THE FLIES THAT CAUSE MYIASIS IN MAX 99 



The larvae exhibit generic differences, but agree in several important 

 respects. There is but one pair of mouth hooks, which are persistent 

 through the last stage; the antennae are short and blunt, and bear two 

 ocelluslike sclerotized structures at their apices; the anterior spiracles 

 are present in the later stages: the posterior spiracles in the mature 

 larva are prominent and oval or kidney-shaped, with or without a dis- 

 tinct button. 



The larvae parasitize various mammals, only under abnormal cir- 

 cumstances living on nonmammalian hosts. They live either in the 

 cavities of the head (Cephenemyia) or in furunculous subcutaneous 

 tumors. 



KEY TO GENERA 



ADtXTS 



1. Long-haired, buinblebeelike species ; mouth parts very greatly reduced 



and not contained in an oral groove; ventral membrane of abdomen 



not exposed Cephenemyia Latreille 



Short though sometimes densely haired species, not bumblebeelike in ap- 

 pearance ; mouth parts somewhat more conspicuous and set in a dis- 

 tinct longitudinal oral groove : ventral membrane of abdomen exposed 2 



2. Face only moderately excavated, with a distinct carina; tarsi broadened 



and flattened : large species, over 15 mm. and frequently over 20 mm. in 

 length, often with more or less conspicuous dense pale hair on the 



thorax Cuterebra Clark 



Face deeply excavated, without a carina : tarsi not broadened and flat- 

 tened ; species smaller than 15 mm. in length, and without conspicuous 

 dense pale hair Dermatobia Brauer 



M ATT- HE LARVAE 



Elongated, cylindrical to club-shaped species, with patches of strong spines ; 

 last segment strongly developed, the posterior spiracles flush with its 

 truncated apex, and a prominent conical extension below and beyond the 

 spiracles (fig. 53) Cephenemyia Latreille 



Thick, ovoid species, thickly set with spines or scales; last segment short, 

 the posterior spiracles set in a shallow spiracular cavity Cuterebra Clark 



Elongated, pear-shaped species, provided with rings of strong hooklike spines 

 on the thicker median segments ; posterior spiracles set in a deep spiracular 

 cavity (fig. 50) Dermatobia Brauer 



The Genus CUTEREBRA Clark 



Rabbit Bots ; Rabbit Warbles ; Rodent Bots 



This genus, strictly American in its distribution, contains a number 

 of species which parasitize rodents and lagomorphs. Bau (10) and 

 Townsend (153) have divided it into a number of genera, some of 

 which, at least, have valid standing. Since the one record of para- 

 sitism of man 9 does not include a specific determination, there is no 

 course possible here other than to treat the genus in its older, broad 

 sense. 



The key characters will suffice to separate Cuterebra from other 

 myiasis-producing Cuterebridae. These flies are among the largest of 

 the muscoids, usually 20 mm. or more in length and robust : the ab- 

 domen is usually, at least in large part, shining black or blue, though 

 sometimes mainly pollinose, hairy, or reddish: the thorax is usually 



'Since This manuscript was submitted for publication a case of human furun- 

 eular cutaneous myiasis caused by Cuterebra buccata was reported from .Massa- 

 chusetts by Bequaert (Psyche 52 : 175-176. 194.1). 



