304 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 15 



uneven in concentration and does not give a constant kill throughout 

 the area sprayed. 



The results obtained from the use of various types of soap are given 

 in Table 1. The spray was applied during the heat of day when the 

 beetles were active. 



The results indicate that the laundry, rosin fish oil and fish oil soaps 

 are not fitted for this purpose. It will be noted that the efficiency of 

 the sodium and potassium soaps is in proportion to the concentration 

 of the spray solution. In warm weather sodium soja-bean soap at 

 the rate of 10 pounds dissolved in 50 gallons of water gave invariably 

 90% kill. Potassium soja-bean when used at the same concentra- 

 tion resulted in a slightly lower mortality. 



The effect upon the individual beetle when it comes in contact with 

 the spray is pronounced. The conspicuous coloring of the insect is 

 obliterated and it assumes a dull grayish black appearance. The legs 

 straighten out, no violent movement takes place and death some- 

 times occurs within thirty seconds. The complete mortality takes 

 place within a few minutes. Seme of the beetles fall to the ground, 

 while others remain hanging to the leaves by their tarsal claws.- 



Addition of Materials to Soap Solutions 



During the course of the experiments a nimiber of materials were 

 tested in this connection alone and with the soap solutions. These 

 materials are included in the following list: 



Sodium ploysulphides Worm seed oil 



Sodium thiosulphate Pine oil 



Carbon disulphide Lemon oil 



Acetone Toluene 



Castor Oil Sulfur 



Gum arable Fusel oil 



Methyl alcohol Potassium sulphide 



Kerosene emulsion Linseed oil 



Nicotine sulfate 



The results indicate that the materials alone were of little or no value 

 in this connection, and when t.hese materials were added to the soap 

 solution they did not improve the efficiency over that of the soap alone. 

 Seemingly of all the materials tested, only one was active; namely 

 the soap. For this reason the use of rosin fish oil or fish oil soaps is 



^During the course of the work the materials enumerated in this paper were tested 

 against the Rose beetle {Macrodaclylus subspinosus). The results were substantially 

 the same as those with the Japanese beetle. 



