516 



FLY MAGGOTS AND MYIASIS 



eggs hatch, and the larvic burrow out through the wall of the 

 oesophagus, migrate through whatever tissues they may find in 

 their path, and ultimately reach a position just under the skin, 

 usually on the back, where they finish their development. Occa- 

 sionally the larvae penetrate the skin directly, but the indirect 



Fig. 247. 



Larva of Hypoderma bovis; A, 

 view. X 2. 



posterior view; B, lateral 



method is the usual one. Recent investigations indicate that the 

 two species differ somewhat in this respect. In Russia the horse 

 botfly, Gastrophilus hamorrhoidalis, which normally develops 

 in the stomach of the horse, occasionally lives under the human 

 skin. 



African Skin Maggots. — The commonest species of maggot 

 which develops in the human skin in Africa is the " ver du Cayor," 



the larva of the tumbu fly, 

 Cordylobia anthropophaga. 

 This fly belongs to the same 

 family as blowflies and 

 houseflies. It is widespread 

 throughout Africa, from 

 Senegal and Khartoum to 

 the Transvaal. To quote 

 from Fuller, " There is no 

 ill the flesh is heir to among 

 the vicissitudes of life in 

 South Africa, which is more 

 offensive than parasitism 

 by (this insect)." Man is not the main host of the larvte of this 

 fly, but he suffers in common with a large number of wild and 

 domesticated animals, especially domestic dogs. 



The adult fly (Fig. 248) is about the size of a blowfly (half an 

 inch long), and is brown in color. The thorax is rusty to yellow- 

 ish brown with indistinct dusky stripes, the abdomen pale brown, 

 a little darker toward its tip, and with two dusky bands. Ex- 



«^^ 



Fig. 248. Adult female of African skin 

 maggot, Cordylobia anthropophaga. X 3. 

 (After Castellani and Chalmers.) 



