CUTANEOUS MYIASIS 513 



mals. Its bite is more painful to nuin than is that of the normal 

 human parasite. 



The attacks of the floor maggot can very easily be avoided by 

 sleeping on mats or beds raised just a few inches from the ground. 



Maggots Under the Skin 



There are several species of flies in which the larva? develop 

 under the human skin, like " warbles " in cattl(>, but they are 

 found only in Africa and in tropical America. The African 

 species are closely related to the blowflies and fleshflics, whereas 

 the American species, of which there is usually believed to be 

 but a single one, is a true botfly, closely allied to the ox warble. 



Fig. 245. Adult of South American skin maggot, Dermatohia honmiis. X 2. 



(After Castellani and Chalmers.) 



Dermatohia. — The American species, sometimes called the 

 human botfly, Dermatohia hominis (Fig. 245), is found through- 

 out tropical America from Mexico to northern Argentina. Its 

 larvse develop not only in man but also in many other animals, 

 as dogs, cattle, mules, hogs, etc. In certain parts of South 

 America the hides of cattle become so riddled with the perfora- 

 tions made b}' these bots that they are rendered quite worthless. 

 The infestation in man is contracted chiefly in forest regions, and 

 apparently very seldom in houses, a fact which possibly accounts 

 for the greater degree to which dogs are parasitized by it than are 

 cats, and men than women or young children. 



The adult ?iy (Fig. 245) is about the size of a blowflv (half an 

 inch in length) with face and legs yellowish, thorax bluish black 

 with a grayish bloom, and the abdomen a beautiful metallic 



