THE FLIES THAT CAUSE MYIASIS IX MAN 6 



Much has been published on the subject of myiasis, but the litera- 

 ture is scattered. The larger works either treat of it in general from 

 a restricted geographical standpoint or deal with certain important 

 species or groups of related species on a broader scale. There are 

 several general reviews, aside from those in textbooks, but they are 

 brief. Much of the literature needs critical reexamination, since 

 misinterpretations of the data and misidentifications of the insects 

 involved have been common. 



The need for a general guide to the subject became evident when, 

 in the progress of World War II. information was sought which could 

 be answered, if at all. only by a search through sources published in 

 many countries and in several languages. Xeeds arising from war 

 have had a large share in shaping the general plans of this work, 

 although much consideration has also been given .to the needs of 

 postwar reconstruction and of civilian life in a peacetime world. 



The aim of this work, then, is to summarize pertinent biological and 

 pathogenic information concerning the myiasis-producing flies of the 

 world insofar as they affect the human host, and to present guides 

 for their identification. In general, species reported as attacking 

 only the lower mammals have been excluded, except in cases where 

 man may be considered a possible host. Much of the information 

 has necessarily been gleaned from the literature. Whenever possible 

 an attempt has been made to evaluate the statements, but, for lack of 

 complete information in the reports, this has often been impossible. 

 For this reason some species undoubtedly have been incorrectly in- 

 cluded in this list wherfeas others of importance may have been omitted. 



Statements regarding pathological and clinical aspects are especially 

 subject to inaccuracies, and many of them must be accepted provi- 

 sionally. Very little experimental work has been done on myiasis, 

 and for most of the information we must depend on case histories, 

 many of which were reported by physicians having little or no ento- 

 mological training. One source of error lies in the possibility of mis- 

 interpreting clinical data. For example, in some cases diagnosed as 

 gastrointestinal myiasis actually the larvae either made their way 

 into chamber vessels which one would ordinarily consider closed suffi- 

 ciently tight to exclude them, or else they were passed with the urine 

 or dropped from infested sores in the rectal or vaginal region. Still 

 another source of error lies in misidentification.. particularly when no 

 adults have been obtained. These errors may be published and per- 

 petuated by repetition, and. unfortunately, in most cases there is no 

 way of distinguishing them from correct reports. 



Some further statements regarding the scope and limitations of this 

 work are desirable. In the first place, no pretense of deciding any 

 taxonomic issues is made, nor is any degree of completeness claimed 

 in dealing with taxonomic groups. Attempts are made to deal only 

 with the known or strongly suspected producers of myiasis in man. 

 Since it is impossible to foresee just what should be included in this 

 category, citations to keys and other references useful in the study of 

 the biology and taxonomy of related species have been included. Such 

 citations, however, have been held to the minimum. 



Most of the keys used here have been adapted from published works, 

 although some of them are original. Those that have been borrowed 

 or adapted have been checked against determined material in the col- 

 lections of the United States National Museum. For this purpose 



