12 INSECTS AFFECTING DOMESTIC ANIMALS. — 
include the mosquitoes which are notably irritating to a great number 
of domestic animals as well as toman. They are distinguished by the 
slender bodies and lancet-like mouth parts. 
The Simuliide include the buffalo gnats, small, heavy-bodied insects, 
which, by their persistent attacks upon the eyes, ears, and other 
exposed parts of the body, as well as by their painful and frequently 
poisonous bites, cause intense suffering and often death to their victims. 
The Tabanide include the large horse-flies. They have a very severe 
bite, and cause much discomfort to horses and cattle, and often to man 
as well. 
The (stride, or bot-flies, are truly parasitic during part of their life- 
time, occupying various localities—the stomach of the horse, the frontal 
sinus of the sheep, subcutaneous tissue of cattle, rabbits, etc., and the 
testes of squirrels. In the adult form they are two-winged insects, 
with rudimentary mouth parts, and simply deposit their eggs in proper 
places for the young to gain entrance to their hosts. In this form they 
may do much harm, however, by worrying animals in their efforts to 
accomplish the deposition of eggs. As larvie they live within the 
tissues of the host, passing from these to the ground to enter the pupal 
stage, and from this they issue in the adult form. 
The Muscide, a large family, including such forms as the common 
house fly, the horn fly, and others, includes a number of species that 
are of direct importance in their attacks upon domestic animals. In 
some cases it is the irritation or bite of the adult; in others, as with 
the screw-worm and blow-fly, the larva becomes the inimical form. 
The Hippoboscidie include the sheep ticks and the bird ticks. The 
latter have the wings common to the other flies; the former is wingless. 
They have mouth parts fitted for puncturing the skin and drawing up 
the liquid contents of the tissues. 
The Nycteribiidie, or spider flies, are found only on bats, and are con- 
stant parasites. They are remarkable for their slender, spider-like 
bodies. They deserve mention because of their peculiar structure and 
special adaptation to parasitic life, notwithtsanding that they are not 
found upon domesticated animals nor likely ever to be. 
The Pulicide, or fleas, are now usually placed in a separate order— 
the Siphonaptera—though in some respects they show affinities to the 
Diptera. They occur on a number of different animals, confining them- 
selves in most cases to different species of hosts. They may live, how- 
ever, much of the time free from the host and the larve develop inde- 
pendently of the host, though in many cases it must be that they are 
confined to the places occupied by the host. 
The Hemiptera are distinguished by having the mouth parts adapted 
for suction and the wings either membranous or with the basal half of 
_ the fore wings thickened and leathery. The order contains three sub- 
_orders, the Heteroptera, Homoptera, and Parasita. The first includes 
thosehaving the fore wings thickened at base. In this division we have 
the bed-bugs and cone-nose, and in the family Belostomatidx insects 
