House fly
originated in central Asia, the insect expanded its range worldwide long ago as a commensal organism to human populations; the housefly is always found in association [...] breeding site to pupate. Flies in the pupal stage are oval-shaped, with bluntly rounded ends, about 8 mm long and change in colour from yellow to red, to [...] abundant manure production create the ideal conditions for maggot development. In extreme cases, large fly populations can even create public health issues