House fly
yellow to red, to brown, to black as the pupa ages. New adult flies will emerge as early as two days after pupation (at temperatures above 30°C) or over [...] viruses (such as the Newcastle Disease virus), bacteria (such as Salmonella and E. coli ), protozoan parasites (such as Giardia ), and the eggs of many parasitic [...] three weeks later at low temperatures (around 15°C). Adult flies have an average life span of 15–25 days, but can live up to two months in the right conditions