Development: Egg → nymph (moults several times) → adult (imago)

the ontogenetic development of insects in which the immature stage (nymph), which already has the rudiments of the external signs of the adult (wings, egg cell, etc.), does not undergo the pupal stage before reaching adulthood.

The gradual metamorphosis, in which the body gradually resembles the adult over several stages, is probably the life cycle of the original primitive insects. This "imperfect" metamorphosis is found in ornithopods, cockroaches, termites, mayflies, dragonflies, scarecrows, praying mantises and bedbugs. Young nymphs do not have wings; older stages have processes on the chest in which wings develop, and after each molt the processes lengthen until the last stage of the nymph is molted and the adult individual hatches. The nymphs of some insects, such as damselflies, live underwater and emerge only before metamorphosing into winged imagoes.