FARMERS BULLETIlSr 851. 



species is shown in figure 5. The "lesser house fly" is distinguished 

 from the ordinary house fly by its paler and more pointed body. 

 The male, which is commoner than the female, has large pale patches 

 at the base of the abdomen, which are translucent when the fly is seen 



Fig. 2.— a stable fly ( Muscina .stabulans). Much Fig. 3.— One of the blue-bottle flies {Phormia 



enlarged. terraenovae). Much enlarged. 



on the window pane. These little flies are not the young of the 

 larger flies. Flies do not grow after the wings have once expanded 

 and dried. Still another fly, and this one is still smaller, is a jet 

 black species known as the window 

 fly.^ Its larva is a white, very 

 slender, almost threadlike creature 

 and is found in cracks of the floor 

 in buildings, where it feeds on other 

 small insects. 



In late summer and autumn many 

 specunens of a small fruit fly, known 

 as the "vinegar fly" (fig. 6), make 

 their appearance, attracted by the 

 odor of overripe fruit. 



AU of these species, however, 

 are greatly dwarfed in numbers 

 by the common house fly. In 1900 

 the senior author made collections 

 of the flies in dining rooms in different parts of the country, and 

 found that the true house fly made up 98.8 per cent of the whole 

 number captured. The remainder comprised various speciesj 

 including those mentioned above. 



One of the green-bottle flies (Liwi'ia • 

 caesar). Much enlarged. ( 



Scenopinus /enestralis L, 



