8 Protection of Meat Commodities against Bloicflies 



cinnamon, aniseed, etc. In addition, formic acid, picric acid, boracic 

 acid, and nitrobenzene were tried. Plienolic and paraffin compounds 

 were not tried as their use in proximity to foodstuffs is scarcely practic- 

 able. 



The following table is typical of some twenty repetitions of the 

 experiments. 



In most cases, the majority of the samples were blown within six 

 hours, if weather conditions were suitable. Samples protected with 

 eucalyptus oil, formic acid and sometimes clove oil, remained untouched 

 for twelve hours, but were generally attacked after that interval. 



Similar results were obtained when the baits were placed in a hot- 

 house, average temperature 78° F., into which blowflies could readily 

 enter. 



The trials with aniseed oil were repeated on a larger scale. A minia- 

 ture market stall was erected. It was divided into two halves by a 

 partition. One half was enclosed on all sides, except the mesh side, by 

 dark material, so as to form a semi-dark chamber; the other half was 

 similarly enclosed by white mosquito netting so as to be quite exposed 

 to sunlight. The cotton netting, after being smeared with oil, was hung 

 loosely upon protruding tacks. A variety of baits was placed within the 

 compartments. As before, the baits placed within the Hght compart- 

 ment, though visited by clouds of blowflies, were rarely blown. 



In no case were the baits that were protected with aniseed oil blown 

 >Yithin twenty-four hours. 



Various types of netting were tried but in no case was greater success 

 obtained than with the quarter-inch mesh. The advantage of cotton 

 netting, apart from the fact that it is cheaper than netting made from 

 other material, costing from sixpence to eighteen-pence per square yard 



