FLIES FOUND IN HOUSES 35 



The larvae emerge about eighteen hours after the eggs are 

 deposited and become full-fed in six to twelve days. The pupal 

 stage lasts nine days or more. 



Anthoniyia radicum. The root fly. 



Many species of the Anthomyid;e occasionally find their way 

 into houses. They are mostly dull, obscurely marked flies about 

 the size of F. cmiicularis, with non-feathered arista and straight 

 4th longitudinal veins. The larvae feed on vegetable matter or 

 excrement and the adults frequent these substances. One of the 

 commonest is A. radiaiui. 



Sarcophaga carnaria L. The flesh fly. 



A large hairy, thick-set but relatively rather elongated fly, 

 with thick legs ; about the size of a blow-fly, but having a grey 

 striped and chequered appearance. (PI. VI, fig. 3.) 



Length. 13 mm. ; span of wings 22 mm. 



Head. Viewed from above has a triangular appearance. Tiie eyes reddish, in the S 



separated by one-fifth and in the ? by one-fourth the diameter of the head. 



Frontal stripe black. PVontal margins of eyes shining white or slightly yellow. 



Cheeks and face white. Antenna black. 

 7'horax. Grey with three well-marked broad longitudinal dark stripes. At each side 



of the middle stripe is a very narrow dark stripe. Numerous long black bristles 



on the thorax and scutellum. 

 Wings. Transparent. Squama large, opaque, white. Ilalteres small. 

 Legs. Black, thick and with numerous bristles. I'ulvilli very marked. 

 Abdomen. Grey and black with distinct chequered appearance, the marking varying 



when the insect is viewed in different lights. All segments, but especially the last 



two, have well-marked black bristles on their posterior margins. 

 The whole body has a very hairy appearance. 



This species is widespread and common in Europe and 

 Australia, and is not infrequently found in houses. It does 

 not occur in the United States. In the United States two 

 other species are common, a large one, S. sarracenics Riley, 

 and a smaller one, S. assidua Walker, about the size of a 

 house-fly. These flies detect the presence of food in a remark- 

 ably short time " and this can only be accounted for on the 

 assumption of a very acute sense of smell. Comparatively 

 fresh fish were exposed, on the shore of L. Erie, N. America, and in 



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