Mayflies are ancient insects that possess a unique life stage not found in other winged insects: Their fully-grown nymphs develop into a winged subadult stage, the so-called subimago, which is not yet capable of reproduction and which, after a short time, sheds its skin along with its wings to become an adult insect. An international team led by Dr Arnold Staniczek, an insect specialist at the Natural History Museum in Stuttgart, used modern technologies to discover and describe a key mechanism in the moulting process from subadult to adult.