FLIES FOUND IN HOUSES 3/ 



IVings. Clear, with smoky patch near the tip. Squama small. Halteres relatively 



large and knob flattened dorso-ventrally. 

 Le^s. Yellow, but last joint of tarsus black. Tibiae show several stout spines. 

 Abdomeu. Shining violet, with four distinct visible segments. One pair of marked 



dorso-lateral bristles on second and fourth segments, and two pairs on third 



segment. 



This fly is not infrequently found in houses, but as a rule 

 stays on the windows and is not attracted to food. It breeds in 

 excreta of various kinds. 



PiopJiila casci L. The cheese fly. 



A small, shining- black, elongated fly, with transparent 

 iridescent wings. (PL VII, fig. 2.) 



Length. 4 mm. ; span of wings 8 mm. 



Head. Globular, eyes separated by an area equal to half the diameter of the head. 



Frons and vertex black, cheeks and face yellow. Antenna; yellow with black 



non-feathered arista;. 

 Thorax. Black with a few bristles. 



Wiitgs. Very transparent. Squama small and rather more opaque. 

 Legs. Femur dark, tibia proximal part yellow, distal portion black, tarsus yellow 



except two terminal joints which are dark. 

 Abdomen. Very dark, with well-marked segments. 



The fly is not uncommonly found in houses. It runs actively 

 and is quick of flight. 



"The larvae, commonly called cheese-skippers, live in cheese, 

 ham, bacon, and any fatty material and do much damage. The 

 cheese fly, under ordinary circumstances, is not a dangerous 

 species, but it is well to remember that not only has it been 

 reared from dead bodies, but that it is also attracted to 

 excreta of all kinds" (Howard, 1911, p. 251). Austen records 

 a case of myiasis of the nasal cavity due to the larvse of this fly 

 (1912, p. 13). 



Scatophaga stercoraria L. The yellow dung fly. 



This is an active, rather slender fly. The male is bright 

 yellow and the female dull brownish yellow. (PL VIII.) 



Length. 8 mm. ; span of wings 18 mm. 



Head. Globular, eyes brown and separated in both sexes by an area equal to half 

 the width of the head. Frontal stripe rich yellowish brown in S , dull yellow 



