46 



HOUSEHOLD IX SECTS 



be said, however, that later experiments by different 

 workers have given only negative results in the trans- 

 mission of this disease. 



It has been suggested, with some show of reason, that 

 this fly may play a role in the transmission of pellagra. 



*v 



THE STABLE-FLY 



Muscina stabulans 



The stable-fly resembles the house-fly considerably 

 but it has a longer and more robust body. It is evidently 



not as abundant in houses 

 as some of the other species. 

 Hewitt says he usually finds 

 it in the early summer be- 

 fore the house-fly has ap- 

 peared in any numbers. It 

 seems to be widely dis- 

 tributed in this country 

 and in Europe and is often 

 mistaken for the house-fly 

 (Fig. 18). The dorsal side 

 of the thorax is gray and 

 bears four dark longitudi- 

 nal lines quite similar to 

 the thorax of the house-fly. 



The eggs of the stable-fly are laid on decaying vegetables, 

 fruits, fungi, and in cow manure. Hewitt says that the 

 larvae sometimes attack growing vegetables, probably 

 having been introduced about the plants in manure. 

 Howard found the flies frequenting human excreta and 

 the larva? breeding in this material. It has been reared 



Fig. 18. — The stable-fly, Muscina 

 stabulans. (X 3.) 



