496 



DISEASES OF CATTLE. 



was found to be very successful at the Mississippi Experiment Station, 

 the effects persisting for several clays. A mixture of one part of crude 

 carbolic acid to about ten parts of fish oil will repel flies for two 

 or three days when applied by means of a cloth or sponge dipped into 

 the liquid, squeezed partly dry and passed lightly over the hair. It 

 should not be rubbed in, as it is liable in that case to cause blistering. 

 The following mixture proved the most useful fly repellaDt of any 

 tried at the South Dakota Experiment Station: Fish oil, 100 parts; 

 oil of tar, 50 parts; crude carbolic acid, 1 part. This was applied by 

 means of a small hand spray pump. One application proved efficient 

 for two days. 



The Stable Fly (Stomoxts calcttrans). 



This fly very closely resembles the house fly, but unlike the latter 

 it is a biting fly. It is common about stables and often enters dwell- 

 ings, especially in cloudy 

 weather. It is the agent of 

 transmission of a parasitic 

 roundworm of cattle (Fila- 

 ria labiato-papillosa, see 

 p. 515). This species has also 

 been accused of transmit- 

 ting anthrax from diseased 

 to healthy animals, and 

 there is some evidence to 

 show that it may transmit 

 surra, a disease due to a 

 blood parasite which affects 

 horses, cattle, and other live 

 stock. 



The annoyance suffered 

 by cattle and horses from 

 stable flies is much lessened 

 if the stables are darkened. 

 This fly breeds in manure, 

 especially fresh horse ma- 

 nure. By promptly disposing of manure dropped in stables and 

 barnyards the number of stable flies about the premises can be 

 greatly reduced. 



The Hornfly (H^matobia sebrata). 



This fly, now found nearly everywhere in the United States, was 

 introduced into this country from Europe about the year 1885. Horn- 

 flies have the habit of clustering about the base of the horn (fig. 4), 

 whence the name by which they are popularly known. They do not 

 damage the horn and congregate there only to rest. They are fre- 

 quently seen in a resting position on other parts of the body as well. 



PiQ. 3.— Hornfly (Sxmatobia serrata) in resting posi- 

 tion. (From Bureau of Entomology.) 



