106 HOUSE, GARDEN, AND FIELD 



Sometimes all the flies in a particular shop (a provision- 

 shop) are found to harbour Chelifers. 



2. The Black Fly (Musca corvina) is very like the common 

 house-fly, and like it is marked with four dark streaks on 

 the thorax ; in the black fly, however, the streaks are con- 

 tinued upon the scutellum. The abdomen of the male 

 is yellowish, that of the female dark grey. This fly is 

 decidedly larger than the common house-fly. It is fre- 

 quent on walls around stables, and occasionally enters 

 houses, as if by mistake, or else to hibernate there. 



3. The Stable- fly (Cyrtoneura stabulans) is larger than 

 the common house-fly, and about as big as the black fly. 

 It is of a grey colour, with a reddish tinge on the scutellum 

 and legs. The four dark streaks on the thorax and the 

 dark streak on the abdomen, which are conspicuous in 

 the common house-fly, seem pale and almost washed out 

 in the stable-fly. This species is common in outhouses 

 and stables in the north of England, as well as out of 

 doors, but is not often seen in houses ; it is comparatively 

 rare in the southern counties. The larva has often been 

 found feeding on radishes or other vegetables in a kitchen- 

 garden ; it is said also to prey upon other larvae. 



4. The Little House-fly (Homalomyia canicularis) is a 

 regular inmate of our houses. It is rather smaller and 

 rather paler in colour than the common house-fly ; the 

 abdomen is of conical shape behind ; the bristle of the 

 antenna is not feathered, and the wing-pattern is slightly 

 different. The males, which are far commoner than the 

 females, have yellowish translucent patches on either side 

 of the base of the abdomen, which may be very conspicu- 

 ous, when the fly is seen against the light shining through 

 the window-pane. The mode of flight also is peculiar. 

 Sometimes we remark only a slow movement to and fro, 

 just beneath the ceiling, but at other times, in hot summer 

 weather, the flies execute a peculiar evolution, which 

 enables us to identify them. One darts at another, and 

 after a sort of hasty kiss the two fly off in different direc- 



