16 thomas say foundation 



Habits. 



The species of Sarcopliaga range in larval habit 

 from scavengers to parasites of warm-blooded ani- 

 mals. Many have been reared from excrement of 

 mammals, a few from carrion, many from dead in- 

 sects. 



Identifications recently made connect Sarcoph- 

 aga hcemorrhoidalis with intestinal myiasis in man, 

 and even suggest that many of the cases may be 

 caused by this widespread species. 



Several species deposit their larvce in the cups or 

 pitchers of the pitcher plant, Sarracenia, and are not 

 known to have any other larval habit than to devour 

 the decomposing insects that occur in the water of 

 these cups. See discussion of this series under Sar- 

 copliaga sarracenice. 



There appears to be a very interesting transition 

 from the habit of devouring dead insect to parasitism 

 upon living ones, in regard to which much more study 

 of a critical nature will be required. Some species 

 apparently may be called facultative parasites, others 

 are obligates, being unable to live on dead tissues. 

 To the latter class seem to belong all those in which 

 the female possesses a more or less developed larvi- 

 positor ; but the habit is probably not limited to these 

 species. 



Without exception as far as known, the species 

 are larviparous. The larvae of several species have 

 been studied by Nathan Banks, who has given (Bull. 

 22, Technical Series, Bureau of Entomology) many 

 figures showing larval structures in this and allied 

 families, with table for their separation. Almost no 

 specific characters are known in the larvae, so the 

 identification can go no further than "Sarcophaga 

 sp." unless the adult is reared. The minute booklets 

 on the integument which serve for locomotion com- 

 pletely encircle the segments in Sarcophaga, which 

 is the main larval differential character. 



