June, '15] 



BISHOPP: FLIES WHICH CAUSE MYIASIS 



319 



In this same family we have three or more species of horse bots with 

 more or less different habits, but all attaching to the stomach or intes- 

 tines of the host. These probably derive their food largely from the 

 secretions of the mucous membranes and from the contents of the 

 digestive tract. The exact relationship to the host is not known and 

 it is important that the extent of injury to the host be carefully de- 

 termined, as is being done in the case of Hypoderma by the German 

 commission which has been studying that problem. 



Among the CEstridse we also find the species Dermatohia hominis, 

 which is a common cause of dermal myiasis in man and a number of 

 the lower animals in tropical America, and the members of the 

 genera Cuterebra, GEdemagena, Gedoelstia and Cephenomyia. None 

 of these latter forms have been known to attack man. 



Comparatively little is known regarding the exact role flies play in 

 myiasis of the intestinal and urinal tracts. Numerous records have 

 been pubhshed showing from one to several species in the following 

 families to be concerned: Therevidse, Syrphidae, Muscidse, An- 

 thomyidse and Sepsidse. In many instances rather serious distur- 

 bances in man are due to the larvae of these flies. No doubt many 

 infestations pass unnoticed or produce only minor symptoms, the 

 larvae depending on the food of the host for sustenance, and thus 

 producing no direct injury. The mode of infestation and the effects 

 of the larvae on the host deserve much more attention than has been 

 accorded them. 



I desire at this time, to deal particularly with the various species of 

 flies, the larvae of which infest man or animals in wounds or, as not in- 

 frequently happens, attack inflamed or even entirely healthy parts. 

 The species concerned are members of the families Muscidae and 

 Sarcophagidae, as recognized by most of our American dipterists. 

 In the United* States the forms which are most important in causing 

 this form of myiasis are Chrysomyia macellaria, Lucilia sericata, L. 

 ccesar, Phormia regina, and one or two species of Sarcophaga. Possibly 

 species of the genus Calhphora and Cynomyia are sometimes concerned. 

 C. macellaria far outranks all others combined in importance. This 

 species occurs in Mexico, the West Indies, Central America, and 

 South America. In South America, Neiva and Gomes de Faria^ 

 have shown that Sarcophaga pyophila is responsible for some cases, at 

 least, of human myiasis, ^hese authors^ also state that S. lamhens 

 is known to cause human myiasis in Brazil. In Hawaii, Van Dine 



1 1913. Neiva, A. and Gomes de Faria. Notal sobre um caso de miiase humana 

 ocasionada por larvas de Sarcophaga pyophila n. sp. Memorias do Oswaldo Cruz, 

 Tomo V, Fasc. 1, pp. 16-22. 



^Ihid. p. 18. 



