8 BULLETIN 131, U. S. DEPARTMENT OF AGRICULTURE. 



were unsatisfactory. The chief defect of the second group seemed 

 to be that they were not lasting. It is stated that these fly repel- 

 lents are sold at retail from $1 to $1.50 a gallon. 



POWDERS AS REMEDIES. 



Smith (1889), of the New Jersey Agricultural Experiment Sta- 

 tion, found by experiment that two powders were adapted for de- 

 stroying hornflies and stable flies, namely, pyrethrum powder and 

 tobacco powder. Pyrethrum acted promptly, but was objectionable 

 from a practical standpoint because of its expense and because it 

 lost its strength soon after application. Tobacco was found very 

 much more satisfactory though the killing power was less. He 

 recommended a proprietary powder having for its base tobacco dust 

 and containing crude carbolic acid or creosote. The method of pro- 

 tecting cattle from the hornfly that he suggested was to apply 

 carbolated fish oil to the belly, udder, and those parts of the animal 

 where powder could not well be used, and to apply tobacco powder 

 to the base of the horns, the back, and at the root of the tail. The 

 effect of the oil is to repel and that of the tobacco to kill flies that 

 attempt to feed. 



OILS AS REPELLENTS. 



Almost any kind of oil, whether it lias a pungent or disagreeable 

 odor or not, will repel flies to a certain extent. The mere physical 

 condition of the hair and skin of an animal treated with oil seems 

 to be repugnant to flies. Oils are used pure or in the form of an 

 emulsion, or in combinations or mixtures. Crude petroleum,, cot- 

 tonseed oil, fish or train oil, and light coal-tar oil may be used pure. 



Crude petroleum may be used in the form of an emulsion. The 

 formula and method of preparing it so as to make 5 gallons of 

 80 per cent emulsion are as follows: 



Hard soap 1 pound. 



Soft water 1 gallon. 



Beaumont crude petroleum 4 gallons. 



In preparing the emulsion the soap should be shaved up and 

 placed in a kettle or caldron containing the required amount of 

 water. The water should be brought to a boil and stirred until the 

 soap is entirely dissolved. Enough water should be added to make 

 up for the loss by evaporation during the process. The soap solu- 

 tion and the required amount of oil are then placed in a convenient 

 receptacle and mixed either by stirring or by means of a spray 

 pump. If properly prepared the stock emulsion will keep indefi- 

 nitely. When required for use the stock emulsion should be diluted, 

 one part of the emulsion to three parts of water being used. The 

 diluted emulsion does not remain uniformly mixed, so if allowed to 

 stand it should be thoroughly mixed by stirring before using. 



