116 journal of economic entomology [vol. 6 



Hosts 



The stable fly does not restrict its feeding to any special hosts. It 

 has been found to feed readily on practically all warm blooded ani- 

 mals, however, certain animals on account of their protective cover- 

 ings or habits are rather less subject to its attack than are others. 

 Mules appear to be very susceptible to attack and much worried by 

 the presence of the fly. 



Horses and cattle are both greatly annoyed. The nervous indi- 

 viduals, however, appear, on account of their frequent movements, 

 to drive many of the flies away. Sheep and goats are both attacked 

 on the legs, but few flies are able to become completely engorged on 

 these animals. Hogs are also commonly bitten, the flies often settling 

 in great numbers just behind the ears. Dogs, cats and chickens have 

 also been seen with flies feeding upon them. Thin haired dogs are 

 exceedingly susceptible to injury and have frequently been seen with 

 blood trickling from the backs of their ears where flies are to be seen 

 most frequently. It is only rarely that the fly attacks poultrj^, on 

 account of the small surface exposed and the quick movement of the 

 birds when attacked. Man is far from being immune from the attack 

 of this pest. Owing to the lightness with which they sit on the ex- 

 posed portion of the body and the quickness with which the beak is 

 inserted, they often succeed in piercing the skin though seldom are 

 allowed to become engorged. It has also been observed that they 

 can readily penetrate moderately heavy clothing. 



Action of Animals Attacked 



As has been stated, the fly usually greatly annoys most animals 

 upon which it attempts to feed. A few of the less nervous individuals 

 permit the flies to engorge without strenuously fighting them, while 

 others may be driven almost frantic. Animals free in pastures have 

 been seen to exhibit various protective actions. When pools of water 

 are within reach they usually enter the water and either lie down or 

 wade into the deep water so as to be largely covered. If only mud is 

 accessible they often stand and lie in this and thus become more or 

 less coated and protected considerably from attack. In open pastures 

 the animals usually come together in a close bunch on a knoll where 

 the breeze is strongest, and there remain for hours stamping and going 

 round and round in an effort to get protection by contact. When 

 shades or stables are accessible the animals often congregate in these, 

 and could hardly be induced to go out to graze for fear of the hordes 

 of flies. Hogs and sheep exhibit habits similar to those of horses and 



