NOTES ON THE MYIASIS-PRODUCING DIPTERA. 243 



Cordvlohia aiitliropophaga, Blanchard. — This is the most important specific 

 myiasis-producing Calhphorine of Africa, where it is widely distributed, ranging 

 from the Bahr-el-Ghazal Province of the Anglo-Egyptian Sudan in the east, and the 

 northern limits of Senegal in the west, to Natal in the south. The most complete 

 account of its life-history and habits will be found in Roubaud's, " Etudes sur la 

 Faune parasitaire de I'Afrique Occidentale Fran9aise," Part 1. In its larval stage 

 it is essentially a parasite of dogs, but is also found in a number of other domestic 

 animals. The female fly lays her eggs in dust, sand, earth, etc., where the host is 

 accustomed to lie. The first stage larva, which is extremely small but very active, 

 on finding itself in the neighbourhood of the skin of a host, attaches itself to it, and 

 then bores its way into the epidermis. It now rapidly passes through its moults, 

 and the third stage larva, which is very distinct from the first instar in external 

 structure, as is the case in many of the allied Calliphorinae and the Oestridae, 

 forms a palpable tumour below the skin, its posterior extremity being in the 

 vicinity of the opening into the tumour, so that air can be taken in through the 

 posterior stigmata. These tumours never suppurate in the ordinary course of events, 

 but may do so, if for any reason the larva dies. 



Cordylobia (Stasisia) rodhaini, Ged. — This Calhphorine is the only other species 

 whose larvae are known to cause cutaneous myiasis in Africa. It appears to be 

 restricted to the damp forest regions of the Congo, and its larvae are normally found 

 under the skin of the duikers, such as the bay duiker, Cephalophus dorsalis, and 

 the common duiker, Cephalophus grimmi, as well in the large rodent, Cricetomys 

 gambianus ; man is only accidentally infested. Thin-skinned animals are the only 

 ones attacked, and the immobihty of the host at the time of the hatching of the 

 larva from the egg is a necessity. As in the case of Cordylobia anthropophaga, the 

 eggs are laid in damp earth, particularly where the hosts are accustomed to lie, and 

 where urine has been voided. The first-stage larva soon makes its way into the 

 epidermis and rapidly passes through its moults, reaching maturity in fifteen days. 



A comparative study of the various larval instars with those of other 

 Calliphorinae would be of great interest, and I trust that those who have oppor- 

 tunities of obtaining them will send me any specimens. 



Wohlfahrtia magnifica, Schiner. — This species is the only European specific 

 myiasis-producing fly, and belongs to the family Sarcophagidae, or Flesh Flies. 

 All the species of Wohlfahrtia can be distinguished from those of Sarcophaga by the 

 well-defined round spots on the abdomen, instead of the shimmering chequered 

 marks, so characteristic of all the species of Sarcophaga. The species of the allied 

 genus Sarcophila also have round spots on the abdomen, but the arista is only 

 plumose towards the base, while in the species of Wohlfahrtia the arista is plumed for 

 some distance. Wohlfahrtia magnifica deposits its larvae in cuts, sores, wounds, 

 and at the entrance to the nostrils and vagina, and on the eyelids, the fly being 

 attracted by an offensive discharge from such tissues or organs. It is widely dis- 

 tributed in Southern Russia, Asia Minor and Egypt, where it is a serious pest to 

 man and animals. Portchinsky has made an exhaustive study of its hfe-history 

 and habits, as well as those of some allied species. None of the other species of 

 Wohlfahrtia appear to be specific myiasis-producing flies. 



Flies of the Family Oestridae. 



In this family are included a large number of highly specialised flies, whose 

 larvae can only reach maturity in certain tissues and organs of special animals 

 and their near allies. For example, the larvae of the horse bots {G aster ophilus) 

 and those of the elephant bots [Cobboldia) can only live in the stomachs and duodenum 

 of the Equidae and the Elephantidae, attaching themselves deeply by their man- 

 dibular hooks to the mucous membrane of the alimentary tract. The exact nature 



