204 LIFE HISTORY OF NORTH AMERICAN TICKS. 
ing animal matter must frequently result in suppuration and exten- 
sive proliferation, as well as forming a suitable place for the breeding 
of screw-worms. 
NATURAL CONTROL. 
No natural enemies of this tick have been recorded in the United 
States. Cold appears to have a decided effect on both adults and 
larve. At Dallas, Tex., during the early winter of 1909, when a 
minimum temperature of 20° F. was reached, many engorged females 
were killed and the few eggs deposited by others failed to hatch. 
ARTIFICIAL CONTROL. 
This tick is undoubtedly the easiest species to deal with that occurs 
im the United States on account of the short life of the larve and the 
ease with which the ticks may be destroyed on the host. The frequent 
application of oil to the ears will assist in keeping horses free from 
them. One of the authors is informed by men at Tampico, Mexico, 
that kerosene and lard are frequently applied to the ears of horses 
and mules in that section in order to destroy the ticks. Reinfestation 
was said to take place again very soon, however, as no effort is made 
to prevent the dropping of the engorged females or to starve the 
larve. The keeping of stock from an infested pasture for four months 
in summer will probably be sufficient to insure the starvation of the 
seed ticks. 
