THE FLIES THAT CAUSE MYIASIS IN MAN 



113 



An excellent account of the African species is given by Rodhain and 

 Bequaert (123) ; the European species have been treated by Pleske 

 (113) andSeguy (135). 



KEY TO GENERA 



ADULTS 



Proboscis very short, not extending between the palpi ; abdominal sternites 

 broad and quadrate, clothed with long, fine hairs Oestrus Linnaeus 



Proboscis very short, but conical and extending backward between the palpi ; 

 abdominal sternites narrow and tending to be triangular, only short- 

 haired Rhinoestrus Brauer 



THIRD-STAGE LARVAE 



Posterior spiracles D-shaped. completely surrounding the button ; dorsal 

 spinous areas of the segments lacking, or at most greatly reduced 



Oestrus Linnaeus 



Posterior spiracles crescent-shaped, not completely surrounding the button 

 but sometimes almost so; 2 or more rows of spines on each of segments 

 3 and 4, these being absent only in one species not within the scope of 

 this work Rhinoestrus Brauer 



FIRST-STAGE LARVAE 



Anal spines arranged in two groups of 9 to 11 each; oral hooks hornlike 



(fig. 59) Oestrus ovis Linnaeus 



Anal spines 8 to 10, medially located ; oral hooks clawlike (fig. 60) 



Rhinoestrus purpureus (Brauer) 



Figure 59. — Oestrus oris, first-stage larva: A, Anterior end; /?. posterior end. 

 (After Galliard {' { 2, p. 179).) 



The Genus OESTRUS Linnaeus 



In this genus the front is broadly and strongly convex: the para- 

 frontals are prominent, with numerous pocklike pits, from each of 

 which a hair arises. The antennae are short and separated by a 



TT.iil 13° — 48 8 



