The lifespan of maggots, or fly larvae, varies based on the temperature. At optimum temperatures of 95 to 100 degrees Fahrenheit, maggots complete their development and become adults in four to 13 days. At lower temperatures of 53 to 62 degrees Fahrenheit, development takes 14 to 30 days.
Other factors, such as the availability of nutritional food, impact the pace of maggot development. Maggots initially feed on their egg material but later rely on manure. Maggots that are able to feed quickly and then find a cool, dry place often progress through development at the lower end of the typical development timeline.