FLIES FOUND IN HOUSES 



17 



TABLE 2. 



Place 



United States^ 



London 

 London 

 Manchester 

 Birmingham 



Manchester 



Flies 

 examined 



23,087 ' 



M. domestica 

 22,808 (98-8 7o) 



35,ooot 28,350: (820/0) 



6,ooo§ 3' 540+ (59 "/o) 



8,553 8,196 (95 »/o) 



24,562 22,360(9170) 



43'430 

 3-856 



30,325 (64 0/0) 



3-374: (87-5 7o) 



F. canicularis 



695o:(i7»/o) 

 1440+ (24%) 



^93(3 7o) 

 "54 (47 "/o) 



9482 (21%) 

 443t("-5''/o) 



Other 

 species 



198 (-8 7o) 



700: (i »/o) 



1020: (i7»/o 



64(1%) 



Observer 



Howard (1912, 



P- ^35) 

 Hamer 



Niven 

 1058 (4'3''/o) Robertson 



(1909) 



3623(8%) ,. (i9'°) 



38:(i"/o) Hewitt (1910, 

 P- 350) 



144,488 118,953 (82 «/o) 19843(14%) 6701(4%) 



* These were collected on sticky fly papers in kitchens and pantries in the States 

 of Massachusetts, New York, Pennsylvania, Virginia, Florida, Georgia, Louisiana, 

 Nebraska, and California and examined in Washington by Mr Coquillet. 



t Flies caught in London on four fly papers exposed in similar situations. 



§ Flies caught in London in four fly traps. 



X Figures calculated from the percentages given. 



Of the whole total of flies examined by these workers 8270 

 were M. domestica. We have seen that the relative proportion 

 of M. domestica to other species varies in different places in the 

 same district and even in different rooms of the same house, and 

 the two sets of figures given by Hamer seem to indicate that 

 different results may be obtained by examining flies caught by 

 different methods. Of the 35,000 flies caught by him on fly 

 papers 82 "/o were M. domestica, whereas of the 6000 caught in 

 balloon traps only 59^/0 belonged to this species. 



Newstead (1907, p. 6) investigating the prevalence of different 

 species says M. domestica " is by far the commonest species met 

 with, and quite 90 "/o of the flies which infest houses in Liverpool 

 are of this kind." Austen (1909, p. 4) examining flies caught in 

 various centres in London also came to the conclusion that this 

 was by far the commonest species. 



All the records that are available emphasize the fact that at 

 the height of the fly season M. domestica largely outnumbers all 

 the other flies caught in traps or on fly papers in houses in 

 towns, and by this means of obtaining statistics F. canicularis is 

 the next most common, forming about 14 "/o of the flies caught. 



G.-S.' 2 



