REPELLENTS FOR PROTECTING ANIMALS FROM FLIES. 23 



GENERAL SUMMARY. 



The biting flies that annoy domestic animals most in this country 

 are the stable fly, Stomoxys calcitrans, and the hornfly, Lyperosia 

 irritans. The bot flies are not biting flies, but are a menace to do- 

 mestic animals because of the parasitic habits of their larvae. This 

 is also the case with the screw-worm fly, Paralucilia macettaria, 

 which deposits its eggs in wounds, and a bluebottle fly, Lucilia seri- 

 cata, occurring in the United Kingdom and Holland, and certain 

 species of Calliphora occurring in Australia, the larvae of which 

 invade the wool and skin of sheep. 



Repellents are more or less effective against all of these flies. 



Opinions differ with regard to the injury by biting flies. The 

 common opinion seems to be that these flies are responsible for great 

 losses. However, a limited amount of experimental evidence relating 

 to cattle seems to indicate that the losses, when they occur, are not 

 great. 



The repellent action of certain colors has been noted by various 

 investigators. Light-colored animals suffer less from flies than dark- 

 colored ones. One author (Marre, 1908) has recorded the observa- 

 tion of a farmer in France who found that a blue color applied to the 

 inside of stables repelled flies. This observation seems to have re- 

 mained uncorroborated. 



Potassium tellurate has been recommended by Ochmann (1911) 

 as an internal remedy for repelling flies. However, Mayer (1911) 

 failed to obtain results with the remedy, and it seems safe to assume 

 that internal remedies will never prove practicable in repelling flies. 



Liquid repellents may be applied by means of a dipping vat, a 

 pail spray pump, an atomizer, or by means of a rag or a paint brush. 

 The method to be employed depends on the individual preference 

 of the farmer and the nature and cost of the preparation used. 



The powder remedies that have been used are pyrethrum powder 

 and tobacco powder. 



Various oils, emulsions of oils, and mixtures of oils are used in 

 repelling flies. Crude petroleum, cottonseed oil, fish or train oil, 

 and light coal-tar oil may be used pure. Jensen (1909) recommends 

 for dairy cows an emulsion of crude petroleum containing an admix- 

 ture of powdered naphthalin. 



Fish oil is rated as one of the best repellents and has been used 

 alone and in combination with various other substances. Other sub- 

 stances that have repellent qualities and that have been used in vari- 

 ous mixtures are pine tar, oil of tar, crude carbolic acid, oil of penny- 

 royal, and kerosene. 



Jensen's formula is said to protect cows for a week. The pro- 

 tective action of fish oil is stated to range from less than two days 



