With an average life of one to 24 hours, mayflies are the insect with the shortest life span, according to Akorra. A mayfly's sole purpose is to hatch and reproduce.
Despite there being more than 2,000 species scattered around the world, mayflies depend on their quantity for survival. Each species has a different average lifespan. Mayflies have four stages in their life cycle: egg, nymph, subimago and imago. A female mayfly lays anywhere from 50 to 10,000 eggs in the water, which hatch in about two weeks. Nymphal life may last up to two weeks and includes as many as 50 molts, or sheddings of the skin. When growth is complete, the nymphal skin splits and wings emerge; a mayfly is then in the subimago stage. This stage lasts anywhere from several minutes to a few days. Once the mayfly emerges in the imago stage, it lives from 30 minutes to a full day.