Carpe Diem

Nous avons déjà observé une larve aquatique d'éphémère et comment elle peut passer plusieurs mois dans le ruisseau, voici l’adulte (l’imago) aérien qui ne vivra qu’une ou deux journées, juste le temps de se reproduire pour donner vie à de nouvelles larves aquatiques.

Comme la larve, elle possède trois appendices au bout de l’abdomen appelées cerques qui permettent de la reconnaître parmi d’autres insectes.

We already met the naiad of a mayfly and the way they can live in the creek. Here is the adult (imago) which will only survive a few hours with the only purpose of mating and give birth to new naiads.

The adult form, as well as the larva form, has three long sender thread-like projections that help in the differentiation among other aquatic anf flying insects.

Just breathing

We already met on February 26 a nice alien in the creek, a mayfly larva. Here is a macro showing how these naiads can stay in the water during years before their short life among us: like fishes they have gills, but with leaves form and on every side of their abomen, as shown with the red arrows. This is an ancestral trait that was already existing in some species of the very old (more than 500 million years ago) Burgess fauna.

Le 26 février, nous avons fait la connaissance d’un petit alien du ruisseau : une larve d’éphémère. Voici une photo macro qui montre comment ces nymphes peuvent vivre des années dans l’eau avant leur courte vie en dehors. Comme les poissons elles ont des branchies pour respirer dans l’eau. Ces branchies ont la forme de petites feuilles disposées de part et d’autre de leur abdomen, indiquées par les flèches rouges. C’est un caractère ancestral que l’on trouvait déjà il y a plus de 500 millions d’années chez certains animaux de la faune de Burgess. 

Alien for one day since ages

Mayflies, also known as fishflies in Canada, are aquatic insects like dragonflies and damselflies. Their immature stages are aquatic fresh water forms called "naiads" or "nymphs" as shown in this picture.

They are part of an ancient group of insects living during the Carboniferous (more than 300 Million years ago) and exhibit a number of ancestral traits that were probably present in the first flying insects, such as long tails and wings that do not fold flat over the abdomen.

Their presence indicates a clean, unpolluted environment. They are unique among insect orders in having a fully winged terrestrial adult stage, the subimago, which moults into a sexually mature adult, the imago.

Mayflies "hatch", they emerge as adults, from spring to autumn, not necessarily in May. Fly fishermen make use of mayfly hatches by choosing artificial fishing flies that resemble the species in question.

The brief lives of mayfly adults have been noted by naturalists and encyclopaedists since Aristotle and Pliny the Elder. The German engraver Albrecht Dürer included a mayfly in his 1495 engraving The Holy Family with the Mayfly.