280 THP HOUSE FLY DISEASE CARRIER 



been attracted by the presence of these food supplies. 

 Of these 23,087 flies, 22,808 were Mitsca domestica, 

 i. e., ninety-eight and eight-tenths per cent, of the whole 

 number captured. The remainder, consisting of one 

 and two-tenths per cent, of the whole, comprised vari- 

 ous species, the most significant ones being Hornalomyia 

 canicularis (the species ordinarily called the "little 

 house fly") of which eighty-one specimens were cap- 

 tured; the stable fly (Muscina stabulans), thirty-seven 

 specimens; Phora femorata, thirty-three; Liicilia cccsar, 

 eighteen; Drosophila ampelophfta, fifteen; Sarcophaga 

 trivialis, ten ; Calliphora crythroccphala, seven. Mnsca 

 domestica is, therefore, the species of great significance. 

 Homalomyia canicularis is important. Muscina stabu- 

 lans is of somewhat lesser importance. Drosophila 

 anipclophila is an important form, and had more of the 

 captures been made in the autumn its numbers would 

 probably have been greater, since beyond doubt it is 

 an abundant species in houses after fruit has begun to 

 make its appearance (say, in August and September 

 and on until winter time) in pantries and on dining- 

 room sideboards. The Calliphora and the Lucilia are 

 of slight importance, not only on account of their rar- 

 ity in houses, but because they are not true excrement 

 insects. Other forms were taken, but either their 

 household occurrence was probably accidental, or from 

 their habits they have no significance in the disease- 

 transfer function. 



Extracted from : A Contribution to the Study of the Insect 

 Fauna of Human Excrement. By L. O. Howard (p. 547). 



