Mayfly – Creature with Shortest lifespan on Earth – Facts

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A human being has eight stages according to developmental psychologist Erik H. Erikson ( 1902-1994) and average human lifespan is 71 years.

  • Infant (0-1)
  • Toddler (2-3)
  • Preschooler (4-6)
  • School Age (7-12)
  • Adolescent (13-18)
  • Young Adult (19-45)
  • Middle Aged Adult (45-65)
  • Old Adult (65+)

Image Source:

So, briefly classifying we have 15 years of childhood and 56 years of adulthood. Imagine if you have just 24 hours of adulthood after childhood, what all on this goddamn earth you would be doing in that short adult lifespan?

That’s the same case with Mayflies, they just live 4 hours of their winged adulthood stage and die. The only thing they do in that short time is, 

If Male

to find a female fly, fornicate and die.

If Female

to find their male fly, fornicate, lay eggs and die.

If by chance any time is left they just swarm around.

The life cycle of mayflies consists of four stages:

  • Egg (2 weeks)
  • Nymph (1-2 years)
  • Subimago – Pre-adult (few minutes to 20 hours, usually overnight)
  • Imago – Adult (4 – 24 hours)

Image Source: Life cycle of the mayfly (order Ephemeroptera). Encyclopædia Britannica, Inc


Depending on the species, a female may produce fewer than 50 or more than 10,000 eggs and are laid in water. They often hatch in about two weeks but may, under certain circumstances, undergo a period of varying duration in which no growth occurs. This cessation of growth, known as diapause, is a highly effective adaptation that enables the insects to avoid environmental conditions hostile to developing nymphs or to emerging winged stages. Nymphal life may be as short as two weeks or as long as two years and they just move around in water eating algae etc. Some don’t even move around too.

Nymph Mayfly | Image Source:

When growth is complete, the nymphal skin splits down and a winged form, called the Subimago emerges. The Subimago flies from the surface of the water to some sheltered resting place nearby. After an interval lasting a few minutes to several hours, but usually overnight, the skin is shed for the last time, and the Imago, or adult stage (sometimes called a spinner), emerges.

Male Subimage Mayfly | Image Source:

Mating takes place soon after the final transformation. In most species, death ensues shortly after mating for males and oviposition (egg deposition) for females. Winged existence may last only a few hours.

Imago Mayfly | Image Source:

Mating Dance

Another interesting fact is that in the final stage Mayflies mate while dancing in the air. Groups of male Imagoes perform a mating flight, or dance, over water as dusk approaches, flying into any breeze or air current. Individuals may fly up and forward, then float downward and repeat the performance. Females soon join the swarm, rising and falling as the dance continues. The male approaches the female from below and behind and grasps her thorax with his elongated front legs. Mating is completed on the wing. After her release by the male, the female deposits her eggs and dies. A few species are ovoviviparous—i.e., eggs hatch within the body of the female generally as she floats, dying, on the surface of a stream or pond.

Mating Dance | Image Source:


Both immature and adult mayflies are an important part of the food web, particularly for carnivorous fish such as trout in cold water streams or bass and catfish in warm water streams. Their presence is an indication of good water quality fish population.

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What do Mayflies Eat?

Adult mayflies don’t eat. Their lifespan is just for few hours, and their only purpose is to reproduce. After this, they die. However, mayfly nymphs, which are aquatic, eat whatever they can. They even scrape algae and other detritus found on rocks and weeds for food. Other larger mayfly nymphs are predators and catch smaller insects and larvae that live in the water. Neither Subimagos (pre-adults) nor Imagoes (adults) eat.

What Eats Mayflies?

Mayflies are hunted by various carnivorous predators throughout the four stages of their lives. As nymphs, they are preyed upon by fish and carnivorous invertebrates. When they are in their winged stage, their natural predators are flying creatures like birds and bats, as well as predatory insects such as hornets and dragonflies. When mayflies are at rest, they are preyed upon by birds, spiders, beetles and some mammals. In North America, mayflies are commonly eaten by flying squirrels. As mayflies transition into their adult stage, their common predators are fish, especially when the female is laying eggs. This relationship is why it is common to see artificial fishing lures that are made to look like adult mayflies.

Mayfly emerging from water | Image Source:

Do mayflies bite?

While they are considered annoying pests, mayflies do not bite or sting. Their presence is actually an indicator of a healthy aquatic environment, as they are a chief food source of birds, dragonfly nymphs and fish. For some, the dead, fragmented bodies of the insects trigger hay fever and asthma, while mass accumulations create an offensive, fish-like smell.

Female Mayfly hatching a ball of eggs | Image Source:

As their name implies, Mayflies emerges from the water in the month of May or early June. Mayflies were one of the first winged insects, with fossils dating back over 300 million years – long before the dinosaurs! There are 51 species of mayfly known from the British Isles today and they range in size from less than 5mm to over 20mm. As most of the life of a mayfly is spent out of sight as a nymph and just 24 hours of adult life is spent on visible earth, it is also called “Dayfly”.


Amazing Video by National Geographic Channel showing Adult cycle of Mayfly

*fornicate = to have sexual intercourse (Merriam-Webster)

Thank You!



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