THE FLIES THAT CAUSE MYIASIS IX MAN 



155 



two cases of intestinal myiasis, both in females, are lacking, these may 

 not be authentic, or they may actually have been cases of urinary 

 myiasis. 



Literature. — For a detailed and apparently careful, though old, de- 

 scription of the immature stages, see Laboulbene (78) ; for a more re- 



FiciURE 92. — Teichomifza fusca, larva: A, Dorsal view; B, enlargement of an- 

 terior spiracle; C, enlargement of abdominal ambulatory protnberance ; 

 D, enlargement of posterior spiracle. (After Laboulbene {18, pi. 5).) 



cent one, see Vogler (1-50) ; for pathogenesis, see Laboulbene (78) and 

 Chevrel (27, p. 384) : for the taxonomy, see Becker (12) . 



The Family DROSOPHILIDAE 



This is a family of small flies, rarely exceeding 5 mm. in length. In 

 its typical members the arista is plumose, the postvertical bristles are 

 convergent, the vibrissae are present, the costa is twice broken, vein 

 8e is rudimentary, and the anal cell is complete; all these characters, 

 however, are subject to variation in some genera. The family includes 

 the small, yellowish flies so well known in genetical research. Only 

 one genus has been reported as involved in human myiasis, and such 

 reports as we have are not convincing as to the actual pathogenic role in 

 this respect. 



For a guide to the taxonomy of the American species, as well as for 

 considerable information on the biology and immature stages, see 

 Sturtevant (147) and Patterson (98). 



The Genus DROSOPHILA Fallen 



Species of Drosophila have all the characters given above as typical. 

 In addition the head and pronotum are of the usual form, the head 

 being no broader than the thorax and the pronotum being shorter 

 than the head; the lower reclinate fronto-orbital bristle is behind the 

 proclinate fronto-orbital, yet much closer to that bristle than to the 

 upper reclinate fronto-orbital; there are two dorsocentrals and no 

 acrostical bristles; the acrostical hairs are short and appressed and 

 arranged in six or more rows; the discal and second basal cells are 

 united. 



