The Danish Mayfly has been chosen as 2021’s Insect of the Year by a group of scientists representing central European research institutions.
The insect, whose scientific name is Ephemera danica, is famous for its short lifespan: it only has a few days to fly, mate and lay new eggs before it dies.
This is because it develops no mouth parts nor a functioning intestine.
It is one of 140 species that live in Central Europe and, although it is described as Danish, is spotted as far afield as the United Kingdom and Ireland.
They are considered a key component in fishing: high quantities of ephemera danica between May and June helps attract trout looking for insects to feed on.
“What makes the mayfly unique is its life cycle: from the egg laid in the water to the insect capable of flight and mating, which dies after a few days,” said Thomas Schmitt, chairman of comission representing experts from Germany, Austria and Switzerland that made the choice.
But despite its short lifespan, it has a much longer development cycle.
Female mayflies zigzag over water between May and September, laying thousands of eggs that then sink.
Larvae hatch within a few days, and eventually develop gills. Buried in riverbeds, they take between one to three years to develop.
Schmitt said: “Shortly before the transition from aquatic to terrestrial life, a layer of air forms between the old and new skin of the adult larvae.
“By reducing its specific weight, the larva rises to the water surface. Once there, the larval skin bursts and within a few seconds a flyable mayfly hatches.”
The commission has been selecting one unique insect each year since 1999 to “bring an exemplary species closer to people.”