DIPTERA OF MINNESOTA. 135 



is raised here. In the same year (1889) seventy-three per cent of 

 cattle marketed in Chicago from IlHnois during the hot season (Janu- 

 ary to June) were infested ; 71 per cent of Iowa shipments showed in- 

 festation, and 48 per cent of the cattle from Indiana ; 33 per cent of 

 the cattle from our neighboring state, Wisconsin ; 56 per cent of Ohio 

 cattle ; 57 per cent of Missouri cattle ; 60 per cent of the cattle from 

 Kansas, and 57 per cent of the Kentucky cattle. In each case the loss 

 on the hide was one-third ; that is, "grubby" hides were docked one- 

 third their value. In summing up it may be said that the loss from 

 warble flies during that year, on cattle shipped to the Chicago market 

 alone, was $3,337'565-00. 



Remedial Measures: 



The bot may be squeezed out of the tumors on the back of milch 

 cows, and killed, enlarging the opening a trifle with a clean knife, 

 if necessary, or a drop of kerosene, or a little mercurial ointment may 

 be introduced through the opening of each tumor. This squeezng 

 out of the bots causes some pain, it must be confessed, as is evidenced 

 by the cattle wincing during the operation. After the bots have been 

 removed or killed within the tumors, the latter should be dressed a 

 few times with vaseline in which carbolic acid has been mixed, or with 

 some other healing and sterilizing ointment. 



These tumors can be easily detected, when present, by running 

 the hand over the back of the animal. A mixture of one part of 

 powdered sulphur and four parts lard rubbed into and over openings 

 of tumors will kill the bots. 



If the eggs on the hairs are moistened with kerosene when first 

 observed they will not hatch. Repellent materials which are persist- 

 ently sticky, such as fish oil, or a compound of pine tar and kerosene 

 (it is not safe to use too much kerosene) and fish oil, may be frequently 

 smeared over the back, sides, belly, fore Jegs and roots of the tail 

 of stock running in pasture, and will in a great measure reduce the 

 evil. This is not always practicable. Of course, the flies will find 

 some animal poorly protected, and this animal will sufifer all the more 

 on account of the protected condition of its mates. Fish oil emulsion, 

 first used against the horn fly, might well be used on stock running in 

 pasture, both for the ox warble and the horse bot fly. It is inexpensive 

 and easily applied, and those who have worked with it claim its effects 



