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WARBLES IN HIDES: 
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The Warble Fly, or Ox Bot Fly {Hypoderma Bovis , De Geer; 
CEstrus Bovis , Clark), is an insect belonging to the order 
Diptera, and is classed in the sub-division CEstridae. There 
are several different insects belonging to this class, and it is 
peculiar that each species is confined to its own quadruped : 
for instance, the Horse Bot Fly attacks the horse, the Ox Bot 
Fly attacks cattle, and that of the sheep, reindeer, &c., attacks 
those animals respectively. They have also each their own 
mode of attack, the Horse Bot Fly laying its eggs on the 
hairs of the leg or mane, the Ox Bot Fly its eggs in or on the 
hide, while those of the Sheep Bot Fly are laid in the nostril 
of the animal. Their maggots reside respectively in the 
stomach, hide, and nostril of the animals before mentioned, 
and from these circumstances the CEstridae are divided into 
three main sections—viz., the Gastric, of which the Horse Bot 
Fly is an example ; the Cutaneous, as the Ox Bot Fly ; and 
the Cervical, as the Sheep Nostril Fly. The Ox Bot Fly, or 
Warble Fly, is slightly more than half an inch long, and is 
rather larger than the common Horse Bot Fly. It is not 
unlike a light-made Humble Bee in appearance, indeed an 
inexperienced observer might easily mistake it for one, at first 
sight. Its body is covered with hairs ; the head is large, the 
Fig. t.—W arble Fly or Ox Bot Fly. Fig. 2.—Head magnified. 
(After George Shaw, M.D., F. R.S., &c.) 
face being of a yellow colour. Very few of the perfect 
insects have a mouth, and they do not feed during the fly 
state. There are four raised lines along its fore body or 
a 2 
