Come May each twelvemonth, a special insect emerges near some of our lakes. And while you may exist familiar with swarms of these summer insects, called mayflies, how much do you know about where they thrive and how long they live? Mayfly life cycles are fascinating to many—but the adult stage is fleeting. We'll delve into when, where, and for how long you lot tin expect to come across adult mayflies in the summer.

mayfly

Why are mayflies unique?

The annual mayfly hatch doesn't just indicate that summertime'due south budgeted—according to Michigan State University ("MSU") Extension, mayflies confirm the quality of the water in which they hatch.

"[Mayflies] are rarely establish in degraded bodies of water because their external gills in the nymph stage are very vulnerable to silting and pollution. Mayflies are, therefore, used as an indicator species when testing for environmental quality," the Michigan Land University research found.

Mayflies may exist seen in big groups due to the synchronous emergence. Likewise known every bit "fishflies," their swarms - which are mutual nearly clean bodies of water such every bit lakes and rivers - are and then big they can sometimes be seen on Doppler radar. In the summertime of 2019, Ohio residents saw swarms of mayflies everywhere due to their proximity to Lake Erie.

What is the mayfly life cycle?

Per the MSU Extension , the mayfly life bike consists of four stages: egg, naiads, subimago, and adult.

  1. Egg: Depending on the species of mayfly, the female tin can produce anywhere from 4,000 to 8,000 eggs on the h2o's surface. The eggs settle to the lesser (or, they may become attached to an object such as a stick or plant that sinks to the bottom of the river bed). The eggs volition remain hither from a twenty-four hours to even weeks until they hatch into naiads.
  2. Naiad: The naiad stage can range anywhere from 2 weeks to two years, notwithstanding, most naiads develop within one-two years. Naiads will then rise to the surface of the water and molt into the subimago grade.
  3. Subimago: The subimago stage is akin to an adolescent stage of life for the mayfly. Subsequently emerging from the naiad phase, the subimago flies from the water's surface towards land. This phase tin last from 24 to 48 hours. The subimago then sheds its pare a final fourth dimension and the adult mayfly emerges. This is unique in the insect globe, as all other flying insects alter from wingless immatures to winged adults. Mayflies are the only insect with a subimago molt.
  4. Adult: The developed lifespan typically lasts from 1 to two days. This phase does not feed, and nigh species die presently afterward mating and laying eggs.

When is mayfly season and what areas do they frequent?

The emergence of adult mayflies can vary based on location. Co-ordinate to Michigan State University Extension, emergence in Southern Michigan occurs in June or July.

Despite their proper noun, adult mayflies frequent the skies near clean water in late spring or early on summer. So, while yous may wish to steer clear of insects while enjoying the summer sun, keep in mind that seeing mayflies virtually a torso of h2o is a sign of healthy water