208 TROPICAL MEDICINE AND HYGIENE 



popularly known as the " Congo floor maggot." The 

 fly in general appearance closely resembles the Cordylobia 

 anthropophaga, but differs from it mainly in the great 

 length of the second abdominal segment. It is known as 

 Auchmeromyia luteola (fig. 84). 



CLASSIFICATION OF DIPTERA CONCERNED IN MYIASIS. 



The more important biting flies were considered briefly 

 in Part I. The non-biting flies that are the cause of the 

 various forms of myiasis, and which are important as 

 scavengers and as mechanical carriers of disease, belong 

 to the division of the Diptera known as Cyclorrhapha. 



In these the imago escapes from the pupal case by 

 pushing off a circular cap at one end. In the adult 

 the Cyclorrhapha can -be recognized by the scar or 

 depression that persists between the eyes and over the 

 bases of the antennae called the lunula. This lunula is 

 the remnant of the bladder-like protrusion ptilinum 

 which forms in the front of the head of the imago whilst 

 it is still in the puparium, and which aids in pushing oft" 

 the circular cap. 



The flies in this group usually have a fairly simple 

 wing venation, in most of them on the same plan as 

 that of the house-fly. The antennae are short, three- 

 pointed, and have, usually at the base, on the third joint 

 a projecting spine arista which may be covered with 

 hairs to a varying extent. The antennae in many cases 

 are dependent, lying along the surface of the face. 



The cyclorrhaphous diptera are a very large group, 

 including over 20,000 species. This large number of 

 species renders it necessary to divide and subdivide 

 according to characters that would be too trivial to be 

 considered of generic importance in other groups of the 

 Diptera. 



The Cyclorrhapha are divided into two big groups : 

 the Schizophora, in which from the tips of the frontal 

 lunule two sutures are continued downwards on the face ; 

 and the Aschiza, in which there is no such continuation 

 of the lunule. 





