Mayflies are unique among insects in that they moult one more time after acquiring functional wings ( this is also known as the alate stage ) ; this last-but-one winged instar usually lives a very short time , often a matter of hours , and is known as a subimago or to fly fishermen as a dun .
Mayflies are unique in that they moult one more time after getting functional wings ( this is also known as the alate stage ) .