Mayflies, interesting insects used as bio indicators, are actually closely tied to water quality. The really huge emergence of mayflies seem to center around mid to late June, so how they got the name "Mayfly" I do not know. Also, commonly cursed as "Canadian Soldiers," I won't even hazard a guess how that was derived. No matter what name you prefer to call them, they are shirt-tail relatives to dragonflies, and called Ephemeroptera, referring to their very short or ephemeral life.
Their larva are water born, hence the connection to water quality. There are many historical photos of dead Mayflies being shoveled off of docks and streets into dump trucks, their numbers were so huge at one time. When Lake Erie suffered contaminants and poor water quality in the 70's their numbers were remarkably low. However, since water quality has been improved, along with the accidental introduction of zebra mussels, a mollusk that processes and "cleans" the lakes waters far beyond what we can remember, the mayflies have prospered.
For a week or two each summer, the mayfly adults emerge at dusk from the waters of Lake Erie and swarm about. With only 24 hours to live, and not even a mouth with which to feed- their soul purpose in life is to make sweet love and reproduce. Clouds of wispy bodies congregate under street lights and are especially drawn to white buildings.
As they were amassing in the skies Saturday evening, I heard the calls of Common Nighthawks, insect eating night birds intent on having their Thanksgiving and Easter dinner all rolled into one!
People eschew the aftermath of the Mayfly love-fest, as the little damp-but-crunchy carcasses litter the streets and sidewalks far and wide. The city of Port Clinton even puts out road signs: Beware! Pavement is slippery with mayflies. Brooms and shop vacs are employed as homeowners and shopkeepers struggle to clean up the very fishy-smelling remains. Successful mayflies laid eggs back into the lake, starting the life-cycle for next year. These little fellows must add an enormous about of biomass to the food chain and deserve a little respect for that alone.
The photo is a macro shot, mayflies about 1-2 inches long, are lined up on the underside of a Toad lily, Tricyrtis hirta, an interesting non-native flower.