upon hatching, "lucilia illustris" enters its larval stages of development, commonly called a maggot. as in other green bottle fly species, their larvae are carrion feeders and will generally infest any decomposing corpse. larvae go through three separate developmental stages called instars. "lucilia illustris" typically prefers cooler weather, and when ambient temperatures are around 7.7 degrees celsius, "l. illustris" will usually be the largest group of maggots on a corpse. between each instar, the "lucilia illustris" larvae will molt. the current instar of the larvae can be determined by examining the respiratory organs, called spiracles. if the maggot mass is successfully identified, tissue loss from the corpse can also be used to determine which instar the larvae are in.