Sept., 19I4-] Severin-Severin : Mediterranean Fruit Fly. 243 



In the next experiment the relative ' attractiveness of kerosene, 

 turpentine, cocoanut oil and water for the Alediterranean fruit fly was 

 tested. This experiment was conducted in the first mentioned orchar 1 

 and the oil traps were arranged as shown in the previous diagram. 

 Since turpentine is very volatile, a man was sent to the orchard 

 several times a day to pour a new supply of this oil into the traps. 

 This experiment was carried on for eight hours during two days with 

 the following results : 



Experiment III. 



Traps. Hours. Males. 



Kerosene 4 i6 172 



Turpentine 4 16 8 



Cocoanut oil 4 16 o 



Water 4 16 o 



The same oils were now tested out separately for a period of eight 

 hours on three different days ; the water, however, was kept in ten 

 traps wired in citrus trees for a period of thirteen days. The results 

 were as follows : 



Experiment IV. 



Traps. Hours. Males. 



Kerosene 4 8 41 



Turpentine 4 8 2 



Cocoanut oil 4 , 8 o 



Water 10 13 days o 



Twelve traps containing vinegar were wired to citrus trees for 

 two days but no fruit flies were captured in these traps. Vanilla 

 extract was also used but gave only negative results. 



Experiments in trapping the Mediterranean fruit fly with oils be- 

 longing to the naphtha distillate derived from crude petroleum were 

 conducted in two orchards. On account of the volatileness of these 

 oils, the experiments were continued for only eight or nine hours a 

 day, but the traps were never allowed to dry out. The number of 

 traps used, the number of hours each experiment was conducted and 

 the results obtained are as follows : 



Naphtha Distillate. 



Experiment V. 



Traps. Hours. Males. 



Kerosene about 120° Be 5 24 81 



Gasoline about 86° Be 5 24 16 



