CHAPTER II 



FLIES, OTHER THAN THE HOUSE-FLY, THAT 

 FREQUENT HOUSES 



AMONG the flies commonly found in houses, the house- 

 fly constitutes the major number ; but there are several 

 other species of flies that frequent dwelling rooms, some 

 of which are often mistaken for the house-fly. Perhaps 

 the most common ones found in houses are the biting 

 house-fly, the small house-fly, the cluster-fly, the stable- 

 fly, the "blue-bottle" flies, and the fruit flies. 



Although the foregoing and a few other species of flies 

 are frequently found in dwelling-houses, the house-fly 

 constitutes, by far, the greater portion of all the flies that 

 may occur in living-rooms. Howard, aided by persons in 

 different parts of the United States, made a collection of 

 the flies found in rooms in which food-stuffs were exposed. 

 Altogether, 23,087 flies were caught from various localities 

 in this country. Of these, 98.8 per cent were the common 

 house-fly. Of the remaining 1.2 per cent, the smaller or 

 lesser house-fly was the commonest species. Hamer, in 

 London, found that more than nine-tenths of the flies in 

 kitchens, and living-rooms of houses near depots for 

 horse-refuse, manure, etc., were the common house-fly. 



The following table adapted from Johannsen will serve 

 to distinguish some of the more common of these allied 

 species. A hand lens will be needed to make out some of 

 the characters : 



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