Jeol
Mayfly.

Phylum: Arthropoda, Class: Insecta , Order: Ephemeroptera.
Common Name: On the Island it is called: Jeol.

The first part of the word "Ephemeroptera" comes from the Greek word ephemeros,
which means “lasting for a remarkably brief period of time.” 
The name in english "Mayfly" meant the Fly occure in the month of May, but
that is not the case; the Mayfly occure also in other months of year.
Mayflies have survived mostly unchanged for 350 million years according to scientists.
So they were around before dinosaurs even existed!
They are one of the few insect groups that cannot fold their wings down over their backs.
Front wings are large, triangular, membranous with numerous veins.
Different Mayfly species range from about 6mm to 25mm long.
The " Jeol " has a lenght of 9 mm excluding the tail.
Like many aquatic insects, Mayfly naiads ( nymphs ) need clean water to live.
Because of this, scientists can tell if a water source is polluted or not based on whether
Mayfly naiads are present.

The adult mayflies are well known for their brief adult lives, just a few hours to max 14 days.
They do not feed or drink during their adult existance. Their mouthpiece is nonfunctional.
they have only one purpose in life and that is to make certain of the continuation
of the species.
The adults will almost immediately die after mating.
" Jeol " mate in swarms and the females return to the water source to lay their eggs.
The females lay their eggs either while flying over the water, by dipping their abdomens
into the water or even by actually entering the water to deposit the eggs on
underwater surfaces.
The nymphs have very strong legs and will even burrow into the sand and mud on
the bottom.  They will typically go through several molts prior to reaching a
pre-mature adult stage called the sub-imago.  The time for this maturity can be
anywhere from a few days to a few weeks or more.
They also hibernate until the water conditions are right.
" Jeol " physical characteristics: Colour: light brown with black dots along the abdomen.
Longwing is bold on the front edge. Tail is decorated with small black colour balls.

IMPORTANT ROLE:
The aquatic nymphs which can live up to two years, play an important ecological role as they feed
on algae and in turn are eaten by fish and other aquatic animals.
They are very sensitive to the environment and are one of the first species to disappear
when the water becomes polluted.  So if water source has them in large numbers…
believe it or not, it is a positive thing.