The lifecycle of Lucilia sericata is typical of flies in the family Calliphoridae in that the egg hatches into a larva that passes through three instars, enters a prepupal and then a pupal stage before emerging into the adult stage or imago. The female lays a mass of eggs in a wound, a carcass or corpse, or in necrotic or decaying tissue. The eggs hatch in about 9 hours in warm, moist weather, but may take as long as three days in cooler weather. In this, they differ from the more opportunistic Sarcophagidae, that lay hatching eggs or completely hatched larvae. A single female L. sericata typically lays 150−200 eggs per clutch and may produce 2,000 to 3,000 eggs in her lifetime. The pale yellow or grayish, conical larvae, like those of most blow flies, have two posterior spiracles through which they respire. These larvae are moderately sized, ranging from 10 to 14 millimeters long.
The larva feeds on dead or necrotic tissue for 3 to 10 days, depending on temperature and the quality of the food. During this period the larva passes through three larval instars. At a temperature of 16 °C, the first larval instar lasts about 53 hours, the second about 42 hours and the third about 98 hours. At higher temperatures (27 °C) the first larval instar lasts about 31 hours, the second about 12 hours, and the third about 40 hours.[4] Third-instar larvae then drop off the host onto soil, where available, where they enter a pupal stage which usually lasts from 6 to 14 days. However, if the temperature is suitably low, a pupa might overwinter in the soil until the temperature rises. After emerging from the pupa, the adult feeds opportunistically on nectar or other suitable food, such as carrion, while it matures. Adults usually lay eggs about 2 weeks after they emerge. Their total lifecycle typically ranges from 2 to 3 weeks, but this varies with seasonal and other circumstances