsuds were poured into a watering-pot con- 

 taining the kerosine, and churned with a garden-syringe until 

 the emulsion was complete. This generally takes about five 

 minutes, but sometimes longer. When this emulsion is made, 

 it can be bottled up for future use. When using it, either 

 as a wash for sponging trees or for spraying, it must be 

 diluted with nine times the quantity of water. Should the 

 oil in the emulsion after a time separate, it is well to warm 

 it, and by violently shaking the bottle it will again become 

 fit for use. In diluting the emulsion use warm water. See 

 p. 14 of * Eeport of Entomologist and Botanist, Department 

 of Agriculture, Canada,' 1887. 



* For other mixtures of soft-soap and paraffin, &c., see Index. 



