nymph

A nymph is the sexually immature stage of certain insects, such as grasshoppers and cockroaches, that undergo incomplete metamorphosis. These nymphs often resemble the adult form but lack fully developed wings and reproductive organs. Aquatic nymphs, like those of dragonflies and mayflies, are adapted for underwater life with gills and undergo a more complex transformation into winged adults.1

In fishing, nymphs are a crucial element, particularly for trout. Anglers imitate these aquatic nymphs with artificial flies to attract fish. Fly-tying involves creating these imitations by attaching various materials to a hook, mimicking different life stages of insects, including the nymphal stage. These artificial nymphs are often weighted to sink, representing larvae that have been dislodged or are rising to the surface to emerge as adults.123