86 INSECTS AFFECTING DOMESTIC ANIMALS. 
It was described as Gstrus nasalis by Linneus (Fauna Suec.) and 
it was also given the name of veterinus by Clark. It was ineluded by 
Fabricius with hemorrhoidalis under Gistrus equi. The description in 
Systema Nature (Turton’s translation) is as follows: 
Wings immaculate, body ferruginous, sides of the thorax and base of the abdomen 
with white hairs. Deposits its eggs on horses and cattle, the larvie probably pass 
through the stomach like the former one. 
Less than (strus equi. Insertion of the wings and base of the abdomen covered 
with whitish hairs; second segment of the abdomen with two hairy tubercles, 
Beneath and legs rusty brown. Female with sometimes a blackish abdomen. 
Of this species Verrill writes (Ext. and Int. Parasites, p. 28): 
The Gastrophilus nasalis is a smaller species, densely hairy, with the thorax yel- 
lowish red or rust-colored. The abdomen is either whitish at base, with the middle 
black and the apex yellowish brown aud hairy; or the base is whitish and all the 
rest brown; or the middle is black, with the base and apex whitish, with grayish 
hairs. The wings are unspotted. The larve are much like those of the preceding 
[hemorrhoidalis], except that they are smaller, and also live in the stomach of horses. 
They change to pupx beneath the manure, and the flies appear from June to Sep- 
tember. It alsu infests the ass and mule, and some authors say that it lives even in 
cattle. 
Zurn! ascribes this parasite to horses, asses, mules, and goats, and 
says the eggs, 1 mm. long, are laid on the lips and margin of nostrils. 
He describes the full-grown larva as 13 to 14 mm. long, deep yellow or 
yellow brown, thicker behind than before, and the segments 2 to 9 above 
and 2 to 10 below with a single row of yellowish, brown-tipped spines. 
The pupa he described as dark-brown or black, the segments with 
only a single series of horny spines, its length of life in this stage 
from thirty to forty-two days. 
Professor Garman? in a recent paper on the subject gives a record of 
the occurrence of this species in Kentucky. 
From this record it would appear that the species is somewhat 
common and troublesome in that region, and as the species has been 
recorded from many places in this country, it may be looked upon as 
having quite a general distribution. 
The most essential point in habit of this species is the fact that the 
eggs are laid on the lips or nostrils, within easy reach of the tongue, 
and as it is quite probable that they hatch more promptly than those 
of equi, it is more difficult to adopt measures of prevention. Measures 
must consist in preventing as far as possible the deposition of eggs, for 
which purpose the application of a little tar and fish oil to the hairs of 
the under lip may be of service, and where eggs are suspected, the use 
of a wash of carbolic acid to the lips and margin of nostrils. 
According to Garman, the eggs are white, and are attached to the 
hairs of the lip and throat by the greater part of one side. The species 
occurs in Europe and has been observed in New England, New York, 
_ Ohio, Kentucky, Kansas, Utah, and probably elsewhere in this country. 
! Die tierischen Parasiten, p. 100. 
7The Bot Flies of the Horse, Seventh An. Rep. Ky. Ag. Exp. Sta., p. xxvii. 
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