320 INSECTS ATTACKING STOCK AND POULTRY 



evidenced by the cattle wincing during the operation (Fig. 326). 

 Or introduce a drop of kerosene or a little mercurial ointment 

 through the opening of each tumor. 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 ointment or sterilizing material. A mixture 

 of one quart of powdered sulfur and four parts lard, rubbed into 

 and over openings of tumors, will kill the bots. 



Repellent Materials. If the eggs on the hairs are moistened 

 with kerosene when first observed, they will not hatch. It is not 



FIG. 325. Striped warble-fly or heel fly. Natural size shown by hair line on right. 



(Lugger.) 



safe to use too much kerosene. Repellent materials, which are 

 persistently sticky, such as fish oil, or a compound of pine tar 

 and kerosene and fish oil, may be frequently smeared over the 

 back, sides, belly, fore-legs, and roots of the tail of stock running 

 in pasture. This 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 suffer 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 inex- 



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