96 THE HOUSE FLY— DISEASE CARRIER 



there are only two records of the finding of house flies, 

 and one of these is somewhat doubtful. 



One of their records shows the finding of thirty-three 

 larvc-e in the stomach of a horned lark, but it is quite 

 possible that these larvae were not those of Musca do- 

 mcstica. The other record shows the finding of a single 

 adult house fly in the stomach of a white-eyed vireo. 

 The writer has watched the house wren feeding its 

 young hour after hour, and has noticed that the in- 

 sects brought to the nest were for the most part small 

 caterpillars, although there were plenty of flies on the 

 porch where the nest was built. 



The great group of insectivorous birds known as the 

 fly-catchers as a matter of fact do not prefer the flies. 

 As the writer has been told by Prof. F. E. L. Beal, an 

 authority on the subject, they feed by preference upon 

 winged hymenopterous insects, which constitute the 

 bulk of. their food. 



W. D. Doan in Bulletin 3 of the West Virginia Ex- 

 periment Station records finding house flies in the 

 stomachs of the cedar bird, the wood pewee, and the 

 palm warbler. 



Domestic poultry, however, when given the oppor- 

 tunity, will feed with some avidity upon house fly lar- 

 vae. Hens given the run of a barnyard destroy very 

 many larvae in scraping about the edge of the manure 

 pile, and more than one letter has been received from 

 persons who, admitting flocks of poultry to the barn- 

 yard for the first time, have discovered an appreciable 

 reduction in the number of adult flies visiting the house. 



