1917 > ENTOMOLOGICAL SOCIETY. 55 



to secure good results. The writer feels sure, however, that if spraying was con- 

 tinued througliout the whole season with the one mixture that the time of spraying 

 could be reduced to once in every two days, or even once in every three days. In 

 the same way probably the strength of the spray could be reduced after using for 

 some time. 



" Amount of Spray Used. 



When used in the proportion of 1 to 2,. one imperial quart was sufficient for 

 eleven cows, that is one gallon as applied at 1 to 2 was sufficient for 44 cows. At 

 1 to 4, one gallon as applied was snfficient for 32 cows. It should be borne in mind 

 that in spraying each cow was absolutely covered from horns to hoofs with the 

 mixture, not simply a band along the back and sides, as is so often done. 



It was found that better results could be secured in spraying the cattle by 

 using a cheap hand-atomizer sprayer than hj using a knapsack-sprayer. 



Working with these hnnd sprayers two men in ten minutes could thoroughly 

 spray 13 cows, averaging about one and two-third minutes per cow. 



The Cost of Speaying. 



The following cost summary is based of course on pre-war prices : 



Fish oil, 1 gal ' $0 80 



Kerosene, 1 gal , 20 



' Milk, 1 gal 20 



Oil of citronella, 6 oz 60 



$1 80 

 i.e., $1.80 for 3 gallons of stock solution. 



In the proi)ortion of 1 to 2, the cost as applied w-as 20 cts. per gallon. 



In the proportion of 1 |o 4, the cost as applied was 12 cts. per gallon. 



The cost then of spraying thoroughly with this mixture at 1 to 2 is 5/11 cts. 

 per cow. The cost of spraying at 1 to 4 is % cts. per cow. 



As mentioned above the writer found this mixture by far the most satis- 

 factory. of all the home-made repellents tested, but he would like it borne in mind 

 that it is the result of only one season's work, and although he is satisfied that it 

 Avill form the basis of a very satisfactory repellent, he feels that the proportions 

 used can probably be improved in another season's work, and so does not recommend 

 this mixture as finally satisfactory. 



Peof. Pabkott: Was any work done while you were carrying on this experi- 

 ment with the repellents to determine the effect of the treatments on the yields 

 of milk or l)utter? 



]\Ie. Baker: None. I hope before I put it in final form to do this work: to 

 run check animals exposed to all the attacks of flies outside, and to treat others 

 with a series of sprays of different proportions, and then keep a record of milk 

 returi;s in both lots. So far as I know tliero has been only one record of systematic 

 work done along this line. 



Prof. Parrott: Nineteen years a,;;o-l ^as given the ])rol)lem of determining 

 the most efficient materials for protecting animals from flies, and the conclusions 

 you have drawn are in the main quite similar to the results I obtained. It was 

 not very hard to decoct a preparation as efficient as some of the repellents on, the 

 market. I found also that both commercial and home-made mixtures gave^ only 

 temporary relief, and there was always the question of wdiether or not the applica- 

 tions had nny effect on flie yiidds of milk or butter. When at the Ohio Experi- 



