THE GULF COAST TICK. 141 
one cluster, 5 or 6 being a frequent number. The following day 
Mr. Mitchell examined the ears of 933 cattle in Refugio County, Tex., 
and found 15 females and several hundred males. In two instances 
specimens were found in coitu. Many of the males were in clusters of 
from 5 to 10. In another locality 567 cows were examined, 1 female 
tick and 3 males being found, all on different animals. Our records 
show that males were removed from hosts a month after all the 
females had dropped, and it is probable that they remain on the host 
for anumber of months. As with some other species, the males, having 
once fed, do not appear to live long after leaving the host. Thus 2 
males removed from the host a month after the females had dropped 
lived less than a month, one dying in 10 days, although kept under 
the most favorable conditions. 
This species attaches largely to the head, particularly to the ears 
both on the inside and outside. 
LIFE CYCLE. 
Larve may live for 6 months during the winter and for 112 days 
in summer; they engorge as soon as 3 days after application to a 
host and molt as soon as 7 days after dropping. A total effective 
temperature of 399° F. is necessary to produce this molt. Nymphs 
engorge as soon as 5 days after application and molt as soon as 17 
days after dropping, a total effective temperature of 694° F. being 
required to produce this transformation. Adults may live for 388 
days; they mate upon the host, may engorge as soon as 14 days after 
attachment, and begin ovipositing the third day after dropping. 
Eggs hatch as soon as 21 days after deposition, a total effective tem- 
perature of 793° F. being required for incubation. Although adults 
may be found at any time during the year they appear to be much 
more numerous in the summer and early fall than at other seasons. 
The nymphs are to be found in considerable numbers upon birds in 
February and March. 
ECONOMIC IMPORTANCE. 
In the sections where this tick occurs in any numbers it is the 
source of great annoyance to domestic animals, particularly to cattle. 
By attaching to the inside of the ears, as frequently occurs, great 
irritation is caused; in the case of calves, this irritation is sufficient to 
cause suppuration and the formation of large scabs. The injury in 
the ears furnishes opportunity for the screw-worm fly (Chrysomyia 
macellaria) to deposit its eggs, which in the case of equines some- 
times results in the destruction of the cartilage, thus causing the ears 
to droop—a condition known as ‘‘gotched”’ ears. The species is 
also of some importance on account of the fact that it sometimes 
attacks man. 
NATURAL CONTROL. 
The natural enemies of the cattle tick undoubtedly destroy many 
ticks of this species. 
