The presence of insects in a corpse is a critical clue towards estimating the time of death for bodies dead for longer periods of time.
Corpse fauna - The Australian Museum
Decomposition: fly life cycle and development times - The
Lifecycle of a Housefly: Eggs, Maggots, and Adulthood
Fly - Wikipedia
Corpse fauna - The Australian Museum
Diving Beetle life cycle - The Australian Museum
Flies – Ausemade
Corpse fauna - The Australian Museum
red-tailed flesh fly - Sarcophaga haemorrhoidalis (Fallen)