Wednesday, June 16, 2010

Fishfly Days and Fishfly Nights

This is the season when fishflies swarm up and out of Lake St. Claire in Michigan and fly west by in their millions with no other aim than to die in peace clinging to innumerable screens and window panes. By night they darken the streetlights in vast clouds of frantic, joyous dance.

The fishfly is actually the mayfly, an aquatic insect in the tantalizingly named Order of Ephemeroptera. The Michigan variety is the Hexagenia limbata, a somewhat obscure name put together from a word meaning “six generations” and another meaning “margined,” the last because the edges of the mayfly nymph’s body are brightly colored.

The fishfly spends most of its life as a wingless nymph living under water in mud burrows; after about a year’s life feeding unseen in water and in mud, the nymph (sometimes dubbed the dun, based on its color) undergoes two moultings, one to a teenaged winged insect still sexually inactive, next to a winged adult in the mood for love up in the air. Fertilized females descend to deposit their eggs on the waters of St. Claire (and many other places in this Great Lakes Region). After the orgy is over, it is time to say goodbye—forever. Within a day the fishflies are dead but still clinging to surfaces where they have settled to dream of recent love in their last brief stage of life. In their two last stages these creatures have mouths that do not feed and stomachs destined to hold nothing but air—which reminds me of the “many difficulties inherent in a teleological view of creation,” as Dorothy Sayers has Inspector Parker remark in her novel Clouds of Witness. (Now that’s the kind of detective I want investigating my demise if it should happen violently.)

In this view the short-timers have found solace on the stone of our study’s window sill where, in nice contrast to the stone’s light surface, the camera can capture them more easily.


  1. The close-up in the first picture shows this insect in all its delicate beauty and elegant form. When masses of them congregate around streetlights at night and eventually die in mounds on the ground around the lamp posts, they seem far less delicate... Stepping through these mounds of mayfly carcasses, one is surprised to feel and hear a crunching underfoot.

  2. thats interesting... here in southern ontario, we call them mayflies.

  3. That close up picture is lovely.

  4. Ahh, the fish flies. Really, nothing quite says "June on the East Side" like walking through piles of fish-fly carcasses under streetlights.


Note: Only a member of this blog may post a comment.