THE MAGGOT FLY 305 



animal often has a rapacious appetite. Ransom, of the United 

 States Bureau of Animal Industry, after making an extensive study 

 of tape-worm in sheep, did not advise a remedy that will remove 

 it from the live animal. However, the following is recommended by 

 several writers: Oil of male shield fern, 1 dram; raw linseed oil, 

 2 to 4 ounces. Give the dose after the animal has been fasted 16 

 to 20 hours. 



Some types of tape 1 - worm infest sheep in the cyst or larval 

 stage only, the adults living in dogs, etc. The cysts are found in 

 brain., liver and muscles, and may cause sheep much discomfort. 



Grub in the Head. The sheep bot-fly (Estrus ovis) deposits 

 larvae instead of eggs. Its favorite place for deposition is in the 

 nostrils of the sheep whence the larvae work their way up into the 

 nasal cavities. The fly causes the sheep a great deal of annoyance 

 at the time it deposits its larvae, both by its buzzing about, and by 

 its coming in contact with the sheep's nose. Anyone who has ob- 

 served sheep much in summer has seen certain individuals in the 

 flock stamping their feet, ducking their heads, and rubbing their 

 noses in the dust or dirt. All of these actions are caused by the 

 bot-fly. 



After the larvae have reached their destination, up in the nasal 

 cavities, they fasten themselves to the lining membranes by means 

 of little hooks. These, along with the pressure of the growing grub, 

 cause a great deal of irritation, and the sheep resorts to a violent 

 snorting cough in its effort to dispel the grub. Not infrequently the 

 grub so affects the brain as to cause death, and they always cause 

 much discomfort, which is attended by loss of flesh. 



The most effective means of combating bot-fly is to keep the 

 noses of the sheep smeared with pine tar through the summer 

 months. The tar repels the fly and the larvae are not deposited 

 where they can gain access to the head. Some sheepmen say that 

 the sheep will attend to the smearing of their own noses if salt or 

 grain is placed in a trough containing tar. 



It is doubtful whether bot-fly causes as much trouble on the 

 prairies as it does in wooded regions. In fact, the writer does not 

 recall having seen flocks affected with grub on the prairie farms 

 of Illinois. 



The Maggot Fly (Musca vomitorium) . Wounds and places 

 befouled by dung or urine are likely to attract the maggot fly. The 

 oily, gummy wool about the base of Merino rams' horns may also 

 20 



