The Common Green Bottle Fly (Lucilla sericata) is found world wide. It is a member of the blow fly genus.
It is commonly associated with injured or decomposing animal material -- dead fish and animals, wounds on animals, manure and refuse.
Its larvae (maggots) follow predictable growth patterns and are used in forensics to determine time of death. It the past, the propensity of the larvae to consume injured flesh was exploited in wound therapy (with the less pleasant name of "maggot therapy").
On a brighter note, they are responsible for cleaning up a lot of decaying material.
