THE HUMP-BACKED FLIES 



(Family Phorida.) 



The little dark flies of this family have no popular name, 

 unless we adopt that of Comstock, "the hump-backed flies," 

 which is characteristic enough. They may easily be recognized 

 by the two very dark, thick veins on the front margin of the 

 wings. There are not many species, but individuals are excess- 

 ively common in this country, flying in swarms, and frequently 

 being found upon window panes. Their larval habits are various, 

 but they breed in decaying animal and vegetable matter. The 

 flies lay their eggs on dead chrysalids, on dead snails and in 

 decaying vegetation, and the maggots which hatch develop 

 rapidly. They are slender, and the pupa which is contained in 

 the hardened last larval skin breathes by means of two slender 

 processes issuing from the fourth segment. There has been 

 some discussion as to whether the larvae of the flies of this family 

 are ever directly parasitic in other insects, but it seems to be 

 accepted that one species is a true parasite in the hives of the 

 honey bee and a most interesting form has recently been discov- 

 ered which is a true parasite of ants. In other cases, these flies 

 undoubtedly lay their eggs on diseased or dying insects. 



Life History of the Ant- Decapitating Fly 



(Apocephalus pergandei Coquillett.) 



It would be rather a misnomer to call this a typical life 

 history since this form seems peculiar in its habits and rather 

 aberrant among the Phoridse, but the observations which have 

 been made upon it by Dr. W. H. Fox and Mr. Theo. Pergande 

 have been more complete than any which have been made upon 

 other members of the family, so it is here included. A common 

 black ant, Camponotus pennsylvanicus, is the host of this little 



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