TICKS— IXODOIDEA 293 



quarts of water added to it before using. Pure kerosene is 

 too strong and causes loss of hair. Stavesacre seeds (gij) 

 boiled in water (Oij) is an efficient agent to destroy lice. 



TICKS. IXODOIDEA. 



Definition.- — ^Ticks are skin parasites which, however, do 

 not remain parasitic throughout life. The females especially 

 attach themselves to the skin into which they bore. The 

 most important tick is the Texas cattle tick (Margaropus 

 annulatus) which transmits the germ of Texas fever. While 

 common on cattle in the Southern States it is only an occa- 

 sional visitor in the North, where it is unable to withstand 

 the cold winter. Ixodes reduvius, which is parasitic on sheep 

 and cattle, is not uncommon. The same treatment recom- 

 mended for lice will destroy ticks. The best treatment for 

 ticks in sheep is the arsenical dip. (For eradication of the 

 Texas fever tick see Texas Fever.) 



SPINOSE EAR TICK. 



A troublesome tick found in the semiarid west (Oklahoma, 

 New Mexico, Arizona, California, and occasionally as far 

 north as Oregon) is the spinose ear tick (Ornithodoros 

 megnini) which infests the outer ear of cattle, horses, dogs, 

 and sheep. In badly infested areas even wild animals, 

 especially jack rabbits, are attacked. 



This tick does serious harm to live stock causing filling of 

 the ear with masses of debris, ear wax and ticks, and not 

 infrequently leads to ulceration, external otitis, a condition 

 known locally as "ear canker." In badly infested animals 

 emaciation, impaired milk secretion in cows, nervous and 

 digestive disorders have been noted. Old range cows and 

 run-down animals have been known to succumb during the 

 late winter or early spring. 



Life History.— The spinose ear ticks enter the ears of 

 animals when small, six-legged larvae invisible to the naked 

 eye. They usually attach themselves to the tender skin 

 inside the ear, just below the hair line. In one to two weeks 

 they have grown to several tunes their original size and 



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