CONTROL OF HORSE FLIES ON CATTLE 



WILLIS N. BRUCE AND GEORGE C. DECKER 



Horse flies are important pests of cattle in many sections of the United States. Known throughout 

 niinois, they are most numerous in the southern third of the state. They are^a source of great annoyance, 

 and sometimes even terror, to the cattle and other animals they attack. By their persistent and painful 

 biting they interfere with the production of milk and meat. For both humane and monetary reasons, they 

 are a cause of concern to many owners of dairy cows and beef cattle. 



From early June to middle or late August in Illinois, horse flies attack cattle, horses, mules, hogs, 

 and other animals. They alight on the backs, shoulders, heads, and necks of their victims, and, if not dis- ^ 

 lodged at once by the terrified animals, they cut through the skin with their knifelike mouthparts and suck 



Automatic microspray applicator used in 1950 experiments for control of horse flies on beef cattle. 



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