11 2 
Leptidce, or Snipe-flies 
Leptidae or Snipe-Flies 
The family Leptidae is made up of moderate or large sized flies, 
predaceous in habit. They are sufficiently characterized in the keys 
of Chapter XII. Four blood¬ 
sucking species belonging to three 
genera have been reported. Of 
these Symphoromyia pachyceras is 
a western species. Dr. J. C. 
Bradley, from personal experience, 
reports it as a vicious biter. 
Oestridae or Bot-flies 
To the family Oestridae belong 
the bot and warble-flies so fre¬ 
quently injurious to animals. 
The adults are large, or of 
medium size, heavy bodied, rather 
hairy, and usually resemble bees in appearance. 
The larvae live parasitieally in various parts of the body of mam¬ 
mals, such as the stomach (horse bot-fly), the subcutaneous con¬ 
nective tissue (warble-fly of cattle), or the nasal passage (sheep bot¬ 
fly or head maggot). 
There are on record many cases of the occurrence of the larvae 
of Oestridae as occasional parasites of man. A number of these have 
been collected and reviewed in a thesis by Mme. Petrovskaia (1910). 
The majority of them relate to the following species. 
Gasirophilus hcemorrhoidalis , the red tailed bot-fly, is one of the 
species whose larvae are most commonly found in the stomach of the 
horse. Schoch (1877) cites the case of a woman who suffered from 
a severe case of chronic catarrh of the stomach, and who vomited, 
and also passed from the anus, larvae which apparently belonged 
to this species. vSuch cases are exceedingly rare but instances of 
subcutaneous infestation are fairly numerous. In the latter type 
these larvae are sometimes the cause of the peculiar “ creeping myasis. 
This is characterized at its beginning by a very painful swelling 
which gradually migrates, producing a narrow raised line four to 
twenty-five millimeters broad. When the larva is mature, sometimes 
after several months, it becomes stationary and a tumor is formed 
which opens and discharges the larva along with pus and scrum. 
80. ( c ) Mouth parts of Tabanus. After Gnin- 
berg. 
