Mayflies are aquatic insects that spend most of their lives in lakes and streams feeding on algae, detritus, or other larvae until they emerge as winged adults to reproduce. There are records for at least 126 different mayfly species in Michigan. Due to the short timeframe of the adult stages of their lifecycle, oftentimes ranging from a few hours to a few days, all mayflies in a population often emerge as adults at one time to optimize reproduction potential, creating a large swarm that is an easy food source for predators.
Many insects and fish feed on mayflies, in both their aquatic nymph and adult life stages, making these insects a very important part of the food chain. Mayflies are very sensitive to changes in water quality and their absence or presence in a body of water is often used by scientists as an indicator of water quality. The ability of rain gardens to slow the flow of water and create natural water filtration can help keep waters clean so mayflies can continue to flourish.
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