WA Site E FLY, 
INTRODUCTORY. 
The wide distribution of the stable fly (Stomozys calcitrans L.), its 
intimate association with man, and its close resemblance to the so- 
called house fly or typhoid fly (Musca domestica L.) have led many 
to consider it identical with that species. Not until the stable fly 
becomes so numerous as greatly to harass live stock, or until the acute 
pain which accompanies the insertion of its proboscis is felt by the 
farmer himself, is man usually brought to a realization of the presence 
of a fly different from that distributor of typhoid germs, the common 
house fly. Severe outbreaks of the stable fly have led many to ob- 
serve the flies more closely and to note their identity. Thus many 
individuals in certain sections speak of the stable fly as the ‘‘wild 
fly,” “straw fly,” or ‘‘biting house fly,” to differentiate it from the 
ordinary house fly. The common name “stable fly” is applied to it 
because of its continual presence around stables, except during cold 
weather, and its comparative scarcity about the dwellings of man. 
Until very recently the stable fly received little attention at the hands 
of the entomologist or others. The recent demonstration by Drs. 
Rosenau and Brues of the possibility of the transmission of a distress- 
ing disease of man, known as infantile paralysis, through the agency 
of this fly, greatly stimulated interest in the study of the insect. A 
similar effect was also produced by the possible connection of this 
pest with the transmission of pellagra in man, as pointed out by 
Messrs. Jennings and King of the Bureau of Entomology. The inves- 
tigations of authorities in this and other countries indicate that an 
important relation exists between certain diseases of domestic ani- 
mals and this fly. Aside from the réle played by the insect in disease 
transmission, it is an all-too-common and persistent pest to domestic 
animals. It will thus be seen that the stable fly may be of impor- 
tance in three ways, namely, as a tormentor of live stock, as a carrier 
of diseases of domestic animals, and as a transmitter of diseases in 
man. 
DISTRIBUTION AND ABUNDANCE. 
The stable fly is one of the most widely distributed of insects. It 
appears to occur commonly in all parts of the world inhabited by man 
and the larger domestic animals. In those parts of the tropical, sub- 
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