I 



Sept., 1914.] Severin-Severin : Mediterranean Fruit Fly. 245 



captured in the different oils. This experiment was carried on for a 

 period of sixteen days and the folowing figures indicate the results 

 obtained: 



Burning Oil Distillate. 



Experiment XI. 



Export oil about 110° Be. 

 Kerosene about 120° Be.. 



Mineral seal oil 



Colza burning oil 



Perfection signal oil 



It is evident from the results of this experiment that the heavy 

 burning oils, such as mineral seal, colza burning and perfection signal, 

 do not attract as many fruit flies as kerosene and export oil. In 

 these three heavier burning oils the volatile part which attracts the 

 Mediterranean fruit fly must be present in still less quantities than in 

 gasoline (about 86° Be.). 



In the following experiment two of the lubricating oils were tested 

 and the results were as follows: 



Lubricating Oil Distillate. 



Experiment XII. 



Traps. Days. ]\[ales. 



Kerosene about 120° Be 4 3 86 



Renown engine oil F. 375 4 3 6 



Atlantic red engine oil F. 350 4 3 



Since all of the oils classified under the naptha distillate, burning 

 oil distillate and lubricating oil distillate are obtained from crude 

 petroleum, it was reasonable to suppose that the crude oil itself would 

 attract the fruit fly. The results with this oil were as follows : 



Experiment XIII. 



Traps. Days. Ma'es. 



Kerosene about 120° Be 4 3 60 



Crude petroleum 4 3 41 



In the following table the relative attractiveness for the Mediter- 

 ranean fruit fly of animal and vegetable oils and oils derived from 

 crude petroleum is given, the attractiveness of kerosene for the fruit 

 fly being taken as 100 per cent. 



