AL CASE OF TEXAS FEVER.
Fig. 2. SPLEEN OF HEALTHY STEER.]

[Illustration: PLATE XLV. TEXAS FEVER.]

[Illustration: PLATE XLVI. THE CATTLE TICK (MARGAROPUS ANNULATUS),
THE CARRIER OF TEXAS FEVER.]

[Illustration: PLATE XLVII. THE CATTLE TICK (MARGAROPUS ANNULATUS).
Figs. 1 and 2 DORSAL AND VENTRAL VIEWS OF MALE.
Figs. 3 and 4 DORSAL AND VENTRAL VIEWS OF REPLETE FEMALE. (GREATLY
ENLARGED.)]

[Illustration: PLATE XLVIII.
PORTION OF A STEER'S HIDE, SHOWING THE TEXAS-FEVER TICK (MARGAROPUS
ANNULATUS) OF THE UNITED STATES. NATURAL SIZE. ORIGINAL.]

[Illustration: PLATE XLIX.
FIG. 1.--TICK-INFESTED STEER.]
FIG. 2.--DIPPING CATTLE TO KILL TICKS.]

[Illustration: PLATE L. FACSIMILE OF POSTER USED IN TICK ERADICATION
WORK.]

The fly lays its eggs in freshly dropped cow manure. They hatch in about 24
hours, and the larvae or maggots in four or five days develop to the pupal
stage, which lasts a week or 10 days. From the pupal stage the mature fly
emerges. The entire process of development from the deposition of the egg
to the appearance of the mature fly therefore may be completed in two
weeks, or even in a shorter time. To protect cattle from attacks of the
hornfly they may be treated with one of the remedies mentioned above (p.
502). Dipping cattle in a vat provided with splashboards set at the proper
angle destroys most of the hornflies present on the animals. Unless the
splashboards are used all but a few of the flies succeed in escaping as the
cattle plunge into the bath and later return to them. Scattering the
droppings of cattle with a shovel, or with brush dragged over pastures, in
order to insure the rapid drying of the manure and consequent destruction
of the larvae, is, when practicable, an efficient means of reducing the
number of these flies.

[Illustration: FIG. 1.--Hornfly (_Lyperosia irritans_) in resting
position. Enlarged. (From Bureau of Entomology.)]

[Illustration: FIG. 2.--Hornflies (_Lyperosia irritans_) on cow
horn. (From Bureau of Entomology.)]

BUFFALO GNATS.

These small flies, also known as black flies, are about one-eighth of an
inch long and have a characteristic "humped" back (fig. 3). They breed in
running water and appear in swarms during spring and summer, often in
enormous numbers, causing great annoyance to stock and human beings, on
account of their bites