Wildlife Photography | The Old Winged
Mayflies are an ancient order of insects. Insects were the first animal group to develop wings, and although most of the living flying things today have the ability to fold up their wings when at rest, those first to take flight had/have wings that are unable to be folded. The two still-living groups of insects that have permanently unfolded wings are the mayflies (Ephemeroptera) and the dragonflies/damselflies (Odonata).
Their name comes from the greek words ephemeros, meaning “lasting only a day” and ptera, meaning “wings”. While they only live for a short period of time as a winged adult, most of their life is spent aquatically in the wingless (nymph) or pre-adult (subimago) phase. What’s unique to the Ephemeroptera in the insect world is that they are the only group that has a pre-adult phase that has functional wings and then molt into the adult phase. The adults don’t even have functioning mouth-parts or a stomach. They actually use that stomach as another air sac to aid in flight. Nutrition consumed in the nymphal phase is stored in fat body reserves that is used when they are adults to give energy for flight/mating/egg laying.
Mayflies are most notable for two things. One, mayflies are a favorite of fly fishermen because those trout just love to slurp up all of the different life stages. Two, they are notable for their swarming behavior and often make the news when this happens because inches-thick dead mayflies have to be plowed off roads (you can always google mayfly swarming to see some end-of-the-world kind of images). Generally the swarming is made up of mostly males, waiting for passing females, but this isn’t a cold, hard truth either because some species swarm with both sexes intermixed. Random mayfly fact…males have a pair of penises.
Those three long “tails” coming off their abdomen are called cerci and are sensory appendages (for tactile and even air movement). The males eyes are divided into two separate parts and its thought that the upper part is for seeing movement and the lower for seeing details. If you are really curious about mayfly swarming and how the divided eye functions in their flight, here is an old school paper that talks a little bit about it.
This species that I photographed (I think, Leptophlebia nebulosa) have been swarming here at my house in the last week (though it looks more sweet and delicate than that, I prefer to think of it as an aerial dance. Swarm just sounds so mean, destructive, and if you have ever watched them it is so much more elegant than that).
The best part of mayflies for me, sitting on my deck and watching them dance in the air, is that they remind me of my first introductions to field work and the insect world. As a wide-eyed, bushy-tailed undergrad I was lucky enough to get to travel to the Channel Islands off the coast of Southern California and help conduct research in the island streams on aquatic insect drift patterns. Working on that island (Santa Cruz) was wildly fun for me and some of the fondest memories I have, in spite of the 4am shifts checking traps and taking flow rates in the streams 😉
“Our troubles are but mayflies, rising and falling between the turn of dawn and dusk.”