THE PUPARIA AND LARVAE OF SARCOPHAGID FLIES 



By Chapj.es T. Greene 



Of the Bureau of Entomology, United States Department of Agriculture 



INTRODUCTION 



The family Sarcophagidae has always been considered a very 

 difficult group of flies and especially difficult in the immature sta<i-es. 

 The adults are determined very easily by the male genitalia. These 

 flies are very important from the fact that some species are parasitic 

 on insects of great economic importance, Avhile other species are 

 parasitic on turtles and the higher animals, including man. Some 

 species are parasitic and others simply scavengers in dead insects, 

 mollusks, and decomposing animal matter, while certain species are 

 either a parasite or a scavenger as the opportunity oilers. The lar- 

 vae of the genus Wohlfahrtia are found under the skin of young 

 infants. There are also records of these larvae Avorking under the 

 skin of some of the lower vertebrates, such as the cat, dog, and rabbit. 

 The larvae of Sarcophaga are often found in the nasal passages of 

 man and also in open wounds of various animals. The larva of 

 Sat'cophaga haemorrhoidalis has been found in the intestinal tract 

 of man on several occasions. The full-grown larva always leaves the 

 wound and pupates elsewhere. The puparium is formed from the 

 molted larval skin. So far as known none of the sjjecies of Sar- 

 cophagidae deposit eggs. All the species deposit first-stage larvae 

 or maggots which start to work in immediately, and they develop 

 very rapidlj' under favorable conditions. 



Up to this time there has been no attempt to classify the larvae o*r 

 pupae. In the larval and pupal stage the main character used for 

 separating this family from the other muscoid flies is the absence 

 of the button on the spiracular plate. This button is also absent in 

 some species in the family Oestridae, but there can be no confusion 

 because the larva and the puparium of this family are of an entirely 



No. 2566.— Proceedings U. S. National Museum. Vol. 66. Art. 29. 



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