Biological basis of the science fiction story "The Dipteroid phenomenon"
After some research, it appears that the phenomenon being discussed was the consumption of Diptera flies by the dung fly, Scatophaga stercoraria. This paper describes their inability to sexually mature without consuming prey (for which Musca domestica flies were provided). 


  Male  Scatophaga  stercoraria must prey on other Diptera before they
  display sexual behavior, develop  the  accessory cells  of  their  ejaculatory ducts, and
  achieve  full elongation of  the testes. The corpus allatum also becomes enlarged
  after predation and is  necessary for  the onset of sexual behavior and development
  of reproductive organs. The complex diet consumed  during predation apparently
  cactivates the corpus allatum, and the hormone released acts  independently on
  organ growth and sexual behavior.