HORN FLY 323 



carbolic acid. A subsequent coating of pine tar may aid in repelling 

 the flies. Creolin may be more effective than carbolic acid. Appli- 

 cations of this sort should be made by some one more or less 

 conversant with the use of these agents. 



The Flesh Fly. The adults of the well-known blow-flies (Sar- 

 cophaga sp.) are always on hand to blow meat in the summer 

 time when left exposed. The female gives birth to a large number 

 of maggots, which are hatched within the mother. When first 

 born they are mere specks, but in a few days they grow to be 

 one-half of an inch in length. These maggots are deposited on 

 any exposed meat or in damp, filthy places. They will also deposit 

 maggots in the interior of the ears of stock, and particularly on 

 wounds and sores, which they enlarge and keep from healing. 

 Transformation from maggot to pupa takes place in the ground 

 the winged adult emerging in a few days, ready to start another 

 generation. 



Value and Injury. To a certain extent these flies are bene- 

 ficial, since they act as scavengers, but they are a great nuisance 

 to man and animals, because they run over them in search of food. 

 Like other flies, they undoubtedly carry filth and disease germs. 

 As intimated above, they attack fresh meat which has been left 

 exposed, as well as carrion, and are particularly annoying through 

 their persistence. 



Control. All wet and filthy hair on animals should be cut, 

 especially that around wounds and sores, and such wounds or 

 sores should be rendered antiseptic. This can be done by applying 

 carbolic acid, one part to fifty of water, or one ounce of oil of tar 

 to twenty ounces of sweet oil. Maggots found in the wounds of 

 infested stock should be removed. 



The Horn Fly. This fly (Lyperosia irritans Linn.) is a little 

 smaller than the house-fly, but more slender. It is about the same 

 color. It is frequently observed clustered at the base of the horns 

 of cattle (Fig. 328). It seeks that location because it is there safe 

 from disturbance. 



Injury. It attacks the back, sides, and flanks of cattle, suck- 

 ing the blood and causing a falling off in milk supply on account 

 of the annoyance to the animal. These flies are small, but the 

 blood taken by a few thousand is considerable. Dark cattle appear 

 to be more attractive to the horn fly than light-colored animals. 



Life History. Eggs are deposited in the field in freshly 

 dropped dung. They hatch quickly, then enter the ground, and 



