Our Earth is full of fascinating creatures that span from massive Blue Whales to invisible-to-naked-eyes microbes. Each one of the animal species has some characteristics that make them special and unique.

The Mayfly is one such unique creature that we will learn about today. In this article on Mayfly facts, we will learn something startling that we will stay stupefied for quite some time.

So, instead of wasting time any further, let us learn about these incredible bugs. But before we start with the list of facts about Mayflies, let us take a quick look at their scientific classification.

SuborderPannota and Schistonota
Scientific NameEphemeroptera

Quick table on Mayfly Facts:

Common NamesMayfly, One-Day Flies
Diet (larval stage)Omnivore
Diet (subadult and adult stage)They cannot eat because of absence of functional mouth
LifespanFew minutes to a few days
HabitatWoodlands and Forests close to water
ColorYellow, Black, Grey, Tan, Brown, Green
Size0.12 inches to 1.18 inches (3 mm to 30 mm)
Ecological ImportanceCapable of surviving only in clean water and hence, are indicators of water pollution

Now that we have the scientific classification in our hands, we can move on to Mayfly facts list. We are sure you will love these facts:

Mayfly Facts: 1-5 | Other Names, Classification, Very Ancient

1. Mayfly is known by several names. In the United States, people call them Canadian Soldiers. In Michigan and Canada, they are known by the names fishflies and shadflies.

In the United Kingdom, they are known by the name Up-Winged flies. They also go by the names salmon flies and June bugs.

2. In case you have noticed in the table above, we did not mention the ‘genus’ and the ‘family’ they belong to.

We stopped at ‘suborder’. That’s because they come from 400 different genera and 42 different families with a total of 3,000 different species!

3. Mayflies are really really ancient. That’s the reason why they are put in the division called ‘Palaeoptera’, which is basically a very ancient group of insects. Just how ancient are Mayflies? Read on…

4. Mayflies have been around for some 350 million years. This means that they existed even before the dinosaurs came to existence and they survived the K-T Extinction event that wiped out the dinosaurs.

5. A coupe of traits that tell scientists that Mayflies were among world’s most primitive flying insects are:

  • They have long tails – a trait of ancient insects.
  • They are incapable of folding their wings flat over their abdomen – another trait of ancient insects.

Mayfly Facts: 6-10 | Description of Mayfly (Nymphs or Naiads)

6. Nymphs are the immature Mayflies. They are also known by the name Naiads. The Nymphs have elongated cylindrical bodies.

The bodies are little bit flattened. The Nymphs go through various stages. At each stage, the size of the body increases.

7. Nymphs are aquatic and that live under water for nearly 2 to 3 years. During this time, they undergo about 20 instars or transformation phases.

8. In the Nymphal stage (basically the larval stage), the Mayflies have very robust legs that are fully covered with hair, spines or bristles. They also have gills designed for breathing under water.

9. In the Nymphal stage, they eat tiny pieces of already dead animals and plants. They also feed on tiny living plants under water.

10. When the Nymphs emerge from water, they get into a stage known as Subimago. This is a subadult phase where the Mayflies will have fully functional wings, will be fully terrestrial but, they will not reach the sexual maturity.

Mayfly Facts: 11-15 | Description of Mayfly (Subimago and Imago)

11. However, in the Subimago stage, the functional wings remain partially cloudy with minute hair fringes on them. The genitalia, legs and eyes are not fully developed.

They cannot fly properly and they will not have distinctive color patters for attracting mates.

12. Once the Mayflies reach the Subimago stage, they will undergo one final molting to become sexually mature adults. The Subimago stage doesn’t last for long.

So some species, the Subimago stage lasts for only a few minutes while for others, it may last for 24 hours.

13. The adult Mayflies (known as Imago) will have large compound eyes. The adults will have flexible and short antennae and will also have two or three tails that are pretty long.

They will have two pairs of wings with both pair being membranous with extensive vein covering. The wings no longer remain cloudy at this stage and become transparent.

14. One of the most interesting features at this stage is that the adult Mayflies have one pair of large wings – the first pair of the pair on the front. The second pair of wings are small and in some species, they are vestigial.

15. Adult Mayflies do not have a well-defined functional mouth. This means that they cannot eat. Simply put, adult Mayflies do not eat. They live for a very short span and their only purpose of survival at this stage is reproduction.

Once they reproduce, they die. Some species will last only for 24 hours in the adulthood (including both Subimago and Imago phases).

The shortest lifespan is seen in the species known as Dolania americana where the adult females survive for just 5 minutes.

Mayfly Facts: 16-20 | Reproduction in Mayflies

16. Reproduction in Mayflies is pretty unique. They insects themselves are very unique in their adulthood. Each individual will have a pair of sex organs.

17. Adult female Mayflies will have two sexual openings known as gonopores. The males will have two organs that resemble penis. They are known as aedeagi.

18. The adult males will fly in swarms in what is known as mating flight. They fly above the water surface (just a few meters above).

This mating flight is basically their nuptial or courtship dance. When a female flies above the swarm, one of the adult males will grasp/clasp the female.

19. Once the female is clasped by a male, the two will move away and mate while the other males will keep performing the nuptial dance.

The copulation or mating will not last for more than a few seconds.

20. Once the females are impregnated, they will lay eggs. Just how quickly they will lay eggs will depend on their lifespan. They will lay somewhere between 400 and 3,000 eggs and then die.

Mayfly Facts: 21-25 | Reproduction in Mayflies

21. When it is time for laying eggs, the females will either drop the eggs on water’s surface or they will fly in such a way that they will dip their abdomen tip in water in successions.

Each time she touches the water surface, she will lay eggs in batches.

22. There are some species in which females will simply stand next to the water and deposit all the eggs in the water at one go.

23. There are other species in which the females will totally submerge themselves in water to lay eggs.

These females will find crevices to lay eggs or will lay the eggs among underwater plants.

24. Whatever format is selected, the eggs eventually sink into the water. That is where the larvae are born.

The incubation time for the eggs depends on many factors and one of those facts is temperature. The incubation time can be a few days to a whole year.

25. Once the larvae are born, their growth rate will also be determined by water temperature and the surrounding environment.

The larvae undergo anywhere between 10 and 50 molts before reaching the Subimago phase.

Mayfly Facts: 26-30 | Weird Facts About Mayflies

26. Mayflies emerge in great numbers (hundreds of thousands) from underwater from Spring to Autumn.

The intensity of light above the water surface is one of the determining factors for their emergence timing.

27. Only a few species emerge during May and this is why they are known as Mayflies. However, there is no reason for them to be called so became many other species emerge in June or other months.

28. Because Mayflies are short-lived, they are collectively known as Ephemeroptera (it is the order and the scientific name).

Ephemeroptera is basically derived from Ephemeros – a Greek word meaning ‘lasting a day’. This is the reason why Mayflies are also known as one-day insects or one-day flies.

29. Mayflies can only survive in clean water environments. They cannot live in pollution. The presence or absence of Mayfly larvae is an important indicator of water pollution.

30. Mayflies – in all three phases (Nymphs, Subimago, and Imago) – are important sources of food for other animals. In the Nymph stage, they are one of the most favorite foods of various fish and amphibians.

In the latter two stages, they are eaten by mammals, rodents, small reptiles, toads, newts, and frogs.

Sources: 1, 2, 3, 4, 5, 6, 7, 8

Image Credit

Categorized in: