1918 ENTOMOLOGLClAL SOCIETY. 93 



due of course to the fact that the cows had poor protection during the heat of 

 the day, when fly attacks were at their height. 



We find that the increased milk production through the use of a repellent in 

 certain periods was approximately 4 per cent, in those periods. However, since 

 the afternoon spraying, which was carried on over considerably more than one- 

 third of the time, was less than 50 per cent, as efficient as the morning spraying 

 it follows that the production during the period when morning spraying was 

 practised must have been increased nearly 6 per cent. I should say in this con- 

 nection that, due to difficulty in securing assistants for summer work on the 

 department, we were forced for a time to use inexperienced and somewhat incom- 

 petent help and I feel that there were times when the spraying- was not as 

 thoroughly done as was necessary. Accordingly, we feel that another season's 

 work will give even more marked results. 



In considering the increase in milk production through protection of cattle 

 from fly attacks by the use of repellents, it must be borne in mind that this 

 increase in production is secured without any increase in plant, stock or equip- 

 ment. There is also no increase in overhead save the £ost. of the spray material, 

 as the time required for spraying is so short that no additional help is required. 

 Two men should spray a herd of thirty cows in 35 to 30 minutes. 



The repellent used in this work was a home-made spray mixture, a modifica- 

 tion of the repellent described in the paper given at the last annual meeting 

 of the Society. 



The ingredients are as follows: — 



Kerosene 1 gallon 



Slightly sour uiilk 1 " 



Fish Oil 1 



Strong hot soap solution (about | cake laundry soap) 1 " 

 Oil of Citronella 6 ounces 



The kerosene and milk are mixed and thoroughly agitated to form an emul- 

 sion ; the fish oil and hot soap solution are then mixed and thoroughly agitated 

 and the two emulsions are then mixed and the whole very thoroughly agitated. 

 The 6 ozs. of oil of citronella is stirred in when the mixture is cold. This makes 

 quite a stable stock solution. It is advisable, however, to stir up the stock solu- 

 tion thoroughly each time any is taken out. When not in use the stock solution 

 should be kept covered. 



The materials for this four gallons of stock solution cost about $1.83. In 

 the work outlined here the repellent was used in the proportion of one part of 

 stock solution to two parts of water. The mixture as applied, therefore, cost 

 1514 cents a gallon. In the proportion of 1 to 2 of water 1 gallon as applied 

 should suffice for one spraying for about forty cows. The cost of the spray 

 material used in the experiment was therefore about 55 cents. 



The pump used was a small, cheap hand sprayer of the atomizer type, such 

 'as is used for spraying small garden patches. 



