FLIES THAT FREQUENT HOUSES 51 



an inch long and that they clung to stones in the stream 

 by a row of eight suckers on the ventral side of the body. 

 When ready to pupate the larvse crawl higher up on stones 

 where the spray dashes on them. The pupa? are small, 

 flatish, and breathe by a pair of respiratory tubes on the 

 thorax. After about three weeks the adults issue and 

 fly to the overhanging weeds. 



It is an interesting fact that one of the species of this 

 family is a carrier of the disease known as phlebotomus 

 fever. This disease occurs in the countries surrounding 

 the Mediterranean Sea and the fly concerned in carrying 

 the fever is Phlebotomus papatasii. The habits of this 

 fly seem to be similar to those of the related species 

 occurring in this country. The adult fly is said to be a 

 vicious biter, although very small, and does its biting 

 entirely at night. We have one species of Phlebotomus 

 in the United States, but it is not known whether it will 

 act as a carrier of this disease or not. 



It seems also to have been demonstrated that a species 

 of Phlebotomus in South America transmits the disease 

 verruga. 



REFERENCES TO ECONOMIC LITERATURE ON THESE FLIES 



THE CLUSTER-FLY 



Pollenia rudis 



1883. DALL, W. H. Proc. U. S. Nat. Mus., Vol. V, p. 635. 

 1893. LINTNER, J. A. Ninth Kept., N. Y. Ins., pp. 309-314. 

 1911. HOWARD, L. O. The house-fly, disease carrier, p. 236. 

 See Lintner's ninth Rept. for further references. 



