MYIASIS 221 



'tumbu' lesion." Blenkinsop (1908) points out that "only the 

 skin and subcutaneous tissue are affected, and the larva does 

 not, like that of the screw-worm fly {Chrysoviyia viacellaria 

 Fabr.) burrow in the deeper tissues." 



Austen (1908) gives the following account of the fly and its 

 larva : 



"■Perfect insect. — A thick set, compactly built fly, of an average length of about 

 9I mm. ; specimens as small as 62, or as large as io| mm. in length are occasionally 

 met with. Head, body and legs straw yellow ; dorsum of thorax and of abdomen 

 with blackish markings; wings with a slight brownish tinge. The eyes meet together 

 for a short distance in the median line above in the case of the male, but are separated 

 by a broad front in the female. On the dorsum of the thora.K the dark markings 

 which are a pair of longitudinal, stripes not reaching the hind margin, are covered 

 with a greyish bloom, and, consequently, not very conspicuous ; this bloom is also 

 present on the abdomen, but here the markings are much more distinct, especially in 

 the female, in which the third segment, as also the fourth segment, with the exception 

 of the hind margin, is entirely black or blackish. In the female the second se"-ment 

 is marked with a blackish quadrate median blotch, and has a similarly coloured hind 

 border, broadening towards the sides, while the first segment has a narrow dark hind 

 margin. In the male these markings are not so extensive ; the dark hind margin to 

 the second segment is interrupted on each side of the median blotch, which is 

 triangular in shape, and there is a yellow area of considerable size on the proximal 

 half of the third segment, on either side of a blackish median quadrate blotch ; the 

 fourth segment is similarly but less conspicuously marked." 



Care is necessary in order not to 'confuse C. antJu'opophao-a 

 with Aiichmeromyia luteola, which is found in the same parts of 

 Africa and presents a deceptive resemblance to the Tumbu-fly 

 in colouration. " The two species may be distinguished by the 

 fact that in A. luteola the eyes are wide apart in both sexes, the 

 body is narrower and more elongate, the hypopygium of the 

 male is in the form of a conspicuous, forwardly directed hook 

 for which the ventral half of the penultimate segment of the 

 abdomen serves as a sheath ; and lastly, by the fact that the 

 second abdominal segment in the female is twice the length of 

 the same segment in the male." C. unthropophaga has also 

 been wrongly identified as Be?igalia depressa. 



'■'■ Lai~va. — The full-grown larva is a fat, yellowish-white maggot, i? to i2i mm. 

 (about half an inch) in length, bluntly pointed at the anterior or cephalic extremity 

 and truncate behind ; its greatest breadth (on the sixth and seventh segments) is s mm. 

 The body consists of twelve visible segments, the divisions between which are strongly 

 marked, except between the cephalic and first body-segment (the latter of which bears 

 the anterior or prothoracic stigmata, or respiratory apertures), and between the 

 eleventh and twelfth segments. On the under side of the cephalic segment the tips 



