The House-fly as a Carrier of Disease 



147 



ff. With legs more or less yellowish; palpi 

 yellow. LarvEe in decaying vegetable 

 substances, dung, etc. M. siabulans 



It is almost universally believed that the adults of Musca domestica 

 hibernate, remaining dormant throughout the winter in attics, 

 around chimneys, and in sheltered but cold situations. This belief 

 has been challenged by Skinner (1913), who maintains that all the 

 adult flies die off during the fall and early winter and that the species 

 is carried over in the pupal stage, and in no other way. The cluster- 

 fly, Pollenia rudis, undoubtedly does hibernate in attics and similar 



108. The house or typhoid fly (Musca domestica C4x)). After Howard. 



situations and is often mistaken for the house-fly. In so far as 

 concerns Musca domestica, the important question as to hibernation 

 in the adult stage is an open one. Many observations by one of the 

 writers (Johannsen) tend to confirm Dr. Skinner's conclusion, in so 

 far as it applies to conditions in the latitude of New York State. 

 Opposed, is the fact that various experimentors, notably Hewitt 

 (1910) and Jepson (1909) wholly failed to carry pupae through the 

 winter. 



The house-fly breeds by preference in horse manure. Indeed, 

 Dr. Howard, whose extensive studies of the species especially qualify 

 him for expressing an opinion on the subject, has estimated that under 

 ordinary city and town conditions, more than ninety per cent of the 

 flies present in houses have come from horse stables or their vicinity. 

 They are not limited to such localities, by any means, for it has been 

 found that they would develop in almost any fermenting organic 

 substance. Thus, they have been bred from pig, chicken, and cow 



