The diagram illustrates the various stages in the life of a fly. We can see that the complete life cycle lasts between two and four weeks. It is also noticeable that there are seven main stages in the development of the fly, from egg to mature adult insect.
The life cycle of the fly begins when the female adult lays an egg; the female typically lays more than one egg. Between 8 and 24 hours later, the egg hatches and the immature insect, or larva, appears.
During the second stage of the life cycle, the larva grows in size. This growing first takes place between 4 and 7 days after the egg hatches. This bigger-sized larva covering itself and transforms into a pupa. After a total of 10 to 20 days from the start of the cycle, the young adult fly emerges from its pupa stage, and reaches its full maturity.